IPAC2012 - List of Keywords (linac)

Paper	Title	Other Keywords	Page
MOYAP01	Accelerator Driven Systems	neutron, proton, target, superconducting-RF	6
	D. Vandeplassche, L. Medeiros Romão SCK•CEN, Mol, Belgium
	Accelerator Driven Systems are promising tools for the efficient transmutation of nuclear waste products in dedicated industrial installations (transmuters). The Myrrha project at Mol, Belgium, placed itself on the path towards these applications with a multipurpose and versatile system based on a liquid PbBi (LBE) cooled fast reactor (80 MWth) which may be operated in both critical and subcritical modes. In the latter case the core is fed by spallation neutrons obtained from a 600 MeV proton beam hitting the LBE coolant/target. The accelerator providing this beam is a CW superconducting linac which is laid out for the highest achievable reliability. The combination of a redundant and of a fault tolerant scheme should allow obtaining an MTBF value in excess of 500 hours that is required for optimal integrity and successful operation of the ADS. Myrrha is expected to be operational in 2023. The forthcoming 4-year period is fully dedicated to R&D activities, and in the field of the accelerator they are entirely focused on the reliability aspects.
	Slides MOYAP01 [6.343 MB]

MOOAA02	Instrumentation and Diagnostics for High Repetition Rate Linac-driven FELs	FEL, emittance, diagnostics, laser	23
	J.M. Byrd, S. De Santis, L.R. Doolittle, D. Filippetto, G. Huang, M. Placidi, A. Ratti LBNL, Berkeley, California, USA
	Funding: Work supported by the Director, Office of Science, of the U.S. Department of Energy under Contract No. DE-AC02-05CH11231. One of the concepts for the next generation of linac-driven FELs is a cw superconducting linac driving an electron beam with MHz repetition rates. The beam is then switched into an array of independently configurable FELs. The demand for high brightness beams and the high rep-rate presents a number of challenges for the instrumentation and diagnostics. The high rep-rate also presents opportunities for increased beam stability because of the ability for much higher sampling rates for beam-based feedbacks. In this paper, we present our plans for instrumentation and diagnostics for such a machine.
	Slides MOOAA02 [1.710 MB]

MOOBA01	Thorium Energy Futures	neutron, target, cyclotron, proton	29
	S. Peggs, W. Horak, T. Roser BNL, Upton, Long Island, New York, USA V.B. Ashley, R.F. Ashworth Jacobs Engineering, Pasadena, USA R.J. Barlow, R. Cywinski, R. Seviour University of Huddersfield, Huddersfield, United Kingdom J.-L. Biarrotte IPN, Orsay, France S. Henderson Fermilab, Batavia, USA A. Hutton JLAB, Newport News, Virginia, USA J. Kelly Thor Energy, Oslo, Norway M. Lindroos ESS, Lund, Sweden P.M. McIntyre Texas A&M University, College Station, Texas, USA A. Norlin IThEO, Sweden H.L. Owen STFC/DL/ASTeC, Daresbury, Warrington, Cheshire, United Kingdom G.T. Parks University of Cambridge, Cambridge, United Kingdom
	The potential for thorium as an alternative or supplement to uranium in fission power generation has long been recognised, and several reactors, of various types, have already operated using thorium-based fuels. Accelerator Driven Subcritical (ADS) systems have benefits and drawbacks when compared to conventional critical thorium reactors, for both solid and molten salt fuels. None of the four options – liquid or solid, with or without an accelerator – can yet be rated as better or worse than the other three, given today's knowledge. We outline the research that will be necessary to lead to an informed choice.
	Slides MOOBA01 [3.887 MB]

MOOBA02	Status and Future Perspectives of the HIE-ISOLDE Project at CERN	cryomodule, cryogenics, solenoid, ion	34
	Y. Kadi, A.P. Bernardes, Y. Blumenfeld, S. Calatroni, R. Catherall, M.A. Fraser, B. Goddard, D. Parchet, E. Siesling, W. Venturini Delsolaro, D. Voulot, L.R. Williams CERN, Geneva, Switzerland
	The High Intensity and Energy (HIE)-ISOLDE project aims at several important upgrades of the present ISOLDE radioactive beam facility at CERN. The main focus lies in the energy upgrade of the post-accelerated radionuclide beams from 3 MeV/u up to 10 MeV/u through the addition of superconducting cavities. This will open the possibility of many new types of experiments including transfer reactions throughout the nuclear chart. The first stage of this upgrade involves the design, construction, installation and commissioning of two high-β cryomodules downstream of REX-ISOLDE, the existing post-accelerator. Each cryomodule houses five high-β sc cavities and one sc solenoid. Prototypes of the Nb-sputtered Quarter Wave Resonators (QWRs) cavities for the new superconducting linear accelerator have been manufactured and are undergoing RF cold tests. The project also includes a design study of improved production targets to accommodate the future increase of proton intensity delivered by the new LINAC4 proton driver. The project has been approved by CERN and its implementation started in January 2010. An overview of the project and the timeline will be presented.
	Slides MOOBA02 [7.044 MB]

MOOBA03	Development of a High-power Coherent THz Sources and THz-TDS System on the basis of a Compact Electron Linac	electron, radiation, polarization, laser	37
	M. Kumaki, K. Sakaue, M. Washio RISE, Tokyo, Japan R. Kuroda, H. Toyokawa, K. Yamada AIST, Tsukuba, Ibaraki, Japan
	The high-power terahertz time-domain spectroscopy (THz-TDS) has been developed on the basis of a compact S-band electron linac at AIST, Japan. It is strongly expected for inspection of dangerous materials in the homeland security field. The linac consists of a photocathode rf-gun, two acceleration tubes and a magnetic bunch compressor. The 40 MeV, 1 nC electron bunch is generated and compressed to less than 1 ps. THz radiations are generated in two methods with the ultra-short bunch. One is THz coherent synchrotron radiation (CSR). The other is THz coherent transition radiation (CTR). In the preliminary experiment, it was observed that the focused CTR had the donut profile in a transverse fields due to its initial radial polarization, so that it made Z-polarization. In case of the THz-TDS experiment, CTR was controlled to linearly polarization with the polarizer and focused to an EO crystal to obtain a THz temporal waveform which leads to THz spectrum with Fourier transform. The timing measurement between CTR and a probe laser was realized with OTR using a same optical photodiode. In this conference, we will describe details of our linac and results of the THz-TDS experiment.
	Slides MOOBA03 [3.342 MB]

MOOAB03	FACET First Beam Commissioning	emittance, damping, sextupole, lattice	46
	G. Yocky, C.I. Clarke, W.S. Colocho, F.-J. Decker, M.J. Hogan, N. Lipkowitz, J. Nelson, P.M. Schuh, J.T. Seeman, J. Sheppard, H. Smith, T.J. Smith, M. Stanek, Y. Sun, J.L. Turner, M.-H. Wang, S.P. Weathersby, G.R. White, U. Wienands, M. Woodley SLAC, Menlo Park, California, USA
	Funding: Work supported by U.S. Department of Energy, Contract DE-AC02-76SF00515. The FACET (Facility for Advanced aCcelerator Experimental Tests) facility at SLAC has been under Construction since summer 2010. Its goal is to produce ultrashort and transversely small bunches of very high intensity (20kA peak current) to facilitate advanced acceleration experiments like PWFA and DLA. In June of 2011 the first electron beam was brought into the newly constructed bunch-compression chicane. Commissioning work included restarting the linac and damping ring, verifying hardware, establishing a good beam trajectory, verifying the optics of the chicane, commissioning diagnostic devices for transverse and longitudinal bunch size, and tuning up the beam size and bunch compression. Running a high-intensity beam through the linac without BNS damping and with large energy spread is a significant challenge. Optical aberrations as well as wakefields conspire to increase beam emittance and the bunch compression is quite sensitive to details of the beam energy and orbit, not unlike what will be encountered in a linear-collider final-focusing system. In this paper we outline the steps we took while commissioning as well as the challenges encountered and how they were overcome.
	Slides MOOAB03 [9.167 MB]

MOOAC03	Superconducting Resonators Development for the FRIB and ReA Linacs at MSU: Recent Achievements and Future Goals	cavity, cryomodule, SRF, ion	61
	A. Facco INFN/LNL, Legnaro (PD), Italy E.C. Bernard, J. Binkowski, C. Compton, J.L. Crisp, L.J. Dubbs, K. Elliott, A. Facco, L.L. Harle, M. Hodek, M.J. Johnson, D. Leitner, M. Leitner, I.M. Malloch, S.J. Miller, R. Oweiss, J. Popielarski, L. Popielarski, K. Saito, J. Wei, J. Wlodarczak, Y. Xu, Y. Zhang, Z. Zheng FRIB, East Lansing, Michigan, USA A. Burrill, G.K. Davis, K. Macha, A.V. Reilly JLAB, Newport News, Virginia, USA
	Funding: This material is based upon work supported by the U.S. Department of Energy Office of Science under Cooperative Agreement DE-SC0000661 The superconducting driver and post-accelerator linacs of the FRIB project, the large scale radioactive beam facility under construction at MSU, require the construction of about 400 low-beta Quarter-wave (QWR) and Half-wave resonators (HWR) with four different optimum velocities. 1st and 2nd generation prototypes of β=0.041 and 0.085 QWRs and β=0.53 HWRs have been built and tested, and have more than fulfilled the FRIB and ReA design goals. The present cavity surface preparation at MSU allowed production of low-beta cavities nearly free from field emission. The first two cryostats of β=0.041 QWRs are now in operation in the ReA3 linac. A 3rd generation design of the FRIB resonators allowed to further improve the cavity parameters, reducing the peak magnetic field in operation and increasing the possible operation gradient , with consequent reduction of the number of required resonators. The construction of the cavities for FRIB, which includes three phases for each cavity type (development, pre-production and production runs) has started. Cavity design, construction, treatment and performance will be described and discussed. Michigan State University designs and establishes FRIB as a DOE Office of Science National User Facility in support of the mission of the Office of Nuclear Physics.
	Slides MOOAC03 [4.009 MB]

MOOBC01	Electron Linac Photo-fission Driver for the Rare Isotope Program at TRIUMF	cryomodule, gun, cavity, TRIUMF	64
	S.R. Koscielniak, F. Ames, R.A. Baartman, I.V. Bylinskii, Y.-C. Chao, D. Dale, R.J. Dawson, A. Koveshnikov, A. Laxdal, R.E. Laxdal, F. Mammarella, L. Merminga, A.K. Mitra, Y.-N. Rao, V.A. Verzilov, D. Yosifov, V. Zvyagintsev TRIUMF, Canada's National Laboratory for Particle and Nuclear Physics, Vancouver, Canada D. Karlen Victoria University, Victoria, B.C., Canada
	The TRIUMF Advanced Rare Isotope Laboratory (ARIEL) is funded since 2010 June by federal and BC Provincial governments. In collaboration with the University of Victoria, TRIUMF is proceeding with construction of a new target building, connecting tunnel, rehabilitation of an existing vault to contain the electron linear accelerator, and a cryogenic compressor building. TRIUMF starts construction of a 300 keV thermionic gun, and 10 MeV Injector cryomodule (EINJ) in 2012; the designs being complete. The 25 MeV Accelerator Cryomodule will follow in 2013. TRIUMF is embarking on major equipment purchases and has signed contracts for 4K cryogenic plant and a 290kW CW klystron, and four 1.3 GHz Nb 9-cell cavities from a local Canadian supplier. Moreover, the low energy beam transport is under construction; and detailing of two intra-cryomodule beam transports has just begun. Procurements are anticipated in mid 2012 for (i) the entire facility quadrupole magnets, and (ii) the klystron's 600kW HV power supply.
	Slides MOOBC01 [4.852 MB]

MOOBC02	Status of Main Linac Cryomodule Development for Compact ERL Project	cavity, HOM, cryomodule, damping	67
	K. Umemori, K. Enami, T. Furuya, H. Sakai, M. Satoh, K. Shinoe KEK, Ibaraki, Japan E. Cenni Sokendai, Ibaraki, Japan M. Sawamura JAEA, Ibaraki-ken, Japan
	The Compact ERL, which is a test facility of ERL, is under construction at KEK, in Japan. For the main linac, one cryomodule, containing two 9-cell superconducting cavities, is under development. The cryomodule has been designed under High Pressure Gas Safety Code in Japan. Thermal design and cavity alignment have been also carefully considered. Two 9-cell cavities were already fabricated and their performances were confirmed by vertical tests. They satisfied ERL main linac specifications. Their accelerating field reached to 25 MV/m, without field limits. Two input couplers, three HOM absorbers and two Slide-Jack tuners are also under fabrication for the cryomodule. High power processing will be applied for input couplers, at a test stand using a 300 kW klystron. Cooling tolerance and HOM damping abilities were tested for HOM absorbers. Some performance studies were also applied for the tuner at room temperature condition. Cryomodule assembly is planned on this summer. After cooling tests and high power tests will be carried out, ERL beam operation will be started.
	Slides MOOBC02 [3.849 MB]

MOOBC03	A Multi Purpose X Band Accelerating Structure	wakefield, FEL, resonance, alignment	70
	M.M. Dehler, A. Citterio, R. Zennaro Paul Scherrer Institut, Villigen, Switzerland G. D'Auria, C. Serpico ELETTRA, Basovizza, Italy D. Gudkov, A. Samoshkin JINR, Dubna, Moscow Region, Russia S. Lebet, G. Riddone, J. Shi CERN, Geneva, Switzerland
	In a collaboration between CERN, PSI and Sincrotrone Trieste (ST), a series of four multipurpose X-band accelerating structures has been designed and fabricated. The structures have 72 cells with a phase advance of 5 pi/6 and include upstream and downstream wakefield monitors to measure the beam alignment. We give an overview of the electrical and mechanical design and describe the fabrication of the first units. We also present the results of the low level RF tests. Using measurements of the internal cell to cell misalignment, the residual transverse wake and the noise floor of the wake field monitors are computed. Furthermore, we present the first experiences running the structures under high power.
	Slides MOOBC03 [15.521 MB]

MOEPPB001	RF-breakdown Kicks at the CTF3 Two-beam Test Stand	extraction, linear-collider, collider, acceleration	73
	A. Palaia, M. Jacewicz, T. Muranaka, R.J.M.Y. Ruber, V.G. Ziemann Uppsala University, Uppsala, Sweden W. Farabolini CEA/DSM/IRFU, France
	The measurement of the effects of RF-breakdown on the beam in CLIC prototype accelerator structures is one of the key aspects of the CLIC two-beam acceleration scheme being addressed at the Two-beam Test Stand (TBTS) at CTF3. RF-breakdown can randomly cause energy loss and transverse kicks to the beam. Transverse kicks have been measured by means of a screen intercepting the beam after the accelerator structure. In correspondence of a RF-breakdown we detect a double beam spot which we interpret as a sudden change of the beam trajectory within a single beam pulse. To time-resolve such effect, the TBTS has been equipped with five inductive Beam Position Monitors (BPMs) and a spectrometer line to measure both relative changes of the beam trajectory and energy losses. Here we discuss the methodology used and we present the latest results of such measurements.

MOEPPB012	High-performance Beam Simulator for the LANSCE Linac	space-charge, simulation, controls, EPICS	103
	X. Pang, S.A. Baily, L. Rybarcyk LANL, Los Alamos, New Mexico, USA
	Funding: U.S. Dept. of Energy, NNSA under contract DE-AC52-06NA25396. The LANSCE accelerator complex is a multi-beam facility that provides high-intensity H⁺ and H⁻ particle beams for a variety of user programs. At the heart of the facility is a room temperature linac that is comprised of a 100-MeV drift tube linac and an 800-MeV coupled cavity linac. During beam operations, linac parameters are adjusted to maintain minimal beam spill, but without detailed knowledge of the beam distribution. A more desirable situation would be one where knowledge of the beam distribution along the linac is available to aid in the optimization of the linac operation and beam performance. We are presently developing a high performance simulator that will provide valuable information about the beam distribution in pseudo real-time during linac operations. The heart of the simulator is based upon the multiparticle beam dynamics code PARMILA, but implemented in C++ using NVIDIA’s CUDA technology for Graphics Processing unit (GPU) hardware. Linac operating set points will be provided by the EPICS control system so that changes are tracked and the simulation results updated automatically. Details regarding the approach, benefits and performance will be presented.

MOEPPB014	Time Jitter Measurements in Presence of a Magnetic Chicane in the FERMI@elettra Linac	electron, FEL, laser, dipole	109
	G. Penco, P. Craievich, S. Di Mitri, M.M. Milloch, F. Rossi ELETTRA, Basovizza, Italy
	Accurate and highly stable temporal synchronization between an electron bunch and a pulse from an external seed laser is one of the key requirements for successful operation of a seeded FEL in the XUV and soft x-ray regime. These requirements become more stringent when the electron bunch is longitudinally compressed to sub-ps durations in order to increase the current for more efficient FEL action. In this paper we present experimental measurements of the electron bunch arrival time jitter after the first magnetic compressor of FERMI@Elettra seeded FEL as a function of the compression factor. The experimental behavior of the pulse-to-pulse time jitter agrees both with results from tracking code simulations and with predictions from an analytical approach that takes into account the different sources of time jitter in FERMI, namely the photoinjector drive laser, the RF accelerating cavity phases and voltages, and fluctuations in the chicane bending magnet currents. We also present predictions for the expected arrival time jitter in the final configuration of FERMI that includes two bunch compressors and for which the synchronization requirement is of order 100 fs or better.

MOPPC045	Scaled Electron Model of a Dogbone Muon RLA with Multi-pass Arcs	electron, quadrupole, dipole, optics	235
	S.A. Bogacz, A. Hutton, G.A. Krafft, V.S. Morozov, Y. Roblin JLAB, Newport News, Virginia, USA K.B. Beard, R.P. Johnson Muons, Inc, Batavia, USA
	Funding: Authored by Jefferson Science Associates, LLC under U.S. DOE Contract No. DE-AC05-06OR23177. Supported in part by USDOE STTR Grant DE-FG02-08ER86351. The design of a dogbone RLA with linear-field multi-pass arcs was earlier developed for accelerating muons for a future Neutrino Factory and Muon Collider. It allows for efficient use of expensive RF while the multi-pass arc design based on linear combined-function magnets exhibits a number of advantages over single pass or pulsed arc designs. Such an RLA may have applications going beyond muon acceleration. This paper describes a possible straightforward test of this concept by scaling a GeV scale muon design for electrons. Scaling muon momenta by the muon-to-electron mass ratio leads to a scheme in which a 4.35 MeV/c electron beam is injected in the middle of a 2.9 MeV/pass linac with two double-pass return arcs, and is accelerated to 17.4 MeV/c in 4.5 passes. All spatial dimensions including the orbit distortion are scaled by a factor of 7.5, which arises from scaling the 200 MHz muon RF to a readily available 1.5 GHz. The footprint of a complete RLA fits in an area of 25 by 7 m. The scheme utilizes only fixed magnetic fields including injection and extraction. The hardware requirements are not very demanding, making it feasible to utilize the existing technologies. The U.S. Government retains a non-exclusive, paid-up, irrevocable, world-wide license to publish or reproduce this manuscript for U.S. Government purposes.

MOPPC054	Multi-code Modelling of Momentum Collimation in the TRIUMF ARIEL Linac	electron, gun, simulation, TRIUMF	253
	F.W. Jones, Y.-C. Chao, C. Gong TRIUMF, Canada's National Laboratory for Particle and Nuclear Physics, Vancouver, Canada
	The electron linac component of the TRIUMF-ARIEL facility will provide CW beams of 50-75 MeV and up to 0.5 MW of beam power, with consequent requirements for low-loss operation. One factor in controlling beam quality is the reduction of the low-momentum tail arising from the rf-modulated 300 KV electron gun and initial capture elements prior to acceleration in the 10 MeV Injector linac. To study momentum collimation in the 10 MeV transfer line to the main linac, and its implications for downstream beam characteristics, a simulation model has been constructed using several tracking and optics codes, linked together by scripts and data converters. The model follows the evolution of the beam from the e-gun through the injector cryo-module and the medium energy transfer line where the proposed collimator is located. The components, methods and results of this application are described in detail.

MOPPC055	A New Platform for Global Optimization	simulation, TRIUMF, solenoid, emittance	256
	C. Gong, Y.-C. Chao TRIUMF, Canada's National Laboratory for Particle and Nuclear Physics, Vancouver, Canada
	Funding: Funding is received from Natural Sciences and Engineering Research Council of Canada and National Research Council of Canada for this research. This paper describes a new platform for the multi-objective global optimization of accelerator design. While local optimization is relatively simple, global optimization for accelerator design remains a challenging task. The user often must write many lines of code to combine the output of a large variety of simulation engines, then send the results to the optimization engine. The optimization code also requires significant revision when applied to different problems. This paper presents an alternative method. The TRIUMF optimization platform, based on the genetic algorithm, is an extension of the PISA framework. It uses a flexible XML input format, in which users can easily combine multiple physics engines, such as ASTRA and PARMELA, into the same optimization problem. The TRIUMF platform is also parallel capable, designed to take advantage of computation clusters such as WestGrid. Results of the optimization platform applied to TRIUMF's 50 MeV, 0.5 MW electron linac are shown.

MOPPC070	Field Emission Simulation for KEK-ERL 9-Cell Superconducting Cavity	cavity, electron, simulation, coupling	295
	E. Cenni Sokendai, Ibaraki, Japan T. Furuya, H. Sakai, M. Satoh, K. Shinoe, K. Umemori KEK, Ibaraki, Japan M. Sawamura JAEA/ERL, Ibaraki, Japan
	In order to develop the Energy Recovery Linac at KEK, we are studying the performance of L-band superconducting cavities by means of vertical tests. One of the limiting factor for the cavities performance is power losses due to field emitted electrons. With regard to this phenomena, a particle tracking code is used to study electron trajectories and deposited energy on the inner surface of the cavity. Different emitters location were tested within a range of accelerating field and phases in order to reproduce different scenario. The final goal of this study is to locate the sources of the electrons inside the cavity through a deeper understanding of the phenomena. To validate the results from the simulation the outcome data are compared with other particle tracking codes.

MOPPC073	Improvements in the PLACET Tracking Code	simulation, ground-motion, alignment, multipole	301
	A. Latina, E. Adli, D. Schulte, J. Snuverink CERN, Geneva, Switzerland B. Dalena CEA/IRFU, Gif-sur-Yvette, France
	The tracking code PLACET simulates beam transport and orbit corrections in linear accelerators. It incorporates single- and multi-bunch effects, static and dynamic imperfections. It has an interface based on both Tcl/Tk and Octave to provide maximum flexibility and easy programming of complex scenarios. Recently, new functionality has been added to expand its simulation and tuning capabilities, such as: tools to perform beam-based alignment of non-linear optical systems, possibility to track through the interaction region in presence of external magnetic fields (detector solenoid), higher order imperfections in magnets, better tools for integrated feedback loops. Moreover, self contained frameworks have been created to ease the simulation of CLIC Drive Beam, CLIC Main Beam, and other existing electron machines such as CTF3 and FACET.

MOPPC082	Beam Dynamics Simulations inProject X RFQ with CST Studio Suite	rfq, simulation, acceleration, quadrupole	328
	G.V. Romanov Fermilab, Batavia, USA
	Typically the RFQs are designed using the Parmteq, DesRFQ and other similar specialized codes, which produces the files containing the field and geometrical parameters for every cell. The beam dynamic simulations with these analytical fields are, of course, ideal realizations of the designed RFQs. The new advanced computing capabilities made it possible to simulate beam and even dark current in the realistic 3D electromagnetic fields in the RFQs that may reflect cavity tuning, presence of tuners and couplers, RFQ segmentation etc. The paper describes the utilization of full 3D field distribution obtained with CST Studio Suite for beam dynamic simulations using both PIC solver of CST Particle Studio and the beam dynamic code TRACK.

MOPPC089	CUDA Kernel Design for GPU-based Beam Dynamics Simulations	simulation, acceleration, space-charge, impedance	343
	I.V. Pogorelov, K.M. Amyx, J. Balasalle, J. James Tech-X, Boulder, Colorado, USA M. Borland, R. Soliday, Y. Wang ANL, Argonne, USA
	Funding: Work supported by the US DOE Office of Science, Office of Basic Energy Sciences under grant number DE-SC0004585. Efficient implementation of general-purpose particle tracking on GPUs can result in significant performance benefits to large-scale particle tracking and tracking-based accelerator optimization simulations. We present our work on CUDA kernels for transfer maps of single-particle-dynamics and collective-effects beamline elements, to be incorporated into a GPU-accelerated version of the ANL's accelerator code ELEGANT. In particular, we discuss techniques for efficient utilization of the device shared, cache, and local memory in the design of single-particle and collective-effects kernels. We also discuss the use of data-parallel and hardware-assisted approaches (segmented scan and atomic updates) for resolving memory contention issues at the charge deposition stage of algorithms for modeling collective effects. We present and discuss performance results for the CUDA kernels developed and optimized as part of this project.

MOPPC095	XAL's Online Model at ReA3 to Understand Beam Performance	simulation, cavity, cryomodule, lattice	358
	C. Benatti NSCL, East Lansing, Michigan, USA P. Chu, M.J. Syphers, X. Wu FRIB, East Lansing, Michigan, USA
	Funding: This material is based on work supported by the National Science Foundation under Grant No. PHY-1102511 and by Michigan State University. The ReA3 facility at the NSCL at MSU has been designed to reaccelerate rare isotope beams to 3MeV/u. ReA3 consists of a charge to mass selection section, a normal conducting RFQ, a superconducting linac, and transport beam lines that deliver the beam to the experiments. The beam optics designs were developed using COSY and IMPACT. A code with an online model capable of interacting with the control system, such as XAL, developed at SNS, would be ideal for studying this system. New elements have been added to XAL’s already extensive list of supported devices in order to model elements unique to the NSCL. The benchmarking process has been completed for establishing the use of XAL’s Online Model at the NSCL, and preliminary results from its use at the ReA3 control room have been obtained. The development of applications to fit the needs of the program is ongoing. A summary of the benchmarking process is presented including both transverse and longitudinal studies. J. Galambos et al., Proc. PAC 2005, p. 79, (2005); doi: 10.1109/PAC.2005.1590365.

MOPPD029	Recent Achievements and Upgrade Programs at RIKEN Radioactive Isotope Beam Factory	ion, cyclotron, ECRIS, electron	430
	H. Okuno, T. Dantsuka, M. Fujimaki, T. Fujinawa, N. Fukunishi, H. Hasebe, Y. Higurashi, K. Ikegami, E. Ikezawa, H. Imao, T. Kageyama, O. Kamigaito, M. Kase, M. Kidera, M. Komiyama, H. Kuboki, K. Kumagai, T. Maie, M. Nagase, T. Nakagawa, M. Nakamura, J. Ohnishi, N. Sakamoto, K. Suda, H. Watanabe, T. Watanabe, Y. Watanabe, K. Yamada, H. Yamasawa RIKEN Nishina Center, Wako, Japan
	Recent achievements and upgrade programs in the near future at RIKEN Radioactive Isotope Beam Factory (RIBF) are presented. The beam intensity and available ion species are increasing at RIBF, owing to the continuous efforts that have been paid since the first beam in 2006. So far, we accelerated deuteron, helium, nitrogen, oxygen, aluminum, calcium, krypton, and uranium beams with the world's first superconducting ring cyclotron, SRC. The extracted beam intensities reached 1,000 pnA for helium and oxygen beams. From the operational point of view, however, the intensity of the uranium beam should be much increased. Therefore we constructed a new injector system for the RIBF, consisting of a 28 GHz ECR ion sources, RFQ and DTL, which was successfully commissioned in the end of 2010. Furthermore we developed low-Z (low atomic number Z) gas stripper* alternative to standard carbon foil stripping, which will be reliable and efficient charge stripping scheme for such high-power uranium beams. * H. Okuno et al., IEEE Trans. Appl. Supercond., 18, 226 (2008). ** H. Okuno et al., Phys. Rev. ST Accel. Beams 14, 033503 (2011).

MOPPD030	Present Status of RIKEN Ring Cyclotron	ion, heavy-ion, cyclotron, vacuum	433
	Y. Watanabe, M. Fujimaki, N. Fukunishi, H. Hasebe, Y. Higurashi, E. Ikezawa, H. Imao, T. Kageyama, O. Kamigaito, M. Kase, M. Kidera, M. Komiyama, H. Kuboki, K. Kumagai, T. Maie, M. Nagase, T. Nakagawa, J. Ohnishi, H. Okuno, N. Sakamoto, K. Suda, H. Watanabe, T. Watanabe, K. Yamada, S. Yokouchi RIKEN Nishina Center, Wako, Japan T. Aihara, S. Fukuzawa, M. Hamanaka, S. Ishikawa, K. Kobayashi, Y. Kotaka, R. Koyama, T. Nakamura, M. Nishida, M. Nishimura, T.O. Ohki, K. Oyamada, J. Shibata, M. Tamura, N. Tsukiori, A. Uchiyama, K. Yadomi, H. Yamauchi SHI Accelerator Service Ltd., Tokyo, Japan
	The RIKEN Ring Cyclotron (RRC K540) has been in stable operation over twenty-five years, and supplying many kinds of heavy-ion beams to experiments. Since 2007, it has also been supplying beams to the RIBF four Ring cyclotrons including the Super-conducting Ring Cyclotron (SRC K2500). Now the RRC has three kinds of injectors, one is K70 AVF cyclotron for light ions, the second is the variable-frequency linac for heavy ions, and the third is the RILAC2 for using the high intensity very heavy ions like U and Xe. The many combinations of accelerators are possible, and in any acceleration modes, the RRC should works as a first energy booster. A total operation time of the RRC is more than 5000 hr in every year. The present status of the RRC operation will be reported.

MOPPD043	Novel Muon Beam Facilities for Project X at Fermilab	proton, target, dipole, electron	457
	C.M. Ankenbrandt, R.J. Abrams, T.J. Roberts, C. Y. Yoshikawa Muons, Inc, Batavia, USA D.V. Neuffer Fermilab, Batavia, USA
	Innovative muon beam concepts for intensity-frontier experiments such as muon-to-electron conversion are described. Elaborating upon a previous single-beam idea, we have developed a design concept for a system to generate four high quality, low-energy muon beams (two of each sign) from a single beam of protons. As a first step, the production of pions by 1 and 3 GeV protons from the proposed Project X linac at Fermilab is being simulated and compared with the 8-GeV results from the previous study.

MOPPD045	Performance Study of the PEFP Microwave Ion Source with Modified Microwave System	ion-source, ion, high-voltage, proton	463
	D.I. Kim, Y.-S. Cho, H.S. Kim, H.-J. Kwon, K.T. Seol KAERI, Daejon, Republic of Korea
	Funding: This work is supported by the Ministry of Science and Technology of the Korean government. A microwave ion source has been developed as a proton injector for the Proton Engineering Frontier Project (PEFP) 100-MeV proton linac. The microwave ion source consists of the 2.45-GHz microwave components, a solenoid magnet, a vacuum system, power supplies for beam extraction and bias electrode, a cooling system. It was operating for 1 year to supply beam to the 20-MeV proton accelerator. Recently, a multi-layer insulation DC break was installed between proton source and 2.45-GHz microwave components. Also, the magnetron was replaced with lower saturation power level. The tests of the microwave system have been done to study the effect of the DC break and new magnetron compared with the former one. Also, the beam test was done after the operating conditions of the microwave system were adjusted. In this paper, the performance studies of the PEFP microwave ion source with DC break and new magnetron are discussed.

MOPPD049	The Layout of the High Energy Beam Transport for the European Spallation Source	target, octupole, quadrupole, beam-transport	475
	A.I.S. Holm, S.P. Møller, H.D. Thomsen ISA, Aarhus, Denmark
	The status of the High Energy Beam Transport (HEBT) line for the European Spallation Source (ESS) is presented. The HEBT brings the beam from the underground linac to the target at surface level. The main design objectives of the HEBT, such as space for upgrades, producing the desired target footprint etc. are discussed and the preferred design is shown. Large amplitude particles, a halo, are formed in the last part of the linac. Hence, every given value of the peak current density at the target is correlated with a certain power deposited outside the beam footprint. This correlation is studied and optimized. Furthermore, first studies of the vertical stability of the beam footprint and profile on target due to misalignment or mismatch of the incoming beam are made.

MOPPD050	Dipole Magnet Design for a Bunch Compressor	dipole, neutron, proton, focusing	478
	T. Kanesue, L.P. Chau, O. Meusel, D. Noll, U. Ratzinger IAP, Frankfurt am Main, Germany
	The FRANZ-ARMADILLO is a Mobley type bunch compressor system at the pulsed intense neutron source FRANZ, under construction at Frankfurt University. The FRANZ-ARMADILLO compresses 9μbunches of a 150 mA, 2 MeV proton beam accelerated by a 175 MHz linac into one short pulse of 1 ns pulse length with 250 kHz repetition rate. In the bunch compressor, two homogeneous dipole magnets and two gradient dipole magnets guide theμbunches, separated by a 5 MHz RF-kicker on individual tracks. The flight path length of theμbunches are determined based on the bunch center velocity and the linac frequency for the longitudinal bunch compression. The gradient dipole magnets provide individual magnetic fields and edge focusing forces to everyμbunch. For the center trajectory, the required parameters are a magnetic field density of 509.2 mT, bending angle of 78.27 deg, and bending radius of 404.5 mm. To satisfy all specifications, field clamps, shims, and chamfer cut will be adopted. The result of the gradient dipole magnet design and the expected performance based on beam dynamics studies will be presented.

MOPPD072	A High Energy Collimation System for the European Spallation Source	collimation, target, beam-losses, optics	529
	H.D. Thomsen, A.I.S. Holm, S.P. Møller ISA, Aarhus, Denmark
	At the European Spallation Source (ESS), a ~160 m high energy beam transport (HEBT) system is to guide the high-power (5 MW) proton beam from a superconducting 2.5 GeV linac to a spallation target station. The HEBT could include a single-pass collimation system to protect all downstream accelerator components, including the vital target. The system would be built to withstand both continuous low-power losses (i.e. introduce halo reduction) and infrequent short-term, high-power beam exposure, essentially a fault scenario. Although a collimation system could reduce the uncontrolled beam losses and thus activation levels elsewhere, it takes up precious longitudinal space intended for future beam power upgrades and sets demands for the beam optics, as will be discussed. Possible materials and specifications will also be described.

MOPPD076	Numerical Study of a Collimation System to Mitigate Beam Losses in the ESS Linac	DTL, beam-losses, collimation, simulation	541
	R. Miyamoto, H. Danared, M. Eshraqi, A. Ponton ESS, Lund, Sweden
	The European Spallation Source (ESS) will be a 5 MW proton linac to produce spallation neutrons. A high power linac has a very low tolerance on beam losses, typically on the order of 1 W/m, to avoid activation of the linac components; hence, emittance and halo of the beam must be well controlled throughout the linac. A system of collimators in beam transport sections has been studied and tested as a means to mitigate the beam losses in several linacs. This paper presents the result of a numerical study of a collimation system for the ESS linac.

MOPPP003	Comparison of Various Sources of Coherent THz Radiation at FLUTE	radiation, electron, synchrotron, synchrotron-radiation	568
	M. Schwarz, E. Huttel, A.-S. Müller, S. Naknaimueang, M.J. Nasse, R. Rossmanith, M. Schuh, P. Wesolowski KIT, Karlsruhe, Germany M.T. Schmelling MPI-K, Heidelberg, Germany
	The "Ferninfrarot Linac- Und Test-Experiment" FLUTE, based on a 50 MeV S-band linac with bunch compressor, is currently under construction at the KIT in Karlsruhe in order to study the production of coherent radiation in the Terahertz frequency range. The three photon generating mechanisms investigated in this paper are coherent synchrotron-, edge-, and transition radiation. For each case, we present the spectra and peak electric fields calculated from longitudinal charge distributions of a short, low charge and a long, high charge bunch. The respective bunch shapes are obtained by a detailed simulation (particle tracking) of FLUTE. We also give the expected temporal evolution of the electric field pulses.

MOPPP006	Inverse Cherenkov Radiation based on Smith-Purcell Effect	radiation, electron, gun, laser	577
	K. Kan, T. Kondoh, K. Norizawa, A. Ogata, J. Yang, Y. Yoshida ISIR, Osaka, Japan M. Hangyo ILE Osaka, Suita, Japan R. Kuroda, H. Toyokawa AIST, Tsukuba, Ibaraki, Japan
	Inverse Cherenkov radiation based on Smith-Purcell effect using metamaterial was investigated. A metallic grating and picosecond electron bunch of 27 MeV beam energy from a thermionic DC gun and linac were used for the inverse radiation. The frequency spectra in terahertz (THz) range were measured by a Michelson interferometer experimentally. Peaks of discrete component in the spectra shifted continuously according to the radiation angles, e. g. discrete peak changing from 0.117 to 0.085 THz with radiation angle along the electron bunch from 102 to 134 degree (backward) using a 2-mm-period metallic grating. In this presentation, experiment using another electron bunch generated by a photocathode RF gun linac will be reported.

MOPPP010	Investigation of CSR Effect for Femtosecond Electron Bunches in an Isochronous Accumulator Ring	simulation, lattice, radiation, electron	589
	N.Y. Huang, H. Hama, F. Hinode, S. Kashiwagi, M. Kawai, T. Muto, I. Nagasawa, K. Nanbu, Y. Shibasaki, K. Takahashi Tohoku University, Research Center for Electron Photon Science, Sendai, Japan
	Coherent synchrotron radiation (CSR) from a novel isochronous ring is a candidate for light source that provides THz radiation with high average flux. A compact isochronous accumulator ring (IAR) for the maximum beam energy of 54 MeV has been designed so as to eliminate the 0th order momentum compaction factor, and the 1st order of it is mostly compensated. In addition, the path length deviation due to betatron motion is mostly compensated in a cell. Though there is no RF cavity in IAR, the injected beam may circulate for certain number of turns. Multi experimental stations can be allocated like synchrotron radiation facilities. However, it has been well known that instability due to the CSR wake field is an issue for the beam stability in the ring operated at low alpha mode. Therefore, a study for effects of the CSR wake on the bunch length and shape in IAR has been in progress. It has turned out that the maximum longitudinal field strength created by CSR would be ~ 0.15 MV/m for the case of 100 fs Gaussian bunch, which is considerably an intense field. To protect the bunch shape from the CSR wake, further study is definitely required.

MOPPP011	Narrow Band Optimization of a Compton Gamma-Ray Source Produced From an X-Band Linac	electron, laser, simulation, emittance	592
	F. Albert, S.G. Anderson, C.P.J. Barty, D.J. Gibson, F.V. Hartemann, R.A. Marsh, S.S.Q. Wu LLNL, Livermore, California, USA
	Funding: This work performed under the auspices of the U.S. Department of Energy by Lawrence Livermore National Laboratory under Contract DE-AC52-07NA27344. Nuclear photonics is an emerging field of research that will require high precision gamma-ray (MeV) sources. In particular, nuclear resonance fluorescence applications necessitate a low (< 1%) relative gamma-ray spectral width. Within this context, Compton scattering, where laser photons are scattered off relativistic electron beams to produce tunable, collimated gamma rays, will produce the desired gamma-ray output. This paper will present the spectral narrowband optimization of such a light source currently being built at LLNL. In this case, PARMELA and elegant simulations of the full 250 MeV, high-gradient X-band linac provide the properties of the high brightness electron bunch. The electron beam simulations are then implemented into our newly developed weakly nonlinear Compton scattering code to produce theoretical gamma-ray spectra. The influence that the electron beam, laser beam and interaction geometry parameters have on the produced gamma-ray spectra will be shown with our simulations.

MOPPP015	Status of the BERLinPro Energy Recovery Linac Project	cavity, SRF, booster, quadrupole	601
	J. Knobloch, M. Abo-Bakr, W. Anders, R. Barday, K.B. Bürkmann-Gehrlein, V. Dürr, S.C. Heßler, A. Jankowiak, T. Kamps, O. Kugeler, B.C. Kuske, P. Kuske, A.N. Matveenko, G. Meyer, R. Müller, A. Neumann, K. Ott, Y. Petenev, D. Pflückhahn, T. Quast, J. Rahn, S.G. Schubert HZB, Berlin, Germany
	Funding: Funding provided by the BMBF and the State of Berlin In October 2010 Helmholtz Zentrum Berlin received funding to design and build the Berlin Energy Recovery Linac Project BERLinPro. The goal of this compact ERL is to develop the accelerator physics and technology required to generate and accelerate a 100-mA, 1 mm·mrad emittance beam. Given the flexibility of ERLs, other operation modes such as short-bunch operation will also be investigated. The BERLinPro technology and know-how can then be transferred to a variety of ERL-based applications. Presently, BERLinPro is in the design phase and the optics has been settled. Furthermore, first beam has been achieved with a superconducting RF photoinjector, which represents an important step towards realizing a CW injector for BERLinPro. An overview of the present status and the conceptual design report is presented.

MOPPP016	Feasibility Study of an ERL-based GeV-scale Multi-turn Light Source	brilliance, undulator, cryomodule, optics	604
	Y. Petenev, T. Atkinson, A.V. Bondarenko, A.N. Matveenko HZB, Berlin, Germany
	A new generation of particle accelerators based on an Energy Recovery Linac (ERL) is a promising tool for a number of new applications. These include high brilliance light sources in a wide range of photon energies, electron cooling of ion beam and ERL-based electron-hadron colliders. Helmholtz-Zentrum Berlin started a feasibility study of GeV-scale multi-turn ERL-based light source (LS). This LS will work in diffraction limited regime in X-rays and with a short length of a light pulse in femtosecond region. The average and peak brightness will be at least an order of magnitude higher than synchrotron-based LS. In this work an overview of the future multi-turn light source is given. Modeling of the Beam Break Up instability is presented.

MOPPP018	Construction Status of the Compact ERL	cryomodule, gun, emittance, radiation	607
	S. Sakanaka, H. Kawata, Y. Kobayashi, N. Nakamura KEK, Ibaraki, Japan R. Hajima JAEA, Ibaraki-ken, Japan
	Future synchrotron light source based on a 3-GeV energy recovery linac (ERL) is under proposal at KEK, and we are conducting extensive R&D efforts. To demonstrate reliable operations of key components for the ERL project, as well as to demonstrate the generation of ultra-low emittance beams, we are constructing the Compact ERL (cERL). The cERL will also be used to demonstrate the generation of brilliant gamma-rays that is useful for analyzing radioisotopes. Key components, such as a photocathode DC gun, both cryomodules for the injector and the main linac, rf sources, magnets, and beam instrumentations, are under fabrication. Construction of radiation shielding for the cERL started in December, 2011. We report up-to-date status of the cERL.

MOPPP021	Longitudinal Beam Dynamics at the ALICE Acclerator R&D Facility	booster, simulation, gun, FEL	610
	F. Jackson, D. Angal-Kalinin, S.P. Jamison, J.W. McKenzie, T.T. Ng, Y.M. Saveliev, P.H. Williams STFC/DL/ASTeC, Daresbury, Warrington, Cheshire, United Kingdom
	The ALICE facility is an energy recovery test accelerator whose applications include an IR-FEL and THz generation. Of primary importance to the performance of the main ALICE applications is the understanding and control of the longitudinal dynamics, which are less amenable to measurement than the transverse. The longitudinal dynamics of the beam evolve are studied in simulation and experiment in several areas of the machine. Simulations of the low energy injector where space charge and velocity bunching may occur are presented. Path length measurement using time-of-arrival monitors are carried out.

MOPPP023	Effect of DC Photoinjector Gun Voltage on Beam Dynamics in ALICE ERL	gun, electron, booster, cavity	616
	Y.M. Saveliev, F. Jackson, J.K. Jones, J.W. McKenzie STFC/DL/ASTeC, Daresbury, Warrington, Cheshire, United Kingdom
	The ALICE ERL employs a DC HV photoelectron gun as an electron source. As with other machines in this class, the electron beam is not always of perfect quality. This is aggravated by that the ALICE gun has been operated so far at lower 230kV voltage compared to the design value of 350kV due to hardware limitations. The “two beams” structure was observed and experimentally investigated and found to be the result of complex processes during initial stages of beam acceleration. The experimental observations and data will be compared with those obtained at a nominal 350kV gun voltage. An investigation of the effect of the DC photogun voltage on longitudinal and transverse beam dynamics will be presented and discussed.

MOPPP026	Cryogenic Distribution System for the Proposed Cornell ERL Main Linac	cryomodule, HOM, cavity, vacuum	619
	E.N. Smith Cornell University, Ithaca, New York, USA Y. He, G.H. Hoffstaetter, M. Liepe, M. Tigner CLASSE, Ithaca, New York, USA
	Funding: This material is based upon work supported by the National Science Foundation under Grant No. DMR-0807731. The proposed Cornell ERL main linac requires a total cooling power of nearly 8kW at 1.8K, 5kW at 5K and over 100kW at 80K. This is distributed over approximately 65 cryomodules, each containing 6 rf cavities and associated input couplers and higher order mode absorbers. situated in two underground tunnels. While the total heat load is comparable to that for each of the 8 individual LHC cryoplants, the very high ratio of dynamic heat load to static heat load, combined with the high power density at various sites produces interesting challenges for the cryogenic distribution system. A schematic view of the design choices selected, some of which are different from existing large cryogenic systems, and the basis for these decisions, is presented in this paper.

MOPPP031	A New Injection System for an Electron/Positron Linac	electron, injection, gun, positron	628
	C. Liebig, M. Hüning, M. Schmitz DESY, Hamburg, Germany
	For the Linac II, which supplies the accelerator chain at DESY with electrons and positrons, a new injection system is planned. It is supposed to ensure reliable operation and to avoid the beam loss of about 60% before the positron converter and the associated activation. The main components are a 6 A/100 kV triode gun, buncher and a dispersive section for energy collimation. The output energy is 5 MeV. The new buncher structure is a hybrid of a standing wave and traveling wave structure and allows a compact design and good electron capture. Its main part is a traveling wave structure in 2π/3 mode, to which one capture cell is coupled in π mode. The function of the injector components, the entire injection system and the acceleration in the linac sections were optimized in simulations. In addition, the design is analysed in a test rig before final installation. Test rig and subsequent injector are equipped with extensive diagnostics. Besides the design of the injection system results of simulations and measurements on the test rig will be presented.

MOPPP042	Modeling Multi-bunch X-band Photoinjector Challenges	emittance, gun, electron, laser	658
	R.A. Marsh, S.G. Anderson, C.P.J. Barty, D.J. Gibson, F.V. Hartemann LLNL, Livermore, California, USA
	Funding: This work performed under the auspices of the U.S. Department of Energy by Lawrence Livermore National Laboratory under Contract DE-AC52-07NA27344. An X-band test station is being developed at LLNL to investigate accelerator optimization for future upgrades to mono-energetic gamma-ray (MEGa-Ray) technology at LLNL. The test station will consist of a 5.5 cell X-band rf photoinjector, single accelerator section, and beam diagnostics. Of critical import to the functioning of the LLNL X-band system with multiple electron bunches is the performance of the photoinjector. In depth modeling of the Mark 1 LLNL/SLAC X-band rf photoinjector performance will be presented addressing important challenges that must be addressed in order to fabricate a multi-bunch Mark 2 photoinjector. Emittance performance is evaluated under different nominal electron bunch parameters using electrostatic codes such as PARMELA. Wake potential is analyzed using electromagnetic time domain simulations using the ACE3P code T3P. Beam-loading effects and low level rf compensation schemes are explored as well, using a semi-analytic formalism and computer algorithm. Plans for multi-bunch experiments and implementation of photoinjector advances for the Mark 2 design will also be discussed.

MOPPP050	Physics Results of the NSLS-II Linac Front End Test Stand	emittance, simulation, gun, electron	673
	R.P. Fliller, F. Gao, J. Rose, T.V. Shaftan, X. Yang BNL, Upton, Long Island, New York, USA G. Blokesch PPT, Dortmund, Germany C. Piel RI Research Instruments GmbH, Bergisch Gladbach, Germany
	Funding: This manuscript has been authored by Brookhaven Science Associates, LLC under Contract No. DE-AC02-98CH10886 with the U.S. Department of Energy. The NSLS-II linac is produced by Research Instruments and will be commissioned in the spring of 2012. As part of the procurement, the linac front end consisting of the gun, prebunching cavity, and diagnostics was delivered early to BNL for testing. We designed a short beamline to supplement the Front End diagnostics to characterize the beam. These tests were instrumental in demonstrating the functioning of the gun, pinpointing technical problems at an early project stage and gaining experience with the linac gun by BNL staff prior to commissioning of the full linac. In this report we show the results of the tests, including charge, bunch length, and transverse emittance measurements and compare them with the relevant linac specifications.

MOPPP051	NSLS-II Transport Line Progress	booster, storage-ring, diagnostics, injection	676
	R.P. Fliller, A.T. Anderson, B. Benish, W. DeBoer, G. Ganetis, R. Heese, H.-C. Hseuh, J. Hu, M.P. Johanson, B.N. Kosciuk, D. Padrazo, K. Roy, T.V. Shaftan, O. Singh, J.L. Tuozzolo, B. Wahl, G.M. Wang BNL, Upton, Long Island, New York, USA
	Funding: This manuscript has been authored by Brookhaven Science Associates, LLC under Contract No. DE-AC02-98CH10886 with the U.S. Department of Energy. The National Synchrotron Light Source II (NSLS-II) is a state-of-the-art 3-GeV third generation light source currently under construction at Brookhaven National Laboratory. The NSLS-II injection system consists of a 200 MeV linac, a 3-GeV booster synchrotron and associated transfer lines. The first part of the Linac to Booster Transport (LBT) line has been installed for linac commissioning. This part includes all components necessary to commission the NSLS-II linac. The second part of this transport line is undergoing installation. Initial results of hardware commissioning will be discussed. The Booster to Storage Ring (BSR) transport line underwent a design review. The first part of the BSR transport line, consisting of all components necessary to commission the booster will be installed in 2012 for booster commissioning. We report on the final design of the BSR line along with the plan to commission the booster.

MOPPP056	Injection Transient Motion at PLS-II	kicker, injection, septum, electron	688
	I. Hwang, T. Ha, Y.D. Joo, C. Kim, M. Kim, S.H. Kim, B.-J. Lee, E.H. Lee, S. Shin PAL, Pohang, Kyungbuk, Republic of Korea
	PLS-II is an upgraded third generation synchrotron which includes many insertion devices with improved beam properties. Top-up operation is short time-interval injection to make roughly constant current and is essential to provide high intensity beam. When the electrons are injected to synchrotron, the stored beam is disturbed by small error of the injection system and the beam quality at the beamline can be decreased. We present this injection transient motion at PLS-II.

MOPPR003	Beam Diagnostic Systems for the TRIUMF e-linac	TRIUMF, diagnostics, EPICS, electron	777
	J.M. Abernathy, D. Karlen, M.O. Pfleger, P.R. Poffenberger, D.W. Storey Victoria University, Victoria, B.C., Canada F. Ames, P.S. Birney, D.P. Cameron, J.V. Holek, S.Y. Kajioka, S. Kellogg, M. Lenckowski, M. Minato, W.R. Rawnsley, J.E. Richards, V.A. Verzilov TRIUMF, Canada's National Laboratory for Particle and Nuclear Physics, Vancouver, Canada
	Funding: NSERC, CFI, BCKDF. The TRIUMF electron linac will include a suite of diagnostics systems, including current, beam position, and beam profile monitors. This talk will present an overview of the diagnostic systems and give details about the view screen system, having both scintillator and OTR foils. Results from tests with the prototype low energy beam transport system will be shown. Diagnostic systems are particularly challenging for the e-linac due to the 500 kW beam power envisaged, with beam currents up to 10 mA at 50 MeV.

MOPPR025	The BPM DAQ System Upgrade for SuperKEKB Injector Linac	electron, emittance, positron, injection	834
	M. Satoh, K. Furukawa, F. Miyahara, T. Suwada KEK, Ibaraki, Japan T. Kudou, S. Kusano MELCO SC, Tsukuba, Japan
	The non-destructive beam position monitor (BPM) is indispensable diagnostic tool for the stable beam operation. In the KEK Linac, approximately nineteen BPMs with the strip-line type electrodes are used for the beam orbit measurement and feedback. In addition, some of them are also used for the beam energy feedback loops. The current DAQ system consists of the fast digital oscilloscopes. A signal from each electrode is analyzed with a predetermined response function up to 50 Hz. The beam position resolution of current system is limited to about 0.5 mm because of ADC resolution. Towards SuperKEKB project, we have a plan to upgrade the BPM DAQ system since the Linac should provide the smaller emittance beam. We will report the system description of the new DAQ system and the results of performance test in detail.

MOPPR039	Development of Beam Position Monitor for PEFP Linac and Beam line	proton, coupling, DTL, quadrupole	864
	J.Y. Ryu, Y.-S. Cho, J.-H. Jang, H.S. Kim, H.-J. Kwon, K.T. Seol KAERI, Daejon, Republic of Korea
	Funding: This work is supported by the Ministry of Education, Science and Technology of the Korean Government. The development of the Beam Position Monitor (BPM) is in progress for the linac and beam lines of the Proton Engineering Frontier Project (PEFP). We choose a strip line BPM for the PEFP 20-MeV and 100-MeV beam lines in order to increase the sensitivity of the relatively long bunches in the beam lines. We also selected the same type BPM for the proton linac in the energy range between 20-MeV and 100-MeV. The prototype BPM was designed, fabricated and tested at KAERI site, where the 20-MeV linac was operated. To check the performance of the BPM, we performed the field mapping. The characteristics and test results of the BPM on the test bench as well as with 20-MeV proton beam will be presented in this paper.

MOPPR040	Design and Measurements of a Test Stand for the SEM-Grid System of the ESS-BILBAO	electron, vacuum, diagnostics, emittance	867
	D. Belver, J. Feuchtwanger, P.J. González ESS Bilbao, LEIOA, Spain F.J. Bermejo Bilbao, Faculty of Science and Technology, Bilbao, Spain V. Etxebarria, J. Jugo University of the Basque Country, Faculty of Science and Technology, Bilbao, Spain
	In the framework of the ESS-Bilbao accelerator, a test stand for the development of Secondary Electron EMission grid (SEM-Grid) has been designed and manufactured as a part of the diagnostics system for beam profile measurements. This test stand is a vacuum system based on an EQ 22/35 electron source from SPECS used as a beam injector. This electron source has an energy range from 0 to 5 KeV and a maximum beam current up to 200 μA. Although we have thought in a SEM-Grid of 40 wires (20 wires in each X and Y direction), two prototypes of 16 wires (8x8) of 250 μm diameter and spaced 1 and 2 mm, respectively, have been developed due to its easier implementation and tested in the test stand. In order to develop an electronics readout system for the SEM-Grid, first studies of the prototype signals have been done. The secondary emission current of each wire will be integrated and amplified to provide a significant voltage signal that can be measured by our acquisition system. A description of the SEM-Grid test stand and the measurements developed is given here.

MOPPR045	Beam Diagnostics for ESS	target, diagnostics, DTL, instrumentation	882
	A. Jansson, C. Böhme, B. Cheymol, H. Hassanzadegan, T.J. Shea, L. Tchelidze ESS, Lund, Sweden
	The European Spallation Source (ESS), to be built in the south of Sweden, will use a 2.5 GeV superconducting linac to produce the worlds most powerful neutron source. The project is currently in a pre-construction phase, during which the linac design is being updated. This paper describes the current plans for beam diagnostics in terms of requirements, number and locations of different systems, and possible technical solutions.

MOPPR048	Beam Instrumentation for the HIE-ISOLDE Linac at CERN	diagnostics, cryomodule, emittance, ion	891
	E. Bravin, A.G. Sosa, D. Voulot, F.J.C. Wenander, F. Zocca CERN, Geneva, Switzerland M.A. Fraser UMAN, Manchester, United Kingdom J.H. Galipienzo AVS, Eibar, Gipuzkoa, Spain M. Pasini Instituut voor Kern- en Stralingsfysica, K. U. Leuven, Leuven, Belgium C.P. Welsch Cockcroft Institute, Warrington, Cheshire, United Kingdom
	In the framework of the High Intensity and Energy (HIE)-ISOLDE project at CERN, a beam instrumentation R&D program is on-going for the superconducting upgrade of the REX-ISOLDE heavy-ion post-accelerator. An overview of the foreseen beam diagnostics system is presented, focusing on the challenging specifications required by the HIE-ISOLDE linac. Due to the low beam intensities, the diagnostic instrumentation will be based on high-sensitivity intercepting devices. The project includes intensity and transverse profile monitors to be implemented in the very narrow longitudinal space that is available for beam diagnostics in the regions between the superconducting cryomodules. A longitudinal profile monitor is foreseen downstream of the linac to measure the beam energy and arrival time distributions and to allow for a fast phase-tuning of the superconducting cavities. A custom-made emittance meter will provide transverse emittance measurements based on a phase space sampling technique. The design status of the different instruments will be presented as well as the results of some experimental tests.

MOPPR057	Development of a Cavity Beam Position Monitor for CLIC	cavity, dipole, coupling, factory	915
	F.J. Cullinan, S.T. Boogert, N.Y. Joshi, A. Lyapin JAI, Egham, Surrey, United Kingdom E. Calvo, N. Chritin, F. Guillot-Vignot, T. Lefèvre, L. Søby CERN, Geneva, Switzerland A. Lunin, M. Wendt, V.P. Yakovlev Fermilab, Batavia, USA S.R. Smith SLAC, Menlo Park, California, USA
	The Compact Linear Collider (CLIC) project presents many challenges to its subsystems and the beam diagnostics in particular must perform beyond current limitations. The requirements for the CLIC main beam position monitors foresee a spacial resolution of 50 nm while delivering a 10 ns temporal resolution within the bunch train. We discuss the design of the microwave cavity pick-up and associated electronics, bench top tests with the first prototype cavity, as well as some of the machine-specific integration and operational issues.

MOPPR070	Beam Profile Measurement in MTA Beam Line for High Pressure RF Cavity Beam Test	cavity, proton, diagnostics, electron	948
	M.R. Jana, A.D. Bross, S. Geer, C. Johnstone, T. Kobilarcik, G.M. Koizumi, M.A. Leonova, A. Moretti, M. Popovic, T.A. Schwarz, A.V. Tollestrup, K. Yonehara Fermilab, Batavia, USA M. Chung Handong Global University, Pohang, Republic of Korea M.G. Collura Politecnico di Torino, Torino, Italy B.T. Freemire, P.M. Hanlet, Y. Torun IIT, Chicago, Illinois, USA
	Funding: This work is supported by the United States Department of Energy under contract DE-AC02-07CH11359. The recent High Pressure RF (HPRF) cavity experiment at the MuCool Test Area (MTA) used a 400 MeV Linac proton beam to study the beam loading effect. When the energetic proton beam passes through the cavity, it ionizes the inside gas and produces electrons. These electrons consume RF power inside the cavity. The number of electrons produced per cm inside the cavity (at 950 psi Hydrogen gas) per incident proton is 1200. The measurement of beam position and profile are necessary. The MTA is a flammable gas (Hydrogen) hazard zone, so we have developed a passive beam diagnostic instrument using a Chromox-6 scintillation screen and CCD camera. This paper presents quantitative information about beam position and beam profile. A neutral density filter was used to avoid saturation of the CCD camera. Image data is filtered and fitted with a Gaussian function to compute the beam size. The beam profile obtained from the scintillation screen will be compared with a multi-wire beam profile.

MOPPR072	Fermilab PXIE Beam Diagnostics Development and Testing at the HINS Beam Facility	diagnostics, laser, emittance, rfq	954
	V.E. Scarpine, B.M. Hanna, V.A. Lebedev, L.R. Prost, A.V. Shemyakin, J. Steimel, M. Wendt Fermilab, Batavia, USA
	Funding: This work was supported by the U.S. Department of Energy under contract No. DE-AC02-07CH11359. Fermilab is planning the construction of a prototype front end of the Project X linac. The Project X Injector Experiment (PXIE) is expected to accelerate 1 mA cw H⁻ beam up to 30 MeV. Some of the major goals of the project are to test a cw RFQ and H⁻ source, a broadband bunch-by-bunch beam chopper and a low-energy superconducting linac. The successful characterization and operation of such an accelerator places stringent requirements on beam line diagnostics. These crucial beam measurements include bunch currents, beam orbit, beam phase, bunch length, transverse profile and emittance, beam halo and tails, as well as the extinction performance of the broadband chopper. This paper presents PXIE beam measurement requirements and instrumentation development plans. Also presented are plans to test many of these instruments at the Fermilab High Intensity Neutrino Source (HINS) beam facility. Since HINS is already an operational accelerator, utilizing HINS for instrumentation testing allows for quicker development of the required PXIE diagnostics.

MOPPR077	ION CHAMBERS AND HALO RINGS FOR LOSS DETECTION AT FRIB	radiation, ion, cryomodule, simulation	969
	Z. Liu IUCF, Bloomington, Indiana, USA D. Georgobiani, M.J. Johnson, M. Leitner, R.M. Ronningen, T. Russo, M. Shuptar, R.C. Webber, J. Wei, X. Wu, Y. Yamazaki, Y. Zhang, Q. Zhao FRIB, East Lansing, Michigan, USA
	Funding: This material is based upon work supported by the U.S. Department of Energy Office of Science under Cooperative Agreement DE-SC0000661. Unlike the high energy proton machines, our radiation transport simulation results show that it will be difficult to use traditional BLMs to detect beam losses for FRIB linac, not only due to the low radiation levels from low energy heavy ion beams, but also resulted by the cross talk effect from one part of the machine to another in the folded machine geometry. A device called “Halo Ring” is introduced as a component of the BLM system to substitute the traditional ion chamber in those regions.

MOPPR080	Wire Scanner Beam Profile Measurements: LANSCE Facility Beam Development	electron, controls, feedback, target	975
	J.D. Gilpatrick, Y.K. Batygin, F. Gonzales, M.E. Gruchalla, V.G. Kutac, D. Martinez, C. Pillai, S. Rodriguez Esparza, J.D. Sedillo, B.G. Smith LANL, Los Alamos, New Mexico, USA
	Funding: Work supported by the U.S. Department of Energy. The Los Alamos Neutron Science Center (LANSCE) is replacing Wire Scanner (WS) beam profile measurement systems. Three beam development tests have taken place to test the new wire scanners under beam conditions. These beam development tests have integrated the WS actuator, cable plant, electronics processors and associated software and have used H⁻ beams of different beam energy and current conditions. In addition, the WS measurement-system beam tests verified actuator control systems for minimum profile bin repeatability and speed, checked for actuator backlash and positional stability, tested the replacement of simple broadband potentiometers with narrow band resolvers, and tested resolver use with National Instruments Compact Reconfigurable Input and Output (cRIO) Virtual Instrumentation. These beam tests also have verified how trans-impedance amplifiers react with various types of beam line background noise and how the cable plants can be simplified without generating unwanted noise currents. This paper will describe these beam development tests and show some resulting data.

MOPPR081	Wire Scanner Beam Profile Measurements for the LANSCE Facility	EPICS, controls, LabView, electron	978
	J.D. Gilpatrick, M.E. Gruchalla, D. Martinez, C. Pillai, S. Rodriguez Esparza, J.D. Sedillo, B.G. Smith LANL, Los Alamos, New Mexico, USA
	Funding: Work supported by the U.S. Department of Energy. The Los Alamos Neutron Science Center (LANSCE) is replacing beam profile measurement systems, commonly known as Wire Scanners (WS’s). Using the principal of secondary electron emission, the WS measurement system moves a wire or fiber across an impinging particle beam, sampling a projected multi-bin distribution. Because existing WS actuators and electronic components are either no longer manufactured or home-built with antiquated parts, a new wire scanner beam profile measurement is being designed, fabricated, and tested. The goals for these new wire scanner include using off-the-shelf components while eliminating antiquated components, providing quick operation while allowing for easy maintainability, and tolerating external radioactivation. The WS measurement system consists of beam line actuators, a simple cable plant, an electronics processor chassis, and software located both in the electronics chassis (National Instruments LabVIEW) and in the Central Control Room (EPICS-based software). This WS measurement system will measure the more common H⁻ and H⁺ LANSCE-facility beams and will also measure less common beams. This paper describes these WS measurement systems.

MOPPR082	Wide-bandwidth Capture of Wire-scanner Signals		981
	M.E. Gruchalla, J.D. Gilpatrick, D. Martinez, J.D. Sedillo LANL, Los Alamos, New Mexico, USA
	Funding: US Department of Energy. Integrated charge collected on the sense wires of wire-scanner systems utilized to determine beam profile is generally the parameter of interest. The LANSCE application requires capturing the charge information macropulse-by-macropulse with macropulse lengths as long as 700us at a maximum macropulse rate of 120Hz. Also, for the LANSCE application, it is required that the integration be performed in a manner that does not require integrator reset between macropulses. Due to the long macropulse which must be accommodated and the 8.33ms minimum pulse period, a simple R-C integrator cannot be utilized since there is insufficient time between macropulses to allow the integrator to adequately recover. The application of wide-bandwidth to provide accurate pulse-by-pulse capture of the wire signals with digital integration of the wire signals to determine captured charge at each macropulse in applications with comparatively long macropulses and high pulse repetition rates is presented.

MOPPR083	Mechanical Design and Evaluation of the MP-11-like Wire Scanner Prototype	laser, controls, vacuum, neutron	984
	S. Rodriguez Esparza, J.D. Gilpatrick, M.E. Gruchalla, A.J. Maestas, J.P. Martinez, J.L. Raybun, F.D. Sattler, J.D. Sedillo, B.G. Smith LANL, Los Alamos, New Mexico, USA
	A wire scanner (WS) is a linearly actuated diagnostic device that uses fiber wires (such as Tungsten or Silicon Carbide) to obtain the position and intensity profile of the proton beam at the Los Alamos Neutron Science Center (LANSCE) particle accelerator. LANSCE will be installing approximately 86 new WS in the near future as part of the LANSCE Risk Mitigation project. These 86 new WS include the replacement of many current WS and some newly added to the current linear accelerator and other beam lines. The reason for the replacement and addition of WS is that many of the existing actuators have parts that are no longer readily available and are difficult to find, thus making maintenance very difficult. One of the main goals is to construct the new WS with as many commercially-available-off-the-shelf components as possible. In addition, faster beam scans (both mechanically and in term of data acquisition) are desired for better operation of the accelerator. This document outlines the mechanical design of the new MP-11-like WS prototype and compares it to a previously built and tested SNS-like WS prototype.

MOPPR087	Transverse Beam Emittance Measurements of a 16 MeV Linac at the Idaho Accelerator Center	quadrupole, electron, emittance, background	990
	S. Setiniyaz, T.A. Forest ISU, Pocatello, Idaho, USA K. Chouffani, Y. Kim IAC, Pocatello, IDAHO, USA A. Freyberger JLAB, Newport News, Virginia, USA
	A beam emittance measurement of the 16 MeV S-band High Repetition Rate Linac (HRRL) was performed at Idaho State University's Idaho Accelerator Center (IAC). The HRRL linac structure was upgraded beyond the capabilities of a typical medical linac so it can achieve a repetition rate of 1 kHz. Measurements of the HRRL transverse beam emittance are underway that will be used to optimize the production of positrons using HRRL's intense electron beam on a tungsten converter. In this paper, we describe a beam imaging system using on an OTR screen and a digital CCD camera, a MATLAB tool to extract beamsize and emittance, detailed measurement procedures, and the measured transverse emittances for an arbitrary beam energy of 15 MeV.

MOPPR094	Preparation for NSLS II Linac to Booster Transport Line Commissioning	controls, emittance, booster, status	1002
	G.M. Wang, M.A. Davidsaver, R.P. Fliller, G. Ganetis, H.-C. Hseuh, Y. Hu, D. Padrazo, T.V. Shaftan, G. Shen, O. Singh, Y. Tian, H. Xu, L. Yang BNL, Upton, Long Island, New York, USA
	The National Synchrotron Light Source II (NSLS-II) is a state-of-the-art 3-GeV third generation light source currently under construction at Brookhaven National Laboratory. The first part of the Linac to Booster Transport (LBT) line has been installed for the linac commissioning. This part will be used for the linac acceptance test. In this paper, we describe the preparation of the LBT sub-system integration test and the high level applications.

TUXA01	Status of the J-PARC Facility	neutron, extraction, hadron, synchrotron	1005
	S. Nagamiya JAEA/J-PARC, Tokai-Mura, Naka-Gun, Ibaraki-Ken, Japan
	This presentation should provide a summary of the status and eventual re-commissioning of the J-PARC facility following the 2011 earth quake and tsunami.
	Slides TUXA01 [33.003 MB]

TUXA02	Upgrade Plans for the LHC Injector Complex	injection, electron, vacuum, feedback	1010
	R. Garoby, H. Damerau, S.S. Gilardoni, B. Goddard, K. Hanke, A.M. Lombardi, M. Meddahi, B. Mikulec, E.N. Shaposhnikova, M. Vretenar CERN, Geneva, Switzerland
	Challenging beams with much higher brightness than today are required for the LHC to achieve its high luminosity objective after the year 2020. It is the purpose of the LHC Injectors Upgrade (LIU) Project to achieve this result, consolidating and upgrading the existing set of ageing synchrotrons (PSB, PS and SPS), and using the new linac presently in construction (Linac4). The anticipated beam characteristics are described and compared to the known limitations in the different accelerators. The foreseen solutions are outlined as well as the planning for their implementation.
	Slides TUXA02 [72.367 MB]

TUXB02	Review of ERL Projects at KEK and Around the World	gun, FEL, electron, emittance	1040
	N. Nakamura KEK, Ibaraki, Japan
	Future synchrotron light sources based on energy-recovery linacs (ERLs) are expected to be capable of producing super-brilliant and/or ultra-short pulses of synchrotron radiation. The Japanese collaboration team is making efforts for realizing an ERL-based VUV and X-ray source with R&D efforts on super-conducting cavities and the electron gun at KEK and elsewhere. This presentation will describe the developments of the compact ERL project and the outline of the 3-GeV ERL light source project at KEK and also review ERL projects around the world, including potential applications to colliders.
	Slides TUXB02 [25.328 MB]

TUOBA02	Beam Commissioning and Operation of New Linac Injector for RIKEN RI-beam Factory	cyclotron, ion, DTL, ECRIS	1071
	K. Yamada, S. Arai, M. Fujimaki, T. Fujinawa, H. Fujisawa, N. Fukunishi, Y. Higurashi, E. Ikezawa, H. Imao, O. Kamigaito, M. Kase, M. Komiyama, K. Kumagai, T. Maie, T. Nakagawa, J. Ohnishi, H. Okuno, N. Sakamoto, K. Suda, H. Watanabe, T. Watanabe, Y. Watanabe, H. Yamasawa RIKEN Nishina Center, Wako, Japan A. Goto NIRS, Chiba-shi, Japan Y. Sato J-PARC, KEK & JAEA, Ibaraki-ken, Japan
	A new linac injector called RILAC2* has successfully commissioned at the RIKEN RI beam factory (RIBF). The RILAC2 can accelerate very heavy ions with m/q of 7, such as 124Xe¹⁹⁺ and 238U³⁵⁺ from a 28 GHz superconducting ECR ion source*, up to an energy of 680 keV/nucleon in the cw mode. Ions are directory injected into the RIKEN Ring Cyclotron without charge stripping in order to increase the beam intensity, as well as performing independent RIBF experiments and super-heavy-element synthesis. The key features of RILAC2 are the powerful ECRIS, higher extraction voltage of the ECRIS compared to the voltage of the existing injector linac to reduce the space charge effect, improvement of the rf voltage and phase stability, improvement of the vacuum level to reduce the loss by charge exchange, and the compact equipments yet to be installed in the existing AVF cyclotron vault. The first beam acceleration was achieved on December 21, 2010. After the several beam acceleration tests in 2011, we started to operate the RILAC2 to supply beams for the RIBF experiments. O. Kamigaito et al., Proc. of PASJ3-LAM31, WP78, p. 502 (2006); K. Yamada et al., Proc. of IPAC'10, MOPD046, p.789 (2010). ** T. Nakagawa et al., Rev. Sci. Instrum. 79, 02A327 (2008).
	Slides TUOBA02 [9.947 MB]

TUOBA03	H⁻ and Proton Beam Loss Comparison at SNS Superconducting Linac	proton, quadrupole, ion, DTL	1074
	A.P. Shishlo, A.V. Aleksandrov, J. Galambos, M.A. Plum ORNL, Oak Ridge, Tennessee, USA E. Laface ESS, Lund, Sweden V.A. Lebedev Fermilab, Batavia, USA
	Funding: ORNL/SNS is managed by UT-Battelle, LLC, for the U.S. Department of Energy under contract DE-AC05-00OR22725. A comparison of beam loss in the superconducting part (SCL) of the Spallation Neutron Source (SNS) linac for H⁻ and protons is presented. During the experiment the nominal beam of negative hydrogen ions in the SCL was replaced by a proton beam created by insertion of a thin stripping carbon foil placed in the low energy section of the linac. The observed significant reduction in the beam loss for protons is explained by a domination of the intra-beam stripping mechanism of the beam loss for H-. The details of the experiment are discussed, and a preliminary estimation of the cross section of the reaction H⁻ + H⁻ -> H⁻ + H⁰ + e is presented.
	Slides TUOBA03 [0.772 MB]

TUOAB03	Five Years of Accelerator Operation Experience at HIT	ion, controls, ion-source, synchrotron	1083
	A. Peters, R. Cee, E. Feldmeier, M. Galonska, Th. Haberer, K. Höppner, S. Scheloske, C. Schömers, T. Winkelmann HIT, Heidelberg, Germany
	Since spring 2007 the HIT company, a 100% daughter of the Heidelberg University Hospital, has taken over the responsibility for the operation of the first dedicated European ion beam tumour therapy facility. In 2009 the clinical operation started and since then more than 800 patients were treated in the facility. This success is based on a well-trained and highly-motivated team of physicists, engineers and technicians responsible for the 24/7 operation scheme as well as for more than 70% of the accelerator maintenance. The paper will give an overview of the operation organization reflecting the overall beam time schedule. In addition, the accelerator statistics will prove the achieved high availability of about 98% besides planned maintenance time. Furthermore, the reliability of the HIT accelerator including the gantry section will be illustrated resulting in long intervals before necessary retuning. At last, an outlook to further enhancements of the facility operation will be presented.
	Slides TUOAB03 [7.526 MB]

TUOBC01	Experimental Verification of the CLIC Two-beam Scheme, Status and Outlook	acceleration, target, emittance, gun	1101
	R. Corsini CERN, Geneva, Switzerland
	The feasibility of the CLIC novel scheme of two-beam acceleration was extensively tested in the CTF3 facility over the last few years. In particular, efficient full beam loading acceleration, isochronous ring operation, beam recombination by transverse RF deflectors have been fully proven. 12 GHz RF power production by high-current drive beam is now part of CTF3 routine operation, and two-beam acceleration up to 150 MV/m has been achieved. Drive beam deceleration tests were carried out as well. In this paper we summarize the main results obtained, including the more recent ones. We also outline and discuss the future experimental program, both in CTF3 and in other beam facilities, as well as the path to a possible facility needed in the initial stage of the CLIC project, CLIC0.
	Slides TUOBC01 [9.921 MB]

TUEPPB005	Novel Technique of Suppressing TBBU in High-energy ERLs	HOM, SRF, lattice, electron	1122
	V. Litvinenko BNL, Upton, Long Island, New York, USA
	Energy recovery linacs (ERLs) is emerging generation of accelerators promising revolutionize the fields of high-energy physics and photon sciences. One potential weakness of these devices is transverse beam-breakup instability, which may severely limit available beam current. In this paper I am presenting novel idea of using natural chromaticity in ERL arcs to suppressing TBBU instabilities. I present the theory of the process and two exact cases demonstrating that the threshold of TBBU instability could be raised by my orders of magnitude using this method. * V.N. Litvinenko, Chromaticity of the lattice and beam stability in energy recovery linacs, submitted to PR ST-AB

TUPPC006	CW Energy Upgrade of the Superconducting Electron Accelerator S-DALINAC	recirculation, dipole, simulation, extraction	1161
	M. Kleinmann, J. Conrad, R. Eichhorn, F. Hug, N. Pietralla TU Darmstadt, Darmstadt, Germany
	Funding: This work is supported by the DFG through SFB 634. The S-DALINAC is a superconducting recirculating electron accelerator with maximum design energy of 130 MeV operating in cw at 3 GHz. Even so the gradients of the superconducting cavities are well above design, their design quality factor of 3*10⁹ have not been reached so far. Due to the limited cooling power of the cryo-plant being 120 W, the final energy achievable in cw operation is around 85 MeV, currently. In order to provide a cw beam with the designed final energy in the future, the installation of an additional recirculation path is projected and to be finished by 2013. We review the design constraints related to the existing beam lines, report in detail on the magnet design (being the key issue) and the lattice calculations for the additional recirculation path.

TUPPC010	Study of Effects of Failure of Beamline Elements and its Compensation in CW Superconducting Linac	cavity, beam-losses, emittance, focusing	1173
	A. Saini, K. Ranjan University of Delhi, Delhi, India C.S. Mishra, J.-F. Ostiguy, N. Solyak, V.P. Yakovlev Fermilab, Batavia, USA
	Project-X is the proposed high intensity proton facility to be built at Fermilab in United States. First stage of the Project-X consists of H^- superconducting linac (SC) which will be operated in continuous wave (CW) mode to accelerate the beam from kinetic energy of 2.1 MeV to 3 GeV. The operation in CW mode puts stringent tolerances on the beam line components, particularly at low energy section. The failure of beam line elements result in mismatch of the beam with the following sections due to different beam parameters than designed parameters. It makes the beam unstable which causes emittance dilution, and ultimately results in beam losses. In worst case, it can affect the reliability of the machine and may lead to the shutdown of the linac to replace the failed elements. Thus, it is important to study impacts of these effects and their compensation to restore linac performance to avoid beam interruption. This paper presents the studies performed for the failure of accelerating cavity and focusing magnets at the critical locations in the Project-X CW superconducting linac

TUPPC011	Beam Steering Correction in FRIB Quarter-wave Resonators	cavity, simulation, cryomodule, solenoid	1176
	A. Facco INFN/LNL, Legnaro (PD), Italy A. Facco, Y. Xu, Y. Zhang, Q. Zhao, Z. Zheng FRIB, East Lansing, Michigan, USA
	Funding: This material is based upon work supported by the U.S. Department of Energy Office of Science under Cooperative Agreement DE-SC0000661 The Quarter-Wave Resonators (QWR) section of the FRIB superconducting driver linac is required to accelerate Uranium beam up to 16 MeV/u in two different charge states simultaneously. This puts severe requirements on resonators alignment and field quality, in order to avoid beam losses and emittance growth. In particular, QWR beam steering can cause transverse oscillations of the beam centroid which reduce the linac acceptance and induces emittance growth. We have studied, with an analytical model and with 3D beam dynamics simulations, correction methods for the FRIB QWRs steering. We found that cavity shifting can provide effective steering cancellation in FRIB QWRs without need of cavity shape modifications, and allows to eliminate transverse beam oscillations and to improve beam quality. Calculation and simulation methods and results will be presented and discussed. Michigan State University designs and establishes FRIB as a DOE Office of Science National User Facility in support of the mission of the Office of Nuclear Physics.

TUPPC019	Beam Dynamics Simulations of J-PARC Main Ring for Damage Recovery from the Tohoku Earthquake in Japan and Upgrade Plan of Fast Extraction Operation	alignment, simulation, injection, acceleration	1200
	Y. Sato, K. Hara, S. Igarashi, T. Koseki, K. Ohmi, C. Ohmori KEK, Ibaraki, Japan H. Hotchi JAEA/J-PARC, Tokai-Mura, Naka-Gun, Ibaraki-Ken, Japan
	Magnets of Japan Proton Accelerator Research Complex (J-PARC) were shaken by the Tohoku Earthquake in Japan on March 11th, 2011. The alignment of J-PARC Main Ring (MR) received 20 mm displacement horizontally and 6 mm vertically. Beam dynamics simulations were performed to estimate the effect of the displacement on closed orbit distortions and beam loss in fast extraction (FX) operation of J-PARC MR. Based on the simulation results, we concluded that re-alignment of J-PARC MR was needed to achieve high-power beam. The re-alignment of MR was finished on October 28th, 2011. We also considered the effects of the earthquake on the upstream of MR to establish our upgrade plan, which was based on beam dynamics simulations optimizing collimator balance of injection beam transport (3-50BT) and MR, and RF patterns. J-PARC MR FX operation was resumed from December 2011.

TUPPC021	Design Study on KEK Injector Linac Upgrade for High-current and Low-emittance Beams	emittance, simulation, wakefield, acceleration	1206
	H. Sugimoto, M. Satoh, M. Yoshida KEK, Ibaraki, Japan
	Injector linac at KEK is now under upgrading to produce high current (5nC for e-, 4nC for e+) and low emittance (20 mm mrad for e-, 6 mm mrad for e+) electron and positron beams to a SuperB collider called SuperKEKB. Emittance growth resulted from both wakefield at the acceleration structure and dispersive effects at the focusing structure are troublesome in keeping the beam quality during the beam propagation. In this study, a possible solution to mitigate these effects in the KEK injector linac is explored by considering bunch compression in an existing bending section, orbit correction to suppress the wakefield excitation, and beam optics design.

TUPPC022	Straight Scaling FFAG Experiment	emittance, vacuum, closed-orbit, instrumentation	1209
	J.-B. Lagrange, Y. Ishi, Y. Kuriyama, Y. Mori, R. Nakano, B. Qin, T. Uesugi, E. Yamakawa Kyoto University, Research Reactor Institute, Osaka, Japan Y. Niwa, K. Okabe, I. Sakai University of Fukui, Faculty of Engineering, Fukui, Japan
	Straight scaling FFAG experiment has been done at Kyoto University research reactor institute. Details and results are presented here.

TUPPC027	Multi Objective Genetic Optimization for Linac Lattice of PAL XFEL	lattice, electron, emittance, quadrupole	1224
	C.H. Yi, M.-H. Cho, S.H. Kim, W. Namkung POSTECH, Pohang, Kyungbuk, Republic of Korea H.-S. Kang PAL, Pohang, Kyungbuk, Republic of Korea K.-J. Kim ANL, Argonne, USA
	Funding: Work supported by MEST and POSTECH Physics BK21 Program. There are a large number of variables and objectives in design of XFEL linac lattices. Recently, most of accelerator physics field, are applying the multi-objective genetic algorithm (MOGA) for these kinds of problems. MOGA was applied to the PAL XFEL linac lattice design. Longitudinal position of all components was fixed before applying MOGA. RF parameters of RF cavities and bending angles of bunch compressors are selected as variables. Various beam parameters computed by ELEGANT were used as objectives. By using MOGA, new linac lattice designs with 2 and 3 bunch compressors was generated and their beam properties are presented in this paper.

TUPPC043	Design of Accumulator and Compressor Rings for the Project-X Based Proton Driver	lattice, proton, optics, synchrotron	1260
	Y. Alexahin, D.V. Neuffer Fermilab, Batavia, USA
	Funding: Work supported by Fermi Research Alliance, LLC, under contract No. DE-AC02-07CH11359 with the U.S. Department of Energy. A Muon Collider (MC) and Neutrino Factory (NF), which may be considered as a step towards MC, both require high-power (~4 MW) proton driver providing short (<1m) bunches for muon production. However, the driver repetition rate required for these two machines is different: ~15 Hz for MC and ~60 Hz for NF. This difference necessitates employing two separate rings: one for accumulation of the proton beam from the Project-X linac in a few (e.g., 4) long bunches, the other for bunch compression - one by one for NF or all at a time for MC with simultaneous delivery to the target. The lattice requirements for these two rings are different: the momentum compaction factor in the accumulator ring should be large (and possibly negative) to avoid the microwave instability, while the compressor ring can be nearly isochronous in order to limit the required RF voltage and reduce the dispersion contribution to the beam size. In the present report we consider ring lattice designs which achieve these goals.

TUPPC044	Emittance and Phase Space Tomography for the Fermilab Linac	emittance, focusing, optics, quadrupole	1263
	C. Johnstone, F.G.G. Garcia, T. Kobilarcik, G.M. Koizumi, C.D. Moore, D.L. Newhart Fermilab, Batavia, USA
	Funding: Work supported by Fermi Research Alliance, LLC, under contract No. DE-AC02-07CH11359 with the U.S. Dept. of Energy. The Fermilab Linac delivers a variable intensity, 400-MeV beam to the The MuCool Test Area experimental hall via a beam line specifically designed to facilitate measurements of the Linac beam emittance and properties. A 10 m, dispersion-free and magnet-free straight utilizes an upstream quadrupole focusing triplet in combination with the necessary in-straight beam diagnostics to fully characterize the transverse beam properties. Since the Linac does not produce a strictly elliptical phase space, tomography must be performed on the profile data to retrieve the actual particle distribution in phase space. This is achieved by rotating the phase space distribution using different waist focusing conditions of the upstream triplet and performing a de-convolution of the profile data. Preliminary measurements using this diagnostic section are reported here.

TUPPC046	Further Analysis of Real Beam Line Optics from a Synthetic Beam	optics, coupling, closed-orbit, electron	1269
	R.M. Bodenstein UVa, Charlottesville, Virginia, USA Y. Roblin, M.G. Tiefenback JLAB, Newport News, Virginia, USA
	Funding: Authored by Jefferson Science Associates, LLC under U.S. DOE Contract No. DE-AC05-06OR23177. The U.S. Government retains a license to publish or reproduce this manuscript for U.S. Government purposes. Standard closed-orbit techniques for Twiss parameter measurement are not applicable to the open-ended Continuous Electron Beam Accelerator Facility (CEBAF) at Jefferson Lab. The evolution of selected sets of real orbits in the accelerator models the behavior of a “synthetic” beam. This process will be validated against beam profile-based Twiss parameter measurements and should provide the distributed optical information needed to optimize beamline tuning for an open-ended system. This work will discuss the current and future states of this technique, as well as an example of its use in the CEBAF machine.

TUPPC052	Longitudinal Beam Tuning at FACET	diagnostics, wakefield, simulation, klystron	1287
	N. Lipkowitz, F.-J. Decker, J. Sheppard, S.P. Weathersby, U. Wienands, M. Woodley, G. Yocky SLAC, Menlo Park, California, USA
	Commissioning of the Facility for Advanced acCelerator Experimental Tests (FACET) at SLAC began in July 2011. In order to achieve the high charge density required for users such as the plasma wakefield acceleration experiment, the electron bunch must be compressed longitudinally from ~6 mm down to 20 microns. This compression scheme is carried out in three stages and requires careful tuning, as the final achievable bunch length is highly sensitive to errors in each consecutive stage. In this paper, we give an overview of the longitudinal dynamics at FACET, including beam measurements taken during commissioning, tuning techniques developed to minimize the bunch length, optimization of the new “W” chicane at the end of the linac, and comparison with particle tracking simulations. In addition, we present additional diagnostics and improved tuning techniques, and their expected effect on performance for the upcoming 2012 user run.

TUPPC053	Longitudinal Tuning of the SNS Superconducting Linac	cavity, optics, acceleration, controls	1290
	T.V. Gorlov ORNL, Oak Ridge, Tennessee, USA
	Funding: This work was supported by SNS through UT-Battelle, LLC, under Contract No. DE-AC05-00OR22725 for the U.S. Department of Energy. The SNS superconducting linac delivers proton beam with about 1 GeV of energy driven by self-consistent RF cavities. Here, we present an experience of the longitudinal tune-up of the SNS superconducting linac where a new application for quick RF phase setup and cavity fault adaptation was created. The routine of superconducting linac tune-up, longitudinal beam manipulation, and radio frequency cavity phase scaling for beam state recovery is presented. The application has direct value for beam optics study and will serve as the basis for longitudinal beam-size manipulation for a laser stripping project.

TUPPC065	High Intensity Beam Analysis for the Superconducting Radio-frequency Linac (SRF-Linac) of the IFMIF-EVEDA Accelerators	emittance, resonance, SRF, space-charge	1323
	W. Simeoni CEA/IRFU, Gif-sur-Yvette, France N. Chauvin, P.A.P. Nghiem, D. Uriot CEA/DSM/IRFU, France
	In this proceeding we analyze space charge effects on the beam dynamics of IFMIF accelerators. The objective is to be able to characterize and understand the crucial issues like halo formation, emittance growth and sudden particle losses in the SRF-Linac. We use the Hofmann stability charts to identify modes of collective space charge density oscillations that are responsible for the transfer and growth of the emittance. With identification of modes we are able to treat the parametric resonance between the modes and the nonlinear motion of an individual ion the amplitude of which is greater than the core radius. The resulting phase space consists of an inner separatrix containing the core and an outer separatrix that becomes the locus near which the halo particles enter and cluster.

TUPPD004	Costing Methodology and Status of the Neutrino Factory	cryogenics, target, solenoid, factory	1410
	A. Kurup Imperial College of Science and Technology, Department of Physics, London, United Kingdom N. Bliss, N.A. Collomb, A.F. Grant STFC/DL, Daresbury, Warrington, Cheshire, United Kingdom
	The International Design Study for the Neutrino Factory will produce a reference design report in 2013 that will contain a detailed performance analysis of the Neutrino Factory and a cost estimate. In order to determine the cost a number of engineering features need to be included in the accelerator physics design, which can require the physics design to be re-optimized. The cost estimate is determined in such a way as to make efficient use of the engineering resources available and to simplify the process of modifying the physics design to include engineering features. This paper will present details of the methodology used to determine the cost estimate and the current status of each subsystem.

TUPPD008	Recent Progress Toward a Muon Recirculating Linear Accelerator	dipole, cryomodule, quadrupole, factory	1422
	K.B. Beard Muons, Inc, Batavia, USA M. Aslaninejad, C. Bonţoiu, A. Kurup, J.K. Pozimski Imperial College of Science and Technology, Department of Physics, London, United Kingdom S.A. Bogacz, V.S. Morozov, Y. Roblin JLAB, Newport News, Virginia, USA
	Both Neutrino Factories (NF) and Muon Colliders (MC) require very rapid acceleration due to the short lifetime of muons. After a capture and bunching section, a linac raises the energy to about 900 MeV, and is followed by one or more Recirculating Linear Accelerators (RLA), possibly followed by a Rapid Cycling Synchrotron (RCS) or Fixed-Field Alternating Gradient (FFAG) ring. A RLA reuses the expensive RF linac section for a number of passes at the price of having to deal with different energies within the same linac. Various techniques including pulsed focusing quadrupoles, beta frequency beating, and multipass arcs have been investigated via simulations to improve the performance and reduce the cost of such RLAs.

TUPPD017	Electromagnetic Design of RF Cavities for Accelerating Low-Energy Muons	cavity, vacuum, resonance, solenoid	1446
	S.S. Kurennoy LANL, Los Alamos, New Mexico, USA
	A high-gradient linear accelerator for accelerating low-energy muons and pions in a strong solenoidal magnetic field has been proposed for homeland defense and industrial applications.* The acceleration starts immediately after collection of pions from a target in a solenoidal magnetic field and brings decay muons, which initially have kinetic energies mostly around 15-20 MeV, to 200 MeV over a distance of ~10 m. At this energy, both ionization cooling and further, more conventional acceleration of the muon beam become feasible. A normal-conducting linac with external-solenoid focusing can provide the required large beam acceptances. The linac consists of independently fed zero-mode (TM010) RF cavities with wide beam apertures closed by thin conducting edge-cooled windows. Electromagnetic design of the cavity, including its RF coupler, tuning and vacuum elements, and field probes, has been developed with the CST MicroWave Studio, and will be presented. * S.S. Kurennoy, A.J. Jason, H. Miyadera, “Large-Acceptance Linac for Accelerating Low-Energy Muons.” Proceed. IPAC10, p. 3518.

TUPPD019	New Injector for the EMMA ns-FFAG Ring	booster, cavity, gun, emittance	1449
	B.D. Muratori STFC/DL/ASTeC, Daresbury, Warrington, Cheshire, United Kingdom
	EMMA is the world’s first non-scaling FFAG which has recently demonstrated acceleration in the serpentine channel. At present, the electron beam is injected into EMMA from the ALICE accelerator. However, funding will be re-directed to an Electron Beam Test Facility (EBTF) in the near future, therefore, in order to continue the broad portfolio of planned experiments required to characterize non-scaling FFAGs, it essential to consider an alternative injection scheme. In this paper, we propose re-utilizing a thermionic gun and a 12 MeV linac from the SRS (Synchrotron Radiation Source) at Daresbury Laboratory. The paper looks at how the required EMMA beam properties can be matched with this new set-up and the advantages and disadvantages involved.

TUPPD023	RFQ LINAC Commissioning and Carbon⁴⁺ Acceleration for Ag¹⁵⁺ Acceleration via Direct Plasma Injection Scheme	ion, rfq, plasma, laser	1458
	T. Yamamoto, M. Washio RISE, Tokyo, Japan K. Kondo, M. Okamura, M. Sekine BNL, Upton, Long Island, New York, USA
	Funding: Work supported by Brookhaven Science Associates, LLC under Contract No. DE-AC02-98CH10886 with the U.S. Department of Energy. High intensity, high charge state, various ion species and small emittance heavy ion beam is required for particle physics, medical uses, inertial fusion, and a simulator of space radiation. Direct Plasma Injection Scheme (DPIS), the way to make laser abrasion plasma developed in the past several years, is used for Heavy Ion beam Accerelation. High density plasma with an initial drift velocity will fly to the entrance of the Radio Frequency Quadropole (RFQ) LINAC; ions will be separated from plasma via high voltage and injected it to RFQ LINAC directly. After RFQ LINAC, ions accepted to the RF buckets are accelerated to a current of over 10mA. Until now, we tried a carbon target using the partial modulation rod of the RFQ LINAC, and succeeded in accelerating carbon⁴⁺, carbon⁵⁺, and carbon⁶⁺ non-bunched beam.* In this instance, we succeeded in commissioning of new full modulation RFQ rod designed for the charge mass ratio(q/A) 1/6. We tested the acceleration of carbon⁴⁺, and it could be catched by the RF bucket and accelerated. After this, we'll try accelerating carbon²⁺ (q/A=1/6) for demonstrating the feasibility of the Ag¹⁵⁺ ion accelerating. * T. Kanesue, M. Okamura, K. Kondo, J. Tamura, H. Kashiwagi, Z. Zhang, Drift distance survey in direct plasma injection scheme for high current beam production, Rev Sci Instrum. 2010 Feb;81(2):02B723

TUPPD025	REVIEWOF LOW-ENERGY POSITRON BEAM FACILITIES	positron, target, neutron, radiation	1464
	S. Golge, B. Vlahovic NCCU, Durham, USA
	Positrons are produced by processes such as positive beta decay from radioactive isotopes, in nuclear reactor cores from both in-situ radioisotope radiation and pair production, and by accelerator driven beams hitting a converter target. The purpose of this paper is to review some of the prominent existing low-energy e⁺ facilities.

TUPPD055	Characterization of ps-spaced Comb Beams at SPARC	simulation, radiation, bunching, laser	1527
	A. Mostacci URLS, Rome, Italy A. Bacci, A.R. Rossi Istituto Nazionale di Fisica Nucleare, Milano, Italy M. Bellaveglia, E. Chiadroni, G. Di Pirro, M. Ferrario, G. Gatti, C. Vaccarezza INFN/LNF, Frascati (Roma), Italy A. Cianchi Università di Roma II Tor Vergata, Roma, Italy C. Ronsivalle ENEA C.R. Frascati, Frascati (Roma), Italy
	SPARC in Frascati is a high brightness photo-injector used to explore advanced beam manipulation techniques. Sub-picosecond, high brightness electron bunch trains (the so called comb beam) can be generated illuminating the cathode of a RF photoinjector with a laser pulse train and via velocity bunching technique. In this paper different aspects of the physics of this advanced beam manipulation technique are discussed combining simulation and measurements. Beam dynamics numerical macroparticle simulations have been compared with the experimental results for model validation; they allow to gain insights on the beam evolution highlighting several aspects which can not be measured. In particular, we focus on the train evolution in the linac sections and in the dog-leg line up to the THz station and on the effective rms length of the single pulses within the train when it becomes shorter than the resolution.

TUPPD065	An Electron Gun Test Stand to Prepare for the MAX IV Project	gun, cathode, injection, coupling	1551
	S. Werin, E. Elafifi, M. Eriksson, D. Kumbaro, F. Lindau, S. Thorin MAX-lab, Lund, Sweden E. Mansten Lund University, Division of Atomic Physics, Lund, Sweden
	The MAX IV facility, currently under construction, will include a 3 GeV linac injector with two RF guns providing beams for the two operations modes: ring injection and the Short Pulse Facility. The ring injection will be done by a thermionic 3 GHz RF gun developing from the current MAX-lab RF gun. The SPF gun will be a laser driven photo cathode 3 GHz RF gun based on the 1.6 cell BNL/SLAC type. The guns will be operated with short (0.7 us) RF pulses from a SLED system. A test stand to fine tune the operation of the two different systems has been assembled at the MAX IV laboratory (former MAX-lab). The experience in RF commissioning and initial measurements of energy, charge and quantum efficiency will be reported and the extension of the test stand for full emittance characterization will be outlined.

TUPPD076	Photocathode Studies for the SPEAR3 Injector RF Gun	cathode, gun, laser, klystron	1575
	S. Park, W.J. Corbett, S.M. Gierman, J.R. Maldonado SLAC, Menlo Park, California, USA
	Funding: Work supported by U.S. Department of Energy Contract DE-AC03- 76SF00515 and Office of Basic Energy Sciences, Division of Chemical Sciences. The electron gun for the SPEAR3 injector operates with a warm thermionic dispenser cathode immersed in a 1.5-cell RF structure. At each injection cycle the gun accelerates several thousand electron bunches up to ~3 MeV during a 2.5us rf pulse. The individual bunches are then compressed by an alpha magnet and a traveling-wave chopper selects 3-5 bunches so they don’t cause beam loading to the linac, where the accelerated bunches reach 120 MeV for subsequent capture in a single booster synchrotron bucket. Tests are underway to operate the dispenser cathode as a cold electron photo-emitter driven by an external laser system. Eventually, without the copper, this will enable multi-bunch injections to the Booster and SPEAR3. In parallel, tests are underway to evaluate quantum efficiency and beam emittance for a beam emitted from a CsBr photocathode with ns- and ps-pulses of UV laser light. In this paper we report on both the cold cathode electron gun operation studies for SPEAR3 and the CsBr research aimed at developing advanced cathode materials for future applications.

TUPPD077	SPEAR3 Booster RF System Upgrade: Performance Requirements and Evaluation of Resources	booster, klystron, cavity, injection	1578
	S. Park, W.J. Corbett, R.O. Hettel, J.F. Schmerge, J.J. Sebek, J.W. Wang SLAC, Menlo Park, California, USA
	Funding: Work supported by U.S. Department of Energy Contract DE-AC03-76SF00515 and Office of Basic Energy Sciences, Division of Chemical Sciences. The SPEAR2 accelerator system originally had 3 RF stations (2 for storage ring, 1 Booster) operating at 358.5 MHz. SPEAR3 now operates at 476.3 MHz with PEP-II type RF system, while the Booster RF frequency remains unchanged. For top-off operation, the Booster injects single 3.0 GeV electron bunches into SPEAR3 at 10 Hz every 5 minutes to replenish lost charge. Due to the frequency mismatch between SPEAR3 and the Booster, only one SPEAR3 bucket can injected per shot limiting injection rate and overall system flexibility. The aging high-power RF subsystems of the Booster pose a reliability issue as well. In order to remove these constraints, studies are underway to replace the Booster RF system using the PEP-II type RF system as a baseline. The new Booster RF system will be tuned to 475.036 MHz, and phase-locked to the SPEAR3 RF system. The project calls for ramping the Booster cavity gap voltage to 0.80 MV at 10 Hz, each with a 40 ms acceleration interval. With very low beam loading and low average RF power, there are many subsystems that can be operationally simplified. In this paper we present the results of analysis leading to a new Booster RF system.

TUPPD079	Design of an L-Band RF Photoinjector for the Idaho Accelerator Center 44 MeV Linac	emittance, gun, laser, solenoid	1584
	M. Titberidze, A.W. Hunt, D.P. Wells IAC, Pocatello, IDAHO, USA Y. Kim ISU, Pocatello, Idaho, USA
	At the Idaho Accelerator Center (IAC) of Idaho State University, we have been operating a 44 MeV L-band RF (1300 MHz) linear accelerator (LINAC) for various user applications such as medical isotope production, Laser Compton Scattering (LCS), positron annihilation energy spectroscopy, and photo fission. But the LINAC is not optimized properly to supply high quality electron beam for those experiments due to limitations of an existing 85 kV thermionic DC gun. In the near future, we are planning to use the L-band LINAC for new user applications such as Accelerator Driven subcritical nuclear reactor System (ADS), photon tagging facility, Ultrafast Electron Diffraction (UED) facility, and high power coherent Terahertz light source facility. Therefore, recently, we have been studying a future upgrade of the L-band LINAC with an RF photoinjector using ASTRA code. In this paper, we describe ASTRA simulation results and a new layout of the L-band LINAC, which is based on an L-band 1.5 cell RF photoinjector. Then, we describe its expected performance for two different single bunch charges (1 nC and 5 nC).

TUPPD083	Raising Photoemission Efficiency with Surface Acoustic Waves	electron, photon, polarization, vacuum	1596
	A. Afanasev, F. Hassani, C.E. Korman GWU, Washington, USA V.G. Dudnikov, R.P. Johnson Muons, Inc, Batavia, USA M. Poelker, K.E.L. Surles-Law JLAB, Newport News, Virginia, USA
	Funding: Supported in part by DOE STTR Grant DE-SC0006256. Notice: Authored by Jefferson Science Associates, LLC under U.S. DOE Contract No. DE-AC05-06OR23177 We are developing a novel technique that may help increase the efficiency and reduce costs of photoelectron sources used at electron accelerators. The technique is based on the use of Surface Acoustic Waves (SAW) in piezoelectric materials, such as GaAs, that are commonly used as photocathodes. Piezoelectric fields produced by the traveling SAW spatially separate electrons and holes, reducing their probability of recombination, thereby enhancing the photoemission quantum efficiency of the photocathode. Additional advantages could be increased polarization provided by the enhanced mobility of charge carriers that can be controlled by the SAW and the ionization of optically-generated excitons resulting in the creation of additional electron-hole pairs. It is expected that these novel features will reduce the cost of accelerator operation. A theoretical model for photoemission in the presence of SAW has been developed, and experimental tests of the technique are underway.

TUPPP012	Optimization of the Beam Optical Parameters of the Linac-based Terahertz Source FLUTE	laser, gun, space-charge, simulation	1629
	S. Naknaimueang, E. Huttel, A.-S. Müller, M.J. Nasse, R. Rossmanith, M. Schuh, M. Schwarz, P. Wesolowski KIT, Karlsruhe, Germany M.T. Schmelling MPI-K, Heidelberg, Germany
	Funding: Karlsruher Institut für Technologie. FLUTE is a compact accelerator (consisting of a 7 MeV laser gun, a 50 MeV linac, and bunch compressors) under construction at KIT in Karlsruhe for producing coherent THz radiation. The programs ASTRA and CSRtrack were used to optimize the beam parameters. The aim was to minimize the bunch length used in various THz experiments, with bunch charges between 100 pC and 3 nC. It was calculated that the bunch length after compression depends both on the bunch current and the transverse beam size. The transverse beam size depends on the laser spot size at the cathode of the 7 MeV laser gun. Further simulations showed that a larger beam size reduces the efficiency of the compressor. This problem is cured by focusing elements with a focusing strength depending on the space charge after the gun and integrated into the various compressors layouts under study (four magnets, two magnets and quadrupoles, etc.). The results of these calculations are presented in this paper.

TUPPP016	Recent Development of PF Ring and PF-AR	undulator, injection, polarization, vacuum	1641
	Y. Tanimoto, T. Aoto, S. Asaoka, K. Endo, K. Haga, K. Harada, T. Honda, Y. Honda, M. Izawa, Y. Kobayashi, A. Mishina, T. Miyajima, H. Miyauchi, S. Nagahashi, N. Nakamura, T. Nogami, T. Obina, T. Ozaki, C.O. Pak, H. Sakai, S. Sakanaka, H. Sasaki, Y. Sato, K. Satoh, M. Shimada, K. Shinoe, T. Shioya, M. Tadano, T. Tahara, T. Takahashi, R. Takai, K. Tsuchiya, T. Uchiyama, A. Ueda, K. Umemori, M. Yamamoto KEK, Ibaraki, Japan H. Takaki ISSP/SRL, Chiba, Japan
	After the earthquake of March 11, two light sources of KEK, PF ring and PF-AR, have recovered the regular operation from October, 2011. We installed tandem variably-polarized undulators at PF ring in 2009. Recently, the orbit switching system has been completed with sufficient feed-forward orbit compensation at 10-Hz. PF ring is usually operated at 450 mA with a top-up injection using the pulsed sextupole magnet instead of the conventional kicker magnets. The transverse and longitudinal instabilities are suppressed by a digital feedback system using the iGp signal processor. In the longitudinal direction, we observed unstable quadrupole mode oscillation which could not be controlled by the feedback system. We had applied the phase modulation of the main RF cavity to stabilize the quadrupole oscillation before. Old-type RF-shielded gate valves damaged by the earthquake were removed from the ring during the summer maintenance. In the operation after autumn, the quadrupole oscillation can be cured by dividing the bunch train of partial-filling. Without the phase modulation, the effective brightness of SR beam has been improved especially at beam lines of finite dispersion function.

TUPPP019	Overview of the Solaris Facility	storage-ring, klystron, dipole, vacuum	1650
	C.J. Bocchetta, M. Bartosik, P.P. Goryl, K. Królas, M. Młynarczyk, W. Soroka, M.J. Stankiewicz, P.S. Tracz, Ł. Walczak, A.I. Wawrzyniak, K. Wawrzyniak, J.J. Wiechecki, M. Zając, L. Zytniak Solaris, Kraków, Poland R. Nietubyć The Andrzej Soltan Institute for Nuclear Studies, Centre Świerk, Świerk/Otwock, Poland
	Funding: Work supported by the European Regional Development Fund within the frame of the Innovative Economy Operational Program: POIG.02.01.00-12-213/09 The Polish synchrotron light source Solaris is under construction in Kraków. The project is based on the MAX IV light source being built in Lund, Sweden. The 1.5 GeV storage ring for Solaris and part of the injector complex are identical to that of MAX IV, although both are housed in buildings that differ from those of MAX IV. Ground breaking on the green field site at the Jagiellonian University campus occurred at the start of 2012. A detail description of the facility infrastructure, services and construction choices is given together with the latest project developments for main accelerator systems.

TUPPP026	RF Rescue Option for TPS Linac	electron, bunching, booster, injection	1668
	K.L. Tsai, H.-P. Chang, C.-T. Chen, C.-S. Fann, K.T. Hsu, S.Y. Hsu, K.-K. Lin, H.M. Shih NSRRC, Hsinchu, Taiwan K. Dunkel, C. Piel RI Research Instruments GmbH, Bergisch Gladbach, Germany
	The 150 MeV linac of Taiwan Photon Source was commissioned in June 2011. It consists of 90 keV electron source, bunching system and three S-band accelerating sections driven by three high-power klystrons. The rf system is equipped with rescue option such that the rf power from second klystron can be split and fed into both accelerating section 1 and 2. The rescue operation will be needed in the event of a failure occurred at the first klystron. In the report, the rescue capability will be illustrated and the test results will also be discussed.

TUPPP038	Electron Beam Collimation for the Next Generation Light Source	collimation, undulator, gun, impedance	1695
	C. Steier, P. Emma, H. Nishimura, C. F. Papadopoulos, F. Sannibale LBNL, Berkeley, California, USA
	Funding: Work supported by the U.S. Department of Energy under Contract No. DE-AC02-05CH11231. The Next Generation Light Source will deliver high (MHz) repetition rate electron beams to an array of free electron lasers. Because of the significant average current in such a facility, effective beam collimation is extremely important to minimize radiation damage to undulators, prevent quenches of superconducting cavities, limit dose rates outside of the accelerator tunnel and prevent equipment damage. This paper describes the conceptual design of the collimator system, as well as the results of simulations to test its effectiveness.

TUPPP054	RF Activation and Preliminary Beam Tests of the X-band Linearizer at the FERMI@Elettra FEL Project	FEL, klystron, emittance, LLRF	1721
	G. D'Auria, S. Di Mitri, G. Penco, C. Serpico ELETTRA, Basovizza, Italy
	FERMI@Elettra is a fourth generation light source facility presently in commissioning at the Elettra Laboratory in Trieste, Italy. It is based on an S-band (3 GHz), 1.5 GeV normal conducting (NC) linac, that provides ultra short e-bunches with high peak current, using two stages of magnetic compression. To linearize the beam longitudinal phase space and to improve the compression process, a forth harmonic RF structure (12 GHz) has been installed downstream the first magnetic chicane. This paper reports the RF activation of the structure and the preliminary tests performed on the beam.

TUPPP061	Status of the PAL-XFEL Project	undulator, gun, electron, FEL	1735
	J.H. Han, H.-S. Kang, I.S. Ko PAL, Pohang, Kyungbuk, Republic of Korea
	Funding: The Ministry of Education, Science and Technology of the Korean Government PAL-XFEL is designed to generate X-ray radiation in the range of 0.1 and 10 nm for users. The machine consists of a 10 GeV linear accelerator and five undulator beamlines. Electron beams are generated at a low emittance S-band photocathode RF gun and accelerated with an S-band normal conducting linac. Three hard X-ray beamlines will be located at the end of the linac. Electron beams for two soft X-ray beamlines will be switched at a medium energy. The project started in 2011 and the building construction is ongoing. Resent progress of the project and an update of the current progress are presented.

TUPPP062	Start to End Simulation of Three Bunch Compressor Lattice for PAL XFEL	lattice, FEL, emittance, simulation	1738
	H.-S. Kang, M.-H. Cho, J.H. Han, T.-H. Kang, I.S. Ko PAL, Pohang, Kyungbuk, Republic of Korea C.H. Yi POSTECH, Pohang, Kyungbuk, Republic of Korea
	The PAL XFEL is a 0.1-nm hard X-ray FEL project starting from 2011 to finish in 2014, which aims at achieving higher photon flux than 10¹² photons/pulse at 0.1 nm using a 10 GeV electron linac. The PAL XFEL is designed to have a hard x-ray undulator line at the end of linac and a branch line at 2.65 GeV point for soft X-ray undulator line. The three bunch compressor lattice (3-BC) is chosen to minimize emitance growth due to CSR and minimize correlated energy spread. The 3-BC lattice makes it possible to operate soft X-ray FEL undulator line simultaneously and independently from hard X-ray FEL undulator line.

TUPPP063	Electron-beam Optimization Studies for the FERMI@Elettra Free-electron Laser	electron, emittance, simulation, alignment	1741
	E. Ferrari, G. De Ninno University of Nova Gorica, Nova Gorica, Slovenia P. Craievich, S. Di Mitri, E. Ferrari, L. Fröhlich, G. Gaio, G. Penco, C. Spezzani, M. Trovò ELETTRA, Basovizza, Italy
	FERMI@Elettra is a single-pass free-electron laser, based on seeded high-gain harmonic generation. Presently, the first phase of the project (covering the spectral range between 100 and 20 nm) is under commissioning. The free-electron laser performance depends on the quality of the electron beam. In the case of the FERMI linear accelerator, the latter is strongly influenced both by the wake-fields present in the accelerating sections and by possible misalignments of the various accelerator components. In order to investigate and compensate these effects, we performed a study based on local trajectory bumps. We demonstrate that this approach significantly improves the electron-beam quality and, eventually, the free-electron laser performance.

TUPPP064	Microbunching Instability Studies in SwissFEL	simulation, laser, booster, FEL	1744
	S. Bettoni, B. Beutner Paul Scherrer Institut, Villigen, Switzerland V.A. Goryashko NASU/IRE, Kharkov, Ukraine
	Shot noise or an initial intensity modulation in the beam pulse may have a strong effect in the FEL linacs and also severely degrade the machine performances in terms of FEL performances. In this paper we present the simulations done to study this effect in SwissFEL, the future free electron laser under design at Paul Scherrer Institute. In particular we calculated the gain of the microbunching instability in the low and high energy part and we performed start-to-end simulations using as initial distribution something as close as possible to the laser profile measured at the SwissFEL injector test facility. We finally present the preliminary calculations to estimate the effect of the laser heater to mitigate this effect.

TUPPP067	Collimation System Design and Performance for the SwissFEL	collimation, undulator, wakefield, electron	1753
	F. Jackson, J.-L. Fernández-Hernando STFC/DL/ASTeC, Daresbury, Warrington, Cheshire, United Kingdom D. Angal-Kalinin Cockcroft Institute, Warrington, Cheshire, United Kingdom H.-H. Braun, S. Reiche Paul Scherrer Institut, Villigen, Switzerland
	Electron beam collimation in the SwissFEL is required for protection of the undulators against radiation damage and demagnetization. The design for the SwissFEL collimation for the hard X-ray undulator (Aramis) includes transverse collimation in the final accelerating linac sections, plus an energy collimator in a post-linac chicane. The collimation system must provide efficient protection of the undulator for various machine modes providing varied final beam energy to the undulator. The performance of the transverse and energy collimation design is studied in simulations including evaluation of the transverse collimation for various beam energies and the effect of grazing particles on the energy collimator. Collimator wakefields are also considered.

TUPPP068	Comparison of Compression Schemes for CLARA	emittance, FEL, sextupole, cavity	1756
	P.H. Williams, J.W. McKenzie STFC/DL/ASTeC, Daresbury, Warrington, Cheshire, United Kingdom J.K. Jones, P.H. Williams Cockcroft Institute, Warrington, Cheshire, United Kingdom
	CLARA (Compact Linear Advanced Research Accelerator) at Daresbury Laboratory is proposed to be the UK’s national FEL test facility. The accelerator will be a ~250 MeV electron linac capable of producing short, high brightness electron bunches. The machine comprises a 2.5 cell RF photocathode gun, one 2 m and three 5 m normal conducting S-band (2998MHz) accelerating structures and a variable magnetic compression chicane. CLARA will be used as a test bed for novel FEL configurations. We present a comparison of acceleration and compression schemes for the candidate machine layout.

TUPPP070	Next Generation Light Source R&D and Design Studies at LBNL	FEL, electron, laser, gun	1762
	J.N. Corlett, B. Austin, K.M. Baptiste, D.L. Bowring, J.M. Byrd, S. De Santis, P. Denes, R.J. Donahue, L.R. Doolittle, P. Emma, D. Filippetto, G. Huang, T. Koettig, S. Kwiatkowski, D. Li, T.P. Lou, H. Nishimura, H.A. Padmore, C. F. Papadopoulos, G.C. Pappas, G. Penn, M. Placidi, S. Prestemon, D. Prosnitz, J. Qiang, A. Ratti, M.W. Reinsch, D. Robin, F. Sannibale, D. Schlueter, R.W. Schoenlein, J.W. Staples, C. Steier, C. Sun, T. Vecchione, M. Venturini, W. Wan, R.P. Wells, R.B. Wilcox, J.S. Wurtele LBNL, Berkeley, California, USA
	Funding: Work supported by the Director, Office of Science, of the U.S. Department of Energy under Contract No. DE-AC02-05CH11231. LBNL is developing design concepts for a multi-beamline soft x-ray FEL array powered by a superconducting linear accelerator, operating with a high bunch repetition rate of approximately one MHz. The cw superconducting linear accelerator is supplied by an injector based on a high-brightness, high-repetition-rate photocathode electron gun. Electron bunches are distributed from the linac to the array of independently configurable FEL beamlines with nominal bunch rates up to 100 kHz in each FEL, and with even pulse spacing. Individual FELs may be configured for different modes of operation, and each may produce high peak and average brightness x-rays with a flexible pulse format, and with pulse durations ranging from sub-femtoseconds to hundreds of femtoseconds. In this paper we describe conceptual design studies and optimizations. We describe recent developments in the design and performance parameters, and progress in R&D activities.

TUPPP071	Design Concepts of a Beam Spreader for a Next Generation Free Electron Laser	electron, kicker, FEL, septum	1765
	M. Placidi, P. Emma, J.-Y. Jung, G.C. Pappas, D. Robin, C. Sun, W. Wan LBNL, Berkeley, California, USA
	LBNL is developing design concepts for a multi-beamline soft x-ray FEL array powered by a superconducting linear accelerator, operating with a high bunch repetition rate of approximately one MHz. Electron bunches are distributed from the linac to the array (up to 10) independently configurable FEL beamlines with nominal bunch rates up to 100 kHz in each FEL, and with even pulse spacing. This distribution to the different FELs is made by the beam spreader for which the design has to relative compact while not significantly perturbing the quality of the electron beam and subsequent performance of the FELs. We report on our conceptual design for the spreader. The spreader lattice has two distinct parts, namely the beam take-off section and the FEL fan-out distributions section. Each section is achromatic and isochronous. The effect of coherent synchrotron radiation and micro-bunching has been studied when passing through the spreader and simulations show no significant deterioration in the beam quality.

TUPPP073	Machine Parameter Studies for an FEL Facility Using STAFF	FEL, photon, undulator, emittance	1768
	M.W. Reinsch, B. Austin, J.N. Corlett, L.R. Doolittle, P. Emma, G. Penn, D. Prosnitz, J. Qiang, A. Sessler, M. Venturini LBNL, Berkeley, California, USA J.S. Wurtele UCB, Berkeley, California, USA
	Designing an FEL facility requires balancing multiple science needs, FEL and accelerator physics constraints, and engineering limitations. STAFF (System Trade Analysis for an FEL Facility) is a MATLAB program that enables the user to rapidly explore a large range of Linac and FEL design options to meet science requirements. The code uses analytical models such as the Ming Xie formulas when appropriate and look-up tables when necessary to maintain speed and flexibility. STAFF's modular design simplifies the inclusion of new physics models for FEL harmonics, wake fields, cavity higher-order modes and aspects of linac design such as the optimization of a laser heater, harmonic linearizer, and one or more bunch compressors. Code for the microbunching instability has been included as well. STAFF also supports multiple undulator technologies. STAFF permits the user to study error tolerances and multiple beamlines so as to explore the full capabilities of an entire user facility. This makes it possible to optimize the integrated system in terms of performance metrics such as photons/pulse, photons/sec and tunability range.

TUPPP074	Beam Dynamics Studies of a High-repetition Rate Linac Driver for a 4th-generation Light Source	FEL, emittance, simulation, laser	1771
	M. Venturini, J.N. Corlett, P. Emma, C. F. Papadopoulos, G. Penn, M. Placidi, J. Qiang, M.W. Reinsch, F. Sannibale, C. Steier, R.P. Wells LBNL, Berkeley, California, USA
	We present progress toward the design of a super-conducting linac driver of a high repetition rate FEL-based soft x-ray light source. The machine is intended to accept beams generated by the APEX* photocathode gun, operating in the MHz range, and deliver them to an array of SASE and seeded FEL beamlines. After reviewing the beam-dynamics considerations that are informing specific lattice choices we discuss the expected performance of the proposed machine design and its ability to meet the desired FEL specifications. We consider the merit of possible alternate designs (e.g., a one-stage compressor vs. a two-stage compressor) and the trade-offs between competing demands on the beam attributes (e.g., high peak current vs. acceptable energy spread). * F. Sannibale et al., this conference.

TUPPP079	Design Alternatives for a Free Electron Laser Facility	FEL, undulator, electron, photon	1777
	K. Jacobs, J. Bisognano, R.A. Bosch, D. Eisert, M.V. Fisher, M.A. Green, R.G. Keil, K.J. Kleman, J.G. Kulpin, G.C. Rogers, R. Wehlitz UW-Madison/SRC, Madison, Wisconsin, USA T. Chiang, T.J. Miller University of Illinois, Urbana, USA J.E. Lawler, D. Yavuz UW-Madison/PD, Madison, Wisconsin, USA R.A. Legg JLAB, Newport News, Virginia, USA R.C. York FRIB, East Lansing, Michigan, USA
	The University of Wisconsin-Madison is continuing design efforts for a vacuum ultraviolet/X-ray Free Electron Laser facility. The design incorporates seeding the FEL to provide fully coherent photon output at energies up to ~1 keV. The focus of the present work is to minimize the cost of the facility while preserving its performance. To achieve this we are exploring variations in the electron beam driver for the FEL, in undulator design, and in the seeding mechanism. Design optimizations and trade-offs between the various technologies and how they affect the FEL scientific program will be presented.

TUPPP087	Commissioning of the Fritz Haber Institute Mid-IR FEL	FEL, wiggler, electron, undulator	1792
	A.M.M. Todd, H. Bluem, D. Dowell, R. Lange, J.H. Park, J. Rathke, L.M. Young AES, Princeton, New Jersey, USA W. Erlebach, S. Gewinner, H. Junkes, A. Liedke, G. Meijer, W. Schöllkopf, W.Q. Zhang, G. von Helden FHI, Berlin, Germany S.C. Gottschalk STI, Washington, USA K. Jordan Kevin Jordan PE, Newport News, Virginia, USA U. Lehnert, P. Michel, W. Seidel HZDR, Dresden, Germany R. Wünsch FZD, Dresden, Germany
	The IR and THz FEL at the Fritz Haber Institute (FHI) in Berlin is designed to deliver radiation from 4 to 400 microns. A single-plane-focusing undulator combined with a 5.4-m-long cavity is used is the mid-IR (< 50 micron), while a two-plane-focusing undulator in combination with a 7.2-m-long cavity with a 1-D waveguide for the optical mode is planned for the far-IR. Beam was delivered to the IR beam dump in November 2011. We describe progress since that time in completing the commissioning of the mid-IR beamline and the status of the far-IR beamline design and fabrication.

TUPPP088	Bunch Compressor Design for Potential FEL Operation at eRHIC	FEL, emittance, electron, simulation	1795
	Y.C. Jing, Y. Hao, V. Litvinenko BNL, Upton, Long Island, New York, USA
	Electron-Relativistic Heavy Ion Collider (eRHIC) is an upgrade project for the current operation of RHIC. It will provide a high quality electron beam with energy recovery scheme to collide with ion beams. One may think of taking advantage of using this electron beam for FEL operation. Bunch compressor is a crucial component to compress the beam to high peak current for undulators and CSR effect needs to be taken care of to preserve the beam quality. In this paper, authors present a novel bunch compressor design with CSR suppression scheme for the potential FEL operation at eRHIC.

TUPPP090	Studies of Controlled Laser-induced Microbunching Instability at Source Development Laboratory	laser, electron, radiation, space-charge	1798
	S. Seletskiy, B. Podobedov, Y. Shen, X. Yang BNL, Upton, Long Island, New York, USA
	We present the studies of controlled microbunching intentionally induced on the beam by the photocathode laser with modulated longitudinal profile. Varying the depth and frequency of longitudinal modulation of the laser pulse allowed us to observe the development of microbunching instability at BNL Source Development Laboratory (SDL) in the controlled environment. That allowed us to benchmark the model of the microbunching gain for the first time. In addition to that, we demonstrated for the first time a constructive work of a so-called longitudinal space charge amplifier, which in case under consideration can be utilized for enhancement of linac-based sources of THz radiation.

TUPPP092	Renovated Two-stage Bunch Compressor for the International Linear Collider	wiggler, positron, linear-collider, collider	1801
	S. Seletskiy BNL, Upton, Long Island, New York, USA N. Solyak Fermilab, Batavia, USA
	The International Linear Collider (ILC) utilizes a Bunch Compressor (BC) in the Damping Ring to Main Linac Transfer Line (RTML) that compresses the RMS bunch length from 6 mm to 300 micrometers before sending the beam to the Main Linac. It was decided to utilize a two stage BC for the design baseline, since it provides an additional option for the ILC to work with 150 micrometers long bunches and reduces the energy spread at the RTML exit under normal operational conditions. In this paper we report the new design of the optimized two-stage bunch compressor.

TUPPR004	ILC Conventional Facility in Asian Sites	site, radiation, HLRF, cryogenics	1816
	A. Enomoto, M. Miyahara KEK, Ibaraki, Japan
	The international linear collider (ILC) is on a stage of preparing technical design report (TDR). Through value engineering to reduce civil construction costs, the tunnel configuration was changed from double- tunnel scheme to single. The double-tunnel schme accomodates superconducting accelerator modules and their power supplies indipendently. This is a very natural scheme for setting an accelerator and its power supply nearby and for preventing radiation damage of the power supply. However, the single-tunnel scheme was proposed to reduce cost, and to avoid such radiation problem three kinds of high-level (HLRF) RF systems are proposed. We report the comparison of ILC main linac costs and construction schedules between eight cases for combinations of diferent tunnel excavation methods and HLRF systems; then, we report the potential facility design for the Asian sites.

TUPPR005	Linac Upgrade in Intensity and Emittance for SuperKEKB	emittance, positron, electron, alignment	1819
	T. Higo, M. Akemoto, D.A. Arakawa, Y. Arakida, A. Enomoto, S. Fukuda, K. Furukawa, Y. Higashi, H. Honma, N. Iida, M. Ikeda, E. Kadokura, K. Kakihara, T. Kamitani, H. Katagiri, M. Kurashina, S. Matsumoto, T. Matsumoto, H. Matsushita, S. Michizono, K. Mikawa, T. Miura, F. Miyahara, T. Mori, H. Nakajima, K. Nakao, T. Natsui, Y. Ogawa, S. Ohsawa, M. Satoh, T. Shidara, A. Shirakawa, H. Sugimoto, T. Suwada, T. Takatomi, T. Takenaka, Y. Yano, K. Yokoyama, M. Yoshida, L. Zang, X. Zhou KEK, Ibaraki, Japan D. Satoh TIT, Tokyo, Japan
	The SuperKEKB is designed to produce 40 times luminosity than that of the KEKB. In order to realize such a high luminosity, the injector linac should provide both electron and positron beams of about 4-5 nC/bunch, which is several times higher than before. In addition, their emittance requirement of the injection beam to the rings is 20 microns, which is a factor of a few tens smaller than before. The intensity and emittance of the electron beam are realized directly by developing the photo RF gun. In contrast, the positron intensity is increased by adopting a higher capture efficiency system with flux concentrator followed by large-aperture accelerators, while its emittance is reduced by a damping ring. For preserving such a low emittance of both beams toward the injection to the rings, the suppression of the emittance growth is crucial. To this end, the alignment of the accelerator components should be a few tens of microns, where we need an improvement by more than a factor 10. The beam-based alignment is definitely needed with better-resolution BPMs. In the present paper are reviewed the overall progress and perspective of the design and the associated component developments.

TUPPR012	Polarized Positron Source with a Compton Multiple Interaction Point Line	positron, electron, laser, simulation	1834
	I. Chaikovska, O. Dadoun, P. Lepercq, A. Variola LAL, Orsay, France R. Chehab IN2P3 IPNL, Villeurbanne, France
	Positron sources are critical components of the future lepton colliders projects. This is essentially due to the high luminosity required, orders of magnitude higher than existing ones. In addition, polarization of the positron beam rather expands the physics research potential of the machine by increasing the precision of the measurements and enhancing certain types of interactions. In this framework, the Compton sources for polarized positron production are taken into account where the high energy gamma rays are produced by the Compton scattering and subsequently converted in the polarized electron-positron pairs in a target. The Compton multiple IP line is proposed as one of the solutions to increase the number of captured positrons. This allows a significant increase in the emitted gamma ray flux impinging on the target. The gamma ray production with the Compton multiple IPs line is simulated and used for polarized positron generation. Later, a capture section based on an adiabatic matching device followed by a pre-injector linac is simulated to capture and accelerate the positron beam. The results obtained are presented and discussed.

TUPPR013	Design Integration and Vision Sharing for the ILC	lattice, linear-collider, collider, damping	1837
	B. List, L. Hagge, S. Sühl, N.J. Walker, N. Welle DESY, Hamburg, Germany
	The Global Design Effort for the International Linear Collider is currently preparing the Technical Design Report, which will be released in early 2013. The starting point of a consistent and correct design is the accelerator lattice, which defines the layout of the machine. Integrating the lattice geometrically and optically provides the basis for civil engineering and conventional facilities planning and finally the cost estimate. Tools that provide three-dimensional visualization of the lattice and tunnel help to perform the design integration and allow sharing a common vision of the final accelerator. We will present the process that was established to arrive at such an integrated design and the tools that were developed to support that process by analyzing and visualizing lattice files.

TUPPR024	CLIC Recombination Scheme for the Low Energy Operation Mode	factory, acceleration, luminosity, collider	1864
	A. Gerbershagen, D. Schulte CERN, Geneva, Switzerland P. Burrows Oxford University, Physics Department, Oxford, Oxon, United Kingdom
	The CLIC recombination scheme is a concept of multiplication of the drive beam frequency in order to generate a 12 GHz RF wave for the main beam acceleration. CLIC is designed to be operated in nominal and in low energy modes. The low energy operation modes require the train length to be increased by different factors in order to maintain the same level of luminosity. Also the number of initial trains that are merged to form each final train is changed. The combination scheme must be able to accommodate and recombine both long and short trains for nominal and low energy CLIC operation modes. The recombination hence becomes a non-trivial process and makes the correction of the errors in the drive beam more challenging. The present paper describes in detail the recombination process and its consequences.

TUPPR026	Conceptual Design of the CLIC Damping Ring RF System	cavity, damping, beam-loading, coupling	1870
	A. Grudiev CERN, Geneva, Switzerland
	In order to achieve high luminosity in CLIC, ultra-low emittance bunches have to be generated in both electron and positron damping rings. To achieve this goal, big energy loss per turn in the wigglers has to be compensated by the RF system. This results in very strong beam loading transients affecting the longitudinal bunch position and bunch length. In this paper, conceptual design of the RF system for the CLIC damping ring is presented. Baseline and several alternatives are discussed and the corresponding requirements for the cavities and the RF power sources are presented in order to meet stringent tolerances on the bunch-to-bunch phase and bunch length variations.

TUPPR029	Performance of Linear Collider Beam-Based Alignment Algorithms at FACET	alignment, simulation, emittance, optics	1879
	A. Latina, J. Pfingstner, D. Schulte CERN, Geneva, Switzerland E. Adli University of Oslo, Oslo, Norway
	The performance of future linear colliders will depend critically on beam-based alignment (BBA) and feedback systems, which will play a crucial role both in the linear and in the non-linear systems of such machines, e.g., the linac and the final-focus. Due to its characteristics, FACET is an ideal test-bench for BBA algorithms and linear collider beam-dynamics in general. We present the results of extensive computer simulations and their experimental verification.

Paper

Title

Other Keywords

Page

MOYAP01

Accelerator Driven Systems

neutron, proton, target, superconducting-RF

6

D. Vandeplassche, L. Medeiros Romão
SCK•CEN, Mol, Belgium

Accelerator Driven Systems are promising tools for the efficient transmutation of nuclear waste products in dedicated industrial installations (transmuters). The Myrrha project at Mol, Belgium, placed itself on the path towards these applications with a multipurpose and versatile system based on a liquid PbBi (LBE) cooled fast reactor (80 MWth) which may be operated in both critical and subcritical modes. In the latter case the core is fed by spallation neutrons obtained from a 600 MeV proton beam hitting the LBE coolant/target. The accelerator providing this beam is a CW superconducting linac which is laid out for the highest achievable reliability. The combination of a redundant and of a fault tolerant scheme should allow obtaining an MTBF value in excess of 500 hours that is required for optimal integrity and successful operation of the ADS. Myrrha is expected to be operational in 2023. The forthcoming 4-year period is fully dedicated to R&D activities, and in the field of the accelerator they are entirely focused on the reliability aspects.

Slides MOYAP01 [6.343 MB]

MOOAA02

Instrumentation and Diagnostics for High Repetition Rate Linac-driven FELs

FEL, emittance, diagnostics, laser

23

J.M. Byrd, S. De Santis, L.R. Doolittle, D. Filippetto, G. Huang, M. Placidi, A. Ratti
LBNL, Berkeley, California, USA

Funding: Work supported by the Director, Office of Science, of the U.S. Department of Energy under Contract No. DE-AC02-05CH11231.
One of the concepts for the next generation of linac-driven FELs is a cw superconducting linac driving an electron beam with MHz repetition rates. The beam is then switched into an array of independently configurable FELs. The demand for high brightness beams and the high rep-rate presents a number of challenges for the instrumentation and diagnostics. The high rep-rate also presents opportunities for increased beam stability because of the ability for much higher sampling rates for beam-based feedbacks. In this paper, we present our plans for instrumentation and diagnostics for such a machine.

Slides MOOAA02 [1.710 MB]

MOOBA01

Thorium Energy Futures

neutron, target, cyclotron, proton

29

S. Peggs, W. Horak, T. Roser
BNL, Upton, Long Island, New York, USA
V.B. Ashley, R.F. Ashworth
Jacobs Engineering, Pasadena, USA
R.J. Barlow, R. Cywinski, R. Seviour
University of Huddersfield, Huddersfield, United Kingdom
J.-L. Biarrotte
IPN, Orsay, France
S. Henderson
Fermilab, Batavia, USA
A. Hutton
JLAB, Newport News, Virginia, USA
J. Kelly
Thor Energy, Oslo, Norway
M. Lindroos
ESS, Lund, Sweden
P.M. McIntyre
Texas A&M University, College Station, Texas, USA
A. Norlin
IThEO, Sweden
H.L. Owen
STFC/DL/ASTeC, Daresbury, Warrington, Cheshire, United Kingdom
G.T. Parks
University of Cambridge, Cambridge, United Kingdom

The potential for thorium as an alternative or supplement to uranium in fission power generation has long been recognised, and several reactors, of various types, have already operated using thorium-based fuels. Accelerator Driven Subcritical (ADS) systems have benefits and drawbacks when compared to conventional critical thorium reactors, for both solid and molten salt fuels. None of the four options – liquid or solid, with or without an accelerator – can yet be rated as better or worse than the other three, given today's knowledge. We outline the research that will be necessary to lead to an informed choice.

Slides MOOBA01 [3.887 MB]

MOOBA02

Status and Future Perspectives of the HIE-ISOLDE Project at CERN

cryomodule, cryogenics, solenoid, ion

34

Y. Kadi, A.P. Bernardes, Y. Blumenfeld, S. Calatroni, R. Catherall, M.A. Fraser, B. Goddard, D. Parchet, E. Siesling, W. Venturini Delsolaro, D. Voulot, L.R. Williams
CERN, Geneva, Switzerland

The High Intensity and Energy (HIE)-ISOLDE project aims at several important upgrades of the present ISOLDE radioactive beam facility at CERN. The main focus lies in the energy upgrade of the post-accelerated radionuclide beams from 3 MeV/u up to 10 MeV/u through the addition of superconducting cavities. This will open the possibility of many new types of experiments including transfer reactions throughout the nuclear chart. The first stage of this upgrade involves the design, construction, installation and commissioning of two high-β cryomodules downstream of REX-ISOLDE, the existing post-accelerator. Each cryomodule houses five high-β sc cavities and one sc solenoid. Prototypes of the Nb-sputtered Quarter Wave Resonators (QWRs) cavities for the new superconducting linear accelerator have been manufactured and are undergoing RF cold tests. The project also includes a design study of improved production targets to accommodate the future increase of proton intensity delivered by the new LINAC4 proton driver. The project has been approved by CERN and its implementation started in January 2010. An overview of the project and the timeline will be presented.

Slides MOOBA02 [7.044 MB]

MOOBA03

Development of a High-power Coherent THz Sources and THz-TDS System on the basis of a Compact Electron Linac

electron, radiation, polarization, laser

37

M. Kumaki, K. Sakaue, M. Washio
RISE, Tokyo, Japan
R. Kuroda, H. Toyokawa, K. Yamada
AIST, Tsukuba, Ibaraki, Japan

The high-power terahertz time-domain spectroscopy (THz-TDS) has been developed on the basis of a compact S-band electron linac at AIST, Japan. It is strongly expected for inspection of dangerous materials in the homeland security field. The linac consists of a photocathode rf-gun, two acceleration tubes and a magnetic bunch compressor. The 40 MeV, 1 nC electron bunch is generated and compressed to less than 1 ps. THz radiations are generated in two methods with the ultra-short bunch. One is THz coherent synchrotron radiation (CSR). The other is THz coherent transition radiation (CTR). In the preliminary experiment, it was observed that the focused CTR had the donut profile in a transverse fields due to its initial radial polarization, so that it made Z-polarization. In case of the THz-TDS experiment, CTR was controlled to linearly polarization with the polarizer and focused to an EO crystal to obtain a THz temporal waveform which leads to THz spectrum with Fourier transform. The timing measurement between CTR and a probe laser was realized with OTR using a same optical photodiode. In this conference, we will describe details of our linac and results of the THz-TDS experiment.

Slides MOOBA03 [3.342 MB]

MOOAB03

FACET First Beam Commissioning

emittance, damping, sextupole, lattice

46

G. Yocky, C.I. Clarke, W.S. Colocho, F.-J. Decker, M.J. Hogan, N. Lipkowitz, J. Nelson, P.M. Schuh, J.T. Seeman, J. Sheppard, H. Smith, T.J. Smith, M. Stanek, Y. Sun, J.L. Turner, M.-H. Wang, S.P. Weathersby, G.R. White, U. Wienands, M. Woodley
SLAC, Menlo Park, California, USA

Funding: Work supported by U.S. Department of Energy, Contract DE-AC02-76SF00515.
The FACET (Facility for Advanced aCcelerator Experimental Tests) facility at SLAC has been under Construction since summer 2010. Its goal is to produce ultrashort and transversely small bunches of very high intensity (20kA peak current) to facilitate advanced acceleration experiments like PWFA and DLA. In June of 2011 the first electron beam was brought into the newly constructed bunch-compression chicane. Commissioning work included restarting the linac and damping ring, verifying hardware, establishing a good beam trajectory, verifying the optics of the chicane, commissioning diagnostic devices for transverse and longitudinal bunch size, and tuning up the beam size and bunch compression. Running a high-intensity beam through the linac without BNS damping and with large energy spread is a significant challenge. Optical aberrations as well as wakefields conspire to increase beam emittance and the bunch compression is quite sensitive to details of the beam energy and orbit, not unlike what will be encountered in a linear-collider final-focusing system. In this paper we outline the steps we took while commissioning as well as the challenges encountered and how they were overcome.

Slides MOOAB03 [9.167 MB]

MOOAC03

Superconducting Resonators Development for the FRIB and ReA Linacs at MSU: Recent Achievements and Future Goals

cavity, cryomodule, SRF, ion

61

A. Facco
INFN/LNL, Legnaro (PD), Italy
E.C. Bernard, J. Binkowski, C. Compton, J.L. Crisp, L.J. Dubbs, K. Elliott, A. Facco, L.L. Harle, M. Hodek, M.J. Johnson, D. Leitner, M. Leitner, I.M. Malloch, S.J. Miller, R. Oweiss, J. Popielarski, L. Popielarski, K. Saito, J. Wei, J. Wlodarczak, Y. Xu, Y. Zhang, Z. Zheng
FRIB, East Lansing, Michigan, USA
A. Burrill, G.K. Davis, K. Macha, A.V. Reilly
JLAB, Newport News, Virginia, USA

Funding: This material is based upon work supported by the U.S. Department of Energy Office of Science under Cooperative Agreement DE-SC0000661
The superconducting driver and post-accelerator linacs of the FRIB project, the large scale radioactive beam facility under construction at MSU, require the construction of about 400 low-beta Quarter-wave (QWR) and Half-wave resonators (HWR) with four different optimum velocities. 1st and 2nd generation prototypes of β=0.041 and 0.085 QWRs and β=0.53 HWRs have been built and tested, and have more than fulfilled the FRIB and ReA design goals. The present cavity surface preparation at MSU allowed production of low-beta cavities nearly free from field emission. The first two cryostats of β=0.041 QWRs are now in operation in the ReA3 linac. A 3rd generation design of the FRIB resonators allowed to further improve the cavity parameters, reducing the peak magnetic field in operation and increasing the possible operation gradient , with consequent reduction of the number of required resonators. The construction of the cavities for FRIB, which includes three phases for each cavity type (development, pre-production and production runs) has started. Cavity design, construction, treatment and performance will be described and discussed.
Michigan State University designs and establishes FRIB as a DOE Office of Science National User Facility in support of the mission of the Office of Nuclear Physics.

Slides MOOAC03 [4.009 MB]

MOOBC01

Electron Linac Photo-fission Driver for the Rare Isotope Program at TRIUMF

cryomodule, gun, cavity, TRIUMF

64

S.R. Koscielniak, F. Ames, R.A. Baartman, I.V. Bylinskii, Y.-C. Chao, D. Dale, R.J. Dawson, A. Koveshnikov, A. Laxdal, R.E. Laxdal, F. Mammarella, L. Merminga, A.K. Mitra, Y.-N. Rao, V.A. Verzilov, D. Yosifov, V. Zvyagintsev
TRIUMF, Canada's National Laboratory for Particle and Nuclear Physics, Vancouver, Canada
D. Karlen
Victoria University, Victoria, B.C., Canada

The TRIUMF Advanced Rare Isotope Laboratory (ARIEL) is funded since 2010 June by federal and BC Provincial governments. In collaboration with the University of Victoria, TRIUMF is proceeding with construction of a new target building, connecting tunnel, rehabilitation of an existing vault to contain the electron linear accelerator, and a cryogenic compressor building. TRIUMF starts construction of a 300 keV thermionic gun, and 10 MeV Injector cryomodule (EINJ) in 2012; the designs being complete. The 25 MeV Accelerator Cryomodule will follow in 2013. TRIUMF is embarking on major equipment purchases and has signed contracts for 4K cryogenic plant and a 290kW CW klystron, and four 1.3 GHz Nb 9-cell cavities from a local Canadian supplier. Moreover, the low energy beam transport is under construction; and detailing of two intra-cryomodule beam transports has just begun. Procurements are anticipated in mid 2012 for (i) the entire facility quadrupole magnets, and (ii) the klystron's 600kW HV power supply.

Slides MOOBC01 [4.852 MB]

MOOBC02

Status of Main Linac Cryomodule Development for Compact ERL Project

cavity, HOM, cryomodule, damping

67

K. Umemori, K. Enami, T. Furuya, H. Sakai, M. Satoh, K. Shinoe
KEK, Ibaraki, Japan
E. Cenni
Sokendai, Ibaraki, Japan
M. Sawamura
JAEA, Ibaraki-ken, Japan

The Compact ERL, which is a test facility of ERL, is under construction at KEK, in Japan. For the main linac, one cryomodule, containing two 9-cell superconducting cavities, is under development. The cryomodule has been designed under High Pressure Gas Safety Code in Japan. Thermal design and cavity alignment have been also carefully considered. Two 9-cell cavities were already fabricated and their performances were confirmed by vertical tests. They satisfied ERL main linac specifications. Their accelerating field reached to 25 MV/m, without field limits. Two input couplers, three HOM absorbers and two Slide-Jack tuners are also under fabrication for the cryomodule. High power processing will be applied for input couplers, at a test stand using a 300 kW klystron. Cooling tolerance and HOM damping abilities were tested for HOM absorbers. Some performance studies were also applied for the tuner at room temperature condition. Cryomodule assembly is planned on this summer. After cooling tests and high power tests will be carried out, ERL beam operation will be started.

Slides MOOBC02 [3.849 MB]

MOOBC03

A Multi Purpose X Band Accelerating Structure

wakefield, FEL, resonance, alignment

70

M.M. Dehler, A. Citterio, R. Zennaro
Paul Scherrer Institut, Villigen, Switzerland
G. D'Auria, C. Serpico
ELETTRA, Basovizza, Italy
D. Gudkov, A. Samoshkin
JINR, Dubna, Moscow Region, Russia
S. Lebet, G. Riddone, J. Shi
CERN, Geneva, Switzerland

In a collaboration between CERN, PSI and Sincrotrone Trieste (ST), a series of four multipurpose X-band accelerating structures has been designed and fabricated. The structures have 72 cells with a phase advance of 5 pi/6 and include upstream and downstream wakefield monitors to measure the beam alignment. We give an overview of the electrical and mechanical design and describe the fabrication of the first units. We also present the results of the low level RF tests. Using measurements of the internal cell to cell misalignment, the residual transverse wake and the noise floor of the wake field monitors are computed. Furthermore, we present the first experiences running the structures under high power.

Slides MOOBC03 [15.521 MB]

MOEPPB001

RF-breakdown Kicks at the CTF3 Two-beam Test Stand

extraction, linear-collider, collider, acceleration

73

A. Palaia, M. Jacewicz, T. Muranaka, R.J.M.Y. Ruber, V.G. Ziemann
Uppsala University, Uppsala, Sweden
W. Farabolini
CEA/DSM/IRFU, France

The measurement of the effects of RF-breakdown on the beam in CLIC prototype accelerator structures is one of the key aspects of the CLIC two-beam acceleration scheme being addressed at the Two-beam Test Stand (TBTS) at CTF3. RF-breakdown can randomly cause energy loss and transverse kicks to the beam. Transverse kicks have been measured by means of a screen intercepting the beam after the accelerator structure. In correspondence of a RF-breakdown we detect a double beam spot which we interpret as a sudden change of the beam trajectory within a single beam pulse. To time-resolve such effect, the TBTS has been equipped with five inductive Beam Position Monitors (BPMs) and a spectrometer line to measure both relative changes of the beam trajectory and energy losses. Here we discuss the methodology used and we present the latest results of such measurements.

MOEPPB012

High-performance Beam Simulator for the LANSCE Linac

space-charge, simulation, controls, EPICS

103

X. Pang, S.A. Baily, L. Rybarcyk
LANL, Los Alamos, New Mexico, USA

Funding: U.S. Dept. of Energy, NNSA under contract DE-AC52-06NA25396.
The LANSCE accelerator complex is a multi-beam facility that provides high-intensity H⁺ and H⁻ particle beams for a variety of user programs. At the heart of the facility is a room temperature linac that is comprised of a 100-MeV drift tube linac and an 800-MeV coupled cavity linac. During beam operations, linac parameters are adjusted to maintain minimal beam spill, but without detailed knowledge of the beam distribution. A more desirable situation would be one where knowledge of the beam distribution along the linac is available to aid in the optimization of the linac operation and beam performance. We are presently developing a high performance simulator that will provide valuable information about the beam distribution in pseudo real-time during linac operations. The heart of the simulator is based upon the multiparticle beam dynamics code PARMILA, but implemented in C++ using NVIDIA’s CUDA technology for Graphics Processing unit (GPU) hardware. Linac operating set points will be provided by the EPICS control system so that changes are tracked and the simulation results updated automatically. Details regarding the approach, benefits and performance will be presented.

MOEPPB014

Time Jitter Measurements in Presence of a Magnetic Chicane in the FERMI@elettra Linac

electron, FEL, laser, dipole

109

G. Penco, P. Craievich, S. Di Mitri, M.M. Milloch, F. Rossi
ELETTRA, Basovizza, Italy

Accurate and highly stable temporal synchronization between an electron bunch and a pulse from an external seed laser is one of the key requirements for successful operation of a seeded FEL in the XUV and soft x-ray regime. These requirements become more stringent when the electron bunch is longitudinally compressed to sub-ps durations in order to increase the current for more efficient FEL action. In this paper we present experimental measurements of the electron bunch arrival time jitter after the first magnetic compressor of FERMI@Elettra seeded FEL as a function of the compression factor. The experimental behavior of the pulse-to-pulse time jitter agrees both with results from tracking code simulations and with predictions from an analytical approach that takes into account the different sources of time jitter in FERMI, namely the photoinjector drive laser, the RF accelerating cavity phases and voltages, and fluctuations in the chicane bending magnet currents. We also present predictions for the expected arrival time jitter in the final configuration of FERMI that includes two bunch compressors and for which the synchronization requirement is of order 100 fs or better.

MOPPC045

Scaled Electron Model of a Dogbone Muon RLA with Multi-pass Arcs

electron, quadrupole, dipole, optics

235

S.A. Bogacz, A. Hutton, G.A. Krafft, V.S. Morozov, Y. Roblin
JLAB, Newport News, Virginia, USA
K.B. Beard, R.P. Johnson
Muons, Inc, Batavia, USA

Funding: Authored by Jefferson Science Associates, LLC under U.S. DOE Contract No. DE-AC05-06OR23177. Supported in part by USDOE STTR Grant DE-FG02-08ER86351.
The design of a dogbone RLA with linear-field multi-pass arcs was earlier developed for accelerating muons for a future Neutrino Factory and Muon Collider. It allows for efficient use of expensive RF while the multi-pass arc design based on linear combined-function magnets exhibits a number of advantages over single pass or pulsed arc designs. Such an RLA may have applications going beyond muon acceleration. This paper describes a possible straightforward test of this concept by scaling a GeV scale muon design for electrons. Scaling muon momenta by the muon-to-electron mass ratio leads to a scheme in which a 4.35 MeV/c electron beam is injected in the middle of a 2.9 MeV/pass linac with two double-pass return arcs, and is accelerated to 17.4 MeV/c in 4.5 passes. All spatial dimensions including the orbit distortion are scaled by a factor of 7.5, which arises from scaling the 200 MHz muon RF to a readily available 1.5 GHz. The footprint of a complete RLA fits in an area of 25 by 7 m. The scheme utilizes only fixed magnetic fields including injection and extraction. The hardware requirements are not very demanding, making it feasible to utilize the existing technologies.
The U.S. Government retains a non-exclusive, paid-up, irrevocable, world-wide license to publish or reproduce this manuscript for U.S. Government purposes.

MOPPC054

Multi-code Modelling of Momentum Collimation in the TRIUMF ARIEL Linac

electron, gun, simulation, TRIUMF

253

F.W. Jones, Y.-C. Chao, C. Gong
TRIUMF, Canada's National Laboratory for Particle and Nuclear Physics, Vancouver, Canada

The electron linac component of the TRIUMF-ARIEL facility will provide CW beams of 50-75 MeV and up to 0.5 MW of beam power, with consequent requirements for low-loss operation. One factor in controlling beam quality is the reduction of the low-momentum tail arising from the rf-modulated 300 KV electron gun and initial capture elements prior to acceleration in the 10 MeV Injector linac. To study momentum collimation in the 10 MeV transfer line to the main linac, and its implications for downstream beam characteristics, a simulation model has been constructed using several tracking and optics codes, linked together by scripts and data converters. The model follows the evolution of the beam from the e-gun through the injector cryo-module and the medium energy transfer line where the proposed collimator is located. The components, methods and results of this application are described in detail.

MOPPC055

A New Platform for Global Optimization

simulation, TRIUMF, solenoid, emittance

256

C. Gong, Y.-C. Chao
TRIUMF, Canada's National Laboratory for Particle and Nuclear Physics, Vancouver, Canada

Funding: Funding is received from Natural Sciences and Engineering Research Council of Canada and National Research Council of Canada for this research.
This paper describes a new platform for the multi-objective global optimization of accelerator design. While local optimization is relatively simple, global optimization for accelerator design remains a challenging task. The user often must write many lines of code to combine the output of a large variety of simulation engines, then send the results to the optimization engine. The optimization code also requires significant revision when applied to different problems. This paper presents an alternative method. The TRIUMF optimization platform, based on the genetic algorithm, is an extension of the PISA framework. It uses a flexible XML input format, in which users can easily combine multiple physics engines, such as ASTRA and PARMELA, into the same optimization problem. The TRIUMF platform is also parallel capable, designed to take advantage of computation clusters such as WestGrid. Results of the optimization platform applied to TRIUMF's 50 MeV, 0.5 MW electron linac are shown.

MOPPC070

Field Emission Simulation for KEK-ERL 9-Cell Superconducting Cavity

cavity, electron, simulation, coupling

295

E. Cenni
Sokendai, Ibaraki, Japan
T. Furuya, H. Sakai, M. Satoh, K. Shinoe, K. Umemori
KEK, Ibaraki, Japan
M. Sawamura
JAEA/ERL, Ibaraki, Japan

In order to develop the Energy Recovery Linac at KEK, we are studying the performance of L-band superconducting cavities by means of vertical tests. One of the limiting factor for the cavities performance is power losses due to field emitted electrons. With regard to this phenomena, a particle tracking code is used to study electron trajectories and deposited energy on the inner surface of the cavity. Different emitters location were tested within a range of accelerating field and phases in order to reproduce different scenario. The final goal of this study is to locate the sources of the electrons inside the cavity through a deeper understanding of the phenomena. To validate the results from the simulation the outcome data are compared with other particle tracking codes.

MOPPC073

Improvements in the PLACET Tracking Code

simulation, ground-motion, alignment, multipole

301

A. Latina, E. Adli, D. Schulte, J. Snuverink
CERN, Geneva, Switzerland
B. Dalena
CEA/IRFU, Gif-sur-Yvette, France

The tracking code PLACET simulates beam transport and orbit corrections in linear accelerators. It incorporates single- and multi-bunch effects, static and dynamic imperfections. It has an interface based on both Tcl/Tk and Octave to provide maximum flexibility and easy programming of complex scenarios. Recently, new functionality has been added to expand its simulation and tuning capabilities, such as: tools to perform beam-based alignment of non-linear optical systems, possibility to track through the interaction region in presence of external magnetic fields (detector solenoid), higher order imperfections in magnets, better tools for integrated feedback loops. Moreover, self contained frameworks have been created to ease the simulation of CLIC Drive Beam, CLIC Main Beam, and other existing electron machines such as CTF3 and FACET.

MOPPC082

Beam Dynamics Simulations inProject X RFQ with CST Studio Suite

rfq, simulation, acceleration, quadrupole

328

G.V. Romanov
Fermilab, Batavia, USA

Typically the RFQs are designed using the Parmteq, DesRFQ and other similar specialized codes, which produces the files containing the field and geometrical parameters for every cell. The beam dynamic simulations with these analytical fields are, of course, ideal realizations of the designed RFQs. The new advanced computing capabilities made it possible to simulate beam and even dark current in the realistic 3D electromagnetic fields in the RFQs that may reflect cavity tuning, presence of tuners and couplers, RFQ segmentation etc. The paper describes the utilization of full 3D field distribution obtained with CST Studio Suite for beam dynamic simulations using both PIC solver of CST Particle Studio and the beam dynamic code TRACK.

MOPPC089

CUDA Kernel Design for GPU-based Beam Dynamics Simulations

simulation, acceleration, space-charge, impedance

343

I.V. Pogorelov, K.M. Amyx, J. Balasalle, J. James
Tech-X, Boulder, Colorado, USA
M. Borland, R. Soliday, Y. Wang
ANL, Argonne, USA

Funding: Work supported by the US DOE Office of Science, Office of Basic Energy Sciences under grant number DE-SC0004585.
Efficient implementation of general-purpose particle tracking on GPUs can result in significant performance benefits to large-scale particle tracking and tracking-based accelerator optimization simulations. We present our work on CUDA kernels for transfer maps of single-particle-dynamics and collective-effects beamline elements, to be incorporated into a GPU-accelerated version of the ANL's accelerator code ELEGANT. In particular, we discuss techniques for efficient utilization of the device shared, cache, and local memory in the design of single-particle and collective-effects kernels. We also discuss the use of data-parallel and hardware-assisted approaches (segmented scan and atomic updates) for resolving memory contention issues at the charge deposition stage of algorithms for modeling collective effects. We present and discuss performance results for the CUDA kernels developed and optimized as part of this project.

MOPPC095

XAL's Online Model at ReA3 to Understand Beam Performance

simulation, cavity, cryomodule, lattice

358

C. Benatti
NSCL, East Lansing, Michigan, USA
P. Chu, M.J. Syphers, X. Wu
FRIB, East Lansing, Michigan, USA

Funding: This material is based on work supported by the National Science Foundation under Grant No. PHY-1102511 and by Michigan State University.
The ReA3 facility at the NSCL at MSU has been designed to reaccelerate rare isotope beams to 3MeV/u. ReA3 consists of a charge to mass selection section, a normal conducting RFQ, a superconducting linac, and transport beam lines that deliver the beam to the experiments. The beam optics designs were developed using COSY and IMPACT. A code with an online model capable of interacting with the control system, such as XAL, developed at SNS, would be ideal for studying this system*. New elements have been added to XAL’s already extensive list of supported devices in order to model elements unique to the NSCL. The benchmarking process has been completed for establishing the use of XAL’s Online Model at the NSCL, and preliminary results from its use at the ReA3 control room have been obtained. The development of applications to fit the needs of the program is ongoing. A summary of the benchmarking process is presented including both transverse and longitudinal studies.
* J. Galambos et al., Proc. PAC 2005, p. 79, (2005); doi: 10.1109/PAC.2005.1590365.

MOPPD029

Recent Achievements and Upgrade Programs at RIKEN Radioactive Isotope Beam Factory

ion, cyclotron, ECRIS, electron

430

H. Okuno, T. Dantsuka, M. Fujimaki, T. Fujinawa, N. Fukunishi, H. Hasebe, Y. Higurashi, K. Ikegami, E. Ikezawa, H. Imao, T. Kageyama, O. Kamigaito, M. Kase, M. Kidera, M. Komiyama, H. Kuboki, K. Kumagai, T. Maie, M. Nagase, T. Nakagawa, M. Nakamura, J. Ohnishi, N. Sakamoto, K. Suda, H. Watanabe, T. Watanabe, Y. Watanabe, K. Yamada, H. Yamasawa
RIKEN Nishina Center, Wako, Japan

Recent achievements and upgrade programs in the near future at RIKEN Radioactive Isotope Beam Factory (RIBF) are presented. The beam intensity and available ion species are increasing at RIBF, owing to the continuous efforts that have been paid since the first beam in 2006. So far, we accelerated deuteron, helium, nitrogen, oxygen, aluminum, calcium, krypton, and uranium beams with the world's first superconducting ring cyclotron, SRC*. The extracted beam intensities reached 1,000 pnA for helium and oxygen beams. From the operational point of view, however, the intensity of the uranium beam should be much increased. Therefore we constructed a new injector system for the RIBF, consisting of a 28 GHz ECR ion sources, RFQ and DTL, which was successfully commissioned in the end of 2010. Furthermore we developed low-Z (low atomic number Z) gas stripper** alternative to standard carbon foil stripping, which will be reliable and efficient charge stripping scheme for such high-power uranium beams.
* H. Okuno et al., IEEE Trans. Appl. Supercond., 18, 226 (2008).
** H. Okuno et al., Phys. Rev. ST Accel. Beams 14, 033503 (2011).

MOPPD030

Present Status of RIKEN Ring Cyclotron

ion, heavy-ion, cyclotron, vacuum

433

Y. Watanabe, M. Fujimaki, N. Fukunishi, H. Hasebe, Y. Higurashi, E. Ikezawa, H. Imao, T. Kageyama, O. Kamigaito, M. Kase, M. Kidera, M. Komiyama, H. Kuboki, K. Kumagai, T. Maie, M. Nagase, T. Nakagawa, J. Ohnishi, H. Okuno, N. Sakamoto, K. Suda, H. Watanabe, T. Watanabe, K. Yamada, S. Yokouchi
RIKEN Nishina Center, Wako, Japan
T. Aihara, S. Fukuzawa, M. Hamanaka, S. Ishikawa, K. Kobayashi, Y. Kotaka, R. Koyama, T. Nakamura, M. Nishida, M. Nishimura, T.O. Ohki, K. Oyamada, J. Shibata, M. Tamura, N. Tsukiori, A. Uchiyama, K. Yadomi, H. Yamauchi
SHI Accelerator Service Ltd., Tokyo, Japan

The RIKEN Ring Cyclotron (RRC K540) has been in stable operation over twenty-five years, and supplying many kinds of heavy-ion beams to experiments. Since 2007, it has also been supplying beams to the RIBF four Ring cyclotrons including the Super-conducting Ring Cyclotron (SRC K2500). Now the RRC has three kinds of injectors, one is K70 AVF cyclotron for light ions, the second is the variable-frequency linac for heavy ions, and the third is the RILAC2 for using the high intensity very heavy ions like U and Xe. The many combinations of accelerators are possible, and in any acceleration modes, the RRC should works as a first energy booster. A total operation time of the RRC is more than 5000 hr in every year. The present status of the RRC operation will be reported.

MOPPD043

Novel Muon Beam Facilities for Project X at Fermilab

proton, target, dipole, electron

457

C.M. Ankenbrandt, R.J. Abrams, T.J. Roberts, C. Y. Yoshikawa
Muons, Inc, Batavia, USA
D.V. Neuffer
Fermilab, Batavia, USA

Innovative muon beam concepts for intensity-frontier experiments such as muon-to-electron conversion are described. Elaborating upon a previous single-beam idea, we have developed a design concept for a system to generate four high quality, low-energy muon beams (two of each sign) from a single beam of protons. As a first step, the production of pions by 1 and 3 GeV protons from the proposed Project X linac at Fermilab is being simulated and compared with the 8-GeV results from the previous study.

MOPPD045

Performance Study of the PEFP Microwave Ion Source with Modified Microwave System

ion-source, ion, high-voltage, proton

463

D.I. Kim, Y.-S. Cho, H.S. Kim, H.-J. Kwon, K.T. Seol
KAERI, Daejon, Republic of Korea

Funding: This work is supported by the Ministry of Science and Technology of the Korean government.
A microwave ion source has been developed as a proton injector for the Proton Engineering Frontier Project (PEFP) 100-MeV proton linac. The microwave ion source consists of the 2.45-GHz microwave components, a solenoid magnet, a vacuum system, power supplies for beam extraction and bias electrode, a cooling system. It was operating for 1 year to supply beam to the 20-MeV proton accelerator. Recently, a multi-layer insulation DC break was installed between proton source and 2.45-GHz microwave components. Also, the magnetron was replaced with lower saturation power level. The tests of the microwave system have been done to study the effect of the DC break and new magnetron compared with the former one. Also, the beam test was done after the operating conditions of the microwave system were adjusted. In this paper, the performance studies of the PEFP microwave ion source with DC break and new magnetron are discussed.

MOPPD049

The Layout of the High Energy Beam Transport for the European Spallation Source

target, octupole, quadrupole, beam-transport

475

A.I.S. Holm, S.P. Møller, H.D. Thomsen
ISA, Aarhus, Denmark

The status of the High Energy Beam Transport (HEBT) line for the European Spallation Source (ESS) is presented. The HEBT brings the beam from the underground linac to the target at surface level. The main design objectives of the HEBT, such as space for upgrades, producing the desired target footprint etc. are discussed and the preferred design is shown. Large amplitude particles, a halo, are formed in the last part of the linac. Hence, every given value of the peak current density at the target is correlated with a certain power deposited outside the beam footprint. This correlation is studied and optimized. Furthermore, first studies of the vertical stability of the beam footprint and profile on target due to misalignment or mismatch of the incoming beam are made.

MOPPD050

Dipole Magnet Design for a Bunch Compressor

dipole, neutron, proton, focusing

478

T. Kanesue, L.P. Chau, O. Meusel, D. Noll, U. Ratzinger
IAP, Frankfurt am Main, Germany

The FRANZ-ARMADILLO is a Mobley type bunch compressor system at the pulsed intense neutron source FRANZ, under construction at Frankfurt University. The FRANZ-ARMADILLO compresses 9μbunches of a 150 mA, 2 MeV proton beam accelerated by a 175 MHz linac into one short pulse of 1 ns pulse length with 250 kHz repetition rate. In the bunch compressor, two homogeneous dipole magnets and two gradient dipole magnets guide theμbunches, separated by a 5 MHz RF-kicker on individual tracks. The flight path length of theμbunches are determined based on the bunch center velocity and the linac frequency for the longitudinal bunch compression. The gradient dipole magnets provide individual magnetic fields and edge focusing forces to everyμbunch. For the center trajectory, the required parameters are a magnetic field density of 509.2 mT, bending angle of 78.27 deg, and bending radius of 404.5 mm. To satisfy all specifications, field clamps, shims, and chamfer cut will be adopted. The result of the gradient dipole magnet design and the expected performance based on beam dynamics studies will be presented.

MOPPD072

A High Energy Collimation System for the European Spallation Source

collimation, target, beam-losses, optics

529

H.D. Thomsen, A.I.S. Holm, S.P. Møller
ISA, Aarhus, Denmark

At the European Spallation Source (ESS), a ~160 m high energy beam transport (HEBT) system is to guide the high-power (5 MW) proton beam from a superconducting 2.5 GeV linac to a spallation target station. The HEBT could include a single-pass collimation system to protect all downstream accelerator components, including the vital target. The system would be built to withstand both continuous low-power losses (i.e. introduce halo reduction) and infrequent short-term, high-power beam exposure, essentially a fault scenario. Although a collimation system could reduce the uncontrolled beam losses and thus activation levels elsewhere, it takes up precious longitudinal space intended for future beam power upgrades and sets demands for the beam optics, as will be discussed. Possible materials and specifications will also be described.

MOPPD076

Numerical Study of a Collimation System to Mitigate Beam Losses in the ESS Linac

DTL, beam-losses, collimation, simulation

541

R. Miyamoto, H. Danared, M. Eshraqi, A. Ponton
ESS, Lund, Sweden

The European Spallation Source (ESS) will be a 5 MW proton linac to produce spallation neutrons. A high power linac has a very low tolerance on beam losses, typically on the order of 1 W/m, to avoid activation of the linac components; hence, emittance and halo of the beam must be well controlled throughout the linac. A system of collimators in beam transport sections has been studied and tested as a means to mitigate the beam losses in several linacs. This paper presents the result of a numerical study of a collimation system for the ESS linac.

MOPPP003

Comparison of Various Sources of Coherent THz Radiation at FLUTE

radiation, electron, synchrotron, synchrotron-radiation

568

M. Schwarz, E. Huttel, A.-S. Müller, S. Naknaimueang, M.J. Nasse, R. Rossmanith, M. Schuh, P. Wesolowski
KIT, Karlsruhe, Germany
M.T. Schmelling
MPI-K, Heidelberg, Germany

The "Ferninfrarot Linac- Und Test-Experiment" FLUTE, based on a 50 MeV S-band linac with bunch compressor, is currently under construction at the KIT in Karlsruhe in order to study the production of coherent radiation in the Terahertz frequency range. The three photon generating mechanisms investigated in this paper are coherent synchrotron-, edge-, and transition radiation. For each case, we present the spectra and peak electric fields calculated from longitudinal charge distributions of a short, low charge and a long, high charge bunch. The respective bunch shapes are obtained by a detailed simulation (particle tracking) of FLUTE. We also give the expected temporal evolution of the electric field pulses.

MOPPP006

Inverse Cherenkov Radiation based on Smith-Purcell Effect

radiation, electron, gun, laser

577

K. Kan, T. Kondoh, K. Norizawa, A. Ogata, J. Yang, Y. Yoshida
ISIR, Osaka, Japan
M. Hangyo
ILE Osaka, Suita, Japan
R. Kuroda, H. Toyokawa
AIST, Tsukuba, Ibaraki, Japan

Inverse Cherenkov radiation based on Smith-Purcell effect using metamaterial was investigated. A metallic grating and picosecond electron bunch of 27 MeV beam energy from a thermionic DC gun and linac were used for the inverse radiation. The frequency spectra in terahertz (THz) range were measured by a Michelson interferometer experimentally. Peaks of discrete component in the spectra shifted continuously according to the radiation angles, e. g. discrete peak changing from 0.117 to 0.085 THz with radiation angle along the electron bunch from 102 to 134 degree (backward) using a 2-mm-period metallic grating. In this presentation, experiment using another electron bunch generated by a photocathode RF gun linac will be reported.

MOPPP010

Investigation of CSR Effect for Femtosecond Electron Bunches in an Isochronous Accumulator Ring

simulation, lattice, radiation, electron

589

N.Y. Huang, H. Hama, F. Hinode, S. Kashiwagi, M. Kawai, T. Muto, I. Nagasawa, K. Nanbu, Y. Shibasaki, K. Takahashi
Tohoku University, Research Center for Electron Photon Science, Sendai, Japan

Coherent synchrotron radiation (CSR) from a novel isochronous ring is a candidate for light source that provides THz radiation with high average flux. A compact isochronous accumulator ring (IAR) for the maximum beam energy of 54 MeV has been designed so as to eliminate the 0th order momentum compaction factor, and the 1st order of it is mostly compensated. In addition, the path length deviation due to betatron motion is mostly compensated in a cell. Though there is no RF cavity in IAR, the injected beam may circulate for certain number of turns. Multi experimental stations can be allocated like synchrotron radiation facilities. However, it has been well known that instability due to the CSR wake field is an issue for the beam stability in the ring operated at low alpha mode. Therefore, a study for effects of the CSR wake on the bunch length and shape in IAR has been in progress. It has turned out that the maximum longitudinal field strength created by CSR would be ~ 0.15 MV/m for the case of 100 fs Gaussian bunch, which is considerably an intense field. To protect the bunch shape from the CSR wake, further study is definitely required.

MOPPP011

Narrow Band Optimization of a Compton Gamma-Ray Source Produced From an X-Band Linac

electron, laser, simulation, emittance

592

F. Albert, S.G. Anderson, C.P.J. Barty, D.J. Gibson, F.V. Hartemann, R.A. Marsh, S.S.Q. Wu
LLNL, Livermore, California, USA

Funding: This work performed under the auspices of the U.S. Department of Energy by Lawrence Livermore National Laboratory under Contract DE-AC52-07NA27344.
Nuclear photonics is an emerging field of research that will require high precision gamma-ray (MeV) sources. In particular, nuclear resonance fluorescence applications necessitate a low (< 1%) relative gamma-ray spectral width. Within this context, Compton scattering, where laser photons are scattered off relativistic electron beams to produce tunable, collimated gamma rays, will produce the desired gamma-ray output. This paper will present the spectral narrowband optimization of such a light source currently being built at LLNL. In this case, PARMELA and elegant simulations of the full 250 MeV, high-gradient X-band linac provide the properties of the high brightness electron bunch. The electron beam simulations are then implemented into our newly developed weakly nonlinear Compton scattering code to produce theoretical gamma-ray spectra. The influence that the electron beam, laser beam and interaction geometry parameters have on the produced gamma-ray spectra will be shown with our simulations.

MOPPP015

Status of the BERLinPro Energy Recovery Linac Project

cavity, SRF, booster, quadrupole

601

J. Knobloch, M. Abo-Bakr, W. Anders, R. Barday, K.B. Bürkmann-Gehrlein, V. Dürr, S.C. Heßler, A. Jankowiak, T. Kamps, O. Kugeler, B.C. Kuske, P. Kuske, A.N. Matveenko, G. Meyer, R. Müller, A. Neumann, K. Ott, Y. Petenev, D. Pflückhahn, T. Quast, J. Rahn, S.G. Schubert
HZB, Berlin, Germany

Funding: Funding provided by the BMBF and the State of Berlin
In October 2010 Helmholtz Zentrum Berlin received funding to design and build the Berlin Energy Recovery Linac Project BERLinPro. The goal of this compact ERL is to develop the accelerator physics and technology required to generate and accelerate a 100-mA, 1 mm·mrad emittance beam. Given the flexibility of ERLs, other operation modes such as short-bunch operation will also be investigated. The BERLinPro technology and know-how can then be transferred to a variety of ERL-based applications. Presently, BERLinPro is in the design phase and the optics has been settled. Furthermore, first beam has been achieved with a superconducting RF photoinjector, which represents an important step towards realizing a CW injector for BERLinPro. An overview of the present status and the conceptual design report is presented.

MOPPP016

Feasibility Study of an ERL-based GeV-scale Multi-turn Light Source

brilliance, undulator, cryomodule, optics

604

Y. Petenev, T. Atkinson, A.V. Bondarenko, A.N. Matveenko
HZB, Berlin, Germany

A new generation of particle accelerators based on an Energy Recovery Linac (ERL) is a promising tool for a number of new applications. These include high brilliance light sources in a wide range of photon energies, electron cooling of ion beam and ERL-based electron-hadron colliders. Helmholtz-Zentrum Berlin started a feasibility study of GeV-scale multi-turn ERL-based light source (LS). This LS will work in diffraction limited regime in X-rays and with a short length of a light pulse in femtosecond region. The average and peak brightness will be at least an order of magnitude higher than synchrotron-based LS. In this work an overview of the future multi-turn light source is given. Modeling of the Beam Break Up instability is presented.

MOPPP018

Construction Status of the Compact ERL

cryomodule, gun, emittance, radiation

607

S. Sakanaka, H. Kawata, Y. Kobayashi, N. Nakamura
KEK, Ibaraki, Japan
R. Hajima
JAEA, Ibaraki-ken, Japan

Future synchrotron light source based on a 3-GeV energy recovery linac (ERL) is under proposal at KEK, and we are conducting extensive R&D efforts. To demonstrate reliable operations of key components for the ERL project, as well as to demonstrate the generation of ultra-low emittance beams, we are constructing the Compact ERL (cERL). The cERL will also be used to demonstrate the generation of brilliant gamma-rays that is useful for analyzing radioisotopes. Key components, such as a photocathode DC gun, both cryomodules for the injector and the main linac, rf sources, magnets, and beam instrumentations, are under fabrication. Construction of radiation shielding for the cERL started in December, 2011. We report up-to-date status of the cERL.

MOPPP021

Longitudinal Beam Dynamics at the ALICE Acclerator R&D Facility

booster, simulation, gun, FEL

610

F. Jackson, D. Angal-Kalinin, S.P. Jamison, J.W. McKenzie, T.T. Ng, Y.M. Saveliev, P.H. Williams
STFC/DL/ASTeC, Daresbury, Warrington, Cheshire, United Kingdom

The ALICE facility is an energy recovery test accelerator whose applications include an IR-FEL and THz generation. Of primary importance to the performance of the main ALICE applications is the understanding and control of the longitudinal dynamics, which are less amenable to measurement than the transverse. The longitudinal dynamics of the beam evolve are studied in simulation and experiment in several areas of the machine. Simulations of the low energy injector where space charge and velocity bunching may occur are presented. Path length measurement using time-of-arrival monitors are carried out.

MOPPP023

Effect of DC Photoinjector Gun Voltage on Beam Dynamics in ALICE ERL

gun, electron, booster, cavity

616

Y.M. Saveliev, F. Jackson, J.K. Jones, J.W. McKenzie
STFC/DL/ASTeC, Daresbury, Warrington, Cheshire, United Kingdom

The ALICE ERL employs a DC HV photoelectron gun as an electron source. As with other machines in this class, the electron beam is not always of perfect quality. This is aggravated by that the ALICE gun has been operated so far at lower 230kV voltage compared to the design value of 350kV due to hardware limitations. The “two beams” structure was observed and experimentally investigated and found to be the result of complex processes during initial stages of beam acceleration. The experimental observations and data will be compared with those obtained at a nominal 350kV gun voltage. An investigation of the effect of the DC photogun voltage on longitudinal and transverse beam dynamics will be presented and discussed.

MOPPP026

Cryogenic Distribution System for the Proposed Cornell ERL Main Linac

cryomodule, HOM, cavity, vacuum

619

E.N. Smith
Cornell University, Ithaca, New York, USA
Y. He, G.H. Hoffstaetter, M. Liepe, M. Tigner
CLASSE, Ithaca, New York, USA

Funding: This material is based upon work supported by the National Science Foundation under Grant No. DMR-0807731.
The proposed Cornell ERL main linac requires a total cooling power of nearly 8kW at 1.8K, 5kW at 5K and over 100kW at 80K. This is distributed over approximately 65 cryomodules, each containing 6 rf cavities and associated input couplers and higher order mode absorbers. situated in two underground tunnels. While the total heat load is comparable to that for each of the 8 individual LHC cryoplants, the very high ratio of dynamic heat load to static heat load, combined with the high power density at various sites produces interesting challenges for the cryogenic distribution system. A schematic view of the design choices selected, some of which are different from existing large cryogenic systems, and the basis for these decisions, is presented in this paper.

MOPPP031

A New Injection System for an Electron/Positron Linac

electron, injection, gun, positron

628

C. Liebig, M. Hüning, M. Schmitz
DESY, Hamburg, Germany

For the Linac II, which supplies the accelerator chain at DESY with electrons and positrons, a new injection system is planned. It is supposed to ensure reliable operation and to avoid the beam loss of about 60% before the positron converter and the associated activation. The main components are a 6 A/100 kV triode gun, buncher and a dispersive section for energy collimation. The output energy is 5 MeV. The new buncher structure is a hybrid of a standing wave and traveling wave structure and allows a compact design and good electron capture. Its main part is a traveling wave structure in 2π/3 mode, to which one capture cell is coupled in π mode. The function of the injector components, the entire injection system and the acceleration in the linac sections were optimized in simulations. In addition, the design is analysed in a test rig before final installation. Test rig and subsequent injector are equipped with extensive diagnostics. Besides the design of the injection system results of simulations and measurements on the test rig will be presented.

MOPPP042

Modeling Multi-bunch X-band Photoinjector Challenges

emittance, gun, electron, laser

658

R.A. Marsh, S.G. Anderson, C.P.J. Barty, D.J. Gibson, F.V. Hartemann
LLNL, Livermore, California, USA

Funding: This work performed under the auspices of the U.S. Department of Energy by Lawrence Livermore National Laboratory under Contract DE-AC52-07NA27344.
An X-band test station is being developed at LLNL to investigate accelerator optimization for future upgrades to mono-energetic gamma-ray (MEGa-Ray) technology at LLNL. The test station will consist of a 5.5 cell X-band rf photoinjector, single accelerator section, and beam diagnostics. Of critical import to the functioning of the LLNL X-band system with multiple electron bunches is the performance of the photoinjector. In depth modeling of the Mark 1 LLNL/SLAC X-band rf photoinjector performance will be presented addressing important challenges that must be addressed in order to fabricate a multi-bunch Mark 2 photoinjector. Emittance performance is evaluated under different nominal electron bunch parameters using electrostatic codes such as PARMELA. Wake potential is analyzed using electromagnetic time domain simulations using the ACE3P code T3P. Beam-loading effects and low level rf compensation schemes are explored as well, using a semi-analytic formalism and computer algorithm. Plans for multi-bunch experiments and implementation of photoinjector advances for the Mark 2 design will also be discussed.

MOPPP050

Physics Results of the NSLS-II Linac Front End Test Stand

emittance, simulation, gun, electron

673

R.P. Fliller, F. Gao, J. Rose, T.V. Shaftan, X. Yang
BNL, Upton, Long Island, New York, USA
G. Blokesch
PPT, Dortmund, Germany
C. Piel
RI Research Instruments GmbH, Bergisch Gladbach, Germany

Funding: This manuscript has been authored by Brookhaven Science Associates, LLC under Contract No. DE-AC02-98CH10886 with the U.S. Department of Energy.
The NSLS-II linac is produced by Research Instruments and will be commissioned in the spring of 2012. As part of the procurement, the linac front end consisting of the gun, prebunching cavity, and diagnostics was delivered early to BNL for testing. We designed a short beamline to supplement the Front End diagnostics to characterize the beam. These tests were instrumental in demonstrating the functioning of the gun, pinpointing technical problems at an early project stage and gaining experience with the linac gun by BNL staff prior to commissioning of the full linac. In this report we show the results of the tests, including charge, bunch length, and transverse emittance measurements and compare them with the relevant linac specifications.

MOPPP051

NSLS-II Transport Line Progress

booster, storage-ring, diagnostics, injection

676

R.P. Fliller, A.T. Anderson, B. Benish, W. DeBoer, G. Ganetis, R. Heese, H.-C. Hseuh, J. Hu, M.P. Johanson, B.N. Kosciuk, D. Padrazo, K. Roy, T.V. Shaftan, O. Singh, J.L. Tuozzolo, B. Wahl, G.M. Wang
BNL, Upton, Long Island, New York, USA

Funding: This manuscript has been authored by Brookhaven Science Associates, LLC under Contract No. DE-AC02-98CH10886 with the U.S. Department of Energy.
The National Synchrotron Light Source II (NSLS-II) is a state-of-the-art 3-GeV third generation light source currently under construction at Brookhaven National Laboratory. The NSLS-II injection system consists of a 200 MeV linac, a 3-GeV booster synchrotron and associated transfer lines. The first part of the Linac to Booster Transport (LBT) line has been installed for linac commissioning. This part includes all components necessary to commission the NSLS-II linac. The second part of this transport line is undergoing installation. Initial results of hardware commissioning will be discussed. The Booster to Storage Ring (BSR) transport line underwent a design review. The first part of the BSR transport line, consisting of all components necessary to commission the booster will be installed in 2012 for booster commissioning. We report on the final design of the BSR line along with the plan to commission the booster.

MOPPP056

Injection Transient Motion at PLS-II

kicker, injection, septum, electron

688

I. Hwang, T. Ha, Y.D. Joo, C. Kim, M. Kim, S.H. Kim, B.-J. Lee, E.H. Lee, S. Shin
PAL, Pohang, Kyungbuk, Republic of Korea

PLS-II is an upgraded third generation synchrotron which includes many insertion devices with improved beam properties. Top-up operation is short time-interval injection to make roughly constant current and is essential to provide high intensity beam. When the electrons are injected to synchrotron, the stored beam is disturbed by small error of the injection system and the beam quality at the beamline can be decreased. We present this injection transient motion at PLS-II.

MOPPR003

Beam Diagnostic Systems for the TRIUMF e-linac

TRIUMF, diagnostics, EPICS, electron

777

J.M. Abernathy, D. Karlen, M.O. Pfleger, P.R. Poffenberger, D.W. Storey
Victoria University, Victoria, B.C., Canada
F. Ames, P.S. Birney, D.P. Cameron, J.V. Holek, S.Y. Kajioka, S. Kellogg, M. Lenckowski, M. Minato, W.R. Rawnsley, J.E. Richards, V.A. Verzilov
TRIUMF, Canada's National Laboratory for Particle and Nuclear Physics, Vancouver, Canada

Funding: NSERC, CFI, BCKDF.
The TRIUMF electron linac will include a suite of diagnostics systems, including current, beam position, and beam profile monitors. This talk will present an overview of the diagnostic systems and give details about the view screen system, having both scintillator and OTR foils. Results from tests with the prototype low energy beam transport system will be shown. Diagnostic systems are particularly challenging for the e-linac due to the 500 kW beam power envisaged, with beam currents up to 10 mA at 50 MeV.

MOPPR025

The BPM DAQ System Upgrade for SuperKEKB Injector Linac

electron, emittance, positron, injection

834

M. Satoh, K. Furukawa, F. Miyahara, T. Suwada
KEK, Ibaraki, Japan
T. Kudou, S. Kusano
MELCO SC, Tsukuba, Japan

The non-destructive beam position monitor (BPM) is indispensable diagnostic tool for the stable beam operation. In the KEK Linac, approximately nineteen BPMs with the strip-line type electrodes are used for the beam orbit measurement and feedback. In addition, some of them are also used for the beam energy feedback loops. The current DAQ system consists of the fast digital oscilloscopes. A signal from each electrode is analyzed with a predetermined response function up to 50 Hz. The beam position resolution of current system is limited to about 0.5 mm because of ADC resolution. Towards SuperKEKB project, we have a plan to upgrade the BPM DAQ system since the Linac should provide the smaller emittance beam. We will report the system description of the new DAQ system and the results of performance test in detail.

MOPPR039

Development of Beam Position Monitor for PEFP Linac and Beam line

proton, coupling, DTL, quadrupole

864

J.Y. Ryu, Y.-S. Cho, J.-H. Jang, H.S. Kim, H.-J. Kwon, K.T. Seol
KAERI, Daejon, Republic of Korea

Funding: This work is supported by the Ministry of Education, Science and Technology of the Korean Government.
The development of the Beam Position Monitor (BPM) is in progress for the linac and beam lines of the Proton Engineering Frontier Project (PEFP). We choose a strip line BPM for the PEFP 20-MeV and 100-MeV beam lines in order to increase the sensitivity of the relatively long bunches in the beam lines. We also selected the same type BPM for the proton linac in the energy range between 20-MeV and 100-MeV. The prototype BPM was designed, fabricated and tested at KAERI site, where the 20-MeV linac was operated. To check the performance of the BPM, we performed the field mapping. The characteristics and test results of the BPM on the test bench as well as with 20-MeV proton beam will be presented in this paper.

MOPPR040

Design and Measurements of a Test Stand for the SEM-Grid System of the ESS-BILBAO

electron, vacuum, diagnostics, emittance

867

D. Belver, J. Feuchtwanger, P.J. González
ESS Bilbao, LEIOA, Spain
F.J. Bermejo
Bilbao, Faculty of Science and Technology, Bilbao, Spain
V. Etxebarria, J. Jugo
University of the Basque Country, Faculty of Science and Technology, Bilbao, Spain

In the framework of the ESS-Bilbao accelerator, a test stand for the development of Secondary Electron EMission grid (SEM-Grid) has been designed and manufactured as a part of the diagnostics system for beam profile measurements. This test stand is a vacuum system based on an EQ 22/35 electron source from SPECS used as a beam injector. This electron source has an energy range from 0 to 5 KeV and a maximum beam current up to 200 μA. Although we have thought in a SEM-Grid of 40 wires (20 wires in each X and Y direction), two prototypes of 16 wires (8x8) of 250 μm diameter and spaced 1 and 2 mm, respectively, have been developed due to its easier implementation and tested in the test stand. In order to develop an electronics readout system for the SEM-Grid, first studies of the prototype signals have been done. The secondary emission current of each wire will be integrated and amplified to provide a significant voltage signal that can be measured by our acquisition system. A description of the SEM-Grid test stand and the measurements developed is given here.

MOPPR045

Beam Diagnostics for ESS

target, diagnostics, DTL, instrumentation

882

A. Jansson, C. Böhme, B. Cheymol, H. Hassanzadegan, T.J. Shea, L. Tchelidze
ESS, Lund, Sweden

The European Spallation Source (ESS), to be built in the south of Sweden, will use a 2.5 GeV superconducting linac to produce the worlds most powerful neutron source. The project is currently in a pre-construction phase, during which the linac design is being updated. This paper describes the current plans for beam diagnostics in terms of requirements, number and locations of different systems, and possible technical solutions.

MOPPR048

Beam Instrumentation for the HIE-ISOLDE Linac at CERN

diagnostics, cryomodule, emittance, ion

891

E. Bravin, A.G. Sosa, D. Voulot, F.J.C. Wenander, F. Zocca
CERN, Geneva, Switzerland
M.A. Fraser
UMAN, Manchester, United Kingdom
J.H. Galipienzo
AVS, Eibar, Gipuzkoa, Spain
M. Pasini
Instituut voor Kern- en Stralingsfysica, K. U. Leuven, Leuven, Belgium
C.P. Welsch
Cockcroft Institute, Warrington, Cheshire, United Kingdom

In the framework of the High Intensity and Energy (HIE)-ISOLDE project at CERN, a beam instrumentation R&D program is on-going for the superconducting upgrade of the REX-ISOLDE heavy-ion post-accelerator. An overview of the foreseen beam diagnostics system is presented, focusing on the challenging specifications required by the HIE-ISOLDE linac. Due to the low beam intensities, the diagnostic instrumentation will be based on high-sensitivity intercepting devices. The project includes intensity and transverse profile monitors to be implemented in the very narrow longitudinal space that is available for beam diagnostics in the regions between the superconducting cryomodules. A longitudinal profile monitor is foreseen downstream of the linac to measure the beam energy and arrival time distributions and to allow for a fast phase-tuning of the superconducting cavities. A custom-made emittance meter will provide transverse emittance measurements based on a phase space sampling technique. The design status of the different instruments will be presented as well as the results of some experimental tests.

MOPPR057

Development of a Cavity Beam Position Monitor for CLIC

cavity, dipole, coupling, factory

915

F.J. Cullinan, S.T. Boogert, N.Y. Joshi, A. Lyapin
JAI, Egham, Surrey, United Kingdom
E. Calvo, N. Chritin, F. Guillot-Vignot, T. Lefèvre, L. Søby
CERN, Geneva, Switzerland
A. Lunin, M. Wendt, V.P. Yakovlev
Fermilab, Batavia, USA
S.R. Smith
SLAC, Menlo Park, California, USA

The Compact Linear Collider (CLIC) project presents many challenges to its subsystems and the beam diagnostics in particular must perform beyond current limitations. The requirements for the CLIC main beam position monitors foresee a spacial resolution of 50 nm while delivering a 10 ns temporal resolution within the bunch train. We discuss the design of the microwave cavity pick-up and associated electronics, bench top tests with the first prototype cavity, as well as some of the machine-specific integration and operational issues.

MOPPR070

Beam Profile Measurement in MTA Beam Line for High Pressure RF Cavity Beam Test

cavity, proton, diagnostics, electron

948

M.R. Jana, A.D. Bross, S. Geer, C. Johnstone, T. Kobilarcik, G.M. Koizumi, M.A. Leonova, A. Moretti, M. Popovic, T.A. Schwarz, A.V. Tollestrup, K. Yonehara
Fermilab, Batavia, USA
M. Chung
Handong Global University, Pohang, Republic of Korea
M.G. Collura
Politecnico di Torino, Torino, Italy
B.T. Freemire, P.M. Hanlet, Y. Torun
IIT, Chicago, Illinois, USA

Funding: This work is supported by the United States Department of Energy under contract DE-AC02-07CH11359.
The recent High Pressure RF (HPRF) cavity experiment at the MuCool Test Area (MTA) used a 400 MeV Linac proton beam to study the beam loading effect. When the energetic proton beam passes through the cavity, it ionizes the inside gas and produces electrons. These electrons consume RF power inside the cavity. The number of electrons produced per cm inside the cavity (at 950 psi Hydrogen gas) per incident proton is 1200. The measurement of beam position and profile are necessary. The MTA is a flammable gas (Hydrogen) hazard zone, so we have developed a passive beam diagnostic instrument using a Chromox-6 scintillation screen and CCD camera. This paper presents quantitative information about beam position and beam profile. A neutral density filter was used to avoid saturation of the CCD camera. Image data is filtered and fitted with a Gaussian function to compute the beam size. The beam profile obtained from the scintillation screen will be compared with a multi-wire beam profile.

MOPPR072

Fermilab PXIE Beam Diagnostics Development and Testing at the HINS Beam Facility

diagnostics, laser, emittance, rfq

954

V.E. Scarpine, B.M. Hanna, V.A. Lebedev, L.R. Prost, A.V. Shemyakin, J. Steimel, M. Wendt
Fermilab, Batavia, USA

Funding: This work was supported by the U.S. Department of Energy under contract No. DE-AC02-07CH11359.
Fermilab is planning the construction of a prototype front end of the Project X linac. The Project X Injector Experiment (PXIE) is expected to accelerate 1 mA cw H⁻ beam up to 30 MeV. Some of the major goals of the project are to test a cw RFQ and H⁻ source, a broadband bunch-by-bunch beam chopper and a low-energy superconducting linac. The successful characterization and operation of such an accelerator places stringent requirements on beam line diagnostics. These crucial beam measurements include bunch currents, beam orbit, beam phase, bunch length, transverse profile and emittance, beam halo and tails, as well as the extinction performance of the broadband chopper. This paper presents PXIE beam measurement requirements and instrumentation development plans. Also presented are plans to test many of these instruments at the Fermilab High Intensity Neutrino Source (HINS) beam facility. Since HINS is already an operational accelerator, utilizing HINS for instrumentation testing allows for quicker development of the required PXIE diagnostics.

MOPPR077

ION CHAMBERS AND HALO RINGS FOR LOSS DETECTION AT FRIB

radiation, ion, cryomodule, simulation

969

Z. Liu
IUCF, Bloomington, Indiana, USA
D. Georgobiani, M.J. Johnson, M. Leitner, R.M. Ronningen, T. Russo, M. Shuptar, R.C. Webber, J. Wei, X. Wu, Y. Yamazaki, Y. Zhang, Q. Zhao
FRIB, East Lansing, Michigan, USA

Funding: This material is based upon work supported by the U.S. Department of Energy Office of Science under Cooperative Agreement DE-SC0000661.
Unlike the high energy proton machines, our radiation transport simulation results show that it will be difficult to use traditional BLMs to detect beam losses for FRIB linac, not only due to the low radiation levels from low energy heavy ion beams, but also resulted by the cross talk effect from one part of the machine to another in the folded machine geometry. A device called “Halo Ring” is introduced as a component of the BLM system to substitute the traditional ion chamber in those regions.

MOPPR080

Wire Scanner Beam Profile Measurements: LANSCE Facility Beam Development

electron, controls, feedback, target

975

J.D. Gilpatrick, Y.K. Batygin, F. Gonzales, M.E. Gruchalla, V.G. Kutac, D. Martinez, C. Pillai, S. Rodriguez Esparza, J.D. Sedillo, B.G. Smith
LANL, Los Alamos, New Mexico, USA

Funding: Work supported by the U.S. Department of Energy.
The Los Alamos Neutron Science Center (LANSCE) is replacing Wire Scanner (WS) beam profile measurement systems. Three beam development tests have taken place to test the new wire scanners under beam conditions. These beam development tests have integrated the WS actuator, cable plant, electronics processors and associated software and have used H⁻ beams of different beam energy and current conditions. In addition, the WS measurement-system beam tests verified actuator control systems for minimum profile bin repeatability and speed, checked for actuator backlash and positional stability, tested the replacement of simple broadband potentiometers with narrow band resolvers, and tested resolver use with National Instruments Compact Reconfigurable Input and Output (cRIO) Virtual Instrumentation. These beam tests also have verified how trans-impedance amplifiers react with various types of beam line background noise and how the cable plants can be simplified without generating unwanted noise currents. This paper will describe these beam development tests and show some resulting data.

MOPPR081

Wire Scanner Beam Profile Measurements for the LANSCE Facility

EPICS, controls, LabView, electron

978

J.D. Gilpatrick, M.E. Gruchalla, D. Martinez, C. Pillai, S. Rodriguez Esparza, J.D. Sedillo, B.G. Smith
LANL, Los Alamos, New Mexico, USA

Funding: Work supported by the U.S. Department of Energy.
The Los Alamos Neutron Science Center (LANSCE) is replacing beam profile measurement systems, commonly known as Wire Scanners (WS’s). Using the principal of secondary electron emission, the WS measurement system moves a wire or fiber across an impinging particle beam, sampling a projected multi-bin distribution. Because existing WS actuators and electronic components are either no longer manufactured or home-built with antiquated parts, a new wire scanner beam profile measurement is being designed, fabricated, and tested. The goals for these new wire scanner include using off-the-shelf components while eliminating antiquated components, providing quick operation while allowing for easy maintainability, and tolerating external radioactivation. The WS measurement system consists of beam line actuators, a simple cable plant, an electronics processor chassis, and software located both in the electronics chassis (National Instruments LabVIEW) and in the Central Control Room (EPICS-based software). This WS measurement system will measure the more common H⁻ and H⁺ LANSCE-facility beams and will also measure less common beams. This paper describes these WS measurement systems.

MOPPR082

Wide-bandwidth Capture of Wire-scanner Signals

981

M.E. Gruchalla, J.D. Gilpatrick, D. Martinez, J.D. Sedillo
LANL, Los Alamos, New Mexico, USA

Funding: US Department of Energy.
Integrated charge collected on the sense wires of wire-scanner systems utilized to determine beam profile is generally the parameter of interest. The LANSCE application requires capturing the charge information macropulse-by-macropulse with macropulse lengths as long as 700us at a maximum macropulse rate of 120Hz. Also, for the LANSCE application, it is required that the integration be performed in a manner that does not require integrator reset between macropulses. Due to the long macropulse which must be accommodated and the 8.33ms minimum pulse period, a simple R-C integrator cannot be utilized since there is insufficient time between macropulses to allow the integrator to adequately recover. The application of wide-bandwidth to provide accurate pulse-by-pulse capture of the wire signals with digital integration of the wire signals to determine captured charge at each macropulse in applications with comparatively long macropulses and high pulse repetition rates is presented.

MOPPR083

Mechanical Design and Evaluation of the MP-11-like Wire Scanner Prototype

laser, controls, vacuum, neutron

984

S. Rodriguez Esparza, J.D. Gilpatrick, M.E. Gruchalla, A.J. Maestas, J.P. Martinez, J.L. Raybun, F.D. Sattler, J.D. Sedillo, B.G. Smith
LANL, Los Alamos, New Mexico, USA

A wire scanner (WS) is a linearly actuated diagnostic device that uses fiber wires (such as Tungsten or Silicon Carbide) to obtain the position and intensity profile of the proton beam at the Los Alamos Neutron Science Center (LANSCE) particle accelerator. LANSCE will be installing approximately 86 new WS in the near future as part of the LANSCE Risk Mitigation project. These 86 new WS include the replacement of many current WS and some newly added to the current linear accelerator and other beam lines. The reason for the replacement and addition of WS is that many of the existing actuators have parts that are no longer readily available and are difficult to find, thus making maintenance very difficult. One of the main goals is to construct the new WS with as many commercially-available-off-the-shelf components as possible. In addition, faster beam scans (both mechanically and in term of data acquisition) are desired for better operation of the accelerator. This document outlines the mechanical design of the new MP-11-like WS prototype and compares it to a previously built and tested SNS-like WS prototype.

MOPPR087

Transverse Beam Emittance Measurements of a 16 MeV Linac at the Idaho Accelerator Center

quadrupole, electron, emittance, background

990

S. Setiniyaz, T.A. Forest
ISU, Pocatello, Idaho, USA
K. Chouffani, Y. Kim
IAC, Pocatello, IDAHO, USA
A. Freyberger
JLAB, Newport News, Virginia, USA

A beam emittance measurement of the 16 MeV S-band High Repetition Rate Linac (HRRL) was performed at Idaho State University's Idaho Accelerator Center (IAC). The HRRL linac structure was upgraded beyond the capabilities of a typical medical linac so it can achieve a repetition rate of 1 kHz. Measurements of the HRRL transverse beam emittance are underway that will be used to optimize the production of positrons using HRRL's intense electron beam on a tungsten converter. In this paper, we describe a beam imaging system using on an OTR screen and a digital CCD camera, a MATLAB tool to extract beamsize and emittance, detailed measurement procedures, and the measured transverse emittances for an arbitrary beam energy of 15 MeV.

MOPPR094

Preparation for NSLS II Linac to Booster Transport Line Commissioning

controls, emittance, booster, status

1002

G.M. Wang, M.A. Davidsaver, R.P. Fliller, G. Ganetis, H.-C. Hseuh, Y. Hu, D. Padrazo, T.V. Shaftan, G. Shen, O. Singh, Y. Tian, H. Xu, L. Yang
BNL, Upton, Long Island, New York, USA

The National Synchrotron Light Source II (NSLS-II) is a state-of-the-art 3-GeV third generation light source currently under construction at Brookhaven National Laboratory. The first part of the Linac to Booster Transport (LBT) line has been installed for the linac commissioning. This part will be used for the linac acceptance test. In this paper, we describe the preparation of the LBT sub-system integration test and the high level applications.

TUXA01

Status of the J-PARC Facility

neutron, extraction, hadron, synchrotron

1005

S. Nagamiya
JAEA/J-PARC, Tokai-Mura, Naka-Gun, Ibaraki-Ken, Japan

This presentation should provide a summary of the status and eventual re-commissioning of the J-PARC facility following the 2011 earth quake and tsunami.

Slides TUXA01 [33.003 MB]

TUXA02

Upgrade Plans for the LHC Injector Complex

injection, electron, vacuum, feedback

1010

R. Garoby, H. Damerau, S.S. Gilardoni, B. Goddard, K. Hanke, A.M. Lombardi, M. Meddahi, B. Mikulec, E.N. Shaposhnikova, M. Vretenar
CERN, Geneva, Switzerland

Challenging beams with much higher brightness than today are required for the LHC to achieve its high luminosity objective after the year 2020. It is the purpose of the LHC Injectors Upgrade (LIU) Project to achieve this result, consolidating and upgrading the existing set of ageing synchrotrons (PSB, PS and SPS), and using the new linac presently in construction (Linac4). The anticipated beam characteristics are described and compared to the known limitations in the different accelerators. The foreseen solutions are outlined as well as the planning for their implementation.

Slides TUXA02 [72.367 MB]

TUXB02

Review of ERL Projects at KEK and Around the World

gun, FEL, electron, emittance

1040

N. Nakamura
KEK, Ibaraki, Japan

Future synchrotron light sources based on energy-recovery linacs (ERLs) are expected to be capable of producing super-brilliant and/or ultra-short pulses of synchrotron radiation. The Japanese collaboration team is making efforts for realizing an ERL-based VUV and X-ray source with R&D efforts on super-conducting cavities and the electron gun at KEK and elsewhere. This presentation will describe the developments of the compact ERL project and the outline of the 3-GeV ERL light source project at KEK and also review ERL projects around the world, including potential applications to colliders.

Slides TUXB02 [25.328 MB]

TUOBA02

Beam Commissioning and Operation of New Linac Injector for RIKEN RI-beam Factory

cyclotron, ion, DTL, ECRIS

1071

K. Yamada, S. Arai, M. Fujimaki, T. Fujinawa, H. Fujisawa, N. Fukunishi, Y. Higurashi, E. Ikezawa, H. Imao, O. Kamigaito, M. Kase, M. Komiyama, K. Kumagai, T. Maie, T. Nakagawa, J. Ohnishi, H. Okuno, N. Sakamoto, K. Suda, H. Watanabe, T. Watanabe, Y. Watanabe, H. Yamasawa
RIKEN Nishina Center, Wako, Japan
A. Goto
NIRS, Chiba-shi, Japan
Y. Sato
J-PARC, KEK & JAEA, Ibaraki-ken, Japan

A new linac injector called RILAC2* has successfully commissioned at the RIKEN RI beam factory (RIBF). The RILAC2 can accelerate very heavy ions with m/q of 7, such as 124Xe¹⁹⁺ and 238U³⁵⁺ from a 28 GHz superconducting ECR ion source**, up to an energy of 680 keV/nucleon in the cw mode. Ions are directory injected into the RIKEN Ring Cyclotron without charge stripping in order to increase the beam intensity, as well as performing independent RIBF experiments and super-heavy-element synthesis. The key features of RILAC2 are the powerful ECRIS, higher extraction voltage of the ECRIS compared to the voltage of the existing injector linac to reduce the space charge effect, improvement of the rf voltage and phase stability, improvement of the vacuum level to reduce the loss by charge exchange, and the compact equipments yet to be installed in the existing AVF cyclotron vault. The first beam acceleration was achieved on December 21, 2010. After the several beam acceleration tests in 2011, we started to operate the RILAC2 to supply beams for the RIBF experiments.
* O. Kamigaito et al., Proc. of PASJ3-LAM31, WP78, p. 502 (2006); K. Yamada et al., Proc. of IPAC'10, MOPD046, p.789 (2010).
** T. Nakagawa et al., Rev. Sci. Instrum. 79, 02A327 (2008).

Slides TUOBA02 [9.947 MB]

TUOBA03

H⁻ and Proton Beam Loss Comparison at SNS Superconducting Linac

proton, quadrupole, ion, DTL

1074

A.P. Shishlo, A.V. Aleksandrov, J. Galambos, M.A. Plum
ORNL, Oak Ridge, Tennessee, USA
E. Laface
ESS, Lund, Sweden
V.A. Lebedev
Fermilab, Batavia, USA

Funding: ORNL/SNS is managed by UT-Battelle, LLC, for the U.S. Department of Energy under contract DE-AC05-00OR22725.
A comparison of beam loss in the superconducting part (SCL) of the Spallation Neutron Source (SNS) linac for H⁻ and protons is presented. During the experiment the nominal beam of negative hydrogen ions in the SCL was replaced by a proton beam created by insertion of a thin stripping carbon foil placed in the low energy section of the linac. The observed significant reduction in the beam loss for protons is explained by a domination of the intra-beam stripping mechanism of the beam loss for H-. The details of the experiment are discussed, and a preliminary estimation of the cross section of the reaction H⁻ + H⁻ -> H⁻ + H⁰ + e is presented.

Slides TUOBA03 [0.772 MB]

TUOAB03

Five Years of Accelerator Operation Experience at HIT

ion, controls, ion-source, synchrotron

1083

A. Peters, R. Cee, E. Feldmeier, M. Galonska, Th. Haberer, K. Höppner, S. Scheloske, C. Schömers, T. Winkelmann
HIT, Heidelberg, Germany

Since spring 2007 the HIT company, a 100% daughter of the Heidelberg University Hospital, has taken over the responsibility for the operation of the first dedicated European ion beam tumour therapy facility. In 2009 the clinical operation started and since then more than 800 patients were treated in the facility. This success is based on a well-trained and highly-motivated team of physicists, engineers and technicians responsible for the 24/7 operation scheme as well as for more than 70% of the accelerator maintenance. The paper will give an overview of the operation organization reflecting the overall beam time schedule. In addition, the accelerator statistics will prove the achieved high availability of about 98% besides planned maintenance time. Furthermore, the reliability of the HIT accelerator including the gantry section will be illustrated resulting in long intervals before necessary retuning. At last, an outlook to further enhancements of the facility operation will be presented.

Slides TUOAB03 [7.526 MB]

TUOBC01

Experimental Verification of the CLIC Two-beam Scheme, Status and Outlook

acceleration, target, emittance, gun

1101

R. Corsini
CERN, Geneva, Switzerland

The feasibility of the CLIC novel scheme of two-beam acceleration was extensively tested in the CTF3 facility over the last few years. In particular, efficient full beam loading acceleration, isochronous ring operation, beam recombination by transverse RF deflectors have been fully proven. 12 GHz RF power production by high-current drive beam is now part of CTF3 routine operation, and two-beam acceleration up to 150 MV/m has been achieved. Drive beam deceleration tests were carried out as well. In this paper we summarize the main results obtained, including the more recent ones. We also outline and discuss the future experimental program, both in CTF3 and in other beam facilities, as well as the path to a possible facility needed in the initial stage of the CLIC project, CLIC0.

Slides TUOBC01 [9.921 MB]

TUEPPB005

Novel Technique of Suppressing TBBU in High-energy ERLs

HOM, SRF, lattice, electron

1122

V. Litvinenko
BNL, Upton, Long Island, New York, USA

Energy recovery linacs (ERLs) is emerging generation of accelerators promising revolutionize the fields of high-energy physics and photon sciences. One potential weakness of these devices is transverse beam-breakup instability, which may severely limit available beam current. In this paper I am presenting novel idea of using natural chromaticity in ERL arcs to suppressing TBBU instabilities. I present the theory of the process and two exact cases demonstrating that the threshold of TBBU instability could be raised by my orders of magnitude using this method.
* V.N. Litvinenko, Chromaticity of the lattice and beam stability in energy recovery linacs, submitted to PR ST-AB

TUPPC006

CW Energy Upgrade of the Superconducting Electron Accelerator S-DALINAC

recirculation, dipole, simulation, extraction

1161

M. Kleinmann, J. Conrad, R. Eichhorn, F. Hug, N. Pietralla
TU Darmstadt, Darmstadt, Germany

Funding: This work is supported by the DFG through SFB 634.
The S-DALINAC is a superconducting recirculating electron accelerator with maximum design energy of 130 MeV operating in cw at 3 GHz. Even so the gradients of the superconducting cavities are well above design, their design quality factor of 3*10⁹ have not been reached so far. Due to the limited cooling power of the cryo-plant being 120 W, the final energy achievable in cw operation is around 85 MeV, currently. In order to provide a cw beam with the designed final energy in the future, the installation of an additional recirculation path is projected and to be finished by 2013. We review the design constraints related to the existing beam lines, report in detail on the magnet design (being the key issue) and the lattice calculations for the additional recirculation path.

TUPPC010

Study of Effects of Failure of Beamline Elements and its Compensation in CW Superconducting Linac

cavity, beam-losses, emittance, focusing

1173

A. Saini, K. Ranjan
University of Delhi, Delhi, India
C.S. Mishra, J.-F. Ostiguy, N. Solyak, V.P. Yakovlev
Fermilab, Batavia, USA

Project-X is the proposed high intensity proton facility to be built at Fermilab in United States. First stage of the Project-X consists of H^- superconducting linac (SC) which will be operated in continuous wave (CW) mode to accelerate the beam from kinetic energy of 2.1 MeV to 3 GeV. The operation in CW mode puts stringent tolerances on the beam line components, particularly at low energy section. The failure of beam line elements result in mismatch of the beam with the following sections due to different beam parameters than designed parameters. It makes the beam unstable which causes emittance dilution, and ultimately results in beam losses. In worst case, it can affect the reliability of the machine and may lead to the shutdown of the linac to replace the failed elements. Thus, it is important to study impacts of these effects and their compensation to restore linac performance to avoid beam interruption. This paper presents the studies performed for the failure of accelerating cavity and focusing magnets at the critical locations in the Project-X CW superconducting linac

TUPPC011

Beam Steering Correction in FRIB Quarter-wave Resonators

cavity, simulation, cryomodule, solenoid

1176

A. Facco
INFN/LNL, Legnaro (PD), Italy
A. Facco, Y. Xu, Y. Zhang, Q. Zhao, Z. Zheng
FRIB, East Lansing, Michigan, USA

Funding: This material is based upon work supported by the U.S. Department of Energy Office of Science under Cooperative Agreement DE-SC0000661
The Quarter-Wave Resonators (QWR) section of the FRIB superconducting driver linac is required to accelerate Uranium beam up to 16 MeV/u in two different charge states simultaneously. This puts severe requirements on resonators alignment and field quality, in order to avoid beam losses and emittance growth. In particular, QWR beam steering can cause transverse oscillations of the beam centroid which reduce the linac acceptance and induces emittance growth. We have studied, with an analytical model and with 3D beam dynamics simulations, correction methods for the FRIB QWRs steering. We found that cavity shifting can provide effective steering cancellation in FRIB QWRs without need of cavity shape modifications, and allows to eliminate transverse beam oscillations and to improve beam quality. Calculation and simulation methods and results will be presented and discussed.
Michigan State University designs and establishes FRIB as a DOE Office of Science National User Facility in support of the mission of the Office of Nuclear Physics.

TUPPC019

Beam Dynamics Simulations of J-PARC Main Ring for Damage Recovery from the Tohoku Earthquake in Japan and Upgrade Plan of Fast Extraction Operation

alignment, simulation, injection, acceleration

1200

Y. Sato, K. Hara, S. Igarashi, T. Koseki, K. Ohmi, C. Ohmori
KEK, Ibaraki, Japan
H. Hotchi
JAEA/J-PARC, Tokai-Mura, Naka-Gun, Ibaraki-Ken, Japan

Magnets of Japan Proton Accelerator Research Complex (J-PARC) were shaken by the Tohoku Earthquake in Japan on March 11th, 2011. The alignment of J-PARC Main Ring (MR) received 20 mm displacement horizontally and 6 mm vertically. Beam dynamics simulations were performed to estimate the effect of the displacement on closed orbit distortions and beam loss in fast extraction (FX) operation of J-PARC MR. Based on the simulation results, we concluded that re-alignment of J-PARC MR was needed to achieve high-power beam. The re-alignment of MR was finished on October 28th, 2011. We also considered the effects of the earthquake on the upstream of MR to establish our upgrade plan, which was based on beam dynamics simulations optimizing collimator balance of injection beam transport (3-50BT) and MR, and RF patterns. J-PARC MR FX operation was resumed from December 2011.

TUPPC021

Design Study on KEK Injector Linac Upgrade for High-current and Low-emittance Beams

emittance, simulation, wakefield, acceleration

1206

H. Sugimoto, M. Satoh, M. Yoshida
KEK, Ibaraki, Japan

Injector linac at KEK is now under upgrading to produce high current (5nC for e-, 4nC for e+) and low emittance (20 mm mrad for e-, 6 mm mrad for e+) electron and positron beams to a SuperB collider called SuperKEKB. Emittance growth resulted from both wakefield at the acceleration structure and dispersive effects at the focusing structure are troublesome in keeping the beam quality during the beam propagation. In this study, a possible solution to mitigate these effects in the KEK injector linac is explored by considering bunch compression in an existing bending section, orbit correction to suppress the wakefield excitation, and beam optics design.

TUPPC022

Straight Scaling FFAG Experiment

emittance, vacuum, closed-orbit, instrumentation

1209

J.-B. Lagrange, Y. Ishi, Y. Kuriyama, Y. Mori, R. Nakano, B. Qin, T. Uesugi, E. Yamakawa
Kyoto University, Research Reactor Institute, Osaka, Japan
Y. Niwa, K. Okabe, I. Sakai
University of Fukui, Faculty of Engineering, Fukui, Japan

Straight scaling FFAG experiment has been done at Kyoto University research reactor institute. Details and results are presented here.

TUPPC027

Multi Objective Genetic Optimization for Linac Lattice of PAL XFEL

lattice, electron, emittance, quadrupole

1224

C.H. Yi, M.-H. Cho, S.H. Kim, W. Namkung
POSTECH, Pohang, Kyungbuk, Republic of Korea
H.-S. Kang
PAL, Pohang, Kyungbuk, Republic of Korea
K.-J. Kim
ANL, Argonne, USA

Funding: Work supported by MEST and POSTECH Physics BK21 Program.
There are a large number of variables and objectives in design of XFEL linac lattices. Recently, most of accelerator physics field, are applying the multi-objective genetic algorithm (MOGA) for these kinds of problems. MOGA was applied to the PAL XFEL linac lattice design. Longitudinal position of all components was fixed before applying MOGA. RF parameters of RF cavities and bending angles of bunch compressors are selected as variables. Various beam parameters computed by ELEGANT were used as objectives. By using MOGA, new linac lattice designs with 2 and 3 bunch compressors was generated and their beam properties are presented in this paper.

TUPPC043

Design of Accumulator and Compressor Rings for the Project-X Based Proton Driver

lattice, proton, optics, synchrotron

1260

Y. Alexahin, D.V. Neuffer
Fermilab, Batavia, USA

Funding: Work supported by Fermi Research Alliance, LLC, under contract No. DE-AC02-07CH11359 with the U.S. Department of Energy.
A Muon Collider (MC) and Neutrino Factory (NF), which may be considered as a step towards MC, both require high-power (~4 MW) proton driver providing short (<1m) bunches for muon production. However, the driver repetition rate required for these two machines is different: ~15 Hz for MC and ~60 Hz for NF. This difference necessitates employing two separate rings: one for accumulation of the proton beam from the Project-X linac in a few (e.g., 4) long bunches, the other for bunch compression - one by one for NF or all at a time for MC with simultaneous delivery to the target. The lattice requirements for these two rings are different: the momentum compaction factor in the accumulator ring should be large (and possibly negative) to avoid the microwave instability, while the compressor ring can be nearly isochronous in order to limit the required RF voltage and reduce the dispersion contribution to the beam size. In the present report we consider ring lattice designs which achieve these goals.

TUPPC044

Emittance and Phase Space Tomography for the Fermilab Linac

emittance, focusing, optics, quadrupole

1263

C. Johnstone, F.G.G. Garcia, T. Kobilarcik, G.M. Koizumi, C.D. Moore, D.L. Newhart
Fermilab, Batavia, USA

Funding: Work supported by Fermi Research Alliance, LLC, under contract No. DE-AC02-07CH11359 with the U.S. Dept. of Energy.
The Fermilab Linac delivers a variable intensity, 400-MeV beam to the The MuCool Test Area experimental hall via a beam line specifically designed to facilitate measurements of the Linac beam emittance and properties. A 10 m, dispersion-free and magnet-free straight utilizes an upstream quadrupole focusing triplet in combination with the necessary in-straight beam diagnostics to fully characterize the transverse beam properties. Since the Linac does not produce a strictly elliptical phase space, tomography must be performed on the profile data to retrieve the actual particle distribution in phase space. This is achieved by rotating the phase space distribution using different waist focusing conditions of the upstream triplet and performing a de-convolution of the profile data. Preliminary measurements using this diagnostic section are reported here.

TUPPC046

Further Analysis of Real Beam Line Optics from a Synthetic Beam

optics, coupling, closed-orbit, electron

1269

R.M. Bodenstein
UVa, Charlottesville, Virginia, USA
Y. Roblin, M.G. Tiefenback
JLAB, Newport News, Virginia, USA

Funding: Authored by Jefferson Science Associates, LLC under U.S. DOE Contract No. DE-AC05-06OR23177. The U.S. Government retains a license to publish or reproduce this manuscript for U.S. Government purposes.
Standard closed-orbit techniques for Twiss parameter measurement are not applicable to the open-ended Continuous Electron Beam Accelerator Facility (CEBAF) at Jefferson Lab. The evolution of selected sets of real orbits in the accelerator models the behavior of a “synthetic” beam. This process will be validated against beam profile-based Twiss parameter measurements and should provide the distributed optical information needed to optimize beamline tuning for an open-ended system. This work will discuss the current and future states of this technique, as well as an example of its use in the CEBAF machine.

TUPPC052

Longitudinal Beam Tuning at FACET

diagnostics, wakefield, simulation, klystron

1287

N. Lipkowitz, F.-J. Decker, J. Sheppard, S.P. Weathersby, U. Wienands, M. Woodley, G. Yocky
SLAC, Menlo Park, California, USA

Commissioning of the Facility for Advanced acCelerator Experimental Tests (FACET) at SLAC began in July 2011. In order to achieve the high charge density required for users such as the plasma wakefield acceleration experiment, the electron bunch must be compressed longitudinally from ~6 mm down to 20 microns. This compression scheme is carried out in three stages and requires careful tuning, as the final achievable bunch length is highly sensitive to errors in each consecutive stage. In this paper, we give an overview of the longitudinal dynamics at FACET, including beam measurements taken during commissioning, tuning techniques developed to minimize the bunch length, optimization of the new “W” chicane at the end of the linac, and comparison with particle tracking simulations. In addition, we present additional diagnostics and improved tuning techniques, and their expected effect on performance for the upcoming 2012 user run.

TUPPC053

Longitudinal Tuning of the SNS Superconducting Linac

cavity, optics, acceleration, controls

1290

T.V. Gorlov
ORNL, Oak Ridge, Tennessee, USA

Funding: This work was supported by SNS through UT-Battelle, LLC, under Contract No. DE-AC05-00OR22725 for the U.S. Department of Energy.
The SNS superconducting linac delivers proton beam with about 1 GeV of energy driven by self-consistent RF cavities. Here, we present an experience of the longitudinal tune-up of the SNS superconducting linac where a new application for quick RF phase setup and cavity fault adaptation was created. The routine of superconducting linac tune-up, longitudinal beam manipulation, and radio frequency cavity phase scaling for beam state recovery is presented. The application has direct value for beam optics study and will serve as the basis for longitudinal beam-size manipulation for a laser stripping project.

TUPPC065

High Intensity Beam Analysis for the Superconducting Radio-frequency Linac (SRF-Linac) of the IFMIF-EVEDA Accelerators

emittance, resonance, SRF, space-charge

1323

W. Simeoni
CEA/IRFU, Gif-sur-Yvette, France
N. Chauvin, P.A.P. Nghiem, D. Uriot
CEA/DSM/IRFU, France

In this proceeding we analyze space charge effects on the beam dynamics of IFMIF accelerators. The objective is to be able to characterize and understand the crucial issues like halo formation, emittance growth and sudden particle losses in the SRF-Linac. We use the Hofmann stability charts to identify modes of collective space charge density oscillations that are responsible for the transfer and growth of the emittance. With identification of modes we are able to treat the parametric resonance between the modes and the nonlinear motion of an individual ion the amplitude of which is greater than the core radius. The resulting phase space consists of an inner separatrix containing the core and an outer separatrix that becomes the locus near which the halo particles enter and cluster.

TUPPD004

Costing Methodology and Status of the Neutrino Factory

cryogenics, target, solenoid, factory

1410

A. Kurup
Imperial College of Science and Technology, Department of Physics, London, United Kingdom
N. Bliss, N.A. Collomb, A.F. Grant
STFC/DL, Daresbury, Warrington, Cheshire, United Kingdom

The International Design Study for the Neutrino Factory will produce a reference design report in 2013 that will contain a detailed performance analysis of the Neutrino Factory and a cost estimate. In order to determine the cost a number of engineering features need to be included in the accelerator physics design, which can require the physics design to be re-optimized. The cost estimate is determined in such a way as to make efficient use of the engineering resources available and to simplify the process of modifying the physics design to include engineering features. This paper will present details of the methodology used to determine the cost estimate and the current status of each subsystem.

TUPPD008

Recent Progress Toward a Muon Recirculating Linear Accelerator

dipole, cryomodule, quadrupole, factory

1422

K.B. Beard
Muons, Inc, Batavia, USA
M. Aslaninejad, C. Bonţoiu, A. Kurup, J.K. Pozimski
Imperial College of Science and Technology, Department of Physics, London, United Kingdom
S.A. Bogacz, V.S. Morozov, Y. Roblin
JLAB, Newport News, Virginia, USA

Both Neutrino Factories (NF) and Muon Colliders (MC) require very rapid acceleration due to the short lifetime of muons. After a capture and bunching section, a linac raises the energy to about 900 MeV, and is followed by one or more Recirculating Linear Accelerators (RLA), possibly followed by a Rapid Cycling Synchrotron (RCS) or Fixed-Field Alternating Gradient (FFAG) ring. A RLA reuses the expensive RF linac section for a number of passes at the price of having to deal with different energies within the same linac. Various techniques including pulsed focusing quadrupoles, beta frequency beating, and multipass arcs have been investigated via simulations to improve the performance and reduce the cost of such RLAs.

TUPPD017

Electromagnetic Design of RF Cavities for Accelerating Low-Energy Muons

cavity, vacuum, resonance, solenoid

1446

S.S. Kurennoy
LANL, Los Alamos, New Mexico, USA

A high-gradient linear accelerator for accelerating low-energy muons and pions in a strong solenoidal magnetic field has been proposed for homeland defense and industrial applications.* The acceleration starts immediately after collection of pions from a target in a solenoidal magnetic field and brings decay muons, which initially have kinetic energies mostly around 15-20 MeV, to 200 MeV over a distance of ~10 m. At this energy, both ionization cooling and further, more conventional acceleration of the muon beam become feasible. A normal-conducting linac with external-solenoid focusing can provide the required large beam acceptances. The linac consists of independently fed zero-mode (TM010) RF cavities with wide beam apertures closed by thin conducting edge-cooled windows. Electromagnetic design of the cavity, including its RF coupler, tuning and vacuum elements, and field probes, has been developed with the CST MicroWave Studio, and will be presented.
* S.S. Kurennoy, A.J. Jason, H. Miyadera, “Large-Acceptance Linac for Accelerating Low-Energy Muons.” Proceed. IPAC10, p. 3518.

TUPPD019

New Injector for the EMMA ns-FFAG Ring

booster, cavity, gun, emittance

1449

B.D. Muratori
STFC/DL/ASTeC, Daresbury, Warrington, Cheshire, United Kingdom

EMMA is the world’s first non-scaling FFAG which has recently demonstrated acceleration in the serpentine channel. At present, the electron beam is injected into EMMA from the ALICE accelerator. However, funding will be re-directed to an Electron Beam Test Facility (EBTF) in the near future, therefore, in order to continue the broad portfolio of planned experiments required to characterize non-scaling FFAGs, it essential to consider an alternative injection scheme. In this paper, we propose re-utilizing a thermionic gun and a 12 MeV linac from the SRS (Synchrotron Radiation Source) at Daresbury Laboratory. The paper looks at how the required EMMA beam properties can be matched with this new set-up and the advantages and disadvantages involved.

TUPPD023

RFQ LINAC Commissioning and Carbon⁴⁺ Acceleration for Ag¹⁵⁺ Acceleration via Direct Plasma Injection Scheme

ion, rfq, plasma, laser

1458

T. Yamamoto, M. Washio
RISE, Tokyo, Japan
K. Kondo, M. Okamura, M. Sekine
BNL, Upton, Long Island, New York, USA

Funding: Work supported by Brookhaven Science Associates, LLC under Contract No. DE-AC02-98CH10886 with the U.S. Department of Energy.
High intensity, high charge state, various ion species and small emittance heavy ion beam is required for particle physics, medical uses, inertial fusion, and a simulator of space radiation. Direct Plasma Injection Scheme (DPIS), the way to make laser abrasion plasma developed in the past several years, is used for Heavy Ion beam Accerelation. High density plasma with an initial drift velocity will fly to the entrance of the Radio Frequency Quadropole (RFQ) LINAC; ions will be separated from plasma via high voltage and injected it to RFQ LINAC directly. After RFQ LINAC, ions accepted to the RF buckets are accelerated to a current of over 10mA. Until now, we tried a carbon target using the partial modulation rod of the RFQ LINAC, and succeeded in accelerating carbon⁴⁺, carbon⁵⁺, and carbon⁶⁺ non-bunched beam.* In this instance, we succeeded in commissioning of new full modulation RFQ rod designed for the charge mass ratio(q/A) 1/6. We tested the acceleration of carbon⁴⁺, and it could be catched by the RF bucket and accelerated. After this, we'll try accelerating carbon²⁺ (q/A=1/6) for demonstrating the feasibility of the Ag¹⁵⁺ ion accelerating.
* T. Kanesue, M. Okamura, K. Kondo, J. Tamura, H. Kashiwagi, Z. Zhang, Drift distance survey in direct plasma injection scheme for high current beam production, Rev Sci Instrum. 2010 Feb;81(2):02B723

TUPPD025

REVIEWOF LOW-ENERGY POSITRON BEAM FACILITIES

positron, target, neutron, radiation

1464

S. Golge, B. Vlahovic
NCCU, Durham, USA

Positrons are produced by processes such as positive beta decay from radioactive isotopes, in nuclear reactor cores from both in-situ radioisotope radiation and pair production, and by accelerator driven beams hitting a converter target. The purpose of this paper is to review some of the prominent existing low-energy e⁺ facilities.

TUPPD055

Characterization of ps-spaced Comb Beams at SPARC

simulation, radiation, bunching, laser

1527

A. Mostacci
URLS, Rome, Italy
A. Bacci, A.R. Rossi
Istituto Nazionale di Fisica Nucleare, Milano, Italy
M. Bellaveglia, E. Chiadroni, G. Di Pirro, M. Ferrario, G. Gatti, C. Vaccarezza
INFN/LNF, Frascati (Roma), Italy
A. Cianchi
Università di Roma II Tor Vergata, Roma, Italy
C. Ronsivalle
ENEA C.R. Frascati, Frascati (Roma), Italy

SPARC in Frascati is a high brightness photo-injector used to explore advanced beam manipulation techniques. Sub-picosecond, high brightness electron bunch trains (the so called comb beam) can be generated illuminating the cathode of a RF photoinjector with a laser pulse train and via velocity bunching technique. In this paper different aspects of the physics of this advanced beam manipulation technique are discussed combining simulation and measurements. Beam dynamics numerical macroparticle simulations have been compared with the experimental results for model validation; they allow to gain insights on the beam evolution highlighting several aspects which can not be measured. In particular, we focus on the train evolution in the linac sections and in the dog-leg line up to the THz station and on the effective rms length of the single pulses within the train when it becomes shorter than the resolution.

TUPPD065

An Electron Gun Test Stand to Prepare for the MAX IV Project

gun, cathode, injection, coupling

1551

S. Werin, E. Elafifi, M. Eriksson, D. Kumbaro, F. Lindau, S. Thorin
MAX-lab, Lund, Sweden
E. Mansten
Lund University, Division of Atomic Physics, Lund, Sweden

The MAX IV facility, currently under construction, will include a 3 GeV linac injector with two RF guns providing beams for the two operations modes: ring injection and the Short Pulse Facility. The ring injection will be done by a thermionic 3 GHz RF gun developing from the current MAX-lab RF gun. The SPF gun will be a laser driven photo cathode 3 GHz RF gun based on the 1.6 cell BNL/SLAC type. The guns will be operated with short (0.7 us) RF pulses from a SLED system. A test stand to fine tune the operation of the two different systems has been assembled at the MAX IV laboratory (former MAX-lab). The experience in RF commissioning and initial measurements of energy, charge and quantum efficiency will be reported and the extension of the test stand for full emittance characterization will be outlined.

TUPPD076

Photocathode Studies for the SPEAR3 Injector RF Gun

cathode, gun, laser, klystron

1575

S. Park, W.J. Corbett, S.M. Gierman, J.R. Maldonado
SLAC, Menlo Park, California, USA

Funding: Work supported by U.S. Department of Energy Contract DE-AC03- 76SF00515 and Office of Basic Energy Sciences, Division of Chemical Sciences.
The electron gun for the SPEAR3 injector operates with a warm thermionic dispenser cathode immersed in a 1.5-cell RF structure. At each injection cycle the gun accelerates several thousand electron bunches up to ~3 MeV during a 2.5us rf pulse. The individual bunches are then compressed by an alpha magnet and a traveling-wave chopper selects 3-5 bunches so they don’t cause beam loading to the linac, where the accelerated bunches reach 120 MeV for subsequent capture in a single booster synchrotron bucket. Tests are underway to operate the dispenser cathode as a cold electron photo-emitter driven by an external laser system. Eventually, without the copper, this will enable multi-bunch injections to the Booster and SPEAR3. In parallel, tests are underway to evaluate quantum efficiency and beam emittance for a beam emitted from a CsBr photocathode with ns- and ps-pulses of UV laser light. In this paper we report on both the cold cathode electron gun operation studies for SPEAR3 and the CsBr research aimed at developing advanced cathode materials for future applications.

TUPPD077

SPEAR3 Booster RF System Upgrade: Performance Requirements and Evaluation of Resources

booster, klystron, cavity, injection

1578

S. Park, W.J. Corbett, R.O. Hettel, J.F. Schmerge, J.J. Sebek, J.W. Wang
SLAC, Menlo Park, California, USA

Funding: Work supported by U.S. Department of Energy Contract DE-AC03-76SF00515 and Office of Basic Energy Sciences, Division of Chemical Sciences.
The SPEAR2 accelerator system originally had 3 RF stations (2 for storage ring, 1 Booster) operating at 358.5 MHz. SPEAR3 now operates at 476.3 MHz with PEP-II type RF system, while the Booster RF frequency remains unchanged. For top-off operation, the Booster injects single 3.0 GeV electron bunches into SPEAR3 at 10 Hz every 5 minutes to replenish lost charge. Due to the frequency mismatch between SPEAR3 and the Booster, only one SPEAR3 bucket can injected per shot limiting injection rate and overall system flexibility. The aging high-power RF subsystems of the Booster pose a reliability issue as well. In order to remove these constraints, studies are underway to replace the Booster RF system using the PEP-II type RF system as a baseline. The new Booster RF system will be tuned to 475.036 MHz, and phase-locked to the SPEAR3 RF system. The project calls for ramping the Booster cavity gap voltage to 0.80 MV at 10 Hz, each with a 40 ms acceleration interval. With very low beam loading and low average RF power, there are many subsystems that can be operationally simplified. In this paper we present the results of analysis leading to a new Booster RF system.

TUPPD079

Design of an L-Band RF Photoinjector for the Idaho Accelerator Center 44 MeV Linac

emittance, gun, laser, solenoid

1584

M. Titberidze, A.W. Hunt, D.P. Wells
IAC, Pocatello, IDAHO, USA
Y. Kim
ISU, Pocatello, Idaho, USA

At the Idaho Accelerator Center (IAC) of Idaho State University, we have been operating a 44 MeV L-band RF (1300 MHz) linear accelerator (LINAC) for various user applications such as medical isotope production, Laser Compton Scattering (LCS), positron annihilation energy spectroscopy, and photo fission. But the LINAC is not optimized properly to supply high quality electron beam for those experiments due to limitations of an existing 85 kV thermionic DC gun. In the near future, we are planning to use the L-band LINAC for new user applications such as Accelerator Driven subcritical nuclear reactor System (ADS), photon tagging facility, Ultrafast Electron Diffraction (UED) facility, and high power coherent Terahertz light source facility. Therefore, recently, we have been studying a future upgrade of the L-band LINAC with an RF photoinjector using ASTRA code. In this paper, we describe ASTRA simulation results and a new layout of the L-band LINAC, which is based on an L-band 1.5 cell RF photoinjector. Then, we describe its expected performance for two different single bunch charges (1 nC and 5 nC).

TUPPD083

Raising Photoemission Efficiency with Surface Acoustic Waves

electron, photon, polarization, vacuum

1596

A. Afanasev, F. Hassani, C.E. Korman
GWU, Washington, USA
V.G. Dudnikov, R.P. Johnson
Muons, Inc, Batavia, USA
M. Poelker, K.E.L. Surles-Law
JLAB, Newport News, Virginia, USA

Funding: Supported in part by DOE STTR Grant DE-SC0006256. Notice: Authored by Jefferson Science Associates, LLC under U.S. DOE Contract No. DE-AC05-06OR23177
We are developing a novel technique that may help increase the efficiency and reduce costs of photoelectron sources used at electron accelerators. The technique is based on the use of Surface Acoustic Waves (SAW) in piezoelectric materials, such as GaAs, that are commonly used as photocathodes. Piezoelectric fields produced by the traveling SAW spatially separate electrons and holes, reducing their probability of recombination, thereby enhancing the photoemission quantum efficiency of the photocathode. Additional advantages could be increased polarization provided by the enhanced mobility of charge carriers that can be controlled by the SAW and the ionization of optically-generated excitons resulting in the creation of additional electron-hole pairs. It is expected that these novel features will reduce the cost of accelerator operation. A theoretical model for photoemission in the presence of SAW has been developed, and experimental tests of the technique are underway.

TUPPP012

Optimization of the Beam Optical Parameters of the Linac-based Terahertz Source FLUTE

laser, gun, space-charge, simulation

1629

S. Naknaimueang, E. Huttel, A.-S. Müller, M.J. Nasse, R. Rossmanith, M. Schuh, M. Schwarz, P. Wesolowski
KIT, Karlsruhe, Germany
M.T. Schmelling
MPI-K, Heidelberg, Germany

Funding: Karlsruher Institut für Technologie.
FLUTE is a compact accelerator (consisting of a 7 MeV laser gun, a 50 MeV linac, and bunch compressors) under construction at KIT in Karlsruhe for producing coherent THz radiation. The programs ASTRA and CSRtrack were used to optimize the beam parameters. The aim was to minimize the bunch length used in various THz experiments, with bunch charges between 100 pC and 3 nC. It was calculated that the bunch length after compression depends both on the bunch current and the transverse beam size. The transverse beam size depends on the laser spot size at the cathode of the 7 MeV laser gun. Further simulations showed that a larger beam size reduces the efficiency of the compressor. This problem is cured by focusing elements with a focusing strength depending on the space charge after the gun and integrated into the various compressors layouts under study (four magnets, two magnets and quadrupoles, etc.). The results of these calculations are presented in this paper.

TUPPP016

Recent Development of PF Ring and PF-AR

undulator, injection, polarization, vacuum

1641

Y. Tanimoto, T. Aoto, S. Asaoka, K. Endo, K. Haga, K. Harada, T. Honda, Y. Honda, M. Izawa, Y. Kobayashi, A. Mishina, T. Miyajima, H. Miyauchi, S. Nagahashi, N. Nakamura, T. Nogami, T. Obina, T. Ozaki, C.O. Pak, H. Sakai, S. Sakanaka, H. Sasaki, Y. Sato, K. Satoh, M. Shimada, K. Shinoe, T. Shioya, M. Tadano, T. Tahara, T. Takahashi, R. Takai, K. Tsuchiya, T. Uchiyama, A. Ueda, K. Umemori, M. Yamamoto
KEK, Ibaraki, Japan
H. Takaki
ISSP/SRL, Chiba, Japan

After the earthquake of March 11, two light sources of KEK, PF ring and PF-AR, have recovered the regular operation from October, 2011. We installed tandem variably-polarized undulators at PF ring in 2009. Recently, the orbit switching system has been completed with sufficient feed-forward orbit compensation at 10-Hz. PF ring is usually operated at 450 mA with a top-up injection using the pulsed sextupole magnet instead of the conventional kicker magnets. The transverse and longitudinal instabilities are suppressed by a digital feedback system using the iGp signal processor. In the longitudinal direction, we observed unstable quadrupole mode oscillation which could not be controlled by the feedback system. We had applied the phase modulation of the main RF cavity to stabilize the quadrupole oscillation before. Old-type RF-shielded gate valves damaged by the earthquake were removed from the ring during the summer maintenance. In the operation after autumn, the quadrupole oscillation can be cured by dividing the bunch train of partial-filling. Without the phase modulation, the effective brightness of SR beam has been improved especially at beam lines of finite dispersion function.

TUPPP019

Overview of the Solaris Facility

storage-ring, klystron, dipole, vacuum

1650

C.J. Bocchetta, M. Bartosik, P.P. Goryl, K. Królas, M. Młynarczyk, W. Soroka, M.J. Stankiewicz, P.S. Tracz, Ł. Walczak, A.I. Wawrzyniak, K. Wawrzyniak, J.J. Wiechecki, M. Zając, L. Zytniak
Solaris, Kraków, Poland
R. Nietubyć
The Andrzej Soltan Institute for Nuclear Studies, Centre Świerk, Świerk/Otwock, Poland

Funding: Work supported by the European Regional Development Fund within the frame of the Innovative Economy Operational Program: POIG.02.01.00-12-213/09
The Polish synchrotron light source Solaris is under construction in Kraków. The project is based on the MAX IV light source being built in Lund, Sweden. The 1.5 GeV storage ring for Solaris and part of the injector complex are identical to that of MAX IV, although both are housed in buildings that differ from those of MAX IV. Ground breaking on the green field site at the Jagiellonian University campus occurred at the start of 2012. A detail description of the facility infrastructure, services and construction choices is given together with the latest project developments for main accelerator systems.

TUPPP026

RF Rescue Option for TPS Linac

electron, bunching, booster, injection

1668

K.L. Tsai, H.-P. Chang, C.-T. Chen, C.-S. Fann, K.T. Hsu, S.Y. Hsu, K.-K. Lin, H.M. Shih
NSRRC, Hsinchu, Taiwan
K. Dunkel, C. Piel
RI Research Instruments GmbH, Bergisch Gladbach, Germany

The 150 MeV linac of Taiwan Photon Source was commissioned in June 2011. It consists of 90 keV electron source, bunching system and three S-band accelerating sections driven by three high-power klystrons. The rf system is equipped with rescue option such that the rf power from second klystron can be split and fed into both accelerating section 1 and 2. The rescue operation will be needed in the event of a failure occurred at the first klystron. In the report, the rescue capability will be illustrated and the test results will also be discussed.

TUPPP038

Electron Beam Collimation for the Next Generation Light Source

collimation, undulator, gun, impedance

1695

C. Steier, P. Emma, H. Nishimura, C. F. Papadopoulos, F. Sannibale
LBNL, Berkeley, California, USA

Funding: Work supported by the U.S. Department of Energy under Contract No. DE-AC02-05CH11231.
The Next Generation Light Source will deliver high (MHz) repetition rate electron beams to an array of free electron lasers. Because of the significant average current in such a facility, effective beam collimation is extremely important to minimize radiation damage to undulators, prevent quenches of superconducting cavities, limit dose rates outside of the accelerator tunnel and prevent equipment damage. This paper describes the conceptual design of the collimator system, as well as the results of simulations to test its effectiveness.

TUPPP054

RF Activation and Preliminary Beam Tests of the X-band Linearizer at the FERMI@Elettra FEL Project

FEL, klystron, emittance, LLRF

1721

G. D'Auria, S. Di Mitri, G. Penco, C. Serpico
ELETTRA, Basovizza, Italy

FERMI@Elettra is a fourth generation light source facility presently in commissioning at the Elettra Laboratory in Trieste, Italy. It is based on an S-band (3 GHz), 1.5 GeV normal conducting (NC) linac, that provides ultra short e-bunches with high peak current, using two stages of magnetic compression. To linearize the beam longitudinal phase space and to improve the compression process, a forth harmonic RF structure (12 GHz) has been installed downstream the first magnetic chicane. This paper reports the RF activation of the structure and the preliminary tests performed on the beam.

TUPPP061

Status of the PAL-XFEL Project

undulator, gun, electron, FEL

1735

J.H. Han, H.-S. Kang, I.S. Ko
PAL, Pohang, Kyungbuk, Republic of Korea

Funding: The Ministry of Education, Science and Technology of the Korean Government
PAL-XFEL is designed to generate X-ray radiation in the range of 0.1 and 10 nm for users. The machine consists of a 10 GeV linear accelerator and five undulator beamlines. Electron beams are generated at a low emittance S-band photocathode RF gun and accelerated with an S-band normal conducting linac. Three hard X-ray beamlines will be located at the end of the linac. Electron beams for two soft X-ray beamlines will be switched at a medium energy. The project started in 2011 and the building construction is ongoing. Resent progress of the project and an update of the current progress are presented.

TUPPP062

Start to End Simulation of Three Bunch Compressor Lattice for PAL XFEL

lattice, FEL, emittance, simulation

1738

H.-S. Kang, M.-H. Cho, J.H. Han, T.-H. Kang, I.S. Ko
PAL, Pohang, Kyungbuk, Republic of Korea
C.H. Yi
POSTECH, Pohang, Kyungbuk, Republic of Korea

The PAL XFEL is a 0.1-nm hard X-ray FEL project starting from 2011 to finish in 2014, which aims at achieving higher photon flux than 10¹² photons/pulse at 0.1 nm using a 10 GeV electron linac. The PAL XFEL is designed to have a hard x-ray undulator line at the end of linac and a branch line at 2.65 GeV point for soft X-ray undulator line. The three bunch compressor lattice (3-BC) is chosen to minimize emitance growth due to CSR and minimize correlated energy spread. The 3-BC lattice makes it possible to operate soft X-ray FEL undulator line simultaneously and independently from hard X-ray FEL undulator line.

TUPPP063

Electron-beam Optimization Studies for the FERMI@Elettra Free-electron Laser

electron, emittance, simulation, alignment

1741

E. Ferrari, G. De Ninno
University of Nova Gorica, Nova Gorica, Slovenia
P. Craievich, S. Di Mitri, E. Ferrari, L. Fröhlich, G. Gaio, G. Penco, C. Spezzani, M. Trovò
ELETTRA, Basovizza, Italy

FERMI@Elettra is a single-pass free-electron laser, based on seeded high-gain harmonic generation. Presently, the first phase of the project (covering the spectral range between 100 and 20 nm) is under commissioning. The free-electron laser performance depends on the quality of the electron beam. In the case of the FERMI linear accelerator, the latter is strongly influenced both by the wake-fields present in the accelerating sections and by possible misalignments of the various accelerator components. In order to investigate and compensate these effects, we performed a study based on local trajectory bumps. We demonstrate that this approach significantly improves the electron-beam quality and, eventually, the free-electron laser performance.

TUPPP064

Microbunching Instability Studies in SwissFEL

simulation, laser, booster, FEL

1744

S. Bettoni, B. Beutner
Paul Scherrer Institut, Villigen, Switzerland
V.A. Goryashko
NASU/IRE, Kharkov, Ukraine

Shot noise or an initial intensity modulation in the beam pulse may have a strong effect in the FEL linacs and also severely degrade the machine performances in terms of FEL performances. In this paper we present the simulations done to study this effect in SwissFEL, the future free electron laser under design at Paul Scherrer Institute. In particular we calculated the gain of the microbunching instability in the low and high energy part and we performed start-to-end simulations using as initial distribution something as close as possible to the laser profile measured at the SwissFEL injector test facility. We finally present the preliminary calculations to estimate the effect of the laser heater to mitigate this effect.

TUPPP067

Collimation System Design and Performance for the SwissFEL

collimation, undulator, wakefield, electron

1753

F. Jackson, J.-L. Fernández-Hernando
STFC/DL/ASTeC, Daresbury, Warrington, Cheshire, United Kingdom
D. Angal-Kalinin
Cockcroft Institute, Warrington, Cheshire, United Kingdom
H.-H. Braun, S. Reiche
Paul Scherrer Institut, Villigen, Switzerland

Electron beam collimation in the SwissFEL is required for protection of the undulators against radiation damage and demagnetization. The design for the SwissFEL collimation for the hard X-ray undulator (Aramis) includes transverse collimation in the final accelerating linac sections, plus an energy collimator in a post-linac chicane. The collimation system must provide efficient protection of the undulator for various machine modes providing varied final beam energy to the undulator. The performance of the transverse and energy collimation design is studied in simulations including evaluation of the transverse collimation for various beam energies and the effect of grazing particles on the energy collimator. Collimator wakefields are also considered.

TUPPP068

Comparison of Compression Schemes for CLARA

emittance, FEL, sextupole, cavity

1756

P.H. Williams, J.W. McKenzie
STFC/DL/ASTeC, Daresbury, Warrington, Cheshire, United Kingdom
J.K. Jones, P.H. Williams
Cockcroft Institute, Warrington, Cheshire, United Kingdom

CLARA (Compact Linear Advanced Research Accelerator) at Daresbury Laboratory is proposed to be the UK’s national FEL test facility. The accelerator will be a ~250 MeV electron linac capable of producing short, high brightness electron bunches. The machine comprises a 2.5 cell RF photocathode gun, one 2 m and three 5 m normal conducting S-band (2998MHz) accelerating structures and a variable magnetic compression chicane. CLARA will be used as a test bed for novel FEL configurations. We present a comparison of acceleration and compression schemes for the candidate machine layout.

TUPPP070

Next Generation Light Source R&D and Design Studies at LBNL

FEL, electron, laser, gun

1762

J.N. Corlett, B. Austin, K.M. Baptiste, D.L. Bowring, J.M. Byrd, S. De Santis, P. Denes, R.J. Donahue, L.R. Doolittle, P. Emma, D. Filippetto, G. Huang, T. Koettig, S. Kwiatkowski, D. Li, T.P. Lou, H. Nishimura, H.A. Padmore, C. F. Papadopoulos, G.C. Pappas, G. Penn, M. Placidi, S. Prestemon, D. Prosnitz, J. Qiang, A. Ratti, M.W. Reinsch, D. Robin, F. Sannibale, D. Schlueter, R.W. Schoenlein, J.W. Staples, C. Steier, C. Sun, T. Vecchione, M. Venturini, W. Wan, R.P. Wells, R.B. Wilcox, J.S. Wurtele
LBNL, Berkeley, California, USA

Funding: Work supported by the Director, Office of Science, of the U.S. Department of Energy under Contract No. DE-AC02-05CH11231.
LBNL is developing design concepts for a multi-beamline soft x-ray FEL array powered by a superconducting linear accelerator, operating with a high bunch repetition rate of approximately one MHz. The cw superconducting linear accelerator is supplied by an injector based on a high-brightness, high-repetition-rate photocathode electron gun. Electron bunches are distributed from the linac to the array of independently configurable FEL beamlines with nominal bunch rates up to 100 kHz in each FEL, and with even pulse spacing. Individual FELs may be configured for different modes of operation, and each may produce high peak and average brightness x-rays with a flexible pulse format, and with pulse durations ranging from sub-femtoseconds to hundreds of femtoseconds. In this paper we describe conceptual design studies and optimizations. We describe recent developments in the design and performance parameters, and progress in R&D activities.

TUPPP071

Design Concepts of a Beam Spreader for a Next Generation Free Electron Laser

electron, kicker, FEL, septum

1765

M. Placidi, P. Emma, J.-Y. Jung, G.C. Pappas, D. Robin, C. Sun, W. Wan
LBNL, Berkeley, California, USA

LBNL is developing design concepts for a multi-beamline soft x-ray FEL array powered by a superconducting linear accelerator, operating with a high bunch repetition rate of approximately one MHz. Electron bunches are distributed from the linac to the array (up to 10) independently configurable FEL beamlines with nominal bunch rates up to 100 kHz in each FEL, and with even pulse spacing. This distribution to the different FELs is made by the beam spreader for which the design has to relative compact while not significantly perturbing the quality of the electron beam and subsequent performance of the FELs. We report on our conceptual design for the spreader. The spreader lattice has two distinct parts, namely the beam take-off section and the FEL fan-out distributions section. Each section is achromatic and isochronous. The effect of coherent synchrotron radiation and micro-bunching has been studied when passing through the spreader and simulations show no significant deterioration in the beam quality.

TUPPP073

Machine Parameter Studies for an FEL Facility Using STAFF

FEL, photon, undulator, emittance

1768

M.W. Reinsch, B. Austin, J.N. Corlett, L.R. Doolittle, P. Emma, G. Penn, D. Prosnitz, J. Qiang, A. Sessler, M. Venturini
LBNL, Berkeley, California, USA
J.S. Wurtele
UCB, Berkeley, California, USA

Designing an FEL facility requires balancing multiple science needs, FEL and accelerator physics constraints, and engineering limitations. STAFF (System Trade Analysis for an FEL Facility) is a MATLAB program that enables the user to rapidly explore a large range of Linac and FEL design options to meet science requirements. The code uses analytical models such as the Ming Xie formulas when appropriate and look-up tables when necessary to maintain speed and flexibility. STAFF's modular design simplifies the inclusion of new physics models for FEL harmonics, wake fields, cavity higher-order modes and aspects of linac design such as the optimization of a laser heater, harmonic linearizer, and one or more bunch compressors. Code for the microbunching instability has been included as well. STAFF also supports multiple undulator technologies. STAFF permits the user to study error tolerances and multiple beamlines so as to explore the full capabilities of an entire user facility. This makes it possible to optimize the integrated system in terms of performance metrics such as photons/pulse, photons/sec and tunability range.

TUPPP074

Beam Dynamics Studies of a High-repetition Rate Linac Driver for a 4th-generation Light Source

FEL, emittance, simulation, laser

1771

M. Venturini, J.N. Corlett, P. Emma, C. F. Papadopoulos, G. Penn, M. Placidi, J. Qiang, M.W. Reinsch, F. Sannibale, C. Steier, R.P. Wells
LBNL, Berkeley, California, USA

We present progress toward the design of a super-conducting linac driver of a high repetition rate FEL-based soft x-ray light source. The machine is intended to accept beams generated by the APEX* photocathode gun, operating in the MHz range, and deliver them to an array of SASE and seeded FEL beamlines. After reviewing the beam-dynamics considerations that are informing specific lattice choices we discuss the expected performance of the proposed machine design and its ability to meet the desired FEL specifications. We consider the merit of possible alternate designs (e.g., a one-stage compressor vs. a two-stage compressor) and the trade-offs between competing demands on the beam attributes (e.g., high peak current vs. acceptable energy spread).
* F. Sannibale et al., this conference.

TUPPP079

Design Alternatives for a Free Electron Laser Facility

FEL, undulator, electron, photon

1777

K. Jacobs, J. Bisognano, R.A. Bosch, D. Eisert, M.V. Fisher, M.A. Green, R.G. Keil, K.J. Kleman, J.G. Kulpin, G.C. Rogers, R. Wehlitz
UW-Madison/SRC, Madison, Wisconsin, USA
T. Chiang, T.J. Miller
University of Illinois, Urbana, USA
J.E. Lawler, D. Yavuz
UW-Madison/PD, Madison, Wisconsin, USA
R.A. Legg
JLAB, Newport News, Virginia, USA
R.C. York
FRIB, East Lansing, Michigan, USA

The University of Wisconsin-Madison is continuing design efforts for a vacuum ultraviolet/X-ray Free Electron Laser facility. The design incorporates seeding the FEL to provide fully coherent photon output at energies up to ~1 keV. The focus of the present work is to minimize the cost of the facility while preserving its performance. To achieve this we are exploring variations in the electron beam driver for the FEL, in undulator design, and in the seeding mechanism. Design optimizations and trade-offs between the various technologies and how they affect the FEL scientific program will be presented.

TUPPP087

Commissioning of the Fritz Haber Institute Mid-IR FEL

FEL, wiggler, electron, undulator

1792

A.M.M. Todd, H. Bluem, D. Dowell, R. Lange, J.H. Park, J. Rathke, L.M. Young
AES, Princeton, New Jersey, USA
W. Erlebach, S. Gewinner, H. Junkes, A. Liedke, G. Meijer, W. Schöllkopf, W.Q. Zhang, G. von Helden
FHI, Berlin, Germany
S.C. Gottschalk
STI, Washington, USA
K. Jordan
Kevin Jordan PE, Newport News, Virginia, USA
U. Lehnert, P. Michel, W. Seidel
HZDR, Dresden, Germany
R. Wünsch
FZD, Dresden, Germany

The IR and THz FEL at the Fritz Haber Institute (FHI) in Berlin is designed to deliver radiation from 4 to 400 microns. A single-plane-focusing undulator combined with a 5.4-m-long cavity is used is the mid-IR (< 50 micron), while a two-plane-focusing undulator in combination with a 7.2-m-long cavity with a 1-D waveguide for the optical mode is planned for the far-IR. Beam was delivered to the IR beam dump in November 2011. We describe progress since that time in completing the commissioning of the mid-IR beamline and the status of the far-IR beamline design and fabrication.

TUPPP088

Bunch Compressor Design for Potential FEL Operation at eRHIC

FEL, emittance, electron, simulation

1795

Y.C. Jing, Y. Hao, V. Litvinenko
BNL, Upton, Long Island, New York, USA

Electron-Relativistic Heavy Ion Collider (eRHIC) is an upgrade project for the current operation of RHIC. It will provide a high quality electron beam with energy recovery scheme to collide with ion beams. One may think of taking advantage of using this electron beam for FEL operation. Bunch compressor is a crucial component to compress the beam to high peak current for undulators and CSR effect needs to be taken care of to preserve the beam quality. In this paper, authors present a novel bunch compressor design with CSR suppression scheme for the potential FEL operation at eRHIC.

TUPPP090

Studies of Controlled Laser-induced Microbunching Instability at Source Development Laboratory

laser, electron, radiation, space-charge

1798

S. Seletskiy, B. Podobedov, Y. Shen, X. Yang
BNL, Upton, Long Island, New York, USA

We present the studies of controlled microbunching intentionally induced on the beam by the photocathode laser with modulated longitudinal profile. Varying the depth and frequency of longitudinal modulation of the laser pulse allowed us to observe the development of microbunching instability at BNL Source Development Laboratory (SDL) in the controlled environment. That allowed us to benchmark the model of the microbunching gain for the first time. In addition to that, we demonstrated for the first time a constructive work of a so-called longitudinal space charge amplifier, which in case under consideration can be utilized for enhancement of linac-based sources of THz radiation.

TUPPP092

Renovated Two-stage Bunch Compressor for the International Linear Collider

wiggler, positron, linear-collider, collider

1801

S. Seletskiy
BNL, Upton, Long Island, New York, USA
N. Solyak
Fermilab, Batavia, USA

The International Linear Collider (ILC) utilizes a Bunch Compressor (BC) in the Damping Ring to Main Linac Transfer Line (RTML) that compresses the RMS bunch length from 6 mm to 300 micrometers before sending the beam to the Main Linac. It was decided to utilize a two stage BC for the design baseline, since it provides an additional option for the ILC to work with 150 micrometers long bunches and reduces the energy spread at the RTML exit under normal operational conditions. In this paper we report the new design of the optimized two-stage bunch compressor.

TUPPR004

ILC Conventional Facility in Asian Sites

site, radiation, HLRF, cryogenics

1816

A. Enomoto, M. Miyahara
KEK, Ibaraki, Japan

The international linear collider (ILC) is on a stage of preparing technical design report (TDR). Through value engineering to reduce civil construction costs, the tunnel configuration was changed from double- tunnel scheme to single. The double-tunnel schme accomodates superconducting accelerator modules and their power supplies indipendently. This is a very natural scheme for setting an accelerator and its power supply nearby and for preventing radiation damage of the power supply. However, the single-tunnel scheme was proposed to reduce cost, and to avoid such radiation problem three kinds of high-level (HLRF) RF systems are proposed. We report the comparison of ILC main linac costs and construction schedules between eight cases for combinations of diferent tunnel excavation methods and HLRF systems; then, we report the potential facility design for the Asian sites.

TUPPR005

Linac Upgrade in Intensity and Emittance for SuperKEKB

emittance, positron, electron, alignment

1819

T. Higo, M. Akemoto, D.A. Arakawa, Y. Arakida, A. Enomoto, S. Fukuda, K. Furukawa, Y. Higashi, H. Honma, N. Iida, M. Ikeda, E. Kadokura, K. Kakihara, T. Kamitani, H. Katagiri, M. Kurashina, S. Matsumoto, T. Matsumoto, H. Matsushita, S. Michizono, K. Mikawa, T. Miura, F. Miyahara, T. Mori, H. Nakajima, K. Nakao, T. Natsui, Y. Ogawa, S. Ohsawa, M. Satoh, T. Shidara, A. Shirakawa, H. Sugimoto, T. Suwada, T. Takatomi, T. Takenaka, Y. Yano, K. Yokoyama, M. Yoshida, L. Zang, X. Zhou
KEK, Ibaraki, Japan
D. Satoh
TIT, Tokyo, Japan

The SuperKEKB is designed to produce 40 times luminosity than that of the KEKB. In order to realize such a high luminosity, the injector linac should provide both electron and positron beams of about 4-5 nC/bunch, which is several times higher than before. In addition, their emittance requirement of the injection beam to the rings is 20 microns, which is a factor of a few tens smaller than before. The intensity and emittance of the electron beam are realized directly by developing the photo RF gun. In contrast, the positron intensity is increased by adopting a higher capture efficiency system with flux concentrator followed by large-aperture accelerators, while its emittance is reduced by a damping ring. For preserving such a low emittance of both beams toward the injection to the rings, the suppression of the emittance growth is crucial. To this end, the alignment of the accelerator components should be a few tens of microns, where we need an improvement by more than a factor 10. The beam-based alignment is definitely needed with better-resolution BPMs. In the present paper are reviewed the overall progress and perspective of the design and the associated component developments.

TUPPR012

Polarized Positron Source with a Compton Multiple Interaction Point Line

positron, electron, laser, simulation

1834

I. Chaikovska, O. Dadoun, P. Lepercq, A. Variola
LAL, Orsay, France
R. Chehab
IN2P3 IPNL, Villeurbanne, France

Positron sources are critical components of the future lepton colliders projects. This is essentially due to the high luminosity required, orders of magnitude higher than existing ones. In addition, polarization of the positron beam rather expands the physics research potential of the machine by increasing the precision of the measurements and enhancing certain types of interactions. In this framework, the Compton sources for polarized positron production are taken into account where the high energy gamma rays are produced by the Compton scattering and subsequently converted in the polarized electron-positron pairs in a target. The Compton multiple IP line is proposed as one of the solutions to increase the number of captured positrons. This allows a significant increase in the emitted gamma ray flux impinging on the target. The gamma ray production with the Compton multiple IPs line is simulated and used for polarized positron generation. Later, a capture section based on an adiabatic matching device followed by a pre-injector linac is simulated to capture and accelerate the positron beam. The results obtained are presented and discussed.

TUPPR013

Design Integration and Vision Sharing for the ILC

lattice, linear-collider, collider, damping

1837

B. List, L. Hagge, S. Sühl, N.J. Walker, N. Welle
DESY, Hamburg, Germany

The Global Design Effort for the International Linear Collider is currently preparing the Technical Design Report, which will be released in early 2013. The starting point of a consistent and correct design is the accelerator lattice, which defines the layout of the machine. Integrating the lattice geometrically and optically provides the basis for civil engineering and conventional facilities planning and finally the cost estimate. Tools that provide three-dimensional visualization of the lattice and tunnel help to perform the design integration and allow sharing a common vision of the final accelerator. We will present the process that was established to arrive at such an integrated design and the tools that were developed to support that process by analyzing and visualizing lattice files.

TUPPR024

CLIC Recombination Scheme for the Low Energy Operation Mode

factory, acceleration, luminosity, collider

1864

A. Gerbershagen, D. Schulte
CERN, Geneva, Switzerland
P. Burrows
Oxford University, Physics Department, Oxford, Oxon, United Kingdom

The CLIC recombination scheme is a concept of multiplication of the drive beam frequency in order to generate a 12 GHz RF wave for the main beam acceleration. CLIC is designed to be operated in nominal and in low energy modes. The low energy operation modes require the train length to be increased by different factors in order to maintain the same level of luminosity. Also the number of initial trains that are merged to form each final train is changed. The combination scheme must be able to accommodate and recombine both long and short trains for nominal and low energy CLIC operation modes. The recombination hence becomes a non-trivial process and makes the correction of the errors in the drive beam more challenging. The present paper describes in detail the recombination process and its consequences.

TUPPR026

Conceptual Design of the CLIC Damping Ring RF System

cavity, damping, beam-loading, coupling

1870

A. Grudiev
CERN, Geneva, Switzerland

In order to achieve high luminosity in CLIC, ultra-low emittance bunches have to be generated in both electron and positron damping rings. To achieve this goal, big energy loss per turn in the wigglers has to be compensated by the RF system. This results in very strong beam loading transients affecting the longitudinal bunch position and bunch length. In this paper, conceptual design of the RF system for the CLIC damping ring is presented. Baseline and several alternatives are discussed and the corresponding requirements for the cavities and the RF power sources are presented in order to meet stringent tolerances on the bunch-to-bunch phase and bunch length variations.

TUPPR029

Performance of Linear Collider Beam-Based Alignment Algorithms at FACET

alignment, simulation, emittance, optics

1879

A. Latina, J. Pfingstner, D. Schulte
CERN, Geneva, Switzerland
E. Adli
University of Oslo, Oslo, Norway

The performance of future linear colliders will depend critically on beam-based alignment (BBA) and feedback systems, which will play a crucial role both in the linear and in the non-linear systems of such machines, e.g., the linac and the final-focus. Due to its characteristics, FACET is an ideal test-bench for BBA algorithms and linear collider beam-dynamics in general. We present the results of extensive computer simulations and their experimental verification.

TUPPR030

Thermo-mechanical Analysis of the CLIC Post-Linac Energy Collimators

injection, simulation, collimation, betatron

1882

J. Resta-López
IFIC, Valencia, Spain
J.L. Fernández-Hernando
STFC/DL/ASTeC, Daresbury, Warrington, Cheshire, United Kingdom
A. Latina
CERN, Geneva, Switzerland

Funding: FPA2010-21456-C02-01
The post-linac energy collimation system of the Compact Linear Collider (CLIC) has been designed for passive protection of the Beam Delivery System (BDS) against mis-steered beams due to failure modes in the main linac. In this paper, a thermo-mechanical analysis of the CLIC energy collimators is presented. This study is based on simulations using the codes FLUKA and ANSYS when an entire bunch train hit the collimators. Different failure mode scenarios in the main linac are considered. Moreover, we discuss the results for different collimator materials. The aim is to improve the collimator design in order to make a reliable and robust design so that it survives without damage from the impact of a full bunch train in case of likely events generating energy errors.

TUPPR031

Experimental Verification of the CLIC Decelerator with theTest Beam Line in the CLIC Test Facility 3

extraction, quadrupole, alignment, lattice

1885

R.L. Lillestøl, S. Döbert, M. Olvegård, A. Rabiller, G. Sterbini
CERN, Geneva, Switzerland
E. Adli
University of Oslo, Oslo, Norway

The Test Beam Line in the CLIC Test Facility 3 is the first prototype of the CLIC drive beam decelerator. The main purpose of the experiment is to demonstrate efficient 12 GHz rf power production and stable transport of an electron drive beam during deceleration. The Test Beam Line consists of a FODO structure with high precision BPMs and quadrupoles mounted on mechanical movers for precise beam alignment. Nine out of the planned 16 Power Extraction and Transfer Structures have currently been installed and commissioned. We correlate rf power production measurements with the drive beam deceleration measurements, and compare the two measurements to the theoretical predictions. We also discuss the impact of the drive beam bunch length and bunch combination on the measurements.

TUPPR032

Beam Stability at CTF3

feedback, klystron, pick-up, cavity

1888

T. Persson, P.K. Skowroński
CERN, Geneva, Switzerland

The two beam acceleration tested in CTF3 imposes very tight tolerances on the drive beam stability. A description of the specialized monitoring tool developed to identify the drifts and jitter in the machine is presented. It compares all the relevant signals in an on-line manner for helping the operator to identify drifts or to log data for off-line analysis. The main sources for the drifts of the drive beam were identified and their causes are described. Feedbacks applied to the RF were implemented to reduce the effects. It works by changing the waveform for the pulse compression to compensate for the drifts.

TUPPR033

Improved Modelling of the Thermo-mechanical Behavior of the CLIC Two-Beam Module

vacuum, RF-structure, alignment, simulation

1891

G. Riddone, T.O. Niinikoski, F. Rossi
CERN, Geneva, Switzerland
R.J. Raatikainen, K. Österberg
HIP, University of Helsinki, Finland
A. Samoshkin
JINR, Dubna, Moscow Region, Russia

The luminosity goal of the CLIC collider, currently under study, imposes micrometer mechanical stability of the 2-m-long two-beam modules, the shortest repetitive elements of the main linacs. These modules will be exposed to variable high power dissipation during operation resulting in mechanical distortions in and between module components. The stability of the CLIC module is being tested in laboratory conditions at CERN in a full-scale prototype module. In this paper, the revised finite element model developed for the CLIC two-beam module is described. In the current model, the structural behavior of the module is studied in more detail compared to the earlier configurations, in particular for what regards the contact modeling. The thermal and structural results for the module are presented considering the thermo-mechanical behavior of the CLIC collider in its primary operation modes. These results will be compared to the laboratory measurements to be done in 2012 with the full-scale prototype module. The experimental results will allow for better understanding of the module behavior and they will be propagated back to the present thermo-mechanical model.

TUPPR039

Beam Dynamics Studies for the CLIC Main Linac

wakefield, damping, emittance, simulation

1903

I. Nesmiyan, R.M. Jones
UMAN, Manchester, United Kingdom
A. Latina, D. Schulte
CERN, Geneva, Switzerland

Implications of the long-range wakefield on beam quality are investigated through a detailed beam dynamics study. Injection offsets are considered and the resulting emittance dilution recorded, including systematic and random sources of error. These simulations have been conducted for damped and detuned structures (DDS) and for waveguide damped structures–both for the CLIC collider.

TUPPR041

Update on ILC Positron Source Start-to-End Simulation

positron, electron, undulator, lattice

1909

W. Liu, W. Gai
ANL, Argonne, USA

As a result of the changes in the new ILC base line, there are many changes in the positron source beamline layouts and thus a new lattice design is required. According to the changes in the ILC baseline, a new lattice design for the ILC positron source has been developed at ANL. In this paper, both the new ILC positron source beamline lattice and the corresponding start to end simulation results are presented.

TUPPR043

New Baseline Design of the ILC RTML System

positron, electron, optics, damping

1915

N. Solyak, V.V. Kapin, A. Vivoli
Fermilab, Batavia, USA
S. Seletskiy
BNL, Upton, Long Island, New York, USA

The new ILC baseline was proposed in 2009 (Strawman baseline - SB2009) to minimize cost of the machine and accommodate many changes made in the design of the accelerator systems. The biggest changes are made in the central area, where BDS, RTML, DR, electron and positron sources are sharing the tunnels. A new layout of the compact DR and re-location of the electron and positron sources to the main tunnel requires a new lattice design for all beamlines in this area. The lattice design was coordinated between accelerator systems and Convention Facility and Siting (CFS) group to eliminate conflicts between beamlines and satisfy construction requirements. In this paper we present a new design of the RTML electron and positron lattices in the central area and other modifications made in the RTML line to accommodate changes to the beamline layouts.

TUPPR048

Short RF Pulse Linear Collider

collider, linear-collider, klystron, wakefield

1924

C.-J. Jing, S.P. Antipov, A. Kanareykin, P. Schoessow
Euclid TechLabs, LLC, Solon, Ohio, USA
M.E. Conde, W. Gai, J.G. Power
ANL, Argonne, USA

Funding: DOE SBIR program under Contractor #DE-SC0004320
In general, a high gradient is desirable for future linear collider designs because it can reduce the total linac length. More importantly, the efficiency and the cost to sustain the high gradient should also be considered in the optimization process of an overall design. In this article, we explore a parametric territory of short rf pulse, high group velocity, high frequency, and high gradient, etc., that may lead to an affordable high energy linear collider in the future.

TUPPR050

Design and simulation of Prebuncher for S-band Traveling Linear Accelerator

cavity, coupling, simulation, electron

1930

S. Zarei, F. AbbasiDavani, S. Ahmadiannamini, F. Ghasemi
sbu, Tehran, Iran
H. Shaker
IPM, Tehran, Iran

An S-band Traveling wave linear accelerator with an RF input peak power level up to 2.5 MW, for accelerating 1 mA beam of electron up to 15 MeV, is under construction in Iran. This article presents design procedure of a prebuncher for this accelerator. One standing-cavity type prebuncher is required for bunching electron beam for this accelerator. The intended prebuncher is driven by a coaxial line at 2 kW and operated at the same frequency of the other parts of the accelerator. The magnetic coupling applied has been applied for power coupling to the prebuncher cavity. The optimum dimensions of the prebuncher were obtained by using 2D and 3D electromagnetic codes in the frequency domain. Prebuncher cavity consists of a copper body and coupling loop feed.

TUPPR053

Conceptual Design of the Linac4 Main Dump

simulation, proton, radiation, booster

1939

I.V. Leitao, C. Maglioni, A. Sarrió Martínez
CERN, Geneva, Switzerland

Linac4 is the new CERN linear accelerator intended to replace the aging Linac2 as the injector to the Proton Synchrotron Booster (PSB) for increasing the luminosity of the Large Hadrons Collider (LHC). By delivering a 160MeV H⁻ beam, Linac4 will provide the necessary conditions to double the brightness and intensity of the beam extracted from the PSB. This paper describes the conceptual design of the Linac4 Main Dump, where two different concepts relying respectively on water and air cooling were compared and evaluated. Based on the application of analytical models for the energy deposited by the beam, heat conduction and cooling concepts, a parametric study was performed. This approach allowed the identification of the “optimal” configuration for these two conceptual geometries and their relative comparison. Besides giving the theoretical guidelines for the design of the new dump, this work also contributes to the development of analytical tools to allow a better understanding of the influence of the several design parameters in this type of low-energy beam intercepting devices.

TUPPR054

Internal H⁰/H⁻ Dump for the Proton Synchrotron Booster Injection at CERN

vacuum, booster, radiation, injection

1942

M. Delonca, C. Maglioni, A.A. Patapenka, A. Sarrió Martínez
CERN, Geneva, Switzerland

In the frame of the LHC Injectors Upgrade Project at CERN (LIU), the new 160MeV H⁻ Linac4 will inject into the four existing PS Booster rings after the conversion of H⁻ into H⁺ in a stripping foil. Given a limited stripping efficiency and possible foil failures, a certain percentage of the beam is foreseen to remain partially (H⁰) or completely (H⁻) unstripped. An internal dump installed into the chicane magnet to stop these unstripped beams is therefore required. This paper presents the conceptual design of the internal dump, reviewing loading assumptions, design constraints, limitations and integration studies. Power evacuation through the thermal contact between the core and the external active cooling is addressed and, finally, results from the numerical thermo-mechanical analyses are reported.

TUPPR072

Status of ESTB: A Novel Beam Test Facility at SLAC

kicker, electron, wakefield, emittance

1990

M.T.F. Pivi, M.P. Dunning, H. Fieguth, C. Hast, R.H. Iverson, J. Jaros, R.K. Jobe, L. Keller, T.V.M. Maruyama, D.R. Walz, M. Woods
SLAC, Menlo Park, California, USA

Funding: Work supported by the U.S. Department of Energy under contract DE-AC02-76SF00515
End Station A Test Beam (ESTB) is a test beam line at SLAC in the large End Station A (ESA) experimental hall. It uses a fraction of the bunches of the 14.7 GeV electron beam from the Linac Coherent Light Source (LCLS). ESTB provides a unique test beam for particle and particle astrophysics detector research, accelerator instrumentation and accelerator R&D, development of radiation-hard detectors, and material damage studies. It has exceptionally clean and well-defined secondary electron beams, a huge experimental area and good existing conventional facilities. Recently, a new kicker magnet has been installed to divert 5 Hz of the LCLS low energy beam into the A-line. The full installation will include 4 kicker magnets to allow diversion of high energy beams. A new beam dump and a new Personnel Protection System (PPS) have been built in ESA. In stage II, a secondary hadron target will be able to produce pions up to about 12 GeV/c at 1 particle/pulse. This paper reports the progress on ESTB construction and commissioning.

TUPPR073

MESA - Sketch of an Energy Recovery Linac for Nuclear Physics Experiments at Mainz

1993

R.G. Heine, K. Aulenbacher
IKP, Mainz, Germany
R. Eichhorn
TU Darmstadt, Darmstadt, Germany

We present the concept of a small superconducting CW accelerator with multi-turn energy recovery. This machine, the Mainz energy recovering superconducting accelerator (MESA), is intended to serve for particle physics experiments in the energy range 100-200MeV.

TUPPR075

Challenges for the Magnet System of LHeC

electron, quadrupole, proton, dipole

1996

S. Russenschuck, B.J. Holzer, G. Kirby, A. Milanese, R. Tomás, D. Tommasini, F. Zimmermann
CERN, Geneva, Switzerland

The main challenges for the normal conducting magnet system are the very compact, low field, and high precision magnets for the ring-ring option and their rapid installation in the crowded LHC tunnel. The superconducting triplet magnets require strong gradients for the protons in close vicinity of a field-free region for the electrons. The field requirements for the ring-ring option allow a number of different magnet designs using the well-proven Nb-Ti superconductor technology and making use of the cable development for the LHC. The separation distance between the electron and proton beams in Q1 requires a half-aperture quadrupole design to limit the overall synchrotron radiation power emitted by the bending of the electron beam. The requirements in terms of aperture and field gradient are more difficult to obtain for the Linac-Ring option. Consequently we present the limitations for the field gradient and septum size achievable with both Nb-Ti and Nb3Sn superconducting technologies.

TUPPR076

The LHeC Project Development Beyond 2012

electron, collider, cavity, dipole

1999

F. Zimmermann, O.S. Brüning
CERN, Geneva, Switzerland
M. Klein
The University of Liverpool, Liverpool, United Kingdom

The LHeC study group is finalizing a Conceptual Design Report for publication early in 2012. This paper discusses the next steps required for developing a Technical Design Report and highlights the R&D developments, test facilities and implementation studies that need to be addressed over the coming years. Particular emphasize will be given to similarities with other ongoing accelerator and detector studies, and to a discussion of possible international collaboration efforts.

TUPPR088

Baseline Design of the SuperB Factory Injection System

positron, electron, injection, emittance

2032

S. Guiducci, A. Bacci, M.E. Biagini, R. Boni, M. Boscolo, D. Pellegrini, M.A. Preger, P. Raimondi, A.R. Rossi, M. Zobov
INFN/LNF, Frascati (Roma), Italy
M.A. Baylac
LPSC, Grenoble, France
J. Brossard, S. Cavalier, O. Dadoun, T. Demma, P. Lepercq, E. Ngo Mandag, C. Rimbault, A. Variola
LAL, Orsay, France
J.T. Seeman
SLAC, Menlo Park, California, USA
D.N. Shatilov
BINP SB RAS, Novosibirsk, Russia

The injection complex of the SuperB, B-factory project of INFN consists of a polarized electron gun, a positron production system, electron and positron linac sections, a positron damping ring and the transfer lines connecting these systems and the collider main rings. To keep the ultra high luminosity nearly constant, continuous injection of 4 GeV electrons and 7 GeV positrons in both Low Energy Ring (LER) and High Energy Ring (HER) is necessary. In this paper we describe the baseline design and the beam dynamics studies performed to evaluate the system performance.

WEXA01

The High Intensity Horizon at Fermilab

proton, collider, kaon, superconducting-RF

2065

R.S. Tschirhart
Fermilab, Batavia, USA

Fermilab’s high intensity horizon is “Project-X” which is a US led initiative with strong international participation that aims to realize a next generation proton source that will dramatically extend the reach of Intensity Frontier research. The Project-X research program includes world leading sensitivity in long-baseline and short-baseline neutrino experiments, a rich program of ultra-rare muon and kaon decays, opportunities for next-generation electric dipole moment experiments and other nuclear/particle physics probes, and a platform to investigate technologies for next generation energy applications. A wide range of R&D activities has been started to support mission critical accelerator subsystems, such as high-gradient superconducting RF accelerating structures, efficient RF power systems, cryo-modules and cryogenic refrigeration plants, advanced beam diagnostics and instrumentation, high-power targetry, as well as the related infrastructure and civil construction preparing for a construction start as early as 2017. The status and prospects of developing the accelerator design, research program, and associated collaborations will be presented.
* The Project X program spans several Sub Classifications: A08, A14 A17, A21, A28.

Slides WEXA01 [9.216 MB]

WEXA03

Accelerator Physics and Technology for ESS

klystron, target, DTL, cryomodule

2073

H. Danared
ESS, Lund, Sweden

A conceptual design of the 2.5 GeV proton linac of the European Spallation Source, ESS, was presented in a Conceptual Design Report in early 2012. Work is now progressing towards a Technical Design Report at the end of 2012. Changes to the linac configuration during the last year include a somewhat longer DTL and a change to fully segmented cryomodules. This paper reviews the current design status of the accelerator and its subsystems.

Slides WEXA03 [15.485 MB]

WEYA01

CLIC Status and Outlook

luminosity, target, emittance, alignment

2076

S. Stapnes
CERN, Geneva, Switzerland

The Compact Linear Collider study (CLIC) is in the process of completing a Conceptual Design Report for a multi-TeV linear electron-positron collider. The CLIC-concept is based on high gradient normal-conducting accelerating structures. The RF power for the acceleration of the colliding beams is produced by a novel two beam acceleration scheme, where power is extracted from a high current drive beam that runs parallel with the main linac. In order to establish the feasibility of this concept a number of key issues have been addressed. A short summary of the progress and status of the corresponding studies will be given, as well as an outline of the preparation and work towards an implementation plan by 2016.

Slides WEYA01 [11.960 MB]

WEYB03

High Average Power UV Free Electron Laser Experiments at JLAB

FEL, wiggler, cavity, electron

2111

D. Douglas, S.V. Benson, P. Evtushenko, J.G. Gubeli, C. Hernandez-Garcia, R.A. Legg, G. Neil, T. Powers, M.D. Shinn, C. Tennant, G.P. Williams
JLAB, Newport News, Virginia, USA

Funding: Authored by JSA LLC under US DOE Contract #DE-AC05-06OR23177. The U.S. Gov. retains non-exclusive, paid-up, irrevocable, world-wide license to publish/reproduce this manuscript for U.S. Gov. purposes.
Having produced 14 kW of average power at ~2 microns, JLAB has shifted its focus to the ultraviolet portion of the spectrum. This presentation will describe the JLab UV Demo FEL, present specifics of its driver ERL, and discuss the latest experimental results from FEL experiments and machine operations.

Slides WEYB03 [2.863 MB]

WEOBB02

Refraction Contrast Imaging via Laser-Compton X-Ray Using Optical Storage Cavity

laser, electron, cavity, photon

2146

K. Sakaue, T. Aoki, M. Washio
RISE, Tokyo, Japan
M.K. Fukuda, Y. Honda, N. Terunuma, J. Urakawa
KEK, Ibaraki, Japan

We have been developing a pulsed-laser storage technique in a super-cavity for a compact x-ray sources. The pulsed-laser super-cavity enables to make high peak power and small waist laser at the collision point with the electron beam. Recently, using 357 MHz mode-locked Nd:VAN laser pulses which stacked in a super-cavity scattered off a multi-bunch electron beam, we obtained a multi-pulse x-rays through the laser-Compton scattering. Then, we performed a X-ray imaging via laser-Compton X-ray. The images have edge enhancement by refraction contrast because the X-ray source spot size was small enough. This is one of the evidences that laser-Compton X-ray is high quality. Our laser-Compton experimental setup, the results of X-ray imaging and future prospective will be presented at the conference.

Slides WEOBB02 [4.393 MB]

WEPPC003

Component Qualification and Final Assembly of the S-DALINAC Injector Upgrade Module

cavity, SRF, niobium, shielding

2206

J. Conrad, R. Eichhorn, T. Kürzeder, A. Richter, S.T. Sievers
TU Darmstadt, Darmstadt, Germany

Funding: This work is supported by the DFG through SFB 634.
The injector of the S-DALINAC delivers currently electron beams of up to 10 MeV with a current of up to 60 μA. With the new cryostat-module an increase of both parameters, energies ranging to 14 MeV and currents up to 150 μA, are expected. For acceleration, the module houses two 20 cell elliptical niobium cavities which are used at a frequency of 3 GHz in liquid helium at 2 K. The RF power is delivered to the cavities through the different temperature stages by a WR-284 transition line which is connected to the resonator by a new waveguide-to-coax power coupler (being one of the major changes compared to the design of the existing module). We review on the design of the module and present the results of the first cool-down. Also, a report on additional new design features, e.g. piezo actuators for tuning at 2 K, and the production of the cavities will be given.

WEPPC009

Status of the European XFEL 3.9 GHz system

cavity, status, diagnostics, HOM

2224

P. Pierini, A. Bosotti, P. Michelato, L. Monaco, R. Paparella, D. Sertore
INFN/LASA, Segrate (MI), Italy
E.R. Harms
Fermilab, Batavia, USA
C. Pagani
UniversitÃ degli Studi di Milano & INFN, Segrate, Italy
E. Vogel
DESY, Hamburg, Germany

The injector of the European XFEL will use a third harmonic RF system at 3.9 GHz to flatten the RF curvature after the first accelerating module before the first bunch compression stage. This paper presents qualification tests of the prototype cavities and the status of the activities for the realization of the third harmonic section of the European XFEL towards its commissioning due in 2014.

WEPPC011

Vertical Test Results for ERL 9-cell Cavities for Compact ERL Project

cavity, cryomodule, radiation, HOM

2227

K. Umemori, T. Furuya, H. Sakai, M. Satoh, K. Shinoe
KEK, Ibaraki, Japan
E. Cenni
Sokendai, Ibaraki, Japan
M. Sawamura
JAEA, Ibaraki-ken, Japan

The Compact ERL project, which is a test facility of ERL, is ongoing in Japan. At the first step of this project, main linac cavities accelerate electron beams by 30 MV. Two 9-cell cavities were fabricated for main linac cryomodule, under High Pressure Gas Safety Code in Japan. A series of surface treatments, such as annealing, pre-tuning, electro-polishing (EP), degreasing, high pressure rinsing by ultra-pure water, cavity assembly and baking, were applied for the cavities. For the final EP, current density was selected to be relatively low. Vertical tests were performed for both cavities. Their field successfully reached to 25 MV/m, without any field limitation. The Q-values were more than 1x10¹⁰, even at 20 MV/m. Field emission on-sets were to be 14 and 22 MV/m, for each cavities. Both cavities satisfied requirements for ERL main linac cavity. Details of vertical tests, with X-ray and temperature mapping data, are shown, in this paper. These cavities will be mounted with titanium He jackets, assembled and installed into a cryomodule.

WEPPC012

High Power Tests of CW Input Couplers for cERL Injector Cryomodule

cryomodule, cavity, vacuum, impedance

2230

E. Kako, S. Noguchi, T. Shishido, K. Watanabe, Y. Yamamoto
KEK, Ibaraki, Japan

High power tests of a pair of the prototype input couplers were performed by using a newly developed 300 kW CW klystron. The input couplers were successfully processed up to 100 kW in a pulsed operation with a duty of 10% and 50 kW in a CW operation for 30 minutes. The conditioning was limited by excessive heating at bellows of an inner conductor at a coaxial line locating between a coaxial RF window and a doorknob-type transition. Improvement of a sufficient cooling at the inner conductor is necessary to achieve the required input RF power of 170 kW in a CW operation. Six input couplers to be installed in the injector cryomodule for the cERL project were completed, and they are under preparation for conditioning at a high power test stand.

WEPPC015

Construction of Injector Cryomodule for cERL at KEK

cryomodule, HOM, cavity, pick-up

2239

E. Kako, S. Noguchi, T. Shishido, K. Watanabe, Y. Yamamoto
KEK, Ibaraki, Japan

The cERL injector cryomodule includes three 2-cell cavities, and each cavity has 2 input couplers and 5 HOM couplers. Three 2-cell cavities for cERL has already completed. Vertical test of the three cavities has been going on. The first cavity have achieved Eacc of 30 MV/m. Vertical tests will be carried out twice in each cavity, till the end of December, 2011. Six cw input couplers for cERL has already completed. RF processing at the high-power test stand with a cw 300kW-klystron will be carried out in Jan.-Feb., 2012. After the cavities were covered with a He jacket, assembly of the cERL injector cryomodule will be carried out in March-April, 2012. The first cool-down of the cryomodule is scheduled in June 2012.

WEPPC022

Elliptical SRF Cavity Design for PEFP Extension

cavity, SRF, coupling, proton

2251

H.S. Kim, Y.-S. Cho, J.-H. Jang, H.-J. Kwon
KAERI, Daejon, Republic of Korea

Funding: * This work is supported by the Ministry of Education, Science and Technology of the Korean Government.
To increase the beam energy up to 1 GeV by extending a PEFP 100-MeV proton linac, a study on the superconducting RF linac is underway. SRF technology is chosen due to its operational flexibility and lower beam loss, as well as its high accelerating performance and low operating cost. Preliminary study on the beam dynamics shows that two types of cavity with geometrical beta of 0.50 and 0.74 can cover the entire energy range from 100 MeV to 1 GeV. Assuming the achievable peak surface electric field to be 30 MV/m and 35 MV/m for medium and high beta cavity, respectively, we designed the six-cell elliptical cavities by optimizing the cavity parameters such as peak field ratio, inter-cell coupling and r/Q through the geometrical parameter sweep. The details of the SRF cavity design for PEFP extension will be presented.

WEPPC030

Second Sound Measurement Using SMD Resistors to Simulate Quench Locations on the 704 MHz Single-cell Cavity at CERN

cavity, simulation, cryogenics, quadrupole

2269

K.C. Liao, O. Brunner, E. Ciapala, T. Junginger, W. Weingarten
CERN, Geneva, Switzerland

Oscillating superleak transducers (OSTs) containing a flexible porous membrane are widely used to detect the so-called second sound temperature wave when a quench event occurs in a superconducting RF cavity. In principle, from the measured speed of this wave and the travel time between the quench event and several OSTs, the location of the quench sites can be derived by triangulation. Second sound behavior has been simulated though different surface mount (SMD) resistors setups on a Superconducting Proton Linac (SPL) test cavity, to help understand the underlying physics and improve quench localisation. Experiments are described that have been conducted to search for explanation of heat transfer mechanism during cavity quench that causes contradictory triangulation results.

Poster WEPPC030 [1.473 MB]

WEPPC035

Design and Construction of a High-Power RF Coupler for PXIE

cryomodule, vacuum, cavity, simulation

2284

M.P. Kelly, Z.A. Conway, M. Kedzie, S.V. Kutsaev, P.N. Ostroumov
ANL, Argonne, USA
S. Nagaitsev
Fermilab, Batavia, USA

A power coupler has been designed and built at Argonne National Laboratory for use with the Project X Injector Experiment (PXIE) 162.5 MHz superconducting (SC) half-wave cavities. The 50 Ω coaxial capacitive coupler will be required to operate CW with up to 10 kW of forward power under any condition for the reflected power. A key feature is a moveable copper plated stainless steel bellows which will permit up to 3 cm of axial stroke and adjustment of Qext by roughly one order of magnitude in the range of 10^-5 to 10^-6. The mechanical and vacuum design will include two ceramic windows, one operating at room temperature and another at 70 Kelvin. The two window design allows the portion of the coupler assembled to the SC cavity in the clean room to be compact and readily cleanable. We present other design features including thermal intercepts to provide a large margin for RF heating and a mechanical guide assembly to operate cold and under vacuum with high reliability.

WEPPC036

Electromagnetic Design of 15 kW CW RF Input Coupler

simulation, cavity, cryomodule, vacuum

2286

S.V. Kutsaev, M.P. Kelly, P.N. Ostroumov
ANL, Argonne, USA

Funding: This work was supported by the U.S. Department of Energy, Office of Nuclear Physics, under Contract No. DE-AC02-06CH11357.
A new power coupler is under development at Argonne National Laboratory for a cw 40 MeV proton/deuteron linac for the SARAF project in Israel. This linac requires one 15 kW RF input power per superconducting cavity. Two different cavity options are still under consideration: 10⁹ MHz quarter-waves and 176 MHz half-waves. A coaxial capacitive input coupler has been designed and analyzed for these purposes. This paper presents the results of 3D electromagnetic simulations of this coupler together with the cavities mentioned above. An analysis of multipacting in the couplers is also presented.

WEPPC037

A Ring-shaped Center Conductor Geometry for a Half-wave Resonator

quadrupole, impedance, cavity, ion

2289

B. Mustapha, Z.A. Conway, P.N. Ostroumov
ANL, Argonne, USA

Funding: This work was supported by the U.S. Department of Energy, Office of Nuclear Physics, under Contract DE-AC02-06CH11357.
Half-wave resonators (HWR) are used and being proposed for the acceleration of high-intensity proton and heavy-ion beams in the 0.1 < β < 0.5 velocity range. The highest performing half-wave resonator geometries use a center conductor with a race-track shaped cross section in the high-electric field region; a feature shared with spoke cavities which are also being proposed for the same velocity regime. We here propose a ring-shaped center conductor instead of the race-track shape. Preliminary studies show that the ring geometry has a similar peak surface electric field as the race-track one, but has several other advantages. In particular, the ring-shaped geometry has: a lower peak surface magnetic field, a much higher Shunt impedance for the same peak fields, and no quadrupole electric field asymmetry which has been observed in the race-track geometry. In a solenoid-based symmetric focusing, the quadrupole component may lead to unnecessary emittance growth which is not acceptable in high-intensity ion linacs. We will present a detailed comparison and a discussion of the two geometries.

WEPPC039

Development of a Half-Wave Resonator for Project X

cavity, SRF, cryomodule, ion

2295

P.N. Ostroumov, Z.A. Conway, R.L. Fischer, S.M. Gerbick, M. Kedzie, M.P. Kelly, B. Mustapha
ANL, Argonne, USA
I.V. Gonin, S. Nagaitsev
Fermilab, Batavia, USA

Funding: This work was supported by the U.S. Department of Energy, Office of High Energy Physics and Nuclear Physics, under Contract DE-AC02-76CH03000 and DE-AC02-06CH11357.
We have developed an optimized electromagnetic and mechanical design of a 162.5 MHz half-wave resonator (HWR) suitable for acceleration of high-intensity proton or H-minus beams in the energy range from 2 MeV to 10 MeV. The cavity design is based on recent advances in SRF technology for TEM-class structures being developed at ANL. Highly optimized EM parameters were achieved by adjusting the shapes of both inner and outer conductors. This new design will be processed with a new HWR horizontal electropolishing system after all mechanical work on the cavity including the welding of the helium jacket is complete. The prototype HWR is being fabricated by domestic vendors under ANL’s supervision.

WEPPC043

Transverse Kick Analysis of SSR1 Due to Possible Geometrical Variations in Fabrication

cavity, simulation, alignment, solenoid

2306

M.H. Awida, P. Berrutti, I.V. Gonin, T.N. Khabiboulline, V.P. Yakovlev
Fermilab, Batavia, USA

Funding: Operated by Fermi Research Alliance, LLC, under Contract DE-AC02-07CH11359 with the U.S. DOE
Due to fabrication tolerance, it is expected that some geometrical variations could happen to the SSR1 cavities of Project X, like small shifts in the transverse direction of the beam pipe or the spoke. It is necessary to evaluate the resultant transverse kick due to these geometrical variations, in order to make sure that they are within the limits of the correctors in the solenoids. In this paper, we report the transverse kick values for various fabrications errors and the sensitivity of the beam to these errors.

WEPPC044

Multipole Effects Study for Project X Front End Cavities

cavity, multipole, quadrupole, focusing

2309

P. Berrutti, M.H. Awida, I.V. Gonin, J.-F. Ostiguy, N. Solyak, V.P. Yakovlev
Fermilab, Batavia, USA

Effects of RF field asymmetry along with multipoles have been studied in Project X front end cavities. One family of half wave resonators operating at 162.5 and two of spoke resonators operating at 325 MHz have been analysed. HWR and spoke resonators unlike elliptical cavities, do not have axial symmetry, hence a quadrupole perturbation to the beam is present. The purpose of this paper is to explain the approach and the calculation method used to understand and overcome the drawbacks due to the RF field asymmetry.

WEPPC045

Optimization of the Geometric Beta for the SSR2 Cavities of the Project X

cavity, cryomodule, factory, proton

2312

P. Berrutti, M.H. Awida, I.V. Gonin, N. Solyak, A. Vostrikov, V.P. Yakovlev
Fermilab, Batavia, USA

Project X based on the 3 GeV CW superconducting Linac and is currently in the R&D phase. The cw SC Linac starts from a low-energy SCRF section (2.1 - 165 MeV) containing three different types of resonators. HWR f=162.5 MHz (2.1 - 11 MeV) having β= 0.11, SSR1 f= 325 MHz (11 - 35 MeV) having β = 0.21. In this paper we present the analysis that lead to the final design of SSR2 f=325 MHz cavity (35 - 165 MeV). We present the results of optimization of the geometric beta and the comparison between single, double and triple spoke resonators used in Project X frontend.

WEPPC046

Overview of Project X Superconducting RF Cavities and Cryomodules

cavity, cryomodule, SRF, focusing

2315

T.N. Khabiboulline, M.S. Champion, C.M. Ginsburg, V.P. Yakovlev
Fermilab, Batavia, USA

The Project X Linac is based primarily on superconducting RF technology starting from a low beam energy of approximately 2.5 MeV up to the exit energy of 8 GeV. The Linac consists of 162.5 MHz half-wave cavities, 325 MHz single-spoke cavities, and two families of 650 MHz elliptical cavities - all operating in continuous-wave mode - up to a beam energy of 3 GeV. The beam is further accelerated up to 8 GeV in a pulsed mode ILC-like Linac utilizing 1.3 GHz cavities. In this paper we will give an overview of the design and status of the Project X superconducting RF cavities and cryomodules.

WEPPC047

Effects of the RF Field Asymmetry in SC Cavities of the Project X

cavity, multipole, acceleration, focusing

2318

I.V. Gonin, M.H. Awida, P. Berrutti, A. Saini, B.G. Shteynas, N. Solyak, V.P. Yakovlev
Fermilab, Batavia, USA
P.N. Ostroumov
ANL, Argonne, USA

The low-energy SCRF section of CW SC linac of Project X starts from Half Wave Resonators (HWR) having operating frequency f=162.5 MHz, optimal β= 0.11 and will accelerate the beam from 2 MeV up to 11 MeV. The preliminary analysis of beam dynamics shows that multipole effects caused by asymmetry of RF fields in HWR cavities aren’t negligible. In this paper we present the analysis of influence of multipole effects on beam dynamics and discuss the possible solutions how to compensate these effects.

WEPPC050

Main Couplers for Project X

vacuum, cavity, radiation, cryomodule

2324

S. Kazakov, M.S. Champion, S. Cheban, T.N. Khabiboulline, M. Kramp, Y. Orlov, V. Poloubotko, O. Pronitchev, V.P. Yakovlev
Fermilab, Batavia, USA

Design of 325MHz and 650MHz multi-kilowatt CW main couplers for superconducting linac of Project X is described. Results of electrodynamics, thermal and mechanical simulations is presented.

WEPPC052

High Gradient Tests of the Fermilab SSR1 Cavity

cavity, multipactoring, vacuum, SRF

2330

T.N. Khabiboulline, C.M. Ginsburg, I.V. Gonin, R.L. Madrak, O.S. Melnychuk, J.P. Ozelis, Y.M. Pischalnikov, L. Ristori, A.M. Rowe, D.A. Sergatskov, A.I. Sukhanov, I. Terechkine, R.L. Wagner, R.C. Webber, V.P. Yakovlev
Fermilab, Batavia, USA

In Fermilab we are build and tested several superconducting Single Spoke Resonators (SSR1, β=0.22) which can be used for acceleration of low beta ions. Fist two cavities performed very well during cold test in Vertical Test Station at FNAL. One dressed cavity was also tested successfully in Horizontal Test Station. Currently we are building 8 cavity cryomodule for PIXIE project. Additional 10 cavities were manufactured in the industry and ongoing cold test results will be presented in this poster.

WEPPC054

Resonance Excitation of Longitudinal High Order Modes in Project X Linac

HOM, collider, factory, kaon

2336

A.I. Sukhanov, M.H. Awida, I.V. Gonin, T.N. Khabiboulline, A. Lunin, N. Solyak, V.P. Yakovlev
Fermilab, Batavia, USA

Results of simulation of power loss due to excitation of longitudinal high order modes (HOMs) in the accelerating superconducting RF system of CW linac of Project X are presented. Beam structures corresponding to the various modes of Project X operation are considered: CW regime for 3 GeV physics program; pulsed mode for neutrino experiments; and pulsed regime, when Project X linac operates as a driver for Neutrino Factory/Muon Collider. Power loss and associated heat load due to resonance excitation of longitudinal HOMs are shown to be small in all modes of operation. Conclusion is made that HOM couplers can be removed from the design of superconducting RF cavities of Project X linac.

WEPPC056

Pressure Sensitivity Characterization of Superconducting Spoke Cavities

cavity, simulation, resonance, electromagnetic-fields

2339

D. Passarelli, M.H. Awida, I.V. Gonin, L. Ristori, V.P. Yakovlev
Fermilab, Batavia, USA

The following proposal illustrates a method to characterize the pressure sensitivity behavior of superconducting spoke cavities. This methodology relies on evaluating the variation of resonant frequency of a cavity by observing only the displacements at designed regions of the cavity. The proposed method permits a reduced computational burden and a systematic approach to achieve a minimum value of pressure sensitivity in a complex system of dressed cavity. This method has been used to characterize the superconducting spoke cavities typs⁻¹ (SSR1), under development for Project X, and to design the helium containment vessel in such way to reduce the pressure sensitivity value to zero.

WEPPC059

A Two-stage Injection-locked Magnetron for Accelerators with Superconducting Cavities

injection, simulation, cavity, controls

2348

G.M. Kazakevich, G. Flanagan, R.P. Johnson, F. Marhauser, M.L. Neubauer
Muons, Inc, Batavia, USA
B. Chase, S. Nagaitsev, R.J. Pasquinelli, N. Solyak, V. Tupikov, D. Wolff, V.P. Yakovlev
Fermilab, Batavia, USA

Funding: Supported in part by SBIR Grant 4743 11SC06261
A concept for a two-stage injection-locked CW magnetron intended to drive Superconducting Cavities (SC) for intensity-frontier accelerators has been proposed. The concept is based on a theoretical model that considers a magnetron as a forced oscillator; the model has been experimentally verified with a 2.5 MW pulsed magnetron. The two-stage CW magnetron can be used as a RF power source for Fermilab’s Project-X to feed separately each of the SC of the 8 GeV pulsed linac. For Project-X the 1.3 GHz two-stage magnetron with output power of 20-25 kW and expected output/input power ratio of about 35-40 dB would operate in a quasi-CW mode with a pulse duration ≤ 10 ms and repetition rate of 10 Hz. The magnetrons for both stages should be based on the commercial prototypes to decrease the cost of the system. An experimental model of the two-stage CW S-band magnetron with peak power of 1 kW, with pulse duration of 1-10 ms, has been developed and built for study. A description of the theoretical and experimental models, simulations, and experimental results are presented and discussed in this work.

WEPPC060

A High-power 650 MHz CW Magnetron Transmitter for Intensity Frontier Superconducting Accelerators

controls, proton, LLRF, injection

2351

G.M. Kazakevich, G. Flanagan, R.P. Johnson, F. Marhauser, M.L. Neubauer
Muons, Inc, Batavia, USA
B. Chase, S. Nagaitsev, R.J. Pasquinelli, V.P. Yakovlev
Fermilab, Batavia, USA
T.A. Treado
CPI, Beverley, Massachusetts, USA

A concept of a 650 MHz CW magnetron transmitter with fast control in phase and power, based on two-stage injection-locked CW magnetrons, has been proposed to drive Superconducting Cavities (SC) for intensity-frontier accelerators. The concept is based on a theoretical model considering a magnetron as a forced oscillator and experimentally verified with a 2.5 MW pulsed magnetron. To fulfill fast control of phase and output power requirements of SC accelerators, both two-stage injection-locked CW magnetrons are combined with a 3-dB hybrid. Fast control in output power is achieved by varying the input phase of one of the magnetrons. For output power up to 250 kW we expect the output/input power ratio to be about 35 to 40 dB in CW or quasi-CW mode with long pulse duration. All magnetrons of the transmitter should be based on commercially available models to decrease the cost of the system. An experimental model using 1 kW, CW, S-band, injection-locked magnetrons with a 3-dB hybrid combiner has been developed and built for study. A description of the model, simulations, and experimental results are presented and discussed in this work.

WEPPC067

Dewar Testing of Coaxial Resonators at MSU

niobium, cryomodule, SRF, cavity

2363

J. Popielarski, E.C. Bernard, A. Facco, M. Hodek, F. Marti, D. Norton, G.J. Velianoff, J. Wlodarczak
FRIB, East Lansing, Michigan, USA
A. Burrill, G.K. Davis
JLAB, Newport News, Virginia, USA

Funding: Work supported by US DOE Cooperative Agreement DE-SC0000661 and Michigan State University
Michigan State University is currently testing prototype and production cavities for two accelerator projects. 80.5 MHz β=0.085 quarter wave resonators (QWR) are being produced as part of a cryomodule for ReA3. 322 MHz β=0.53 half wave resonators (HWR) are being prototyped for a driver linac for the Facility for Rare Isotope Beams. This paper will discuss test results and how different cavity preparations effect cavity performs. Also various diagnostics methods have been developed, such as second sound quench location determination, and temperature mapping to determine hot spots from defects and multipacting location.

WEPPC068

Multipacting Simulation and Analysis for the FRIB β = 0.085 Quarter Wave Resonators using Track3P

cavity, simulation, resonance, niobium

2366

L. Ge, C. Ko, Z. Li
SLAC, Menlo Park, California, USA
J. Popielarski
FRIB, East Lansing, Michigan, USA

Funding: Work supported by DOE Office of Science under Cooperative Agreement DE- SC0000661, DOE Contract No. DE-AC02-76SF00515, and used resources of NERSC supported by DOE Contract No. DE-AC02- 05CH11231.
The drive linac for the Facility for Rare Isotope Beams (FRIB) utilizes several types of low beta superconducting resonators to accelerate the ion beams from 0.3 MeV per nucleon to 200 MeV per nucleon. Multipacting is an issue of concern for such superconducting resonators as they have unconventional shapes. We have used the parallel codes Tack3P and Omega3P, developed at SLAC under the support of the DOE SciDAC program, to analyze the multipacting barriers of such resonators. In this paper, we will present the simulation results for the β(v/c) = 0.085 Quarter Wave Resonator (QWR) for the FRIB project. Experimental data will also be presented to benchmark with the simulation results.

WEPPC070

Automated Cavity Test Suite for Cornell's ERL Program

cavity, controls, EPICS, radiation

2372

D. Gonnella, M. Liepe, N.R.A. Valles
CLASSE, Ithaca, New York, USA

As of 2011, fabrication and testing of main linac 7-cell cavities has begun for Cornell's Energy Recovery Linac prototype project. To standardize the testing process, minimize errors and allow for quick and precise measurements of these cavities, a suite of MatLab programs has been written to automate cavity tests. The programs allow measuring the quality factor versus temperature, and quality factor vs. accelerating gradient, and allow extracting material properties such as RRR and residual resistance. They are compatible with EPICS input/output controllers or standalone computers. Finally, the program can measure continuous Q vs E curves from a single high field decay curve, and can perform temperature mapping and quench localization from oscillating superleak transducer data.

WEPPC073

Progress on Superconducting RF Work for the Cornell ERL

cavity, SRF, cryomodule, HOM

2381

M. Liepe, F. Furuta, G.M. Ge, Y. He, G.H. Hoffstaetter, T.I. O'Connell, S. Posen, J. Sears, M. Tigner, N.R.A. Valles, V. Veshcherevich
CLASSE, Ithaca, New York, USA

Cornell University is developing the superconducting RF technology required for the construction of a 100 mA hard X-ray light source driven by an Energy-Recovery Linac. Prototypes of all beam line components of the 5 GeV cw SRF main linac cryomodule have been fabricated and tested in detail. This work includes an optimized 7-cell SRF cavity, a broadband HOM beamline absorber, a cold frequency tuner, and a 5 kW CW RF input coupler. A one-cavity test cryomodule has been assembled for a first full cryomodule test of the main linac cavity, and is currently under testing. In this paper we give an overview of these extensive R&D activities at Cornell.

WEPPC074

HOM Studies on the Cornell ERL Prototype Cavity in a Horizontal Test Cryomodule

cavity, HOM, higher-order-mode, simulation

2384

N.R.A. Valles, M.G. Billing, G.H. Hoffstaetter, M. Liepe, C.E. Mayes
CLASSE, Ithaca, New York, USA

The main linac 7-cell cavity for Cornell's Energy Recovery Linac was optimized to maximize threshold current through the ERL. This was achieved by designing center and end cells that reduce the strength of dipole higher-order modes. A prototype cavity was fabricated based on the optimized RF design and found to meet fundamental mode specifications in a vertical test. The higher-order-mode spectrum was measured when the cavity was installed in a horizontal test cryomodule and is compared to 2D and 3D EM simulations.

WEPPC075

Testing of the Main-Linac Prototype Cavity in a Horizontal Test Cryomodule for the Cornell ERL

cavity, cryomodule, cryogenics, HOM

2387

N.R.A. Valles, F. Furuta, G.M. Ge, Y. He, K.M.V. Ho, G.H. Hoffstaetter, M. Liepe, T.I. O'Connell, S. Posen, P. Quigley, J. Sears, M. Tigner, V. Veshcherevich
CLASSE, Ithaca, New York, USA

Cornell has recently finished producing and testing the first prototype 7-cell main linac cavity for the Cornell Energy Recovery Linac (ERL). The cavity construction met all necessary fabrication constraints. After a bulk BCP, 650C outgassing, final BCP, and 120C bake the cavity was vertically tested. The cavity met quality factor and gradient specifications (2·10¹⁰ at 16.2 MV/m) in the vertical test. Progressing with the ERL linac development, the cavity was installed in a horizontal test cryomodule and the quality factor versus accelerating gradient was again measured. This baseline measurement is the first test in a sequence of tests of the main linac cavity in the test cryomodule. Subsequent tests will be with increased complexity of the beam line, e.g. with HOM beamline loads installed, to study potential sources of reducing the cavity’s quality factor.

WEPPC078

Recent Developments in the Cornell Nb3Sn Initiative

cavity, niobium, SRF, accelerating-gradient

2390

S. Posen, G.H. Hoffstaetter, M. Liepe, Y. Xie
CLASSE, Ithaca, New York, USA

Superconducting accelerator cavities coated with Nb3Sn have already demonstrated significantly higher unloaded quality factors than standard niobium cavities at surface magnetic fields <30 mT. Theoretical predictions suggest that the maximum critical field of such cavities could be twice that of niobium cavities. Significant facilities have been developed at Cornell University to fabricate Nb3Sn using the vapor diffusion technique. In this paper, recent progress is presented from our Nb3Sn program. The first RF results from a test of a Nb3Sn sample in a TE pillbox sample cavity are presented as well as first images of the newly constructed apparatus for coating full 1.3 GHz single cell cavities.

WEPPC079

Residual Resistance Studies at Cornell

cavity, SRF, simulation, accelerating-gradient

2393

S. Posen, D. Gonnella, G.H. Hoffstaetter, M. Liepe
CLASSE, Ithaca, New York, USA
J. Oh
Cornell University, Ithaca, New York, USA

The Cornell single-cell temperature mapping system has been adapted for use with ILC and Cornell ERL-shape superconducting accelerator cavities. The system was optimized for low-noise, high-precision measurements with the goal of measuring resistances as low as 1 nohms. Using this system, a T-map of an ILC single cell was obtained at accelerating fields below the onset of Q-slope and at temperatures at which BCS resistance is small, producing a measurement of the distribution of residual resistance over the surface of the cavity. Standard procedures were used in preparing the cavity to avoid Q-disease and trapped flux caused by cooling the cavity through its transition in the presence of magnetic fields. Studying the T-map gives clues to the source of residual resistance, so that steps can be taken to reduce it, thereby lowering losses and increasing Q0. The temperature map noise-reduction studies as well as the residual resistance results are presented in this paper.

WEPPC080

Minimizing Helium Pressure Sensitivity in Elliptical SRF Cavities

cavity, simulation, factory, beam-loading

2396

S. Posen, M. Liepe
CLASSE, Ithaca, New York, USA

Superconducting cavities in CW operation with small beam loading can operate at high QL to significantly reduce power requirements. However, the resulting small bandwidth makes them vulnerable to microphonics from helium pressure fluctuations, which can detune the cavity and cause it to trip. In this paper, we present a mechanical optimization of elliptical cavities for minimization of df/dp, the sensitivity to helium pressure changes. Using the Cornell ERL main linac cavity as an example, an analytical model is developed to illustrate the factors that contribute to df/dp. Methods to reduce df/dp are presented. In addition, df/dp measurements made at the Cornell Horizontal Test Cryostat are presented and corrections to the model are made to account for the thickness of the welds in the helium vessel.

WEPPC081

Measurement of the Mechanical Properties of Superconducting Cavities During Operation

cavity, resonance, feedback, simulation

2399

S. Posen, M. Liepe
CLASSE, Ithaca, New York, USA

The Horizontal Test Cryostat (HTC) contains the first prototype 7-cell 1.3 GHz superconducting cavity for the Cornell ERL main linac. In this paper, experimental measurements of the cavity's mechanical properties are presented. The mechanical resonances were studied using a Dynamic Signal Analyzer, which measured the transfer function from the fast piezo tuner to itself and the cavity frequency. The microphonics detuning of the cavity was measured, and found to satisfy the specification that the maximum detuning be below 20 Hz, even without feedback from the piezos. Correlations were studied between the microphonics detuning and the helium pressure, piezo sense signal, and the ground vibrations. The Lorentz force detuning (LFD) coefficient was also measured. The frequencies of the mechanical resonances were compared to simulation. In addition, the performance of the frequency tuners was evaluated. Both the mechanical tuner and the piezo were found to be highly linear with very little hysteresis even on small scales.

WEPPC106

The First ASME Code Stamped Cryomodule at SNS

cryomodule, vacuum, cavity, neutron

2465

M.P. Howell, D.R. Bruce, M.T. Crofford, D.L. Douglas, S.-H. Kim, S.E. Stewart, W.H. Strong
ORNL, Oak Ridge, Tennessee, USA
R. Afanador, B.S. Hannah, J. Saunders
ORNL RAD, Oak Ridge, Tennessee, USA
J.D. Mammosser
JLAB, Newport News, Virginia, USA

The first spare cryomodule for the Spallation Neutron Source (SNS) has been designed, fabricated, and tested by SNS personnel. The approach to design for this cryomodule was to hold critical design features identical to the original design such as bayonet positions, coupler positions, cold mass assembly, and overall footprint. However, this is the first SNS cryomodule that meets the pressure requirements put forth in the 10 CFR 851: Worker Safety and Health Program. The most significant difference is that Section VIII of the ASME Boiler and Pressure Vessel Code was applied to the vacuum vessel of this cryomodule. Applying the pressure code to the helium vessels within the cryomodule was considered. However, it was determined to be schedule prohibitive because it required a code case for materials that are not currently covered by the code. Good engineering practice was applied to the internal components to verify the quality and integrity of the entire cryomodule. The design of the cryomodule, fabrication effort, and cryogenic test results will be reported in this paper.

WEPPC108

Status of SRF Facilities at SNS

cryomodule, SRF, cavity, controls

2471

J. Saunders, R. Afanador, T. Xu
ORNL RAD, Oak Ridge, Tennessee, USA
M.T. Crofford, M.P. Howell, S.-H. Kim, S.E. Stewart
ORNL, Oak Ridge, Tennessee, USA

SNS has recognized the need for developing in-house capability to ensure long term sustainability of the SCL. SNS has made substantial gains in the last 6 years in understanding SCL operation, including system and equipment limiting factors, and resolution of system and equipment issues. Significant effort and focus is required to assure ongoing success in the operation, maintenance, and improvement of the SCL and to address the requirements of the upgrade project for the Second Target Station. This interdependent effort includes implementation of demonstrated improvements, fabrication of spare cryomodules, cavity R&D to enhance machine performance, and related SRF facility developments. Cryomodule and vertical cavity testing facilities are being developed to demonstrate process capabilities and to further understand the collective limitations of installed cavities. The status and future plans for SRF facilities at SNS will be presented.

WEPPC109

Superconducting RF Systems for eRHIC

SRF, electron, cavity, hadron

2474

S.A. Belomestnykh, I. Ben-Zvi, J.C. Brutus, H. Hahn, D. Kayran, G.J. Mahler, G.T. McIntyre, C. Pai, I. Pinayev, V. Ptitsyn, J. Skaritka, R. Than, J.E. Tuozzolo, Q. Wu, W. Xu, A. Zaltsman
BNL, Upton, Long Island, New York, USA
S.A. Belomestnykh, V. Litvinenko, T. Xin
Stony Brook University, Stony Brook, USA

Funding: Work supported by Brookhaven Science Associates, LLC under Contract No. DE-AC02-98CH10886 with the U.S. Department of Energy.
Future electron-hadron collider eRHIC will consist of a six-pass 30-GeV electron ERL and one of RHIC storage rings operating with energy up to 250 GeV. The collider design extensively utilizes superconducting RF (SRF) technology in both electron and hadron parts. This paper describes various SRF systems, their requirements and parameters.

WEPPC112

Development of a Fundamental Power Coupler for High-Current Superconducting RF Cavity

simulation, cavity, collider, electron

2483

P. Jain
Stony Brook University, Stony Brook, USA
S.A. Belomestnykh, I. Ben-Zvi, W. Xu
BNL, Upton, Long Island, New York, USA

Funding: Work supported by Brookhaven Science Associates, LLC under Contract No. DE-AC02-98CH10886 with the U.S. DOE and by the DOE grant DE-SC0002496 to Stony Brook University.
Brookhaven National Laboratory has undertaken a project to design a five-cell superconducting 703.75 MHz RF cavity for the Energy Recovery Linac (ERL) and the planned RHIC electron cooler. The earlier developed cavity, viz., the BNL1 is fed by a klystron using a co-axial Fundamental Power Coupler (FPC), which delivers 50 kW of cw RF power to the cavity. During the cavity operation, it has been observed that a 5 K cooling line intercept in the FPC introduces undesirable microphonics. A modification in the existing FPC has been planned to determine the feasibility of getting rid of the 5 K cooling line. The modified coupler will be incorporated in the newly designed, under construction BNL3 cavity. In order to accommodate this modification, peak microphonics of 12 Hz and 20 kW of cw RF power will be considered. This paper describes the design of the new FPC starting from the analysis of thermal profile along its length from first principles.

WEPPD017

Development of a New RF Finger Concept for Vacuum Beam Line Interconnections

vacuum, impedance, higher-order-mode, simulation

2531

C. Garion, A. Lacroix, H. Rambeau
CERN, Geneva, Switzerland

RF contact fingers are primarily used as a transition element to absorb the thermal expansion of vacuum chambers during bake-out and also to compensate for mechanical tolerances. They have to carry the beam image current to avoid the generation of Higher Order Modes and to reduce beam impedances. They are usually made out of copper beryllium thin sheets and are therefore very fragile and critical components. In this paper, a robust design based on a deformable finger concept is proposed. It allows the compensation of large longitudinal movements and also defaults such as transverse offset, twist or bending. The concept of this new RF fingers is first explained, then the design of the component is presented. The mechanical study based on a highly non linear Finite Element model is shown as well as preliminary tests, including fatigue assessment, carried out on prototypes.

WEPPD033

Design of 100 MeV Proton Beam Irradiation Facility for the PEFP 100 MeV Linac

proton, target, radiation, octupole

2579

S.P. Yun, Y.-S. Cho, J.-H. Jang, H.S. Kim, H.-J. Kwon, B.-S. Park, K.T. Seol, Y.-G. Song
KAERI, Daejon, Republic of Korea

Funding: This work is supported by the Ministry of Education, Science and Technology of the Korean Government.
The Proton Engineering Frontier Project (PEFP) will install a 100-MeV proton linear accelerator at Gyeong-ju site. Two target rooms ( TR 103, TR 23) will be prepared in the beam commissioning stage for 20-MeV and 100-MeV proton beams, respectively. To design the irradiation equipment in TR 103, we have investigated general propagation shape and spatial distribution of proton beam by using Monte carlo method, when 100 MeV proton beam extracted from vacuum in the beam lines through beam window. On the basis of this result, we have designed beam irradiation components and their configuration. The beam irradiation facility consists of beam dump, support frame, sample support and beam current monitor. To minimize residual radioactivity induced by incident proton beam, the graphite was selected as the material of beam dump and the aluminum alloy was selected as material of other irradiation equipment. These residual radioactivity of equipment were estimated by Monte carlo method. In this paper, the details of this irradiation equipment design are presented.

WEPPD050

Upgrade of the RF Reference Distribution System for 400 MeV LINAC at J-PARC

controls, acceleration, klystron, injection

2630

K. Futatsukawa, Z. Fang, Y. Fukui, T. Kobayashi, S. Michizono
KEK, Ibaraki, Japan
F. Sato, S. Shinozaki
JAEA/J-PARC, Tokai-mura, Japan

In J-PARC, the accelerator systems are controlled using the 12 MHz master clock in center control building. In the present J-PARC Linac, the negative hydrogen is accelerated by 181 MeV using the RFQ, DTLs, and SDTLs which have the resonance frequency of 324 MHz. The low-level radio frequency (LLRF) system is based on the reference signal of 312 MHz (LO) synchronized with the master clock. We are planning to upgrade Linac by the accelerated energy to 400 MeV by the installation of ACS cavities with the resonance frequency of 972 MHz. Then, not only 312 MHz but also 960 MHz reference signals are necessary. Therefore, a new RF reference signal oscillator was installed at J-PARC LINAC. The phase noise of the output signal in this module was measured by the signal source analyzer. The jitter of the output signal, which was estimated from the integration of phase noise from 10 Hz to 1 MHz, becomes about 40 fs and was two order smaller than that of the old system (about 1700 fs) by the installation of new oscillator and the optimization of the path of the master clock. It can be expected to improve the operating ratio in J-PARC LINAC.

WEPPD051

Timing System for the PEFP 100-MeV Proton LINAC and Multipurpose Beamlines

proton, EPICS, diagnostics, controls

2633

Y.-G. Song, Y.-S. Cho, J.-H. Jang, H.-J. Kwon, K.T. Seol
KAERI, Daejon, Republic of Korea

Funding: This work is supported by the 21C frontier R&D program in the ministry of science and technology of the Korean government.
The PEFP 100-MeV Linac requires precision synchronization of timing trigger signals for various accelerator and diagnostic components. A timing event system is selected as the main timing system, which is operated based on an event distribution system and can be constructed with COTS hardware. This system broadcasts the precise timing information globally. This paper describes the architecture, construction and performance of the PEFP timing event system.

WEPPD058

The Project-X 3 GeV Beam Distribution System

cavity, cryogenics, kaon, ion

2651

D.E. Johnson, M.H. Awida, M.S. Champion, I.V. Gonin, A.L. Klebaner, N. Solyak, V.P. Yakovlev
Fermilab, Batavia, USA

In the Project X facility, a 3 GeV H⁻ CW beam is delivered to three users simultaneously. This will be accomplished by selectively filling appropriate RF buckets at the front end of the linac and then utilizing a RF splitter to transversely separate bunches to three different target halls. A compact TE113 squashed-wall superconducting RF cavity has been proposed to produce the initial vertical deflection. The transport line optics, cavity design parameters, and cryogenic system requirements will be presented.

WEPPD063

Construction of Disk-loaded Buncher for S-Band Low Energy TW Electron Linear Accelerator

electron, impedance, coupling, cavity

2666

F. Ghasemi, F. AbbasiDavani, S. Ahmadiannamini, M.Sh. Shafiee
sbu, Tehran, Iran
M.L. Lamehi Rashti, H. Shaker
IPM, Tehran, Iran

The project of design and construction of Traveling linear electron accelerator is being performed by the Institute for Research in Fundamental Sciences (IPM) and Shahid Beheshti University in Iran. By using the results of the calculations and by dynamic simulation of electron beam in the designed buncher, the dimensions of the designed sample have been obtained. This paper discuss construction of this buncher.

WEPPD064

Quick Recovery of the KEK e⁻/e⁺ Injector Linac from the Great East Japan Earthquake

vacuum, injection, positron, electron

2669

A. Enomoto
KEK, Ibaraki, Japan

The KEK e⁻/e⁺ injector linac is under operation for the KEK Photon Factory (PF) storage ring and Photon Factory - Advanced Ring (PF-AR). And the linac has just started the upgrade for the SuperKEKB project. On March 11, the linac suffered great damage from the Great East Japan Earthquake. Due to an extraordinary strong vibration, many bellows of vacuum pipes were violently torn and the entire linac vacuum was exposed to the atmosphere. Without electricity, highly humid air entered the inside of accelerator structures. Some people supposed the linac would not be recovered within a year. However, it resumed operation after only two months. We report the memorable disaster and how we recovered the linac so quickly.

WEPPD065

Development of a Laser-based Alignment System Utilizing Fresnel Zone Plates at the KEKB Injector Linac

laser, alignment, scattering, focusing

2672

T. Suwada, M. Satoh
KEK, Ibaraki, Japan
K. Minoshima, S. Telada
AIST, Tsukuba, Japan

A new laser-based alignment system is under development in order to precisely align accelerator components along an ideal straight line at the 600-m-long KEKB injector linac. A well-known sequential three-point method with Fresnel zone plates and a CCD camera is revisited in the alignment system. The high-precision alignment system is strongly required in order to stably accelerate high-brightness electron and positron beams with high bunch charges and also to keep the beam stability with higher quality towards the Super B-factory at KEK. A new laser optics has been developed and the laser propagation characteristics has been systematically investigated at a 100-m-long straight section in vacuum. In this report, the experimental developments and investigations are reported along with the design of the new laser-based alignment system.

WEPPD068

High Power Collinear Load Coated with FeSiAl

cavity, simulation, resonance, factory

2678

L.G. Shen, X.L. Fu, Y. Sun, F. Zhang
USTC/PMPI, Hefei, Anhui, People's Republic of China
Y.J. Pei
USTC/NSRL, Hefei, Anhui, People's Republic of China

Funding: This work is supported by the NSFC (NO. 10775128 and NO.51075381)
Aimed at substituting output coupler to absorb remnant power of the LINAC, collinear load coated with high loss materials is expected to come reality. FeSiAl load is studied. The effect of the coating volume upon the cavity frequency and Q factor is analyzed and the dimension compensations of the cavities are suggested to tune the load cavities at 2856 MHz. Orthogonal Experimental Method is utilized to investigate the sensitivity of permittivity (both real part and imaginary part) and permeability (both real part and imaginary part) to cavity characteristics. Five cavities with different coating dimensions are manufactured and their operating frequencies and Q are measured. Compared with the simulations, they show that the Q factor, which is characterization of the actual attenuation of the FeSiAl, agrees very well with the theoretical value and Q factor of the resonant cavity is measured with the probe method. The relationship between Q factor and the length of the test probe is deduced and eventually the individual Q value of a load cavity is extracted. Simulation shows the FeSiAl load can support average power over 15 kW and the one-way attenuation is about 30 dB.

WEPPD069

PLS-II Linac Upgrade

electron, klystron, gun, emittance

2681

B.-J. Lee, J.Y. Choi, S. Chunjarean, T. Ha, J.Y. Huang, I. Hwang, Y.D. Joo, C. Kim, M. Kim, S.H. Kim, S.J. Kwon, S.H. Nam, S.S. Park, S.J. Park, S. Shin, Y.G. Son
PAL, Pohang, Kyungbuk, Republic of Korea

This paper reports on the recent status of the Pohang Light Source (PLS)-II linac at Pohang Accelerator Laboratory (PAL). From 2009, the linac upgrade has been started increasing its energy from 2.5 GeV to 3 GeV aiming stable top-up mode operation. First, we show that the stability status of the two different types of modulators to meet the top-up condition which requires very stable modulator system in linac. Next, we introduce upgrade status those differ from their PLS (2.5 GeV) such as installation of the dual vacuum systems for the electron gun to replace it immediately, adding important diagnostic tools, and reutilization of the beam analysis system just after pre-injector. Finally we present the electron beam parameters measured by those diagnostic system.

WEPPD073

Strategy and Validation of Fiducialization for the Pre-alignment of CLIC Components

alignment, laser, controls, target

2693

S. griffet, A. Cherif, J. Kemppinen, H. Mainaud Durand, V. Rude, G. Sterbini
CERN, Geneva, Switzerland

The feasibility of the high energy e⁺ e⁻ linear collider CLIC (Compact Linear Collider) is very dependent on the ability to accurately pre-align its components. There are two 20-km-long Main Linacs which meet in an interaction point (IP). The Main Linacs are composed of thousands of 2 m long modules. One of the challenges is to meet very tight alignment tolerances at the level of CLIC module: for example, the center of a Drive Beam Quad needs to be aligned within 20 μm rms with respect to a straight line. Such accuracies cannot be achieved using usual measurement devices. Thus it is necessary to work in close collaboration with the metrology lab. To test and improve many critical points, including alignment, a CLIC mock-up is being assembled at CERN. This paper describes the application of the strategy of fiducialization for the pre-alignment of CLIC mock-up components. It also deals with the first results obtained by performing measurements using a CMM (Coordinate Measuring Machine) to ensure the fiducialization, using a Laser Tracker to adjust or check components’ positions on a girder and finally using a Measuring Arm to perform dimensional control after assembling steps.

WEPPD082

Characterization of Photocathode Damage during High Current Operation of the Cornell ERL Photoinjector

ion, gun, site, vacuum

2717

J.M. Maxson, S.S. Karkare
Cornell University, Ithaca, New York, USA
I.V. Bazarov, S.A. Belomestnykh, L. Cultrera, D.S. Dale, J. Dobbins, B.M. Dunham, K. Finkelstein, R.P.K. Kaplan, V.O. Kostroun, Y. Li, X. Liu, F. Löhl, B. Pichler, P. Quigley, D.H. Rice, K.W. Smolenski, M. Tigner, V. Veshcherevich, Z. Zhao
CLASSE, Ithaca, New York, USA

The Cornell ERL Photoinjector prototype has recently demonstrated successful operation at 20 mA for 8 hours using a bi-alkali photocathode grown on a Si substrate. The photocathode film was grown off center, and remained relatively undamaged; however, upon removal from the gun, the substrate at the gun electrostatic center displayed significant visible damage. Here we will describe not only the parameters of that particular high current run, but a suite of post-operation surface morphology and crystallographic measurements, including X-ray fluorescence, X-ray diffraction, contact profilometry, scanning electron microscopy, performed about the damage site and photocathode film. The data indicate violent topological changes to the substrate surface, as well as significant induced crystallographic strain. Ion back-bombardment is proposed as a possible mechanism for damage, and a simple model for induced crystal strain is proposed (as opposed to ion induced sputtering), and is shown to have good qualitative agreement with the spatial distribution of damage.

WEPPP010

FACET: SLAC's New User Facility

electron, positron, acceleration, wakefield

2741

C.I. Clarke, F.-J. Decker, R.J. England, R.A. Erickson, C. Hast, M.J. Hogan, S.Z. Li, M.D. Litos, Y. Nosochkov, J.T. Seeman, J. Sheppard, U. Wienands, M. Woodley, G. Yocky
SLAC, Menlo Park, California, USA

Funding: Work supported by the U.S. Department of Energy under contract number DE-AC02-76SF00515.
FACET (Facility for Advanced Accelerator Experimental Tests) is a new User Facility at SLAC National Accelerator Laboratory. The first User Run started in spring 2012 with 20 GeV, 3 nC electron beams. The facility is designed to provide short (20 um) bunches and small (20 um wide) spot sizes, producing uniquely high power beams. FACET supports studies from many fields but in particular those of Plasma Wakefield Acceleration and Dielectric Wakefield Acceleration. The creation of drive and witness bunches and shaped bunch profiles is possible with "Notch" Collimation. FACET is also a source of THz radiation for material studies. Positrons will be available at FACET in future user runs. We present the User Facility and the available tools and opportunities for future experiments.

WEPPP025

A Test-bed for Future Linear Collider Technology: Argonne Wakefield Accelerator Facility (AWA)

wakefield, gun, electron, acceleration

2778

M.E. Conde, D.S. Doran, W. Gai, R. Konecny, W. Liu, J.G. Power, Z.M. Yusof
ANL, Argonne, USA
S.P. Antipov, C.-J. Jing
Euclid TechLabs, LLC, Solon, Ohio, USA
E.E. Wisniewski
Illinois Institute of Technology, Chicago, Illinois, USA

Funding: Work supported by the U.S. Department of Energy under contract No. DE-AC02-06CH11357.
Research at the AWA Facility has been focused on the development of electron beam driven wakefield structures. Accelerating gradients of up to 100 MV/m have been excited in dielectric loaded cylindrical structures operating in the microwave range of frequencies. Several upgrades, presently underway, will enable the facility to explore higher accelerating gradients, and also be able to generate longer RF pulses of higher intensity. The upgraded 75 MeV drive beam will consist of bunch trains of up to 32 bunches spaced by 0.77 ns with up to 100 nC per bunch. The RF pulses generated by the drive bunches are expected to reach GW power levels, establishing accelerating gradients of hundreds of MV/m.

WEPPP066

Performance Simulations of a Phase Stabilization System Prototype for CTF3

feedback, kicker, simulation, collider

2858

A. Gerbershagen, T. Persson, D. Schulte, P.K. Skowroński
CERN, Geneva, Switzerland
P. Burrows, G.B. Christian
Oxford University, Physics Department, Oxford, Oxon, United Kingdom
A. Gerbershagen, C. Perry
JAI, Oxford, United Kingdom
E. Ikarios
National Technical University of Athens, Athens, Greece

The CLIC drive beam provides RF power for acceleration of the main beam, and hence the drive beam’s longitudinal phase tolerances are very tight. A feedforward chicane consisting of four electromagnetic kickers is proposed as a correction system for the phase errors, which should allow loosening of the tolerances. A prototype of such a chicane system, developed by CERN, INFN and the University of Oxford, is planned to be installed at CFT3 in 2012. The present paper summarizes the parameters of the planned phase correction system and presents simulations, which are used to make predictions of the performance of such a feedforward system at CTF3.

WEPPP072

Beam Characterization and Coherent Optical Transition Radiation Studies at the Advanced Photon Source Linac

emittance, diagnostics, laser, radiation

2876

J.C. Dooling, R.R. Lindberg, N. Sereno, C.-X. Wang
ANL, Argonne, USA
A.H. Lumpkin
Fermilab, Batavia, USA

Funding: Work supported by the U.S. Department of Energy, Office of Science, Office of Basic Energy Sciences, under contract number DE-AC02-06CH11357.
The Advanced Photon Source facility includes a 450-MeV S-band linac with the option for injection from a photocathode (PC) rf gun. A diode-pumped, twice-frequency doubled Nd:glass regen laser (263 nm) is used with the Cu PC to generate the electron beams. Characterization of these beams and studies of the microbunching instability following beam compression in the four-dipole magnetic chicane are described. A suite of diagnostics is employed including a three-screen emittance section, a FIR coherent transition radiation autocorrelator, electron spectrometers, and an optical diagnostics end station. An energy chirp impressed on the beam is used to compress the 1-2 ps, rms bunch as it passes through the chicane. With compression, bunch lengths of 170-200 fs, rms at 450 pC are measured, and coherent optical transition radiation (COTR) due to the microbunching instability is observed. Mitigation techniques of the COTR in the beam profile diagnostics are demonstrated both spectrally and temporally. At 100 pC without compression normalized transverse emittances of 1.8 and 2.7 microns are observed in the x and y planes, in reasonable agreement with initial ASTRA simulations.

WEPPP073

Dynamic Feedback Model for High Repetition Rate Linac-driven FELs

feedback, FEL, cavity, beam-loading

2879

J.M. Byrd, L.R. Doolittle, P. Emma, G. Huang, A. Ratti, C. Serrano
LBNL, Berkeley, California, USA

Funding: Work supported by the Director, Office of Science, of the U.S. Department of Energy under Contract No. DE-AC02-05CH11231.
One of the concepts for the next generation of linac-driven FELs is a cw superconducting linac driving an electron beam with MHz repetition rates. One of the challenges for next generation FELs is improve the shot-to-shot stability of the energy, charge, peak current, and timing jitter of the electron beam. The use of a cw RF system with MHz beam repetition rates presents an opportunity to use broadband feedback to stabilize the beam parameters. To understand the performance of such a feedback system, we are are developing a dynamic feedback model of the machine with a focus on the longitudinal beam properties. The model is being developed as an extension of the LITrack code and will include the dynamics of the beam-cavity interaction, RF feedback, beam-based feedback, and multibunch effects. In this paper, we will present the status of this model along with results.

WEPPP077

Control of RF Transients in Cavities Induced by Pulsed High Current Beams

cavity, SRF, controls, feedback

2891

F. Löhl, J. Dobbins, R.P.K. Kaplan, C.R. Strohman
CLASSE, Ithaca, New York, USA

Funding: Supported by NSF award DMR-0807731.
The Cornell ERL prototype injector is operated either in a cw or in a pulsed mode. In the latter case, the bunch trains, which have a duration of 100 ns to 10 microseconds and a beam current of up to 100 mA, generate transients in the RF cavity fields which severely distort the beam quality and cause beam loss. In this paper, we present a scheme we use to correct the fast transients based on an adaptive feed-forward method.

WEPPP081

Fast Beam Tuning for Accelerator Driven Systems

controls, target, laser, proton

2897

S. Bhattacharyya, R.K. Yedavalli
Ohio State University, USA
A. Mukherjee
Fermilab, Batavia, USA

The biggest challenge for Accelerator Driven Systems (ADS) is the stringent availability requirement of >99% compared to ~80% achieved by a typical accelerators. In addition to overall availability, due to thermal stress problems, ADS is also sensitive to the length of each downtime. A significant source of downtime is re-adjustment – “tuning” – of the system to account for drift in component behavior, or substitution of a backup device for one that failed. Tuning at present is done “by hand,” i.e. with human observation, interpretation, and decision, a process which takes hours; whereas ADS requires recovery in minutes. In this research, we apply intelligent controls in a (simulated) proton linac to automate fine-tuning. Beam monitor data is fed into a controller which adjusts magnet currents and RF power to minimize beam loss. We consider fluctuations in ion source characteristics; drift in magnet behavior (mechanical motion, or change in calibration); and failure of an accelerating cavity.

WEPPP086

Positioning the 100MeV Linac and Magnets with Two Laser Trackers

proton, target, alignment, klystron

2912

B.-S. Park, Y.-S. Cho, J.-H. Jang, D.I. Kim, H.S. Kim, H.-J. Kwon, J.Y. Ryu, K.T. Seol, Y.-G. Song, S.P. Yun
KAERI, Daejon, Republic of Korea

Funding: * This work is supported by the Ministry of Education, Science and Technology of the Korean Government.
Proton Engineering Frontier Project(PEFP) is developing a 100MeV high-duty-factor proton linac and 10 beam lines. The total length of PEFP linac is about 80m and each beam line is about 30m in length. The reference points were set up on the wall of the tunnel in the lst floor, the klystron gallery in the 2nd floor and the modulator gallery in the 3rd floor to built a survey network. Before the beam commissioning, the accelerator components and beam line magnets have been positioned within the tolerance limit by using two laser tracker systems. In this paper, the schemes for the alignment and the network survey are presented together with the results.

WEPPP090

Stable RF Distribution System for the S-band Linac

controls, klystron, feedback, extraction

2924

T. Naito, K. Ebihara, S. Nozawa, N. Terunuma, J. Urakawa
KEK, Ibaraki, Japan
M. Amemiya
AIST, Tsukuba, Japan

The phase stabilization of the RF phase is key issue for the stable linac operation. An RF distribution system with femto-second stability has been developed for S-band linac using optic fiber links. The system uses a phase stabilized optical fiber (PSOF) and an active fiber length stabilization.* The phase stability is 0.1 degree (100f s) for 24 hours observation. In this paper, we present the test results of the system stability and evaluation of the existing RF reference line by using this system.
* Naito et. al. IPAC10 MOPC146

WEPPR019

Catalogue of Losses for the IFMIF Prototype Accelerator

rfq, SRF, solenoid, quadrupole

2982

P.A.P. Nghiem, N. Chauvin, D. Uriot
CEA/DSM/IRFU, France
M. Comunian
INFN/LNL, Legnaro (PD), Italy
C. Oliver
CIEMAT, Madrid, Spain

For machine and personal protection purposes, precise knowledge of beam loss location and power are crucial, especially in a high intensity, high power accelerator like the IFMIF prototype. This paper aims at discussing the protocol of appropriate studies in order to give the catalogue of beam losses in different conditions: nominal, tuning and accidental. Then results of these studies are given.

WEPPR029

Alternative Cavity for H E Part of the Project X linac

cavity, HOM, cryomodule, emittance

2997

A. Lunin, A. Saini, N. Solyak, A.I. Sukhanov, V.P. Yakovlev
Fermilab, Batavia, USA

An alternative superconducting elliptical cavity is suggested for High Energy (HE) part of the Project X linac. The cavity is suitable to operate at CW regime with high beam current (10 mA), which is critical for Accelerator-Driven Subcritical (ADS) systems and for intense muon source for future Neutrino Factory or Muon Collider. We present the algorithm of the cavity shape optimization, comprehensive tolerances analysis and the solution for monopole High Order Modes (HOM) damping. Based on these results we estimated the probabilities of cryogenic losses per cryomodule and a growth of the beam longitudinal emittance due to the resonance excitation of monopole HOMs in the HE linac for Project X.

WEPPR031

Injector Beam Dynamics for a High-repetition Rate 4th-generation Light Source

emittance, electron, space-charge, gun

3000

C. F. Papadopoulos, J.N. Corlett, P. Emma, D. Filippetto, G. Penn, J. Qiang, M.W. Reinsch, F. Sannibale, C. Steier, M. Venturini, R.P. Wells
LBNL, Berkeley, California, USA

Funding: This work was supported by the Director of the Office of Science of the US Department of Energy under Contract no. DEAC02-05CH11231.
We report on the beam dynamics studies and optimization methods for a high-repetition (1 MHz) photoinjector based on a VHF normal conducting electron source. The simultaneous goals of beam compression and preservation of 6-dimensional beam brightness have to be achieved in the injector, in order to accommodate a linac driven FEL light source. For this, a parallel, multiobjective optimization algorithm is used. We discuss the relative merits of different injector design points, as well as the constraints imposed on the beam dynamics by technical considerations such as the high repetition rate.

WEPPR038

Independent Component Analysis (ICA) Applied to Long Bunch Beams in the Los Alamos Proton Storage Ring

betatron, injection, extraction, coupling

3018

J.S. Kolski, R.J. Macek, R.C. McCrady, X. Pang
LANL, Los Alamos, New Mexico, USA

Independent component analysis (ICA) is a powerful blind source separation (BSS) method. Compared to the typical BSS method, principal component analysis (PCA), which is the BSS foundation of the well known model independent analysis (MIA), ICA is more robust to noise, coupling, and nonlinearity. ICA of turn-by-turn beam position data has been used to measure the transverse betatron phase and amplitude functions, dispersion function, linear coupling, sextupole strength, and nonlinear beam dynamics. We apply ICA in a new way to slices along the bunch and discuss the source signals identified as betatron motion and longitudinal beam structure.

WEPPR040

Intensity Effects of the FACET Beam in the SLAC Linac

emittance, quadrupole, wakefield, alignment

3024

F.-J. Decker, N. Lipkowitz, J. Sheppard, G.R. White, U. Wienands, M. Woodley, G. Yocky
SLAC, Menlo Park, California, USA

Funding: Work supported by U.S. Department of Energy, Contract DE-AC02-76SF00515.
The beam for FACET (Facility for Advanced aCcelerator Experimental Tests) at SLAC requires an energy-time correlation ("chirp") along the linac, so it can be compressed in two chicanes, one at the mid point in sector 10 and one W-shaped chicane just before the FACET experimental area. The induced correlation has the opposite sign to the typical used for BNS damping, and therefore any orbit variations away from the center kick the tail of the beam more than the head, causing a shear in the beam and emittance growth. Any dispersion created along the linac has similar effects due to the high (>1.2% rms) energy spread necessary for compression. The initial huge emittances could be reduced by a factor of 10, but were still bigger than expected by a factor of 2-3. Normalized emittance of 2 um-rad in Sector 2 blew up to 150 um-rad in Sector 11 but could be reduced to about 6-12 um-rad for the vertical plane although the results were not very stable. Investigating possible root causes for this, we found locations where up to 10 mm dispersion was created along the linac, which were finally verified with strong steering and up to 7 mm settling of the linac accelerator at these locations.

WEPPR041

Design of a Compact Linear Accelerator for the Ultrafast Electron Diffraction Facility

electron, gun, space-charge, emittance

3027

M. Mamtimin, A.W. Hunt, Y. Kim, D.P. Wells
IAC, Pocatello, IDAHO, USA

Ultrafast Electron Diffraction (UED) is a powerful tool to find 3-dimensional structures and dynamical transitions of chemical or biological samples with a femtosecond-range temporal resolution and an angstrom-range spatial resolution. Due to the columbic field of electrons, UED can provide a higher cross section and a higher time resolution than those of the ultrafast photon diffraction with X-ray Free Electron Lasers (XFELs). In this paper, we describe the design concepts and ASTRA simulation results of a compact linac for an UED facility.

WEPPR051

Issues for a Multi-bunch Operation with SPARC C-band Cavities

wakefield, HOM, betatron, dipole

3042

A. Mostacci, M. Migliorati, L. Palumbo
URLS, Rome, Italy
D. Alesini, B. Spataro, C. Vaccarezza
INFN/LNF, Frascati (Roma), Italy

SPARC C-band traveling wave cavities were originally designed for the SPARC energy upgrade in the single bunch operation mode. In the context of a gamma source based on Compton backscattering and based on the SPARC C-band technology, we investigated the issues related to the use of these structures in the multi-bunch operation mode. Several beam configurations have been considered and the effects of transverse and longitudinal long range wakefields on beam dynamics have been studied. In the paper we present the results of these studies and, in particular, the issues related to transverse beam break-up that could prevent the multi-bunch operation. Possible HOM damped structures are also proposed.

WEPPR060

Short range wakefields in MAX IV and FERMI Linac

wakefield, cavity, electron, dipole

3063

O. Karlberg, F. Curbis, S. Thorin, S. Werin
MAX-lab, Lund, Sweden
P. Craievich, E. Ferrari, G. Penco
ELETTRA, Basovizza, Italy

Ultra-short electron pulses suffer from transverse wake fields resulting in a degradation of the beam quality. Since transverse emittance is a crucial parameter for possible FEL drivers, a careful characterization of wakefields is necessary in the design and commissioning phase of a high-brightness linear accelerator. In this paper we investigate the effect of short-range transverse wakefields in the MAXIV linac in various compression modes. Estimations of the wake potentials have been done with 3D modeling of the accelerating structures as well as with analytical models.

WEPPR064

Very Short Range Wake in Strongly Tapered Disk Loaded Waveguide Structures

simulation, wakefield, FEL, impedance

3072

A. Grudiev
CERN, Geneva, Switzerland

Electron bunches are very short, both in linear collider and in X-FEL projects. Furthermore, typical disk-loaded waveguide structures used for particle acceleration are tapered. For example in CLIC, in order to achieve high accelerating gradient, the structure is only 26 cells long, which results in strong tapering. In this paper, very short range wake is investigated in the regime where the number of cells needed to arrive at steady state is much larger than the number of cells in a single tapered structure. In this case the very short range wake is dominated by the wake from the smallest aperture. The results of an analytical model and numeric solutions are compared.

WEPPR066

Effects of the External Wakefield from the CLIC PETS

wakefield, luminosity, emittance, dipole

3078

A. Latina, D. Schulte
CERN, Geneva, Switzerland
J. Gao, Y. Wang
IHEP, Beijing, People's Republic of China

The CLIC main linac accelerating structures will be powered by the Power Extraction and Transfer Structure (PETS) located in the drive beam decelerators. Misalignments of the PETS will excite dipolar modes in the couplers of the main linac structures that will kick the beam leading to beam quality degradation. In this paper, the impact of such dipolar kicks is studied, and tolerances, based on analytical estimations, are found both in the single- and the multi-bunch regimes. Numerical simulation obtained using the tracking code PLACET are shown to confirm the analytical estimates.

WEPPR067

Study of Fundamental Mode Multipolar Kicks in Double- and Single-feed Power Couplers for the CLIC Main Linac Accelerating Structure

simulation, emittance, multipole, cavity

3081

A. Latina, A. Grudiev, D. Schulte
CERN, Geneva, Switzerland

Multipolar kicks from the fundamental mode have been calculated in the CLIC baseline accelerating structure with double–feed input and output power couplers. The influence of such multipolar kicks on the main linac beam dynamics has been investigated. Furthermore, an alternative design of the couplers with single-feed has been studied and compared with the double-feed. Such an alternative would significantly simplify the waveguide system of the main linac but potentially introduce an harmful dipolar kick from the fundamental mode. The geometry of the coupler has been optimized in order to minimize such a dipolar kick and keep it below threshold levels determined with beam dynamics simulations. Influence of the higher order multipoles has been investigated as well and acceptable levels have been determined.

WEPPR096

Recirculating Beam Breakup Study for the 12 GeV Upgrade at Jefferson Lab

HOM, cryomodule, cavity, simulation

3162

I. Shin, S. Ahmed, R.M. Bodenstein, S.A. Bogacz, T. Satogata, M. Stirbet, H. Wang, Y. Wang, B.C. Yunn
JLAB, Newport News, Virginia, USA
I. Shin
University of Connecticut, Storrs, Connecticut, USA

Two new high gradient C100 cryostats with a total of 16 new cavities were installed at the end of the CEBAF south linac during the 2011 summer shutdown as part of the 12 GeV upgrade project at Jefferson Lab. We ran recirculating beam breakup (BBU) study in November 2011 to evaluate CEBAF low energy performance, measure transport optics, and evaluate BBU thresholds due to higher order modes (HOMs) in these cavities. This paper discusses the experiment setup, cavity measurements, machine setup, optics measurements, and lower bounds on existing CEBAF C100 BBU thresholds established by this experiment.

WEPPR099

Shielding of a Hadron in a Finite e-Beam

plasma, electron, shielding, hadron

3171

A. Elizarov, V. Litvinenko, G. Wang
BNL, Upton, Long Island, New York, USA

Funding: Work supported by Brookhaven Science Associates, LLC under Contract No. DE-AC02-98CH10886 with the U.S. Department of Energy.
The thorough study of coherent electron cooling, the modern cooling technique capable to deal with accelerators operating in the range of few TeVs*, rises many interesting questions. One of them is a shielding dynamics of a hadron in an electron beam. Now this effect is computed analytically in an infinite beam approximation**. Many effects are drastically different in finite and infinite plasmas. Here we propose a method to compute the dynamical shielding effect in a finite cylindrical plasma - the realistic model of an electron beam in accelerators.
* V. N. Litvinenko, Y. S. Derbenev, Phys. Rev. Lett. 10², 114801 (2009).
** G. Wang, M. Blaskiewicz, Phys. Rev. E 78, 026413 (2008).

THXA01

Producing Medical Isotopes using X-rays

target, electron, neutron, extraction

3177

M.S. de Jong
CLS, Saskatoon, Saskatchewan, Canada

Funding: Natural Resources Canada Non-reactor-based Isotope Supply Program Contribution Agreement Saskatchewan Crown Investment Corporation Contribution Agreement
In recent years, there has been frequent shortages of Mo-99 and its daughter isotope, Tc-99m, which are the most heavily used medical diagnostic radio-isotopes. The Canadian Light Source is leading a project to demonstrate large-scale photo-neutron production of Mo-99 using a high-power 35 MeV electron linac as an alternative to production of Mo-99 from fission of highly enriched U-235 in research reactors. This talk will present the results that have been obtained to date and discuss the commercial potential for this alternative production scheme.

Slides THXA01 [6.482 MB]

THYB03

Collective Effects in the LHC and its Injector Complex

emittance, luminosity, impedance, injection

3218

E. Métral
CERN, Geneva, Switzerland

Operation during 4-8 hours at a constant luminosity of five times the nominal one (with “leveling”) is required for the CERN HL-(High Luminosity)-LHC project to be able to reach integrated luminosities of ~ 250 fb-1 per year and ~ 3 ab-1 twelve years after the upgrade. This means that the potential peak luminosity should be at least two times larger than the leveled one, i.e. a factor more than ten compared to the nominal case is contemplated. Even though the LHC had a bold beginning, reaching one third of the nominal peak luminosity at the end of the 2011 run, a factor more than thirty remains to be gained, which will be achieved only if all the collective effects are deeply understood and mastered both in the LHC and its injectors. The observations made during the 2010-2011 runs are first reviewed and compared to predictions to try and identify possible bottlenecks. The lessons learned and the possible solutions and/or mitigation measures to implement in the HL-LHC and the LHC Injectors Upgrade (LIU) projects are then discussed.

Slides THYB03 [34.295 MB]

THAP01

Secondary-electron Emission from Hydrogen-terminated Diamond

electron, vacuum, high-voltage, simulation

3223

E. Wang, I. Ben-Zvi, T. Rao, Q. Wu
BNL, Upton, Long Island, New York, USA
D.A. Dimitrov
Tech-X, Boulder, Colorado, USA
T. Xin
Stony Brook University, Stony Brook, USA

Diamond amplifiers demonstrably are an electron source with the potential to support high-brightness, high-average-current emission into a vacuum. We recently developed a reliable hydrogenation procedure for the diamond amplifier. The systematic study of hydrogenation resulted in the reproducible fabrication of high gain diamond amplifier. Furthermore, we measured the emission probability of diamond amplifier as a function of the external field and modeled the process with resulting changes in the vacuum level due to the Schottky effect. We demonstrated that the decrease in the secondary electrons’ average emission gain was a function of the pulse width and related this to the trapping of electrons by the effective NEA surface. The findings from the model agree well with our experimental measurements. As an application of the model, the energy spread of secondary electrons inside the diamond was estimated from the measured emission.

Slides THAP01 [2.034 MB]

THEPPB008

Inverse Compton Scattering Experiment in a Bunch Train Regime Using Nonlinear Optical Cavity

laser, electron, photon, cavity

3245

A.Y. Murokh, R.B. Agustsson, S. Boucher, P. Frigola, T. Hodgetts, A.G. Ovodenko, M. Ruelas, R. Tikhoplav
RadiaBeam, Santa Monica, USA
M. Babzien, M.G. Fedurin, T.V. Shaftan, V. Yakimenko
BNL, Upton, Long Island, New York, USA
I. Jovanovic
Penn State University, University Park, Pennsylvania, USA

Inverse Compton Scattering (ICS) is a promising approach towards achieving high intensity, directional beams of quasi-monochromatic gammas, which could offer unique capabilities in research, medical and security applications. Practicality implementation of ICS sources, however, depends on the ability to achieve high peak brightness (~0.1-1.0 ICS photons per interacting electron), while increasing electron-laser beam interaction rate to about 10,000 cps. We discuss the results of the initial experimental work at the Accelerator Test Facility (ATF) at BNL to demonstrate ICS interaction in a pulse-train regime, using a novel laser recirculation scheme termed Recirculation Injection by Nonlinear Gating (RING). Initial experimental results and outlook are presented.

THPPC002

Design and Construction of Turnkey Linacs as Injectors for Light Sources

beam-loading, electron, simulation, synchrotron

3272

A.S. Setty, D. Jousse
THALES, Colombes, France

Turnkey linacs were manufactured by Thales Communications & Security in order to inject electrons into boosters of SOLEIL*, ALBA and BESSY II synchrotrons. This paper will describe the beam dynamics tools and methods for the design and construction of those linacs. Cavities tuning and prebunching characterization methods will be given. Beam loading compensation and simulations will be explained. Specified and measured beam parameters will be compared.
* A. Setty et al, "Commissioning of the 100 MeV preinjector HELIOS for the SOLEIL synchrotron", EPAC 06, Scotland, Edinburgh, June 2006.

THPPC007

Coupling Cavity Design of RF Input Coupler Tests for the IFMIF/EVEDA Prototype RFQ Linac

coupling, cavity, rfq, beam-transport

3284

S. Maebara
JAEA, Ibaraki-ken, Japan
M. Ichikawa
Japan Atomic Energy Agency (JAEA), International Fusion Energy Research Center (IFERC), Rokkasho, Kamikita, Aomori, Japan

In the design of prototype RFQ linac for the IFMIF/EVEDA Project, a 175MHz RFQ, which has a longitudinal length of 9.78m, was proposed to accelerate deuteron beam up to 5MeV. The operation frequency of 175MHz was selected to accelerate a large current of 125mA in cw mode. The overall driving RF power of 1.28 MW by 8 RF input couplers has to be injected to the RFQ cavity. For the transmitted RF power tests of RF couplers, a coupling cavity to connect with two RF couplers is needed. For this purpose, two types of coupling cavities for the 175MHz have been designed. One is a capacitive coupling cavity with a co-axial waveguide and double loop coupling structures, and the other one is a ridge cavity type with a rectangular waveguide. In this article, these RF designs and engineering designs will be presented in detail.

THPPC008

Coupling Factor Evaluation of the RF Input Coupler for the IFMIF/EVEDA RFQ Linac

rfq, coupling, beam-loading, cavity

3287

S. Maebara
JAEA, Ibaraki-ken, Japan
M. Ichikawa
Japan Atomic Energy Agency (JAEA), International Fusion Energy Research Center (IFERC), Rokkasho, Kamikita, Aomori, Japan
A. Palmieri
INFN/LNL, Legnaro (PD), Italy

In the design of prototype RFQ linac for the IFMIF/EVEDA Project, a 175 MHz RFQ, which has a longitudinal length of 9.78m, was proposed to accelerate deuteron beam up to 5MeV. The operation frequency of 175MHz was selected to accelerate a large current of 125mA in CW mode. The overall driving RF power of 1.28 MW by 8 RF input couplers has to be injected to the RFQ cavity. As a part of the validation of the coupler design, the beta factor (coupling coefficient) was measured on Aluminum RFQ at INFN Legnaro with on-purpose, real-scale dummy aluminum couplers for the installed depths of L=27, 40, 45, 48 and 73 mm. In this article, measurement and calculation results performed with the 3D code HFSS for coupling factor evaluation will be presented in details.

THPPC009

Investigation of the Approaches to Measure the RF Cable Attenuation

controls, insertion, acceleration, radio-frequency

3290

K. Futatsukawa, Z. Fang, Y. Fukui, T. Kobayashi, S. Michizono
KEK, Ibaraki, Japan
F. Sato, S. Shinozaki
JAEA/J-PARC, Tokai-mura, Japan

In the accelerator facilities, many RF cables are used for the various purposes such as the transmission system and the cavity monitor. The knowledge of the power attenuation in those cables is important role to control RF. In general, the cable attenuation is measured from S parameters to use a network analyzer. However, the control system is located far from the place of the cavities, and it difficult to measure by a network analyzer. Then we investigated other methods to measure the RF cable attenuation.

THPPC010

Beam Start-up of J-PARC Linac after the Tohoku Earthquake

DTL, quadrupole, acceleration, radiation

3293

M. Ikegami, Z. Fang, K. Futatsukawa, T. Miyao
KEK, Ibaraki, Japan
T. Maruta, A. Miura, H. Sako, J. Tamura, G.H. Wei
JAEA/J-PARC, Tokai-mura, Japan

The beam operation of J-PARC linac was interrupted by the Tohoku earthquake in March 2011. After significant recovering effort including the realignment of most linac components, we have resumed the beam operation of J-PARC linac in December 2011. In this paper, we present the experience in the beam start-up tuning after the earthquake and the status of the linac operation thereafter.

THPPC011

Design of an Accelerating Structure for a 500 GeV CLIC using Ace3P

damping, wakefield, simulation, beam-loading

3296

K.N. Sjobak, E. Adli
University of Oslo, Oslo, Norway
A. Grudiev, W. Wuensch
CERN, Geneva, Switzerland

Funding: Research Council of Norway
An optimized design of the main linac accelerating structure for a 500 GeV first stage of CLIC is presented. A similar long-range wakefield suppression scheme as for 3 TeV CLIC based on heavy waveguide damping is adopted. The accelerating gradient for the lower energy machine is 80 MV/m. The 500 GeV design has larger aperture radius in order to increase the maximum bunch charge and length which is limited by the short-range wakefields. The cell geometries have been optimized using a new parametric optimizer for Ace3P and details of the RF cell design are described. Parameters of the full structure are calculated and optimized using a power flow equation.

THPPC016

PLSII Linac RF Conditioning Status

klystron, high-voltage, storage-ring, vacuum

3311

H.-S. Lee, J.Y. Huang, W.H. Hwang, H.-G. Kim, K.R. Kim, S.H. Kim, S.H. Kim, S.H. Nam, W. Namkung, S.S. Park, S.J. Park, Y.J. Park, S. Shin
PAL, Pohang, Kyungbuk, Republic of Korea

PLS linac has been upgraded in energy from 2.5 to 3.0 GeV. A klystron supplies RF power of 80 MW four acceleration structures through a SLED. But our machine is not enough RF power to get 3 GeV beam energy. So we have changed the RF scheme in four modules as a klystron supplies RF power of 80 MW two accelerating structures through a SLED. There were several problems during the RF conditioning and beam operation. So we will describe the conditioning results and the current status in this paper.

THPPC017

Study of Physical Processes of Acceleration of Electron Bunches with Extremal Density by Means of Stored Energy in Disk Loaded Waveguide Sections

electron, acceleration, radiation, electromagnetic-fields

3314

S. Proskin, A. Kulago
MEPhI, Moscow, Russia

This presentation should consider a new theoretical method of SHF power increasing in DWLG sections. Within the presentation physical processes of the acceleration of extremely charge densities in the sections of a DWLG by the stored energy are described. As a result optimum travelling wave DWLG is taken and a simulation of acceleration processes of 20 ns electron beams is conducted.

THPPC024

Design, Construction and Power Conditioning of the First C-band Test Accelerating Structure for SwissFEL

cavity, klystron, vacuum, impedance

3329

R. Zennaro, J. Alex, H. Blumer, M. Bopp, A. Citterio, T. Kleeb, L. Paly, J.-Y. Raguin
Paul Scherrer Institut, Villigen, Switzerland

The SwissFEL C-band linac will consist of 26 RF modules with a total acceleration voltage of 5.4 GV. Each module will be composed of a single 50 MW klystron and its solid-state modulator feeding a pulse compressor and four two-meter long accelerating structures. PSI has launched a vigorous R&D program of development of the accelerating structures including structure design, production and high-power RF tests. The baseline design is based on ultra-precise cup machining to avoid dimple tuning. The first test structure is a constant impedance structure composed of eleven double-rounded cups. We report here on the structure design, production, low-level RF measurements, high-power conditioning and breakdown analysis.

THPPC032

Conditioning and Future Plans for a Multi-purpose 805 MHz Pillbox Cavity for Muon Acceleration

cavity, vacuum, acceleration, solenoid

3353

G.M. Kazakevich, A. Dudas, G. Flanagan, R.P. Johnson, F. Marhauser, M.L. Neubauer, R. Sah
Muons, Inc, Batavia, USA
S.S. Kurennoy
LANL, Los Alamos, New Mexico, USA
A. Moretti, M. Popovic, G.V. Romanov, K. Yonehara
Fermilab, Batavia, USA
Y. Torun
IIT, Chicago, Illinois, USA

Funding: Supported in part by grant 4735 · 10 LANL and Dept. of Energy STTR grant DE-FG02-08ER86352.
An 805 MHz RF pillbox cavity has been designed and constructed to investigate potential muon beam acceleration and cooling techniques for a Muon Collider or Neutrino Factory. The cavity can operate in vacuum or under pressure to 100 atmospheres, at room temperature or in a liquid nitrogen bath at 77 K. The cavity has been designed for easy assembly and disassembly with bolted construction using aluminum seals. To perform vacuum and high pressure breakdown studies of materials and geometries most suitable for the collider or factory, the surfaces of the end walls of the cavity can be replaced with different materials such as copper, aluminum, beryllium, or molybdenum, and with different geometries such as shaped windows or grid structures. The cavity has been designed to fit inside the 5-Tesla solenoid in the MuCool Test Area at Fermilab. In this paper we present the vacuum conditioning results and discuss plans for testing in a 5-Tesla magnetic field. Additionally, we discuss the testing plan for beryllium (a material research has shown to be ideal for the collider or factory) end walls.

THPPC041

704 MHz Fast High-power Ferroelectric Phase Shifter for Energy Recovery Linac Applications

cavity, coupling, controls, pulsed-power

3374

S.V. Shchelkunov
Yale University, Beam Physics Laboratory, New Haven, Connecticut, USA
J.L. Hirshfield
Omega-P, Inc., New Haven, USA
A. Kanareykin
Euclid TechLabs, LLC, Solon, Ohio, USA
S. Kazakov, V.P. Yakovlev
Fermilab, Batavia, USA
A.B. Kozyrev
LETI, Saint-Petersburg, Russia
E. Nenasheva
Ceramics Ltd., St. Petersburg, Russia

Funding: Research supported by the U.S. Department of Energy, Office of High Energy Physics
Development, tests, and evaluation of a fast electrically-controlled 704 MHz tuner for Energy Recovery Linacs that employs an electrically -controlled ferroelectric component are presented. The tuner is a refinement of an already tested prototype described elsewhere. In the new concept, a collection of ferroelectric assemblies behave as cavities configured as transmission components within a coaxial waveguide. Each assembly is based on a ring-like ferroelectric ceramic with its height, inner and outer diameters, and the shape of edges adjusted to insure a clean operating mode, and relatively low field strength. Several assemblies serve to widen the passband and increase tunability. The tuner is to deliver fast (~100-200 ns) phase adjustment from 0-to-100 degrees when biased by voltages from 0-to-15kV; the design promises to handle 50 kW CW and 900 kW of pulsed power. A scaled version is also considered to operate at 1300 MHz while handling 500 kW of pulsed power. Our latest findings, related issues, and plans for experiments are discussed.

THPPC044

Development of the Dual Slot Resonance Linac

coupling, cavity, resonance, impedance

3383

N. Barov, X. Chang, R.H. Miller, D.J. Newsham
Far-Tech, Inc., San Diego, California, USA

Funding: Work supported by DOE Grant DE-FG02-08ER85034
We report the status of the Dual Slot Resonance (DSR) linac under development by FAR-TECH. In this linac type, cell-to-cell coupling is provided by a pair of close-coupled resonant slots, resulting in very strong coupling vs. a typical side-coupled linac design, as well as a much more compact radial space requirement. We discuss the status of the structure fabrication, the RF distribution system, and installation and testing at the UCLA Pegasus facility.

THPPC047

Fabrication and Initial Tests of an Ultra-High Gradient Compact S-Band (HGS) Accelerating Structure

coupling, klystron, vacuum, accelerating-gradient

3392

L. Faillace, R.B. Agustsson, P. Frigola, A.Y. Murokh
RadiaBeam, Santa Monica, USA
V.A. Dolgashev
SLAC, Menlo Park, California, USA
J.B. Rosenzweig
UCLA, Los Angeles, California, USA
V. Yakimenko
BNL, Upton, Long Island, New York, USA

Funding: Work supported by US DOE grant # DE-SC000866.
RadiaBeam Technologies reports on the RF design and fabrication of a ultra-high gradient (50 MV/m) S-Band accelerating structure (HGS) operating in the pi-mode at 2.856 GHz. The compact HGS structure offers a drop-in replacement for conventional S-Band linacs in research and industrial applications such as drivers for compact light sources, medical and security systems. The electromagnetic design (optimization of the cell shape in order to maximize RF efficiency and minimize surface fields at very high accelerating gradients) has been carried out with the codes HFSS and SuperFish while the thermal analysis has been performed by using the code ANSYS. The initial cold tests are presented together with the plans for high-power tests currently ongoing at Lawrence Livermore National Laboratory (LLNL).

THPPC050

Effects of Grids in Drift Tubes

beam-transport, impedance, proton, DTL

3401

M. Okamura
BNL, Upton, Long Island, New York, USA
H. Yamauchi
Time Corporation, Hiroshima, Japan

In 2011, we upgraded a 200 MHz buncher in the proton injector for the AGS – RHIC complex. In the buncher we installed four grids made of tungsten to improve a transit time factor of the buncher. The grid installed drift tubes have 32 mm of inner diameter and the each grid consists of four quadrants. The quadrants were cut out precisely from 1mm thick tungsten plates by a CNC wire cutting EDM. In the conference the 3D electric field design and performance of the grid will be discussed.
Work supported by Brookhaven Science Associates, LLC under Contract No. DE-AC02-98CH10886 with the U.S. Department of Energy.

THPPC053

First Experience at ELBE with the New 1.3 GHz CWRF Power System Equipped with 10 kW GHz Solid State Amplifiers (SSPA)

klystron, cavity, radiation, electron

3407

H. Büttig, A. Arnold, A. Büchner, M. Justus, M. Kuntzsch, U. Lehnert, P. Michel, R. Schurig, G.S. Staats, J. Teichert
HZDR, Dresden, Germany

The superconducting CW- LINAC (1.3 GHz) of the radiation source ELBE is in permanent operation since May 2001/1/. During the winter shut-down 2011 - 1212 an upgrade program of ELBE was realized. One part of the program was to double the RF-power per cavity using two 10 kW Solid State Amplifiers in parallel per cavity. The poster gives an overview on the new RF-system and the experience gained within the first three months of operation.

THPPC057

S-band High Power RF System for 10 GeV PAL-XFEL

coupling, cavity, simulation, klystron

3419

W.H. Hwang, J.Y. Huang, Y.D. Joo, H.-S. Kang, H.-G. Kim, S.H. Kim, H.-S. Lee, Y.J. Park
PAL, Pohang, Kyungbuk, Republic of Korea

In PAL, We are constructing a 10GeV PxFEL project. The output power of the klystron is 80 MW at the pulse width of 4 ㎲ and the repetition rate of 120 Hz. In high power operation, it is important to decrease the rf electric field to protect rf break-down in high power rf components. To obtain the maximum beam, we must reduce the phase difference between waveguide branches including accelerating structure and minimize the environment influences. This paper describes the waveguide system and high power rf components for the PxFEL.

THPPC058

S-band Low-level RF System for 10 GeV PAL-XFEL

LLRF, klystron, FEL, controls

3422

W.H. Hwang, J.Y. Huang, H.-S. Kang, H.-S. Lee, W.W. Lee
PAL, Pohang, Kyungbuk, Republic of Korea

In PAL, We are constructing a 10GeV PxFEL project. The output power of the klystron is 80 MW at the pulse width of 4 ㎲ and the repetition rate of 120 Hz. And the specifications of the rf phase and amplitude stability are 0.05 degrees(rms) and 0.01%(rms) respectively. We achieved the stability of 0.03 degrees(p-p) at low power rf output using a phase amplitude detection system(PAD) and phase amplitude control(PAC) system. This paper describes the microwave system and the PAD and PAC system for the PxFEL.

THPPC070

A High Power Test Facility for New 201.25 MHz Power Amplifiers and Components

power-supply, controls, DTL, status

3449

J.T.M. Lyles, J. Davis, D. Rees, G. M. Sandoval, Jr., A. Steck, D.J. Vigil
LANL, Los Alamos, New Mexico, USA
D. Baca, R.E. Bratton, R.D. Summers
Compa Industries, Inc., Los Alamos, New Mexico, USA
N.W. Brennan
Texas A&M University, College Station, Texas, USA

Funding: Work supported by the United States Department of Energy, National Nuclear Security Agency, under contract DE-AC52-06NA25396
A new test facility was designed and constructed at Los Alamos Neutron Science Center (LANSCE) for testing a new Thales TH628 Diacrode® final power amplifier and associated driver stages. Anode power requirements for the TH628 are 28 kV DC, with 190 Amperes in millisecond pulses. A 225 uF capacitor bank supplies this current demand, with a crowbar circuit to rapidly discharge 88 kJ of stored energy. Charging current was obtained by re-configuring a 2 MW beam power supply remaining from another project. The power tubes are operated with DC anode voltage, and beam pulsing is done with control grid bias switching at relatively low power. A new Fast Protect and Monitor System was designed to take samples of RF reflected power, anode HV, and various tube currents, with logic outputs to promptly remove high voltages, RF drive and beam pulsing during faults. The entire test system is controlled with a programmable logic controller, for normal startup sequencing, protection against loss of cooling, and operator GUI. This test facility has been used over the past year to test the amplifiers along with high power coaxial components such as hybrid couplers and various water loads.

THPPC073

Development of the Energy-Efficient Solid State RF Power Source for the Jefferson Laboratory CEBAF Linac

controls, klystron, insertion, high-voltage

3455

X. Chang, N. Barov, D.J. Newsham, D. Wu
Far-Tech, Inc., San Diego, California, USA

Funding: Work supported by DOE Office of Nuclear Physics, DOE-SBIR #DE-SC0002529
We present the current status of FAR-TECH's Solid State RF Power Source for the Jefferson Laboratory CEBAF Linac. This power source design features up to 8 kW CW RF output power, GaN amplifier stages with high efficiency (>60%), and a compact design to fit existing rack space and cooling requirements at the installation site. We have finished most of the designs and have performed successfully the most critical tests of this project, the 4 to 1 combiner test and the cooling test. FAR-TECH’s solid state amplifier design has high efficiency, a wide range of design frequency (DC-3GHz), and long lifetime, which provides a good RF power source.

THPPC075

Development of a Digital Low-level RF Control System for the p-Linac Test Stand at FAIR

controls, cavity, low-level-rf, proton

3461

M. Konrad, U. Bonnes, C. Burandt, R. Eichhorn, J. Enders, P.N. Nonn, N. Pietralla
TU Darmstadt, Darmstadt, Germany

Funding: Work supported by DFG through CRC 634 and by the BMBF under 06 DA 9024 I
A test stand for a proton Linac is currently built at GSI in the context of the FAIR project. Its low-level RF control system will be based on a system that has been developed for the S-DALINAC at TU Darmstadt operating at 3 GHz. This system converts the RF signal coming from the cavity down to the base band using a hardware I/Q demodulator. The base-band signals are digitized by ADCs and fed into an FPGA. A custom CPU implemented in the FPGA executes the control algorithm. The resulting signals are I/Q modulated before they are sent back to the cavity. The RF module has to be adapted to the p-LINAC's operating frequency of 325 MHz. Moreover, the p-LINAC will run in pulsed operation whereas the S-DALINAC is operated in CW mode. Different quality factors of the cavities and the pulsed operation require a redesign of the control algorithm. We will report on the modifications necessary to adapt the S-DALINAC's control system to the p-LINAC test stand and on first results obtained from tests with a prototype.

THPPD009

Accelerator Magnets R&D Programme at CERN

dipole, quadrupole, permanent-magnet, luminosity

3512

D. Tommasini, L. Bottura, G. De Rijk, L. Rossi
CERN, Geneva, Switzerland

The exploitation and evolution of the CERN accelerator complex pose a continuous challenge for magnet engineers. Superconducting and resistive magnets have a comparable share. The overall mass of either is approximately 50,000 tons, spread over 3 major machines (PS, SPS and LHC), two large experimental area, and a number of smaller experiments and accelerator rings. On the short term (2012-2014) the CERN plan is to upgrade its injection chain (Linac4) and experimental area (HIE-Isolde, ELENA) that require mostly a multitude of resistive magnets. The medium-term plan for the evolution of the LHC complex (2015-2021), also referred to as High-Luminosity LHC, foresees interventions on about 1 km of the machine, with magnets to be substituted with higher field, larger aperture, or both. On the long term (2025-2035) we are exploring the technological challenges of very high field magnets, at the verge of 20 T for a High Energy LHC (HE-LHC), or extremely stable high gradient quadrupoles for the Compact Linear Collider (CLIC). In this paper we provide an overview of the R&D activities addressing the various lines of development, the technology milestones, and a broad time schedule.

THPPD051

New Power Supply of the Injection Bump Magnet for Upgrading the Injection Energy in the J-PARC 3-GeV RCS

power-supply, injection, superconductivity, proton

3626

T. Takayanagi, N. Hayashi, M. Kinsho, N. Tani, T. Togashi, T. Ueno
JAEA/J-PARC, Tokai-Mura, Naka-Gun, Ibaraki-Ken, Japan

With the energy upgrading of LINAC (Linear accelerator) to 400 MeV in the J-PARC (Japan Proton Accelerator Research Complex), a new power supply of the injection bump magnet has been designed for the 3-GeV RCS (Rapid Cycling Synchrotron). The new power supply is composed with the capacitor bank which has function to form the output current pattern. This power supply is a commutation strategy using the electrical charge and discharge of the capacitor, and the frequency of the switch that becomes the source of the noise is a little. Comparing to the conventional switching-type power supply, this power supply is switched only twice for the pattern formation. Thus, the ripple due to the switching can be expected to be much lower. The 1/16 scale model was manufactured and the characteristics was evaluated. This paper summarizes the design parameter and the experimental result of the new power supply.

THPPD073

Development and Management of the Modulator System for PLS-II 3.0 GeV Electron Linac

controls, power-supply, klystron, feedback

3683

S.H. Kim, J.Y. Huang, S.J. Kwon, B.-J. Lee, Y.J. Moon, S.H. Nam, S.S. Park, S. Shin
PAL, Pohang, Kyungbuk, Republic of Korea

Funding: This work is supported by MEST(Ministry of Education, Science and Technology) and POSCO(Pohang Steel and Iron Company).
The Pohang Accelerator Laboratory (PAL) had started the upgrade project (called PLS-II) of the Pohang Light Source (PLS) from 2009 for increasing its energy from 2.5 GeV to 3 GeV and changing the operation mode from fill-up to top-up mode. Top-up mode operation requires high energy stability of the linac beam and machine reliability in the linac modulator systems. For providing the additional 0.5 GeV energy from the 2.5 GeV PLS linac, we added four units of the modulator system. We have two different types of the pulse modulator system for using existing pulse modulators, thyristor control type, in the upgrade project (PLS-II). The two types are thyristor control type and inverter power type. In the thyristor control type, a de-Qing system controls the modulator pulse forming network (PFN) charging voltage stability, and in the inverter power supply type, CCPS provides highly stable charging voltage to the modulator. We will present development and management of the pulse modulator system for obtaining machine reliability and stability from 3.0 GeV linac.

THPPD077

ISIS Injector 2 MW Pulsed RF System Power Supply Upgrade

controls, simulation, power-supply, cathode

3695

R.J. Anderson
STFC/RAL/ISIS, Chilton, Didcot, Oxon, United Kingdom
M. Keelan
STFC/RAL, Chilton, Didcot, Oxon, United Kingdom

The ISIS pulsed neutron and muon source uses a 4-stage 70 Mev linear accelerator powered by TH116 triode valves. The TH116 anode supply capacitor banks have until recently been supplied by conventional 6-pulse silicon controlled rectifier (SCR) bridges delivering up to 40 kV at 5 A direct current. This dated system has become increasingly difficult to maintain. Early trials of an upgraded system using modern, compact, capacitor charging, switch mode supplies (SMPSs) resulted in severe supply power quality issues due to the pulsed nature of the current demanded from the capacitor banks. Measurements and Spice simulations of the old and replacement supplies allowed the power quality issues to be investigated and an additional external-to-the-SMPS regulator control loop to be developed. The new SMPSs operating with the additional control loop have been tested successfully on several of the linear accelerator stages and are now in continuous operational use. The process of replacing all the original SCR 6-pulse bridges is now well advanced and the operational benefits for ISIS are becoming evident.

THPPD079

Compact, High Current, High Voltage Solid State Switches for Accelerator Applications

high-voltage, pulsed-power, klystron, laser

3701

H.D. Sanders, S.C. Glidden
APP, Freeville, USA

Most switches used for high current, high voltage accelerator applications are vacuum or gas switches, such as spark gaps and thyratrons. Recently, high voltage IGBT based switches have become common, but are limited in current and are not compact. This paper will describe a compact, high current, high voltage solid state switch. These switches have been tested to 50kV, to greater than 12kA, to greater than 50kA/μs, to 360Hz, and to 3x10⁸ pulses, without failure. They have been used in accelerators to drive klystrons and kickers, and have been used as crowbars while offering advantages over thyratron switches for cost, lifetime, size and weight. The switches are based on series connected fast thyristors with 3cm² die in a 20cm² package. This package is more compact than TO-200 Puk sized devices, and does not require compression for proper operation. Each package is rated for 4kV, 14kA and 30kA/μs. One example, a 48kV switch which includes the trigger and snubber circuits, fits in a volume of 200mm x 85mm x 65mm, and requires only a fiber-optic trigger input. Such switches have been used on SRS and EMMA at Daresbury Laboratory in the UK, and at several US national laboratories.

THPPD082

A Novel Solid-State Marx Modulator Topology with Voltage Droop Self-Compensation

controls, simulation, high-voltage, factory

3707

P. Chen, M. Lundquist, D. Yu
DULY Research Inc., Rancho Palos Verdes, California, USA

Funding: Work supported by U.S. Department of Energy SBIR grant no. DE-FG02-08ER85052.
Solid-state Marx modulators are preferred over conventional modulators in accelerators and radar applications because of their high flexibility, high reliability and long life. However, voltage droop is a notable issue. A novel topology of solid-state Marx modulators is described in this paper for raising their electric energy utilization ratios (EEURs). The new Marx modulator incorporates a buck regulator circuit into each Marx cell and adopts a higher charge voltage than that of application. The topology allows Marx cells to store more electric energy and utilize the energy more efficiently than others. Initial theoretical analysis and preliminary experiments show that solid-state Marx modulators constructed with this topology and under proper control of the stepwise energy release are able to significantly enhance their EEURs. The cost effective Marx modulators with compact energy storage sizes will resolve the issue of voltage droop when they are used in high power, long pulse applications.

THPPP014

Design Parameters of a High-Power Proton Synchrotron for Neutrino Beams at Cern

proton, space-charge, synchrotron, injection

3755

Y. Papaphilippou, M. Benedikt, I. Efthymiopoulos, F. Gerigk, R. Steerenberg
CERN, Geneva, Switzerland

Design studies have been initiated at CERN for exploring the prospects of future high-power proton beams for producing neutrinos within the LAGUNA-LBNO project. These studies include a possible increase of the SPS beam power from 500kW to 700kW for a new conventional neutrino beam line based on the CNGS technology, and at a second stage a 2~MW High-Power Proton Synchrotron (HP-PS) using the Low Power Superconducting Proton Linac (LP-SPL) as injector. A low energy 5GeV-4MW neutrino super-beam alternative based on a high-power version of SPL is also considered. This paper concentrates on the HP-PS by exploring the parameter space and constraints regarding beam characteristics, machine hardware and layout, for reaching the 2~MW average beam power.

THPPP031

RF Design of ESS RFQ

rfq, simulation, coupling, cavity

3800

O. Piquet, M. Desmons, A. France
CEA/DSM/IRFU, France
O. Delferrière
CEA/IRFU, Gif-sur-Yvette, France

The low energy front end of ESS is based on a 352 MHz, 5-m long Radiofrequency Quadrupole (RFQ) cavity. It will accelerate and bunch proton beams from 75 keV to 3 MeV. The beam current is 50 mA (75 mA as an upgrade scenario) for 4% duty cycle. A complete RF analysis of the ESS RFQ has been performed using 3D RF simulating codes and a RFQ 4-wire transmission line model. Proposed RFQ is a 4 vane-type structure where 2D cross-section is optimized for lower power dissipation, while featuring simple geometrical shape suitable for easy machining. RF calculations are performed for the whole RFQ, and mainly for the following parts: end cells, vacuum port, tuners and RF coupling ports. Power losses are particularly calculated in order to achieve Thermo-mechanical calculations.

THPPP032

Advanced Layout Studies for the GSI CW-Linac

solenoid, cavity, ion, heavy-ion

3803

W.A. Barth, S. Mickat
GSI, Darmstadt, Germany
S. Jacke
HIM, Mainz, Germany

Beam dynamics studies were made with the LORASR code for the planned superconducting (sc)continuous wave (cw) linear accelerator. It comprises a fixed accelerating part with an output energy of 3.5 MeV/u at a design mass/charge ratio of 6 and an energy variable part with an output energy of up to 7.3 MeV/u. The general layout, which provides for nine cavities combined with seven separate solenoids for a total length of 12.7 m, is based on a basic design by A. Minaev*. The recent studies show the parameter study for output energy variation. The statistical rotational and transverse offset error calculations illuminate the tolerances for acceptable errors. These are particularly relevant in the beam dynamics within a superconducting environment. Further calculations focus on varying the charge-to-mass ratio to reach linac energies up to 10 MeV/u, meeting the requirements of future UNILAC experiments.
*A. Minaev et al., “Superconducting, energy variable heavy ion linac with constant beta, multicell cavities of CH-type,” PRST-AB 12, 120101 (2009).

THPPP033

New Developments for the Present and Future GSI Linacs

ion, cavity, emittance, proton

3806

L. Groening, W.A. Barth, G. Clemente, V. Gettmann, B. Schlitt
GSI, Darmstadt, Germany
M. Amberg, K. Aulenbacher, S. Mickat
HIM, Mainz, Germany
F.D. Dziuba, H. Podlech, U. Ratzinger, C. Xiao
IAP, Frankfurt am Main, Germany

For more than three decades, GSI has successfully operated the Universal Linear Accelerator (UNILAC), providing ions from protons to uranium at energies from 3 to 11 MeV/u. The UNILAC will serve for a comparable period as injector for the upcoming FAIR facility which will ask for short pulses of high peak currents of heavy ions. The UNILAC Alvarez-type DTL has been in operation since the earliest days of the machine, and it needs to be replaced to assure reliable operation for FAIR. This new DTL will serve the needs of FAIR, while demands of high duty cycles of moderate currents of intermediate-mass ions will be met by construction of a dedicated superconducting cw-linac. FAIR requires additionally provision of primary protons for its pbar physics program. A dedicated proton linac is under design for that task. The contribution will present the future linacs to be operated at GSI. Finally we introduce a novel method to provide flat ion beams for injection into machines having flat injection acceptances.

THPPP034

Optimization of a CW RFQ Prototype

rfq, simulation, impedance, DTL

3809

U. Bartz, J. Gerbig, H.C. Lenz, A. Schempp
IAP, Frankfurt am Main, Germany

A short RFQ prototype was built for RF-tests of high power RFQ structures. We studied thermal effects to determine critical points of the design. HF-simulations with CST Microwave Studio and measurements were done. The cw-tests with 20 kW/m RF-power and simulations of thermal effects with ALGOR were finished successfully. The optimization of some details of the RF design is on focus now. Results and the status of the project will be presented

THPPP036

First Measurements of an Coupled CH Power Cavity for the FAIR Proton Injector

cavity, coupling, proton, DTL

3812

R. M. Brodhage, H. Podlech, U. Ratzinger
IAP, Frankfurt am Main, Germany
G. Clemente, L. Groening
GSI, Darmstadt, Germany

For the research program with cooled antiprotons at FAIR a dedicated 70 MeV, 70 mA proton injector is required. The main acceleration of this room temperature linac will be provided by six CH cavities operated at 325 MHz. Each cavity will be powered by a 2.5 MW klystron. For the second acceleration unit from 11.5 MeV to 24.2 MeV a 1:2 scaled model has been built. Low level RF measurements have been performed to determine the main parameters and to prove the concept of coupled CH cavities. For this second tank technical and mechanical investigations have been performed to develop a complete technical concept for manufacturing. In Spring 2011, the construction of the first power prototype has started. The main components of this cavity were ready for measurements in fall 2011. At that time, the cavity was tested with a preliminary aluminum drift tube structure, which will allow precise frequency and field tuning. This paper will report on the recent technical developments and achievements. It will outline the main tuning and commissioning steps towards that novel type of proton DTL and it will show very promising results of the latest measurements.

THPPP037

Status of the 325 MHz 4-ROD RFQ

simulation, rfq, dipole, HOM

3815

B. Koubek, A. Schempp, J.S. Schmidt
IAP, Frankfurt am Main, Germany
L. Groening
GSI, Darmstadt, Germany

For the FAIR project of GSI as part of the proton linac, a 325 MHz 4-ROD RFQ with an output energy of 3 MeV is planned. Due to the simulations regarding the RF design, a prototype of this RFQ was built. Measurements with this prototype to verify the simulation results have been done. In addition, simulations with increasing cell numbers and simulations concerning the boundary fields of the electrodes are presented in this paper.

THPPP038

Simulations of the Influence of 4-Rod RFQ Elements on its Voltage Distribution

rfq, simulation, resonance, insertion

3818

J.S. Schmidt, B. Koubek, A. Schempp
IAP, Frankfurt am Main, Germany

The influence of tuning methods and other design elements of 4-rod-RFQs on the voltage distribution have been studied during the last months. Every change in the field geometry or the voltage distribution could for example lead to particle losses or a raise in the surface current on single parts of the RFQ. That’s why further research had to be done about the behavior of the 4-rod-RFQ especially in the comparison of structures at 100 or 200 MHz. The results of an analysis which is concentrated on simulations using CST Microwave Studio to evaluate the effects of the overhang of electrodes, modulation and piston tuners on the fields in the RFQ are presented in this paper.

THPPP041

A CW High Charge State Heavy Ion RFQ Accelerator for SSC-LINAC Injector

rfq, resonance, focusing, ion

3826

G. Liu, J.E. Chen, S.L. Gao, Y.R. Lu, Z. Wang, X.Q. Yan, Q.F. Zhou, K. Zhu
PKU/IHIP, Beijing, People's Republic of China
Y. He, C. Xiao, Y.Q. Yang, Y.J. Yuan, H.W. Zhao
IMP, Lanzhou, People's Republic of China

Funding: Supported by NSFC(11079001).
The cooler storage ring synchrotron CSR of HIRFL started running in 2008. The SFC (Sector Focusing Cyclotron) and SSC (Separator Sector Cyclotron) form an injector for the CSR. To improve beam intensity and/or injection efficiency, a new linear injector, the SSC-LINAC, for the SSC has been proposed to replace the existing SFC. The SSC-LINAC consists of an ECR ion source, LEBT, a RFQ, MEBT, and four IH-DTLs. This paper only represents the design research of the RFQ accelerator, which has a frequency of 53.667MHz. The ions up to uranium with ratio of mass-to-charge up to 7 are accelerated and injected into the CSR by the SSC-LINAC. The SSC-LINAC works on CW mode. The RFQ beam dynamic design study is based on 238U³⁴⁺ beams with intensity of 0.5mA. The inter-vane voltage is 70kV with a maximum modulation factor of 1.93. It uses a 2.5m-long 4-rod structure to accelerate uranium ions from 3.728keV/u to 143keV/u with transmission efficiency of 94%. The RFQDYN code checks the transmission of different kinds of ions in the RFQ. The specific shunt impedance of RFQ is optimized to 438kΩ.m. The design of cavity tuning and the water cooling system are also included in this paper.
Corresponding authors: yrlu@pku.edu.cn, hey@impcas.ac.cn

THPPP043

Installation of 100-MeV Proton Linac for PEFP

proton, DTL, klystron, site

3832

Y.-S. Cho, S. Cha, J.S. Hong, J.-H. Jang, D.I. Kim, H.S. Kim, H.-J. Kwon, B.-S. Park, J.Y. Ryu, K.T. Seol, Y.-G. Song, S.P. Yun
KAERI, Daejon, Republic of Korea

Funding: This work was supported by the Ministry of Education, Science and Technology of the Korean Government.
The Proton Engineering Frontier Project (PEFP) at Korea Atomic Energy Research Institute (KAERI) is developing a 100-MeV proton linac in order to supply 20-MeV and 100-MeV proton beams to users for proton beam application. The linac consists of a 50-keV injector, a 3-MeV radio frequency quadrupole (RFQ) and a 100-MeV drift tube linac (DTL). The operation of the 20-MeV part of linac at Daejeon site was finished on November 2011. It was disassembled and moved to the Gyeongju site for installation as a low energy part of the linac. We completed the fabrication and test of the accelerating structures. The installation of the proton linac started in December 2011 at the new project site. The user service is scheduled for 2013 through the beam commissioning in 2012. This work summarized the installation status of the proton linac.

THPPP044

RF Set-up Scheme for PEFP DTL

DTL, proton, rfq, simulation

3835

J.-H. Jang, Y.-S. Cho, H.S. Kim, H.-J. Kwon
KAERI, Daejon, Republic of Korea

Funding: This work was supported by the Ministry of Education, Science and Technology of the Korean Government.
The proton engineering frontier project (PEFP) is developing a 100-MeV proton linac which consists of a 50 keV injector, a 3-MeV radio frequency quadrupole (RFQ) and a 100-MeV drift tube linac (DTL). The installation of the linac was started in December 2011. The beam commissioning is scheduled for 2012. The phase scan signature method is a common technique to determine the rf set point including the amplitude and phase in DTL tanks. This work summarized the rf set-up scheme for PEFP DTL tanks by using the phase scan signature method.

THPPP045

Five Year Operation of the 20-MeV Proton Accelerator at KAERI

proton, ion-source, site, ion

3838

H.-J. Kwon, Y.-S. Cho, J.-H. Jang, D.I. Kim, H.S. Kim, B.-S. Park, J.Y. Ryu, K.T. Seol, Y.-G. Song, S.P. Yun
KAERI, Daejon, Republic of Korea

Funding: This work was supported by the Ministry of Science and Technology of the Korean Government.
A 20-MeV proton linear accelerator has been operating since 2007 by Proton Engineering Frontier Project (PEFP) at Korea Atomic Energy Research Institute (KAERI), Daejeon site. The performance test of the accelerator itself has been done with limited operating conditions. In addition, the 20-MeV accelerator was used as a test bench of the 100-MeV accelerator components. Besides the machine study itself, it supplied proton beams to more than 1600 samples for users. The 20-MeV accelerator was disassembled at the end of 2011 and will be installed at Gyeong-Ju site as an injector for the 100-MeV linac in 2012. In this paper, the 5 year operation experiences of the 20-MeV linac at Daejeon site are summarized and the technical issues are discussed.

THPPP046

ESS End-to-End Simulations: a Comparison Between IMPACT and MADX

simulation, space-charge, cavity, DTL

3841

E. Laface, R. Miyamoto
ESS, Lund, Sweden
D.C. Plostinar, C.R. Prior
STFC/RAL/ASTeC, Chilton, Didcot, Oxon, United Kingdom

The European Spallation Source will be a 5 MW superconducting proton linac for the production of spallation neutrons. It is composed of an ion source, a radio frequency quadrupole, a drift tube linac and a superconducting linac as well as the low, medium and high, energy beam transport sections. At present these components of the linac are in the design phase: the optimization of the accelerator parameters requires an intensive campaign of simulations to test the model of the machine under possible operational conditions. In this paper the results of simulations performed with the IMPACT and MADX-PTC codes are presented and a comparison is made between them and independent simulations using TraceWin. The dynamics of the beam envelope and single and multi-particle tracking are reported.

THPPP048

Linac4 - Low Energy Beam Measurements

solenoid, emittance, rfq, ion

3847

L.M. Hein, G. Bellodi, J.-B. Lallement, A.M. Lombardi, O. Midttun, P.A. Posocco, R. Scrivens
CERN, Geneva, Switzerland

Linac4 is a160 MeV normal-conducting linear accelerator for negative Hydrogen ions (H−), which will replace the 50 MeV proton Linac (Linac2) as linear injector for the CERN accelerators. The low energy part, comprising a 45 keV Low Energy Beam Transport system (LEBT), a 3 MeV Radiofrequency Quadrupole (RFQ) and a Medium Energy Beam Transport (MEBT) is being assembled in a dedicated test stand for pre-commissioning with a proton beam. During 2011 extensive measurements were done after the source and after the LEBT with the aim of preparing the RFQ commissioning and validating the simulation tools, indispensable for future source upgrades. The measurements have been thoroughly simulated with a multi-particle code, including 2D magnetic field maps, error studies, steering studies and the generation of beam distribution from measurements. Emittance, acceptance and transmission measurements will be presented and compared to the results of the simulations.

THPPP049

Tuning Procedure for the LINAC4 PI Mode Structure (PIMS)

simulation, cavity, coupling, electron

3850

P. Ugena Tirado, F. Gerigk, R. Wegner
CERN, Geneva, Switzerland

PI-Mode-Structure (PIMS) cavities will be used in the high energy section of LINAC4 (10²-160 MeV). Each cavity is made of 7 coupled cells, operated in the π-mode at a resonant frequency of 352.2 MHz. The cell length remains constant for each of the 12 cavities but changes from cavity to cavity to synchronise with the increased beam energy. This paper reports on the tuning process required to get a constant voltage in each cell at the resonant frequency and consisting in re-machining to the required level the tuning rings located on each cell-wall. An algorithm based on single cell detuning, equivalent circuit simulations and precise 3D simulations for the 3 different cell types of each cavity has been developed and successfully applied to the tuning of the first PIMS cavity. In order to reduce the simulation effort for the remaining 11 cavities, an interpolation algorithm based on 3 cavities has been developed and validated. In a second tuning step, after the electron beam welding of all cells, the final adjustment of single-cell frequencies and field flatness is achieved by cutting the length of one plunger tuner per cell.

THPPP050

HIE-ISOLDE SC Linac: Operational Aspects and Commissioning Preparation

emittance, diagnostics, cryomodule, ion

3853

D. Voulot, E. Bravin, M.A. Fraser, B. Goddard, Y. Kadi, D. Lanaia, A.S. Parfenova, M. Pasini, A.G. Sosa, F. Zocca
CERN, Geneva, Switzerland

In the framework of the HIE-ISOLDE project, the REX linac will be upgraded in stages to 5.5 MeV/u and 10 MeV/u using superconducting (SC) quarter-wave cavities. The linac lattice is now frozen and the beam dynamics has been checked. The beam properties at the output of the NC linac for the different stages have been measured and are compatible with the SC linac acceptance. The high-energy beam transfer design is being finalised and a study has been launched for a buncher/chopper system allowing 100 ns bunch spacing for time-of-flight measurements. A compact diagnostic box for the inter-cryomodule region is under development and a new Si-detector based monitor for energy and phase measurements has been tested.

THPPP052

Modelling the ISIS 70 MeV Linac

DTL, rfq, quadrupole, simulation

3859

D.C. Plostinar, C.R. Prior, G.H. Rees
STFC/RAL/ASTeC, Chilton, Didcot, Oxon, United Kingdom
A.P. Letchford
STFC/RAL/ISIS, Chilton, Didcot, Oxon, United Kingdom
A.W. Mitchell
University of Warwick, Coventry, United Kingdom

The ISIS linac consists of four DTL tanks that accelerate a 50 pps, 20 mA H⁻ beam up to 70 MeV before injecting it into an 800 MeV synchrotron. Over the last decades, the linac has proved to be a stable and reliable injector for ISIS, which is a significant achievement considering that two of the tanks are nearly 60 years old. At the time the machine was designed, the limited computing power available and the absence of modern modeling codes, made the creation of a complex simulation model almost impossible. However, over the last few years, computer tools have became an integral part of any accelerator design, so in this paper we present a beam dynamics model of the ISIS linac. A comparison between the simulation results and machine operation data will be discussed, as well as possible linac tuning scenarios and recommended upgrades based on the new model.

THPPP056

Beam Loss Due to Misalignments, RF Jitter and Mismatch in the Fermilab Project-X 3GeV CW Linac

solenoid, quadrupole, lattice, beam-losses

3868

J.-P. Carneiro, V.A. Lebedev, S. Nagaitsev, J.-F. Ostiguy, A. Saini, B.G. Shteynas, N. Solyak
Fermilab, Batavia, USA

This paper presents an analysis of beam losses along the current design of the FNAL 3 GeV superconducting cw linac. Simulations from the RFQ exit up to the end of the linac (~430 meters) are performed on the FermiGrid using the beam dynamics code TRACK. The impact of beam mismatch, element misalignments, and RF jitter on the beam dynamics is discussed and corresponding beam loss patterns are presented. A correction scheme to compensate for misalignments is described.

THPPP063

CW Room Temperature Re-buncher for the Project X Front End

cavity, simulation, beam-transport, vacuum

3880

G.V. Romanov, M.H. Awida, M. Chen, I.V. Gonin, S. Kazakov, R.A. Kostin, V.A. Lebedev, N. Solyak, V.P. Yakovlev
Fermilab, Batavia, USA

At Fermilab there is a plan to construct the Project X Injector Experiment (PXIE) facility - a prototype of the front end of the Project X, a multi-MW proton source based on a superconducting linac. The construction and successful operations of this facility will validate the concept for the Project X front end, thereby minimizing the primary technical risk element within the Project. The front end of the linac contains a cw room-temperature MEBT section which comprises an ion source, RFQ, and high-bandwidth bunch selective chopper. The length of the MEBT exceeds 9 m, so three re-bunching cavities are used to support the beam longitudinal dynamics. The paper reports RF design of the re-bunchers along with preliminary beam dynamic and thermal analysis of the cavities.

THPPP066

Beam Tuning Strategy of the FRIB Linac Driver

cavity, solenoid, coupling, ion

3889

Y. Zhang
FRIB, East Lansing, Michigan, USA

Funding: This material is based upon work supported by the U.S. Department of Energy Office of Science under Cooperative Agreement DE-SC0000661.
The FRIB linac driver will deliver heavy ion beams up to uranium, with an energy of 200 MeV/u and total power on target of 400 kW. To reach the design power for heaviest ions, multi-charge-state beams will be accelerated simultaneously in this SRF linac. Beam tuning of the linac driver is among the most challenging tasks. In this paper, we discuss the beam tuning strategy, which includes the cavity synchronous phase and acceleration gradient setup, beam trajectory correction, and transverse matching with horizontal-vertical coupled beams as superconducting solenoids are used for transverse focusing in the linac segments.

THPPP067

H⁻ Beam Loss and Evidence for Intrabeam Stripping in the LANSCE Linac

ion, electron, radiation, emittance

3892

L. Rybarcyk, C.T. Kelsey, R.C. McCrady, X. Pang
LANL, Los Alamos, New Mexico, USA

Funding: U.S. Dept. of Energy, NNSA, under contract DE-AC52-06NA25396.
The LANSCE accelerator complex is a multi-beam, multi-user facility that provides high-intensity H⁺ and H⁻ particle beams for a variety of user programs. At the heart of the facility is a room temperature linac that is comprised of 100-MeV drift tube and 800-MeV coupled cavity linac (CCL) structures. Although both beams are similar in intensity and emittance, the beam-loss monitors along the CCL show a trend of increased loss for H⁻ that is not present for H⁺. This difference is attributed to stripping mechanisms that affect H⁻ and not H⁺. We present the results of an analysis of H⁻ beam loss along the CCL that incorporates beam spill measurements, beam dynamics simulations, analytical models and radiation transport estimates using the MCNPX code. The results indicate a significant fraction of these additional losses result from intrabeam stripping.

THPPP069

Double-Gap Rebuncher Cavity Design of SNS MEBT

cavity, DTL, simulation, impedance

3898

K.R. Shin
ORNL RAD, Oak Ridge, Tennessee, USA
A.E. Fathy
University of Tennessee, Knoxville, Tennessee, USA
Y.W. Kang
ORNL, Oak Ridge, Tennessee, USA

A double-gap rebuncher cavity has been studied through design and analysis with computer simulations. This cavity shape is a two cell abridged form of drift tube linac (DTL), instead an omega form of existing single gap elliptical cavity. The cavity operates in TM010 mode, likewise the commonly used single-gap cavities in some medium energy beam transport (MEBT) line of proton accelerators. The new cavity is more power efficient even with slightly lower Q factor because of utilization of two interactive gaps. The breakdown field can be lowered with adjustment of gap and tube length ratio. Electromagnetic, beam envelope, and thermal simulations are presented with comparison to the properties of the conventional elliptical cavity.

THPPP071

Design of the ESS Accelerator

klystron, target, DTL, cryomodule

3904

H. Danared
ESS, Lund, Sweden

The European Spallation Source, ESS, has produced a Conceptual Design Report at the end of 2011 which will evolve towards a Technical Design Report at the end of 2012. This paper is presented on behalf of the ESS Accelerator Design Update Collaboration and will describe the current design of the ESS linear accelerator.

THPPP075

Present Status and Developments of the Linear IFMIF Prototype Accelerator (LIPAc)

rfq, cavity, solenoid, SRF

3910

A. Mosnier, P. Cara, R. Heidinger
Fusion for Energy, Garching, Germany
P.-Y. Beauvais, S. Chel
CEA/IRFU, Gif-sur-Yvette, France
A. Facco, A. Pisent
INFN/LNL, Legnaro (PD), Italy
A. Ibarra, J. Molla
CIEMAT, Madrid, Spain
V. Massaut, D. Vandeplassche
SCK•CEN, Mol, Belgium
H. Matsumoto, G. Pruneri, Ch. Vermare
IFMIF/EVEDA, Rokkasho, Japan
M. Sugimoto, H. Suzuki
JAEA, Aomori, Japan

The International Fusion Materials Irradiation Facility (IFMIF) aiming at generating materials irradiation test data for DEMO and future fusion power plants is based on an accelerator-driven, D-Li neutron source to produce high energy neutrons at sufficient intensity and irradiation volume. IFMIF Engineering Validation and Engineering Design Activities (EVEDA) have been conducted since mid 2007 in the framework of the Broader Approach Agreement and the scope of the project has been recently revised to set priority on the validation activities, especially on the Accelerator Prototype (LIPAc) with extending the duration up to mid 2017 in order to better fit the development of the challenging components and the commissioning of the whole accelerator. This paper summarizes the present status of the LIPAc, currently under construction at Rokkasho in Japan, outlines the engineering design and the developments of the major components, as well as the expected outcomes of the engineering work, associated with the experimental program.

THPPP080

Beam Halo Reduction in the J-PARC 3-GeV RCS

emittance, injection, bunching, extraction

3918

H. Hotchi, H. Harada, P.K. Saha, Y. Shobuda, F. Tamura, K. Yamamoto, M. Yamamoto, M. Yoshimoto
JAEA/J-PARC, Tokai-Mura, Naka-Gun, Ibaraki-Ken, Japan
Y. Irie, T. Koseki, Y. Sato, M.J. Shirakata
KEK, Ibaraki, Japan
K. Satou
J-PARC, KEK & JAEA, Ibaraki-ken, Japan

The J-PARC RCS (3-GeV rapid cycling synchrotron) has two functions as a proton driver to the MLF (Materials and life science facility) and an injector to the MR (50-GeV main ring synchrotron). One of important issues in the current RCS bam tuning is to suppress the beam halo formation, which is essential especially to reduce the beam loss at the MR. In this paper, we present beam study results on the formation mechanism and reduction of the beam halo in the RCS.

THPPP085

End to End Beam Dynamics of the ESS Linac

proton, target, DTL, quadrupole

3933

M. Eshraqi, H. Danared, A. Ponton
ESS, Lund, Sweden
I. Bustinduy
ESS Bilbao, Bilbao, Spain
L. Celona
INFN/LNS, Catania, Italy
M. Comunian
INFN/LNL, Legnaro (PD), Italy
A.I.S. Holm, S.P. Møller, H.D. Thomsen
ISA, Aarhus, Denmark
J. Stovall
CERN, Geneva, Switzerland

The European Spallation Source, ESS, uses a linear accelerator to deliver a high intensity proton beam to the target station. The nominal beam power on target will be 5~MW at an energy of 2.5~GeV. We briefly describe the individual accelerating structures and transport lines through which we have carried out multiparticle beam dynamics simulations. We will present a review of the beam dynamics from the source to the target.

THPPP087

Beta Beams for Precision Measurements of Neutrino Oscillation Parameters

target, ion, proton, acceleration

3939

E.H.M. Wildner, E. Benedetto, T. De Melo Mendonca, C. Hansen, T. Stora
CERN, Geneva, Switzerland
D. Berkovits
Soreq NRC, Yavne, Israel
A. Brondi, A. Di Nitto, G. La Rana, R. Moro, E. Vardaci
Naples University Federico II, Napoli, Italy
G. Burt
Cockcroft Institute, Lancaster University, Lancaster, United Kingdom
A. Chancé, J. Payet
CEA/DSM/IRFU, France
M. Cinausero, G. De Angelis, F. Gramegna, V. Kravtchouk, T. Marchi, G.P. Prete
INFN/LNL, Legnaro (PD), Italy
G. Collazuol
Univ. degli Studi di Padova, Padova, Italy
G. De Rosa, V.C. Palladino
INFN-Napoli, Napoli, Italy
F. Debray, C. Trophime
GHMFL, Grenoble, France
T. Delbar, T. Keutgen, M. Loiselet, S. Mitrofanov
UCL, Louvain-la-Neuve, Belgium
M. Hass, T. Hirsch
Weizmann Institute of Science, Physics, Rehovot, Israel
I. Izotov, V. Sidorov, V. Skalyga, V. Zorin
IAP/RAS, Nizhny Novgorod, Russia
T. Lamy, L. Latrasse, M. Marie-Jeanne, P. Sortais, T. Thuillier
LPSC, Grenoble, France
M. Mezzetto
INFN- Sez. di Padova, Padova, Italy
A. Stahl
RWTH, Aachen, Germany

Funding: CERN and European Community under the European Commission Framework Programme 7 Design Study: EUROnu, Project Number 212372
Neutrino oscillations have implications for the Standard Model of particle physics. The “CERN Beta Beam” has outstanding capabilities to contribute to precision measurements of the parameters governing neutrino oscillations. The FP7 collaboration “EUROnu” (2008-2012) is a design study that will review three facilities (Super-Beams, Beta Beams and Neutrino Factories) and perform a cost assessment that, coupled with the physics performance, will give means to the European research authorities to make decisions on future European neutrino oscillation facilities. "Beta Beams" produce collimated pure electron (anti)neutrino beams by accelerating beta active ions to high energies and having them decay in a storage ring. Using existing machines and infrastructure is an advantage for the cost evaluation; however, this choice is also constraining the Beta Beams. Recent work to make the Beta Beam facility a solid option will be described: production of Beta Beam isotopes, the 60 GHz pulsed ECR source development, integration into the LHC-upgrades, ensure the high intensity ion beam stability, and optimizations to get high neutrino fluxes. The costing approach will also be described.

THPPP090

Project X Functional Requirements Specification

proton, collider, factory, target

3945

S.D. Holmes, S. Henderson, R.D. Kephart, J.S. Kerby, I. Kourbanis, V.A. Lebedev, C.S. Mishra, S. Nagaitsev, N. Solyak, R.S. Tschirhart
Fermilab, Batavia, USA

Funding: Work supported by the Fermi Research Alliance, under contract to the U.S. Department of Energy.
Project X is a multi-megawatt proton facility being developed to support a world-leading program in Intensity Frontier physics at Fermilab. The facility is designed to support programs in elementary particle and nuclear physics, with possible applications to nuclear energy research. A Functional Requirements Specification has been developed in order to establish performance criteria for the Project X complex in support of these multiple missions, and to assure that the facility is designed with sufficient upgrade capability to provide U.S. leadership for many decades to come. This paper will describe the Functional Requirements for the Project X facility, their recent evolution, and the rationale for these requirements.

THPPP091

Status of the Project-X CW Linac Design

cryomodule, emittance, lattice, rfq

3948

J.-F. Ostiguy, P. Berrutti, J.-P. Carneiro, V.A. Lebedev, S. Nagaitsev, A. Saini, B.G. Shteynas, N. Solyak, V.P. Yakovlev
Fermilab, Batavia, USA

Superconducting CW linac was proposed for Project X to accelerate H⁻ beam from 2.1 MeV to 3 GeV with nominal peak and average currents of respectively 5 mA and 1 mA. Linac built of 5 different families of resonators: half-wave, spoke (2), and elliptical (2) working at 162.5 MHz 325 MHz and 650 MHz to cover all energy range. Cavities and focusing elements are assembled in cryomodules. In baseline design all cryomodules are separated by short warm sections. It makes machine more reliable and maintainable and provide space for beam diagnostics and collimation. A long (~10m) gap between cryomodules at1 GeV is also being considered to provide space for beam extraction for nuclear experimental program. In paper we present the latest lattice of the linac baseline design and results of beam studies for this lattice. We briefly compare performance of the baseline design with alternative one without half-wave resonator section.

THPPP097

Diagnostic Pulse for Single-particle-like Beam Position Measurements During Accumulation/Production Mode in the Los Alamos Proton Storage Ring

diagnostics, injection, betatron, LLRF

3960

J.S. Kolski, S.A. Baily, E. Björklund, G.O. Bolme, M.J. Hall, S. Kwon, M.P. Martinez, M.S. Prokop, F.E. Shelley, P.A. Torrez
LANL, Los Alamos, New Mexico, USA

Beam position monitors (BPMs) are the primary diagnostic in the Los Alamos Proton Storage Ring (PSR). Injecting one turn, the transverse motion is approximated as a single particle with initial betatron position and angle (x0 and x0'). With single-turn injection, we fit the betatron tune, closed orbit (CO), and injection offset (x0 and x0' at the injection point) to the turn-by-turn beam position. In production mode, we accumulate multiple turns, the transverse phase space fills after 5 injections (horizontal and vertical fractional betatron tunes ~0.2) resulting in no coherent betatron motion, and only the CO may be measured. The injection offset, which determines the accumulated beam size and is very sensitive to steering upstream of the ring, is not measurable in production mode. We describe our approach and ongoing efforts to measure the injection offset during production mode by injecting a ‘‘diagnostic'' pulse ~50 us after the accumulated beam is extracted. We also study the effects of increasing the linac RF gate length to accommodate the diagnostic pulse on the production beam position, transverse size, and loss.

THPPR004

Development Status of Data Acquisition System for LIPAc

EPICS, status, controls, target

3972

H. Takahashi, T. Kojima, T. Narita, H. Sakaki
Japan Atomic Energy Agency (JAEA), International Fusion Energy Research Center (IFERC), Rokkasho, Kamikita, Aomori, Japan
S. Komukai
Gitec, Hachinohe, Japan

Control System for LIPAc* for IFMIF/EVEDA** realizes the remote control and monitoring and data acquisition by use of EPICS. LIPAc consists of the basic components for IFMIF Accelerator, and the purpose of LIPAc project is engineering validation of these components. Therefore, for the validations of each subsystem performance and the activity of IFMIF Accelerator design, it is very important data obtained by commissioning of LIPAc and each subsystem. To certainly archive the important data for LIPAc and to efficiently search the LIPAc data, for design and validation, we started developing Data Acquisition System (DAC) based on Relational Database (RDB) has been developed. The first design for DAC of LIPAc control system is configured (1) using PostgreSQL for RDB and (2) several RDB for data archiving to ensure the data archive performance and to consider the increasing data amount. In addition, (3) only one RDB for data search is included in DAC and users can search the data via this RDB. In this way, several RDB for DAC can behave only one RDB against users. In this article, the development status of DAC for LIPAc is presented.
* LIPAc: Linear IFMIF Prototype Accelerator
** IFMIF/EVEDA: International Fusion Material Irradiation Facility/Engineering Validation and Engineering Design Activity

THPPR012

Lorentz Force Compensation for Long Pulses in SRF Cavities

cavity, controls, SRF, cryomodule

3990

Y.M. Pischalnikov, G.I. Cancelo, B. Chase, D.J. Crawford, D.R. Edstrom, Jr, E.R. Harms, R.A. Kostin, W. Schappert, N. Solyak
Fermilab, Batavia, USA

Lorentz force compensation of 8ms pulses in Tesla style elliptical cavities has been studied in Fermilab SRF Test Facility. Detuning measurements and compensation results are presented.

THPPR017

The First Development of an EPICS Control System for the IAC Accelerators

power-supply, EPICS, controls, emittance

4002

A. Andrews, C.F. Eckman, A.W. Hunt, Y. Kim, D.P. Wells
IAC, Pocatello, IDAHO, USA
K.H. Kim
SLAC, Menlo Park, California, USA

At the Idaho Accelerator Center (IAC) of Idaho State University, we have been operating 15 low energy accelerators for nuclear physics applications and medical isotope production. But those accelerator do not have good computer based system to control the various accelerator components remotely. To obtain stable accelerator operations with a good reproducibility, we adapted the EPICS accelerator control system. After developing one full set of the EPICS accelerator control system for various components, we will apply the same EPICS control system for all other operating accelerators at the IAC. Since January 2011, we have been developing an EPICS control system for a 16 MeV S-band linac by collaborating with SLAC control group. In this paper, we describe our first EPICS accelerator control system to control magnet power supplies of the S-band linac at the IAC.

THPPR018

Development Progress of NSLS-II Accelerator Physics High Level Applications

controls, lattice, alignment, EPICS

4005

L. Yang, J. Choi, Y. Hidaka, G. Shen, G.M. Wang
BNL, Upton, Long Island, New York, USA

Funding: Work supported by Brookhaven Science Associates, LLC under Contract No. DE-AC02-98CH10886 with the Department of Energy.
The High Level Applications (HLA) for NSLS-II commissioning is a development in progress. It is in a client-server framework and uses Python programming language for scripting and graphical user interface application development. This new development provides both scripting and graphical user interface (GUI) controls. The services developed in controls group provide name server, archiving, machine snapshot etc. The clients are developed mainly in the physics group and have measurement, analysis and modeling capabilities.

THPPR026

Automated Phase Optimization for the HDSM at MAMI

synchrotron, injection, microtron, acceleration

4020

M. Dehn
IKP, Mainz, Germany

Funding: This work has been supported by CRC 443 of the Deutsche Forschungsgemeinschaft.
The Harmonic Double Sided Microtron (HDSM) at Mainz University is a very reliable stage of the 1.6 GeV CW microtron cascade MAMI. Nevertheless setting up and operating the machine depends largely upon an appropriate adjustment of the RF systems. To assist the MAMI operators, a new approach basing on the analysis of the synchrotron oscillation has been developed and enables the optimization of the RF phases of the linacs for the given RF amplitudes.

THPPR027

Sustaining the Reliability of the MAMI-C Accelerator

microtron, electron, controls, klystron

4023

H.-J. Kreidel, K. Aulenbacher, M. Dehn, F. Fichtner, R.G. Heine, P. Jennewein, W. Klag, U.L. Ludwig, J.R. Röthgen, V. Tioukine
IKP, Mainz, Germany

Funding: This work has been supported by CRC 443 of the Deutsche Forschungsgemeinschaft.
A status report of the 1.6 GeV electron accelerator MAMI-C is given together with an outlook towards its future operation. We describe problems which are imposed by some aging technical subcomponents in the first stages which have in part been in operation for almost 30 years. We present measures how to sustain the achieved extremely high reliability during the upcoming new research programs which are foreseen to last at least for one more decade.

THPPR029

A New Control Room for SLAC Accelerators

controls, synchrotron, electron, target

4029

R.A. Erickson, E. Guerra, M. Stanek, Z. Van Hoover, J. Warren
SLAC, Menlo Park, California, USA

Funding: This work was supported by the Department of Energy contract DE-AC02-76SF00515.
We propose to construct a new control room at SLAC to unify and improve the operation of the LCLS, SPEAR3, and FACET accelerator facilities, and to provide the space and flexibility needed to support the LCLS-II and proposed new test beam facilities. The existing control rooms for the linac and SPEAR3 have been upgraded in various ways over the last decade, but their basic features have remained unchanged. We propose to build a larger modern Accelerator Control Room (ACR) in the new Research Support Building (RSB), which is currently under construction at SLAC. Shifting the center of control for the accelerator facilities entails both technical and administrative challenges. In this paper, we describe the motivation and design concept for the ACR and the remaining challenges to completing this project.

THPPR031

Reliability Modeling Method for Proton Accelerator

cryomodule, simulation, proton, target

4035

S. Bhattacharyya, R.K. Yedavalli
Ohio State University, USA
J.S. Kerby, A. Mukherjee
Fermilab, Batavia, USA

Reliability Analysis is an essential part of designing any complex system in order to predict performance and understand availability. However modeling complex systems has been a challenging task due to the large number of components and inter-dependencies. The options have been custom written simulation packages, requiring large investment of programming and debugging time; or standard commercial software running for many days. In our research we developed a hierarchical method to represent the reliability model of “Project X,”* a proposed linear accelerator at Fermi National Accelerator Laboratory. The system is first divided into subsystems small enough to readily simulate. Each subsystem is then separately simulated and parameterized so they can be represented as simple blocks in the top level system diagram. This allows standard, commercial software to model systems with many tens of thousands of components without requiring many days of computer time. Simulation were run and compared with data gathered from existing accelerators.
* S.D. Holmes, "Project X: A Multi-MW Proton Source at Fermilab," Proc. of IPAC’10, TUYRA01, p. 1299 (2010).

THPPR033

Tests and Measurements with the Embedded Radiation-monitor-system Prototype for Dosimetry at the European XFEL

radiation, undulator, electron, neutron

4041

F. Schmidt-Föhre, D. Nölle, R. Susen, K. Wittenburg
DESY, Hamburg, Germany

A new Embedded Radiation-Monitor-System is currently under development for use in the upcoming European XFEL, that is being built at a length of approx. 3.4 km between the campus of the Deutsches Elektronen-Synchrotron DESY at Hamburg and Schenefeld at Schleswig-Holstein. Most of the electronic systems cabinets for machine control, diagnostics and safety of the XFEL will be located inside the accelerator tunnel. To prevent significant radiation damage at electronic systems in certain sections of the XFEL, all electronic cabinets inside the tunnel will be sufficiently shielded according to pre-estimated radiation levels. In addition, accumulated dose inside these electronic cabinets and in undulator regions will be monitored for the impact of Gamma- and Neutron-radiation by a new radiation monitor system. Life cycle estimations for these electronics and the undulators will provide safety limits for correct function and in time part exchange due to radiation, before significant radiation damage occurs. A prototype of the Gamma radiation-monitor system section has been successfully designed and tested at the DESY Linac II. Prototype tests and according measurements will be presented.

THPPR034

Safety Interlock Implementation of Top-up Operation in the SSRF Control System

controls, injection, storage-ring, booster

4044

L.R. Shen, G.H. Chen, J.F. Chen, W.D. Fang
SINAP, Shanghai, People's Republic of China

The SSRF has performed two years stable operation on decay mode. In order to realize the Top-up operation, the upgrade of control system has been carried out for Top-up trial run. Control system sets up the operation mode control center and accomplishes the upgrading of the MPS system. According to the requirements of the physical design, control system accomplished the design and implementation of the interface for interoperate with PPS system, beam diagnosis system and power supply system and set up the interlocks of the radiation dose, energy, injection efficiency, beam current and beam life in Top-up mode. The kernel of top-up operation safety interlock system is based on hardware interlock system and also provides software interlocking as auxiliary. In the meantime, the reliability of software interlock has been improved.

THPPR035

Design of Machine Protection System for the PEFP 100MeV Linac

proton, status, EPICS, controls

4047

K.T. Seol, Y.-S. Cho, J.-H. Jang, D.I. Kim, H.S. Kim, H.-J. Kwon, B.-S. Park, J.Y. Ryu, Y.-G. Song, S.P. Yun
KAERI, Daejon, Republic of Korea

Funding: * This work is supported by the Ministry of Education, Science and Technology of the Korean Government.
The 100MeV proton linear accelerator of the Proton Engineering Frontier Project (PEFP) has been developed and will be installed in Gyeong-ju site. After the installation, the beam commissioning of the 100MeV linac will be performed in 2012. A machine protection system (MPS) to shut off beam and to protect the 100MeV machine has been designed. Hardwares for an RF interlock, a modulator interlock, beam loss monitors, fast closing valves for vacuum window faults and so on have been manufactured and tested. With a hard-wired protection for a fast interlock, beam should be shut off within a few μs from the faults. The operator interface for MPS has been also designed to monitor and reset the faults easily. The details of the MPS design for the 100MeV machine are presented.

THPPR038

Failure Studies at the Compact Linear Collider: Main Linac and Beam Delivery System

quadrupole, betatron, wakefield, extraction

4056

C.O. Maidana, M. Jonker, A. Latina
CERN, Geneva, Switzerland

The proposed Compact Linear Collider (CLIC) is based on a two-beam acceleration scheme. The energy of two high-intensity, low-energy drive beams is extracted and transferred to two low-intensity, high-energy main beams. The machine protection and electrical integrity group has the mission to protect the various machine components from damage caused by ill controlled beams. Various failure scenarios were studied and the potential damage these failures could cause to the machine structures were estimated. In this paper, first results of the beam response to correctors and/or quadrupole kick failures in the main linac and in the beam delivery system (BDS) sections are presented as well as possible collimator damage scenarios. The use of the code PLACET for machine protection analysis is described as well.

THPPR043

Applications of X-band 950 keV and 3.95 MeV Linac X-ray Source for On-site Inspection

radiation, focusing, coupling, shielding

4071

M. Uesaka, K. Demachi, K. Dobashi, T. Fujiwara, H.F. Jin, M. Jin, H. Zhu
The University of Tokyo, Nuclear Professional School, Ibaraki-ken, Japan
Y. Hattori
Hitachi Engineering & Services Co.,Ltd., Japan
J. Kusano, N. Nakamura, M. Yamamoto
Accuthera Inc., Kawasaki, Kanagawa, Japan
I. Miura
Mitsubishi Chemical Corporation, Japan
E. Tanabe
AET, Kawasaki-City, Japan

Our portable X-band (9.3GHz) 950KeV linac has been successfully upgraded. The problems of RF power oscillation, beam current oscillation and reduction and finally lack of X-ray intensity were solved by replacing the axial coupling cavities with the side-coupled ones. Designed X-ray dose rate of 0.05 Sv/min@1m is going to be achieved. X-ray source part with the local radiation shielding is connected by the flexible waveguide with the box of a 250 kW magnetron and a cooling unit. The total system consists of the three suit-case-size units, the last of which is one for the electric power supply. We have also developed a portable X-band (9.3GHz) 3.95MeV linac for on-site bridge inspection. The system consists of a 62kg X-ray source part without 80kg target collimator, a 62kg RF power source and other utility box of 116kg. Designed X-ray dose rate is 2 Sv/min@1m with 200pps repetition rate and we have achieved 0.5 Sv/min@1m with 50pps repetition rate. Demonstration of the measurement of wall thinning of metal pipes with thick thermal shielding by 950keV linac and degradation of reinforced concrete sample by 3.95MeV is under way. Updated measurement results will be presented.

THPPR058

Pulse Radiolysis using Double-decker Femtosecond Electron Beam from a Photocathode RF Gun

electron, laser, gun, radiation

4106

K. Kan, T. Kondoh, K. Norizawa, A. Ogata, J. Yang, Y. Yoshida
ISIR, Osaka, Japan

Pulse radiolysis, which utilizes an electron bunch and a probe light (laser), is a powerful tool that can be used for an observation of ultrafast radiation-induced phenomena. The time resolution in pulse radiolysis depends on the electron bunch length, the probe-light width, and the timing jitter between the electron bunch and the probe light. In order to reduce the jitter, double-decker accelerator, in which separated laser was injected on a photocathode RF gun for a generation of synchronized double electron beams, was applied to pulse radiolysis. One electron beam was used as a pump source of a material, e. g. water, and another as a probe light at 800 nm wavelength with Cherenkov radiation.

THPPR059

Progress of the Equivalent Velocity Spectroscopy Method for Femtosecond Pulse Radiolysis by Pulse Rotation and Pulse Compression

electron, laser, cathode, radiation

4109

T. Kondoh, K. Kan, K. Norizawa, A. Ogata, S. Tagawa, J. Yang, Y. Yoshida
ISIR, Osaka, Japan
H. Kobayashi
KEK, Ibaraki, Japan

Femtosecond pulse radiolysis is developed for studies of electron beam induced ultra-fast reaction in matter. 98 fs electron pulse was generated by a photocathode RF gun LINAC with a magnetic bunch compressor. However for more fine time resolution, the Equivalent velocity spectroscopy (EVS) method is required to avoid degradation of time resolution caused by velocity difference between electron and analysing light in sample. In the EVS method, incident analysing light is oblique toward electron beam with an angle associated with refractive index of sample, and then, electron pulse is rotated toward the direction of travel to overlap with light pulse. In previous studies, pulse rotation had not been compatible with pulse compression. However, by oblique incident of light to the photocathode, pulse rotation was compatible with pulse compression, and the time resolution was improved by principle of the equivalent velocity spectroscopy.

THPPR066

Racetrack Microtron for Nondestructive Nuclear Material Detection System

electron, acceleration, gun, microtron

4127

T. Hori, T. Kii, R. Kinjo, H. Ohgaki, M. Omer, H. Zen
Kyoto University, Institute for Advanced Energy, Kyoto, Japan
I. Daito, R. Hajima, T. Hayakawa, M. Kando, H. Kotaki
JAEA, Kyoto, Japan

A nuclear material detection system using the quasi-monochromatic gamma-ray beam from a laser Compton Backscattering source has been proposed for the container inspection, where nuclear resonance fluorescence method would be employed for the specific isotope identification such as U-235. In the system an electron beam of good quality at about 220 MeV for the laser Compton backscattering is required. One candidate for such the practical use is a racetrack microtron which design is based on the existing 150 MeV microtron at JAEA.

THPPR067

A Conceptual 3-GeV LANSCE Linac Upgrade for Enhanced Proton Radiography

proton, neutron, rfq, cryomodule

4130

R.W. Garnett, F.E. Merrill, J.F. O'Hara, D. Rees, L. Rybarcyk, T. Tajima, P.L. Walstrom
LANL, Los Alamos, New Mexico, USA

Funding: Work supported by the United States Department of Energy, National Nuclear Security Agency, under contract DE-AC52-06NA25396
A conceptual design of a 3-GeV linac upgrade that would enable enhanced proton radiography at LANSCE is presented. The upgrade is based on the use of superconducting accelerating cavities to increase the present LANSCE linac output energy from 800 MeV to 3 GeV. The LANSCE linac at Los Alamos National Laboratory currently provides H⁻ and H⁺ beams to several user facilities that support Isotope Production, NNSA Stockpile Stewardship, and Basic Energy Science programs. Required changes to the front-end and to the RF systems to meet the new performance goals, and changes to the existing beam switchyard to maintain operations for a robust user program are also described.

THPPR069

Compact, Inexpensive X-Band Linacs as Radioactive Isotope Source Replacements

simulation, radiation, electron, coupling

4136

S. Boucher, R.B. Agustsson, X.D. Ding, L. Faillace, P. Frigola, A.Y. Murokh, M. Ruelas, S. Storms
RadiaBeam, Santa Monica, USA

Funding: Work supported by DNDO Phase II SBIR HSHQDC-10-C-00148 and DOE Phase II SBIR DE-SC0000865.
Radioisotope sources are still commonly used in a variety of industrial and medical applications. The US National Research Council has identified as a priority the replacement of high-activity sources with alternative technologies, due to the risk of accidents and diversion by terrorists for use in radiological dispersal devices (“dirty bombs”). RadiaBeam Technologies is developing novel, compact, inexpensive linear accelerators for use in a variety of such applications as cost-effective replacements. The technology is based on the MicroLinac (originally developed at SLAC), an X-band linear accelerator powered by an inexpensive and commonly available magnetron. Prototypes are currently under construction. This paper will describe the design, engineering, fabrication and future testing of these linacs at RadiaBeam. Future development plans will also be discussed.

THPPR070

Development of Multi-collision Laser Compton Scattering X-ray Source on the Basis of Compact S-band Electron Linac

laser, electron, cavity, photon

4139

R. Kuroda, M. Koike, E. Miura, Y. Taira, H. Toyokawa, K. Yamada, E. Yamaguchi
AIST, Tsukuba, Ibaraki, Japan
M. Kumaki
RISE, Tokyo, Japan

A compact hard X-ray source via laser Compton scattering is required for biological, medical and industrial science because it has many benefits about generated X-rays such as short pulse, quasi-monochromatic, energy tunability and good directivity. Our X-ray source is conventionally the single collision system between an electron pulse and a laser pulse. To increase X-ray yields, we have developed a multi-collision system with a multi-bunch electron beam and a laser optical cavity. The multi-bunch electron beam has already been generated from a Cs-Te photocathode rf gun system using a multi-pulse UV laser. The laser optical cavity have developed like a regenerative amplification including the collision point between the electron pulse and the laser pulse which is based on the Ti:Sa laser with a mode-locked frequency of 79.33 MHz. In this preliminary experiment, the modulated seed laser pulses were generated and leaded to the cavity, so that laser build-up amplification was performed in the cavity length of 3.78 m with two seed pulses. In this conference, we will describe the results of preliminary experiments for the multi-collision system and future plans.

THPPR072

High Power of 10 MeV, 25 kW Electron LINAC for Irradiation Applications

electron, vacuum, simulation, radiation

4142

Y.J. Pei, G. Feng, Y. Hong, K. Jin, S. Lu, L. Shang
USTC/NSRL, Hefei, Anhui, People's Republic of China

Using the electron beam to sterilize medical products and cosmetics, and food preservation and so on, has become important and efficient manners recently in number and variety. This paper describes the design, construction, and commissioning of a high power electron LINAC which can provide beam energy of 10 MeV, beam power of 25 kW. The paper also gives beam dynamic simulation results where beam loading effect was taken into account, and running parameters.

FRYAP01

The Future of X-ray FELs

FEL, undulator, electron, laser

4180

H.-H. Braun
Paul Scherrer Institut, Villigen, Switzerland

Recent years have brought enormous progress with X-ray FELs. With LCLS and SACLA two facilities with quite different technological approaches have shown the feasibility of SASE FELs in the hard X-ray regime while the SASE FEL FLASH and the recently commissioned laser seeded FEL FERMI@ELETTRA provide coherent light beams of unprecedented brightness at EUV and soft X-ray wavelength. First user experiments at these facilities demonstrate the vast scientific potential of this new type of instrument and have accelerated and triggered R&D and planning for other facilities of its kind worldwide. Projects under construction or in advanced stage of planning are European XFEL, LCLS II, SwissFEL, PAL XFEL, Shanghai XFEL and NGLS. Worldwide R&D efforts for XFELs try to improve performance and reduce size and cost. Focuses are on injector, linac and undulator technologies as well as on FEL seeding methods.

Slides FRYAP01 [24.324 MB]

FRYBP01

Accelerators for Intensity Frontier Research

proton, target, booster, kaon

4185

P. Derwent
Fermilab, Batavia, USA

This presentation should present recent developments in the accelerator physics and technology supporting the intensity frontier research in high energy physics. It should discuss the long and short base line neutrino experiments and the experiments with muons (muon-to-electron conversion and g-2).

Slides FRYBP01 [3.908 MB]