LINAC2014 - List of Keywords (linac)

Paper	Title	Other Keywords	Page
MOIOA01	Linear Collider Studies	emittance, linear-collider, collider, FEL	1
	S. Stapnes CERN, Geneva, Switzerland
	Status and comparison of the two remaining linear collider designs following publication of their CDRs
	Slides MOIOA01 [11.279 MB]

MOIOA02	Commissioning of the Low-Energy Part of Linac4	emittance, rfq, DTL, solenoid	6
	A.M. Lombardi CERN, Geneva, Switzerland
	The Linac4 front-end (3MeV) was first commissioned in a dedicated test stand and then moved to its final position in the Linac4 tunnel. Accelerating cavities will be added progressively over two years to allow the characterisation of the beam with a dedicated measurement line at several energy stages (3,12,30,50, 100 and finally160MeV). This paper reports about the progress and the commissioning experience up to today.
	Slides MOIOA02 [5.339 MB]

MOIOB01	Early Commissioning Experience and Future Plans for the 12 GeV Continuous Electron Beam Accelerator Facility	cryomodule, operation, cavity, SRF	11
	M. Spata JLab, Newport News, Virginia, USA
	Jefferson Lab has recently completed the accelerator portion of the 12 GeV Upgrade for the Continuous Electron Beam Accelerator Facility. All 52 SRF cryomodules have been commissioned and operated with beam. The initial beam transport goals of demonstrating 2.2 GeV per pass, greater than 6 GeV in 3 passes to an existing experimental facility and greater than 10 GeV in 5-1/2 passes have all been accomplished. These results along with future plans to commission the remaining beamlines and to increase the performance of the accelerator to achieve reliable, robust and efficient operations at 12 GeV are presented.
	Slides MOIOB01 [2.754 MB]

MOIOB02	Optimizing RF Linacs as Drivers for Inverse Compton Sources: the ELI-NP Case	electron, emittance, laser, photon	16
	C. Vaccarezza, D. Alesini, M. Bellaveglia, R. Boni, E. Chiadroni, G. Di Pirro, M. Ferrario, A. Gallo, G. Gatti, A. Ghigo, B. Spataro, P. Tomassini INFN/LNF, Frascati (Roma), Italy A. Bacci, D.T. Palmer, V. Petrillo, A.R. Rossi, L. Serafini Istituto Nazionale di Fisica Nucleare, Milano, Italy A. Cianchi Università di Roma II Tor Vergata, Roma, Italy I.V. Drebot Universita' degli Studi di Milano e INFN, Milano, Italy A. Giribono, A. Mostacci, L. Palumbo Rome University La Sapienza, Roma, Italy C. Ronsivalle ENEA C.R. Frascati, Frascati (Roma), Italy
	The design guide-lines of RF Linacs to fulfill the requirements of high spectral density Inverse Compton Sources for the photo-nuclear science are mostly mutuated from the expertise coming from high brightness electron Linacs driving X-ray FEL's. The main difference is the quest for maximum phase space density (instead of peak brightness), but many common issues and techniques are exploited, in order to achieve an optimum design and lay-out for the machine. A relevant example in this field is the design of the hybrid C-band multi-bunch RF Linacs for the ELI-NP Gamma Beam System, aiming at improving by two orders of magnitude the present state of the art in spectral density available for the gamma-ray beam produced.
	Slides MOIOB02 [2.542 MB]

MOIOB04	Current Status of PAL-XFEL	undulator, gun, electron, experiment	26
	I.S. Ko, J.H. Han PAL, Pohang, Kyungbuk, Republic of Korea
	The PAL-XFEL project aims to produce 0.1~nm coherent X-ray laser to photon beam users. In order to produce such photons, there are 10 GeV electron linac based on S-band normal conducting accelerating structures and a 150 m long out-vacuum undulator system. The project was already started in April 2011, and the 1.1 km long building is expected to be completed by December 2014. The injector test facility (ITF) which is for a test of the first 139 MeV section of the main linac has been installed and is in normal operation at the extension of the PLS linac building. In this paper, we introduce the project in general, a brief summary of site preparation and building construction, beam test results of ITF, and test results of subsystems produced by domestic manufacturers
	Slides MOIOB04 [9.901 MB]

MOIOC01	Status of Superconducting Electron Linac Driver for Rare Ion Beam Production at TRIUMF	cavity, cryomodule, electron, TRIUMF	31
	R.E. Laxdal, F. Ames, R.A. Baartman, I.V. Bylinskii, Y.-C. Chao, D. Dale, K. Fong, E.R. Guetre, P. Kolb, S.R. Koscielniak, A. Koveshnikov, M.P. Laverty, Y. Ma, M. Marchetto, L. Merminga, A.K. Mitra, N. Muller, R.R. Nagimov, T. Planche, W.R. Rawnsley, V.A. Verzilov, Z.Y. Yao, Q. Zheng, V. Zvyagintsev TRIUMF, Canada's National Laboratory for Particle and Nuclear Physics, Vancouver, Canada
	A MW class cw superconducting electron linac is being installed at TRIUMF as a driver for radioactive beam production through photo-fission. The ARIEL e-linac will house five 1.3GHz nine-cell cavities in three cryomodules and accelerate up to 10mA of electrons to 50MeV. A first phase of installation will see three cavities in two cryomodules installed by the end of 2014. Presently the injector cryomodule is installed and undergoing cryogenic and rf characterizations and beam acceleration tests with beam from the 300kV DC gun. The second cryomodule is being prepared for first tests. The linac status including descriptions and operating performance of installed cryogenic and rf systems, electron gun performance, cryomodule performance and the results of first beam acceleration tests will be reported.
	Slides MOIOC01 [6.383 MB]

MOIOC03	Model and Beam Based Setup Procedures for a High Power Hadron Superconducting Linac	cavity, simulation, laser, quadrupole	41
	A.P. Shishlo ORNL, Oak Ridge, Tennessee, USA
	This presentation will review methods for experimental determination of optimal operational set points in a multi-cavity superconducting high power hadron linac. A typical tuning process, including establishing correct acceleration profile and RMS bunch size matching, is based on comparison between measured data and the results of simulations from envelope, single and multi-particle models. Presence of significant space charge effects requires simulation and measurement of bunch dynamics in 3 dimensions to ensure low loss beam transport. This is especially difficult in a superconducting linac where use of interceptive diagnostics is usually restricted because of the risk of SRF cavity surface contamination. The procedures discussed here are based on non-interceptive diagnostics such as beam position monitors and laser wires, and conventional diagnostics devices such as wire scanners and bunch shape monitors installed outside the superconducting linac. The longitudinal Twiss analysis based on the BPM signals will be described. The superconducting SNS linac tuning experience will be used to demonstrate problems and their solution for real world linac tune-up procedures.
	Slides MOIOC03 [1.954 MB]

MOPP002	Design of a Superconducting Quarter-Wave Resonator for eRHIC	cavity, electron, SRF, niobium	49
	S.V. Kutsaev, Z.A. Conway, M.P. Kelly, B. Mustapha, P.N. Ostroumov ANL, Argonne, USA S.A. Belomestnykh, I. Ben-Zvi Stony Brook University, Stony Brook, USA S.A. Belomestnykh, I. Ben-Zvi, Q. Wu, W. Xu BNL, Upton, Long Island, New York, USA B. P. Xiao SBU, Stony Brook, New York, USA
	Funding: Work is supported by Brookhaven Science Associates, LLC under contract No. DE-AC02-98CH10886 and by the U.S. Department of Energy, Office of Nuclear Physics, under Contract No. DE-AC02-06CH11357 The electron-ion collider project (eRHIC) at Brookhaven National Laboratory requires a 50 mA 12 MeV electron injector linac for eRHIC main linac and an SRF electron gun for a Coherent electron Cooling (CeC) linac. The necessity to deal with long electron bunches required for both the eRHIC injector and the coherent electron cooler sets the frequency requirement of 84.5 MHz. Quarter wave resonator is a perfect choice for this frequency because of its dimensions, RF parameters and good experience with manufacturing and using them at ANL. Here we present the design and optimization of an 84.5 MHz 2.5 MV superconducting quarter-wave cavity suitable for both machines. One such QWR will be used as a bunching cavity in the injector linac, the other one as the photoemission electron source for the CeC linac. In addition to the optimization of the QWR electromagnetic design we will discuss the tuner design, approaches to cavity fabrication and processing.

MOPP003	A Compact Linac Design for an Accelerator Driven System	cavity, cryomodule, lattice, focusing	52
	B. Mustapha, S.V. Kutsaev, J.A. Nolen, 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 compact linac design has been developed for an Accelerator Driven System (ADS). The linac is under 150 meters in length and comprises a radio-frequency quadrupole (RFQ) and 20 superconducting modules. Three types of half-wave cavities and two types of elliptical cavities have been designed and optimized for high performance at frequencies of 162.5, 325 and 650 MHz. The lattice is being designed and optimized for operation with a peak power of 25 MW for a 25 mA – 1 GeV proton beam. The cavities RF design as well as the linac lattice will be presented along with end-to-end beam dynamics simulations for beam currents ranging from 0 to 25 mA.

MOPP004	Design and Development of Pulsed Modulators for RF Electron Linacs	electron, klystron, gun, operation	55
	K.P. Dixit, S. Chandan, N. Chaudhary, R.B. Chavan, L.M. Gantayet, S.R. Ghodke, M. Kumar, K.C. Mittal, H.E. Sarukte, A.R. Tillu, H. Tyagi, V. Yadav BARC, Mumbai, India
	Pulsed Modulators required for RF sources, based on klystrons and magnetrons, for RF electron linacs have been designed and developed at Electron Beam Centre, BARC, Mumbai, India. Electron guns in these linacs have also been powered by pulsed modulators. Line-type modulators, as well as IGBT-based solid-state modulators have been developed for these applications. A 150 kV/100 A line-type modulator has been tested on klystron to generate 7 MW peak RF Power. Magnetron modulator has undergone testing up to 40 kV, 165 A on resistive load. Solid-state modulator, using fractional-turn pulse transformer has been designed, developed and tested successfully on magnetron load up to output power of 1.3 MW peak. A transformerless solid-state modulator for electron gun of 6 MeV cargo-scanning linac, uses the Marx adder configuration and has been successfully tested up to 40 kV. In addition, line-type modulators for electron guns up to 85 kV have been successfully commissioned and are in operation in the linac systems. This paper describes the salient design features of these modulators, development of pulse transformers, details of test set-up and discusses the test results of these modulators.
	Poster MOPP004 [2.343 MB]

MOPP005	High Power Electron Accelerator Programme at BARC	electron, neutron, experiment, acceleration	58
	K.C. Mittal, S. Acharya, R.I. Bakhtsingh, R. Barnwal, D. Bhattacharjee, S. Chandan, N. Chaudhary, R.B. Chavan, S.P. Dewangan, K.P. Dixit, S. Gade, L.M. Gantayet, S.R. Ghodke, S. Gond, D. Jayaprakash, M. Kumar, M.K. Kumar, H.K. Manjunatha, R.L. Mishra, J. Mondal, B. Nayak, S. Nayak, V.T. Nimje, S. Parashar, R. Patel, R.N. Rajan, P.C. Saroj, H.E. Sarukte, D.K. Sharma, V. Sharma, S.K. Srivasatava, N.T. Thakur, A.R. Tillu, R. Tiwari, H. Tyagi, A. Waghmare, V. Yadav BARC, Mumbai, India
	Bhabha Atomic Research Centre in India has taken up the indigenous design & development of high power electron accelerators for industrial, research and cargo-scanning applications. For this purpose, Electron Beam Centre (EBC) has been set up at Navi Mumbai, India. Pulsed RF Linacs, with on-axis coupled cavity configuration, include the 10 MeV Industrial RF linac, as well as 9 MeV linac and compact 6 MeV linac for cargo-scanning applications. Industrial DC accelerators include a 500 keV Cockroft-Walton machine and 3 MeV Dynamitron. Several radiation processing applications, such as material modification, food preservation, flue-gas treatment, etc. have been demonstrated using these accelerators. Cargo-scanning linacs have been successfully commissioned and are being characterized for the required x-ray output. A 30 MeV RF Linac, for research applications, such as shielding studies and n-ToF experiments, is being designed and developed. For ADS studies, a 100 MeV, 100 kW RF Linac system is proposed. This paper presents the details of the design of these accelerators, their development, current status and utilization for various applications.

MOPP011	Reliability and Intensity Upgrade for 200 MeV Linac at Brookhaven National Laboratory	detector, operation, ion, target	67
	D. Raparia, J.G. Alessi, B. Briscoe, D.M. Gassner, O. Gould, T. Lehn, V. Lo Destro, J. Ritter, W. Shaffer, A. Zelenski BNL, Upton, Long Island, New York, USA
	Brookhaven 200 MeV H⁻ linac has been operating for last 44 years and providing beam to nuclear physics program and isotope program. Two upgrade programs are in progress to make machine more reliable and to double the intensity. This paper will discuss in detail these upgrade programs.

MOPP015	High Energy Electron Radiography Experiment Research Based on Picosecond Pulse-width Bunch	experiment, electron, proton, quadrupole	76
	Q.T. Zhao, S. Cao, R. Cheng, X.K. Shen, Z.M. Zhang, Y.T. Zhao IMP, Lanzhou, People's Republic of China Y.-C. Du TUB, Beijing, People's Republic of China W. Gai ANL, Argonne, Illinois, USA
	A new scheme is proposed that high energy electron beam as a probe is used for time resolved imaging measurement of high energy density materials, especially for high energy density matter and inertial confinement fusion. The first picosecond pulse-width electron radiography experiment was achieved by Institute of Modern Physics, Chinese Academy of Sciences and Tinghua University (THU), based on THU Linear electron accelerator (LINAC). It is used for principle test and certifying that this kind of LINAC with ultra-short pulse electron bunch can be used for electron radiography. The experiment results, such as magnifying factor and the imaging distortion, are consistent with the beam optical theory well. The 2.5 um RMS spatial resolution has been gotten with magnifying factor 46, with no optimization the imaging lens section. It is found that in the certain range of magnifying factor, the RMS spatial resolution will get better with bigger magnifying factor. The details of experiment set up, results, analysis and discussions are presented here.
	Poster MOPP015 [2.866 MB]

MOPP017	Cool Down and Flux Trapping Studies on SRF Cavities	cavity, SRF, cryomodule, operation	84
	D. Gonnella, M. Liepe Cornell University (CLASSE), Cornell Laboratory for Accelerator-Based Sciences and Education, Ithaca, New York, USA
	Recent results from Cornell and FNAL have shown that cool down rate can have a strong impact on the residual resistance of a superconducting RF cavity during operation. We have studied the effect of cool down rate, gradient, and external magnetic field during cool down on the residual resistance of an EP, EP+120C baked, and nitrogen-doped cavities. For each cavity, faster cool down and large gradient resulted in lower residual resistance in vertical test. The nitrogen-doped cavities showed the largest improvement with fast cool down, while the EP+120C cavity showed the smallest. The cavities were also placed in a uniform external magnetic field and residual resistance was measured as a function of applied field and cool down rate. We show that the nitrogen-doped cavity was the most susceptible to losses from trapped flux and the EP+120C cavity was least susceptible. These measurements provide new insights into understanding the physics behind the observed impact of cool down rates and gradients on the performance of cavities with differing preparations.

MOPP018	Nitrogen-Doped 9-Cell Cavity Performance in the Cornell Horizontal Test Cryomodule	cavity, cryomodule, SRF, radiation	88
	D. Gonnella, R.G. Eichhorn, F. Furuta, G.M. Ge, D.L. Hall, Y. He, G.H. Hoffstaetter, M. Liepe, T.I. O'Connel, S. Posen, P. Quigley, J. Sears, V. Veshcherevich Cornell University (CLASSE), Cornell Laboratory for Accelerator-Based Sciences and Education, Ithaca, New York, USA A. Grassellino, A. Romanenko Fermilab, Batavia, Illinois, USA
	Funding: U.S. Department of Energy Cornell has recently completed construction and qualification of a horizontal cryomodule capable of holding a 9-cell ILC cavity. A nitrogen-doped niobium 9-cell cavity was assembled into the Horizontal Test Cryomodule (HTC) with a high Q input coupler and tested. We report on results from this test of a nitrogen-doped cavity in cryomodule and discuss the effects of cool down rate and thermal cycling on the residual resistance of the cavity.

MOPP020	Input Couplers for Cornell ERL	cryomodule, coupling, cavity, impedance	95
	R.G. Eichhorn, P. Quigley, V. Veshcherevich Cornell University (CLASSE), Cornell Laboratory for Accelerator-Based Sciences and Education, Ithaca, New York, USA S.A. Belomestnykh BNL, Upton, Long Island, New York, USA
	Cornell has developed two types of input couplers for the Energy Recovery Linac (ERL) Project. Both couplers are 1.3 GHz CW coaxial couplers. The coupler for ERL injector is a 65 kW CW coupler with variable coupling (Qext = 9E4 to 9E5). The coupler for ERL main linac is a 5 kW CW coupler with fixed coupling. It can be easily modified for variable coupling operation. Couplers have been tested on test stands and in cryomodules and showed good performance.

MOPP023	X-band Technology for FEL Sources	FEL, emittance, operation, experiment	101
	G. D'Auria, S. Di Mitri, C. Serpico Elettra-Sincrotrone Trieste S.C.p.A., Basovizza, Italy E. Adli University of Oslo, Oslo, Norway A.A. Aksoy, O. Yavaş Ankara University, Accelerator Technologies Institute, Golbasi / Ankara, Turkey D. Angal-Kalinin, J.A. Clarke STFC/DL/ASTeC, Daresbury, Warrington, Cheshire, United Kingdom C.J. Bocchetta, A.I. Wawrzyniak Solaris, Kraków, Poland M.J. Boland, T.K. Charles, R.T. Dowd, G. LeBlanc, Y.E. Tan, K.P. Wootton, D. Zhu SLSA, Clayton, Australia G. Burt Lancaster University, Lancaster, United Kingdom N. Catalán Lasheras, A. Grudiev, A. Latina, D. Schulte, S. Stapnes, I. Syratchev, W. Wuensch CERN, Geneva, Switzerland W. Fang, Q. Gu SINAP, Shanghai, People's Republic of China E.N. Gazis National Technical University of Athens, Athens, Greece M. Jacewicz, R.J.M.Y. Ruber, V.G. Ziemann Uppsala University, Uppsala, Sweden X.J.A. Janssen VDL ETG, Eindhoven, The Netherlands
	As is widely recognized, fourth generation Light Sources are based on FELs driven by Linacs. Soft and hard X-ray FEL facilities are presently operational at several laboratories, SLAC (LCLS), Spring-8 (SACLA), Elettra-Sincrotrone Trieste (FERMI), DESY (FLASH), or are in the construction phase, PSI (SwissFEL), PAL (PAL-XFEL), DESY (European X-FEL), SLAC (LCLS II), or are newly proposed in many laboratories. Most of the above mentioned facilities use NC S-band (3 GHz) or C-band (6 GHz) linacs for generating a multi-GeV low emittance beam. The use of the C-band increases the linac operating gradients, with an overall reduction of the machine length and cost. These advantages, however, can be further enhanced by using X-band (12 GHz) linacs that operate with gradients twice that given by C-band technology. With the low bunch charge option, currently considered for future X-ray FELs, X-band technology offers a low cost and compact solution for generating multi-GeV, low emittance bunches. The paper reports the ongoing activities in the framework of a collaboration among several laboratories for the development and validation of X-band technology for FEL based photon sources.

MOPP024	Perspectives of the S-Band Linac of FERMI	operation, klystron, FEL, electron	105
	A. Fabris, P. Delgiusto, M. Milloch, C. Serpico Elettra-Sincrotrone Trieste S.C.p.A., Basovizza, Italy A. Grudiev CERN, Geneva, Switzerland
	The S-band linac of FERMI, the seeded Free Electron Laser (FEL) located at the Elettra laboratory in Trieste, has reached the peak on-crest electron energy of 1.55 GeV required for FEL-2 with the present layout. Different ways are being considered to extend the operating energy of the S-band linac up to 1.8 GeV. At the same time upgrades on the existing systems are investigated to address the requirements of operability of a users facility. This paper provides an overview of the developments that are under consideration and discusses the requirements and constraints for their implementation.

MOPP025	Longitudinal Beam Profile Measurements in Linac4 Commissioning	rfq, cavity, electron, emittance	108
	G. Bellodi, V.A. Dimov, J.-B. Lallement, A.M. Lombardi, U. Raich, F. Roncarolo, F. Zocca CERN, Geneva, Switzerland M. Yarmohammadi Satri IPM, Tehran, Iran
	Linac4, the future 160 MeV H⁻ injector to the CERN Proton Synchrotron Booster, is presently under construction at CERN as a central step of the planned upgrade of the LHC injectors. The Linac front-end, composed of a 45 keV ion source, a Low Energy Beam Transport (LEBT), a 352.2 MHz Radio Frequency Quadrupole (RFQ) and a Medium Energy Beam Transport (MEBT) housing a beam chopper, has been installed and commissioned. Precise measurements of the longitudinalμbunch profiles of ion beams were possible with the help of a Bunch Shape Monitor (BSM) developed at INR Moscow. These were crucial for the successful commissioning of the three RF buncher cavities mounted along the MEBT and well complemented with higher precision the information provided in parallel by spectrometer measurements.

MOPP026	Actively Cooled RF Power Coupler : Theoretical and Experimental Studies	cryomodule, cryogenics, cavity, proton	111
	R. Bonomi, V. Parma CERN, Geneva, Switzerland
	In cryostats for Super-conducting Radio Frequency Cavities, the heat loads introduced by the high-power RF couplers represent an important fraction of the overall static thermal budget. Working at low operating temperature benefits from a reduced surface resistance (low dynamic losses) but is penalized by the high refrigeration cost. The external conductor of RF coaxial couplers provides a direct conduction path from ambient to cryogenic temperature plus is heated by resistive power deposition. Heat interception is therefore essential to contain heat in-leaks: a double-walled external conductor with a properly designed gas cooling effectively reduces heat loads to the cold bath by 1 order of magnitude. This paper presents the thermal design of the RF power coupler of the Superconducting Proton Linac (SPL) at CERN, featuring a helium vapour cooling between 4.5 K and ambient temperature. Numerical models, which can be used as design tools for other applications, have been developed to assess efficiency and thermal performance. A full-size mock-up cooled by nitrogen has been built for experimental validation. Comparison between calculations and measurements is presented and discussed.

MOPP029	Overview of the New High Level Software Applications Developed for the HIE-ISOLDE Superconducting Linac	controls, cavity, software, pick-up	117
	D. Lanaia, M.A. Fraser, D. Voulot CERN, Geneva, Switzerland
	The High Intensity and Energy (HIE) ISOLDE project consists of an upgrade of the ISOLDE facility. With the installation of 32 independently-phased, superconducting quarter-wave cavities the energy of post-accelerated radioactive beams will be increased from 3 MeV/u to over 10 MeV/u. The large number of cavities will increase the number of parameters to optimise. In order to ensure a fast set-up of the machine during operation and commissioning, new software applications have been developed and an upgrade of the existing software was carried out. Four high level applications have been specifically developed for the SC linac. The first allows the conversion of optics settings into machine settings, and vice versa. The second will aid the phasing of the cavities using beam energy measurements. A third application will provide absolute measurements of the beam energy by means of a time-of-flight system. The last application will automatically generate the phase and voltage settings for the cavities SC linac. In this contribution we will present the new applications and outline how these will be used in the operation of the new SC linac.
	Poster MOPP029 [1.568 MB]

MOPP036	Estimation of the Thermal Load and Signal Level of the ESS Wire Scanner	DTL, detector, photon, cryomodule	137
	B. Cheymol ESS, Lund, Sweden
	The European Spallation Source (ESS), to be built in the south of Sweden, will use a 2 GeV superconducting linac to produce the worlds most powerful neutron source with a beam power of 5 MW. A number of wire scanners will be used to characterize the beam transverse profile. The design of the wire has to cope with the high power density of the beam and must satisfy the overall measurement robustness, accuracy and sensitivity for the commissioning and the regular retuning phase of the ESS linac. This paper describes the preliminary design of the wire scanner system in the normal conducing linac as well as in the superconducting linac.

MOPP037	Conceptual Design of the ESS DTL Faraday Cup	DTL, simulation, cavity, beam-transport	140
	B. Cheymol, E. Lundh ESS, Lund, Sweden
	The DTL section of the ESS linac will accelerate the beam form 3.6 MeV to 90 MeV at a peak current of 62.5 mA. It is foreseen to install after each DTL tank a Faraday cup for beam current and the beam transmission measurements during retuning phase. An energy degrader will be positioned in front of the in order to perform a low resolution phase scan of the DTL tank before injecting the beam in the downstream structure. This paper describes the preliminary studies of the Faraday cup, mainly focus on the energy degrader.

MOPP038	Longitudinal Bunch Profile Monitoring at the ESS Linac	simulation, proton, neutron, target	143
	I. Dolenc Kittelmann, B. Cheymol ESS, Lund, Sweden
	The European Spallation Source (ESS), which is currently under construction, will be a neutron source based on 5MW, 2GeV proton linac. This high intensity linac will among other beam instrumentation require longitudinal bunch profile monitors. These shall be used during the commissioning phase and start-up periods for beam dynamics optimization and beam loss reduction. The paper focuses on the preliminary studies concerning the longitudinal bunch profile monitoring at the ESS linac.

MOPP039	Dynamics of Bunches Partially Chopped with the MEBT Chopper in the ESS Linac	DTL, lattice, simulation, quadrupole	146
	R. Miyamoto, B. Cheymol, R. De Prisco, M. Eshraqi, A. Ponton, E. Sargsyan ESS, Lund, Sweden I. Bustinduy ESS Bilbao, Bilbao, Spain
	The front-end of a hadron linac typically has a transient time during turning on and off and bunches in the head and tail of a pulse from this period likely have wrong parameters and a risk to cause beam losses. A risk of losses must be avoided as possible in a high power machine so these bunches are removed with deflectors called choppers in the ESS Linac. From experiences of other machines, a rise time of a chopper as fast as one RF period (2.84~ns for ESS) is challenging to achieve and not necessarily needed with no ring to inject like ESS, and hence a 10~ns rise time is planned for a chopper in the medium energy beam transport of ESS. This, however, means that several bunches receive intermediate deflections and may propagate with large trajectory excursions. This paper studies dynamics of such partially chopped bunches in detail to ensure no significant loss is caused by them.

MOPP041	Commissioning Plan for the FRIB Driver Linac*	radiation, ion, cryomodule, operation	152
	M. Ikegami, L.T. Hoff, S.M. Lidia, F. Marti, G. Pozdeyev, T. Russo, R.C. Webber, J. Wei, Y. Yamazaki FRIB, East Lansing, Michigan, USA
	Funding: * Work supported by the U.S. Department of Energy Office of Science under Cooperative Agreement DE-SC0000661. The FRIB driver linac accelerates CW beams of all stable ions up to uranium to the energy of 200 MeV/u with the beam power of 400 kW. We plan to start staged beam commissioning in December 2017 in parallel with ongoing installation activities. This allows early recognition of technical issues, which is essential for smooth commissioning and early completion of commissioning goals. As the interlaced nature of commissioning and installation poses both scheduling challenges and special safety issues, it is essential to develop a commissioning plan with focused consideration of each. In this paper, we present a commissioning plan with emphasis on its characteristic features.

MOPP044	MSU RE-Accelerator ReA3 0.085 QWR Cryomodule Status	cryomodule, cavity, solenoid, alignment	155
	T. Xu, B. Bird, F. Casagrande, J.L. Crisp, K.D. Davidson, C. Dudley, A. Facco, P.E. Gibson, I. Grender, L. Hodges, K. Holland, M.J. Johnson, S. Jones, B. Laumer, D. Leitner, A. Mccartney, S.J. Miller, D. Morris, S. Nash, J.P. Ozelis, J. Popielarski, L. Popielarski, R. Rosas, R.J. Rose, K. Saito, M. Thrush, R. Walker, J. Wei, W. Wittmer, Y. Xu FRIB, East Lansing, Michigan, USA B. Arend, J. Ottarson, D.P. Sanderson, D. Wahlquist, J. Wenstrom NSCL, East Lansing, Michigan, USA M. Leitner LBNL, Berkeley, California, USA
	ReA3 β=0.085 QWR cryomodule is the third cryomodule for the superconducting LINAC of ReA3 reaccelerated beam facility, which will bring the maximum beam energy to 3 MeV/u for heavy ions. This cryomodule consists of 8 β=0.085 QWR cavities and 3 9T superconducting solenoids and operates at 4K. Qualification of cavities and FPCs and the construction of cold mass was completed in 2013. The installation of the module was completed this summer. Functioning not only as an important part of the ReA3 facility, cryomodule 3 also serves as a test bed for FRIB driver Linac and demonstrated the technology needed for FRIB CMs. Here we report the construction, installation and testing of the β=0.085 cryomodule and the development of the critical components. Project funded by Michigan State University

MOPP045	Progress and Plan of Open XAL Physics Application for FRIB	solenoid, cryomodule, database, software	158
	Y. Zhang, P. Chu, D.G. Maxwell 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 FRIB driver linac will deliver heavy ion beams with beam energy above 200 MeV/u, and beam power on target up to 400 kW. Commissioning, tuning, and beam power ramping up of the world’s first SRF linac for high-power heavy-ion beams will be challenge, and developments of necessary physics application software tools are very important. In this paper, our major progress and the development plan of physics application software for the FRIB linac within Open XAL frameworks are discussed, which include the FRIB linac online model, MySQL database for physics applications, virtual accelerator application, and several other pilot physics applications. Deploying and initial testing of Open XAL and those pilot applications for FRIB are currently ongoing for a new cryomodule at Michigan State University.

MOPP049	Dipole Kick due to Geometry Asymmetries in HWR for PXIE	cavity, dipole, multipole, cryomodule	165
	P. Berrutti, T.N. Khabiboulline, V.A. Lebedev, V.P. Yakovlev Fermilab, Batavia, Illinois, USA
	Funding: Work supported by D.O.E. Contract No. DE-AC02-07CH11359 Project X Injector Experiment (PXIE) will have a family of half wave resonators having frequency=162.5 MHz and beta optimal=0.11. During cavity production, when the niobium parts are assembled and welded together, it is fundamental to control the frequency of the accelerating mode in order to meet the specified operating value. For the HWR of PXIE the tuning will be achieved by trimming one end of the resonator only, this will introduce unwanted asymmetry in the cavity geometry leading to a dipole kick for the particles traveling through the cavity. The cavity geometry will be different from the ideal, once the cavity is assembled, because of small misalignment of the niobium parts and because of the welding shrinkage. Misalignments of the inner conductor and the beam pipes can be expected. The asymmetry due to tuning process along with production misalignments, have been simulated and the equivalent dipole kick has been calculated.
	Poster MOPP049 [1.441 MB]

MOPP052	Development of 5-Cell β=0.9 650 MHz Elliptical Cavities for Project X	cavity, HOM, coupling, accelerating-gradient	171
	I.V. Gonin, M.H. Awida, M.H. Foley, A. Grassellino, C.J. Grimm, T.N. Khabiboulline, A. Lunin, A.M. Rowe, V.P. Yakovlev Fermilab, Batavia, Illinois, USA
	Several 5-cell 650 MHz elliptical cavities have been fabricated for the PIP-II Project. Two versions of the cavities have been designed to accelerate protons of relative group velocity of β=0.9 and β=0.92 in the high energy region of the linac. In this paper, we report the development status of these cavities, summarize the results of the quality control measurements performed on five initial prototypes, and outline the VTS test results.

MOPP054	Continuous-Wave Horizontal Tests of Dressed 1.3 GHz SRF Cavities for LCLS-II	cavity, HOM, controls, SRF	177
	A. Hocker, A.C. Crawford, M. Geynisman, J.P. Holzbauer, A. Lunin, D.A. Sergatskov, N. Solyak, A.I. Sukhanov Fermilab, Batavia, Illinois, USA
	Funding: United States Department of Energy, Contract No. DE-AC02-07CH11359 Fermilab’s Horizontal Test Stand has recently been upgraded to provide CW RF testing capabilities in support of the LCLS-II project at SLAC. Several cavities have been tested in this new configuration in order to validate component designs and processes for meeting the requirements of LCLS-II. Areas of study included gradient and Q0 performance and their dependence on extrinsic factors, thermal performance of the input coupler and HOM feedthroughs, and microphonics and RF control. A description of the testing and the results obtained are presented.
	Poster MOPP054 [0.276 MB]

MOPP059	Study and Design of the High Power RF Coupler for the CH-Cavity of the Fair pLINAC	coupling, cavity, proton, resonance	187
	F. Maimone, G. Clemente, W. Vinzenz GSI, Darmstadt, Germany
	At GSI a proton Linac has been designed and developed in order to provide a 70 MeV proton beam for the FAIR facility. The pLINAC consists of an RFQ followed by six CH-DTL accelerating cavities and the electromagnetic field inside each cavity is generated by seven Klystrons providing up to 2.8 MW power at 325.224 MHz. The high power RF coupling between the Klystron and the accelerating CH-cavity has been studied and an inductive coupling loop has been designed. The coupler insertion inside the cavity and the rotation angle with respect to the magnetic field lines have been adjusted and the results of the analysis of the coupler positioning are presented. A prototype coupler is under construction and the measurement of RF coupling with the CH-cavity is scheduled within this year.

MOPP060	Status of the GSI Poststripper - HE-Linac	DTL, rfq, ion, simulation	190
	S. Mickat, W.A. Barth, G. Clemente, X. Du, L. Groening, A. Orzhekhovskaya, B. Schlitt, H. Vormann, C. Xiao, S.G. Yaramyshev GSI, Darmstadt, Germany M. Droba, H. Hähnel, U. Ratzinger, R. Tiede IAP, Frankfurt am Main, Germany
	The High-Energy (HE) Linac is proposed to substitute the existing UNILAC post-stripper section. The post-stripper is an Alvarez DTL, which is in operation over four decades successfully. A quasi Front-to-End simulation along the UNILAC shows, that by taking future upgrade options into account already, with the existing Alvarez section the Fair requirements are not reached. Even by substituting the Alvarez section by the HE Linac the aim is not reached per se regarding the existing boundary conditions. Currently workpackages are defined together with the Institute of Applied Physics at Frankfurt University. Starting from the Ion sources to the SIS18 transfer channel every section is reinvestigated for improvements in beam quality and intensity.

MOPP061	First RF Measurements of the Superconducting 217 MHz CH Cavity for the CW Demonstrator at GSI	cavity, simulation, status, ion	193
	F.D. Dziuba, M. Amberg, M. Basten, M. Busch, H. Podlech, U. Ratzinger IAP, Frankfurt am Main, Germany M. Amberg, K. Aulenbacher, W.A. Barth, S. Mickat HIM, Mainz, Germany K. Aulenbacher IKP, Mainz, Germany W.A. Barth, S. Mickat GSI, Darmstadt, Germany
	Funding: Work supported by GSI, HIM, BMBF Contr. No. 05P12RFRBL Presently, a superconducting (sc) 217 MHz Crossbar-Hmode (CH) cavity is under construction at Research Instruments (RI), Bergisch Gladbach, Germany. Among the horizontal cryomodule and two sc 9.5 T solenoids the cavity is the key component of the cw demonstrator at GSI. To show the operation ability of sc CH cavity technology under a realistic linear accelerator environment is one major goal of the demonstrator project. A successful beam operation of the demonstrator will be a milestone regarding the continuing advanced sc cw linac project at GSI for a competitive production of Super Heavy Elements (SHE) in the future. The fabrication status as well as first rf measurements at room temperature of the 217 MHz CH cavity are presented.
	Poster MOPP061 [1.741 MB]

MOPP064	R&D of the 17 MeV MYRRHA Injector	emittance, cavity, proton, rfq	202
	D. Mäder, M. Basten, D. Koser, H.C. Lenz, N.F. Petry, H. Podlech, A. Schempp, M. Schwarz, M. Vossberg IAP, Frankfurt am Main, Germany C. Zhang GSI, Darmstadt, Germany
	Funding: Project supported by the EU, FP7 MAX, Contract No. 269565 MYRRHA is designed as an accelerator driven system (ADS) for transmutation of long-lived radioactive waste. The challenge of the linac development is the very high reliability of the accelerator to limit the thermal stress inside the reactor. With the concept of parallel redundancy the injector will supply a cw proton beam with 4 mA and 17 MeV to the main linac. The new MYRRHA injector layout consists of a very robust beam dynamics design with low emittance growth rates. Sufficient drift space provides plenty room for diagnostic elements and increases the mountability. Behind a 4-Rod-RFQ and a pair of two-gap QWR rebunchers at 1.5 MeV the protons are matched into the CH cavity section. A focussing triplet between the rebunchers ensures an ideal transversal matching into the doublet lattice. Each of the 7 RT CH structures has a constant phase profile and does not exceed thermal losses of 29 kW/m. The transition to the 5 SC CH cavities with constant beta profile is at 5.9 MeV. For a safe operation of the niobium resonators the electric and magnetic peak fields are defined below 25 MV/m and 57 mT respectively.
	Poster MOPP064 [4.024 MB]

MOPP066	High Gradient CH-Type Cavity Development for 10 – 100 AMeV Beams	cavity, quadrupole, ion, heavy-ion	208
	A. Almomani, U. Ratzinger IAP, Frankfurt am Main, Germany
	Funding: This work is supported by Federal Ministry of Education and Research - BMBF No. 05P12RFRB9. The development in pulsed linac activities aims on compact designs and on an increase of the voltage gain per meter. At IAP - Frankfurt, a CH design was developed for these studies, where the mean effective accelerating field is expected to reach well above 10 MV/m at 325 MHz, β=0.164. Within a funded project, this cavity is systematically developed. Currently, the cavity is under construction at NTG GmbH and expected to be ready for copper plating in autumn 2014. The results should give an impact on the rebuilt of the UNILAC - Alvarez section, optimized for achieving the beam intensities specified for the GSI – FAIR project. A mid- and long- term aim is a compact pulsed high current linac. The new GSI 3 MW Thales klystron test stand will be very important for these investigations. Detailed studies on two different types of copper plating can be performed on this cavity. Additionally, operating of normal conducting cavities at cryogenic temperatures will be discussed. In this work, the cavity status will be presented.

MOPP067	Operation of the LINAC and the LINAC RF System for the Ion-Beam Therapy Center Heidelberg	ion, operation, DTL, rfq	211
	E. Feldmeier, R. Cee, Th. Haberer HIT, Heidelberg, Germany
	The Heidelberg Ion Therapy Center HIT is in clinical operation since 2009. It is the first dedicated european particle accelerator for medical treatment. Its central location on the campus of the Heidelberg University Hospital fits perfectly in the clinical everyday life. The accelerator complex consists of a linear accelerator and a synchrotron and is designed for protons and carbon ions, but can also provide helium and oxygen ions. The LINAC, build in 2006, operates since 5 years in a 24/7 schema which leads to 60000 operating hours up to now. The performance with an availibility of better than 99% is much higher than expected and is caused by a solid design and a well planned and foresighted maintenance. Unavoidable failures during operation can be solved very fast with the on site experts for each section. The combination of personnel spare parts and permanent ongoing developments is very successful. An upgrade program for parts of the linac and also for the RF system is in planning to keep the uptime high and to improve the performance for further needs.

MOPP070	Final Design for the BERLinPro Main Linac Cavity	HOM, cavity, emittance, dipole	217
	A. Neumann, J. Knobloch HZB, Berlin, Germany K. Brackebusch, T. Flisgen, T. Galek, U. van Rienen Rostock University, Faculty of Computer Science and Electrical Engineering, Rostock, Germany B. Riemann, T. Weis DELTA, Dortmund, Germany
	Funding: This work is partly funded by BMBF contract no. 05K10PEA and 05K10HRC The Berlin Energy Recovery Linac Project (BERLinPro) is designed to develop and demonstrate CW LINAC technology for 100-mA-class ERLs. High-current operation requires an effective damping of higher-order modes (HOMs) of the 1.3 GHz main-linac cavities. We have studied elliptical 7-cell cavities based on a modified Cornell ERL design combined with JLab's waveguide HOM damping approach. This paper will summarize the final optimization of the end-cell tuning for minimum external Q of the HOMs, coupler kick calculations of the single TTF fundamental power coupler as well as multipole expansion analysis of the given modes and a discussion on operational aspects.
	Poster MOPP070 [1.561 MB]

MOPP072	Present Status of J-PARC LINAC LLRF Systems	controls, operation, timing, feedback	224
	Z. Fang, Y. Fukui, K. Futatsukawa, T. Kobayashi, S. Michizono KEK, Ibaraki, Japan E. Chishiro, F. Sato, S. Shinozaki JAEA/J-PARC, Tokai-mura, Japan
	The RF control systems have been developed for the J-PARC proton linac, which consists of 324-MHz and 972-MHz acceleration sections. From October 2006, we started the commissioning of the 324-MHz sections. Then the J-PARC 324-MHz 181-MeV proton linac had been operated nearly for 7 years, until May 2013. In the summer of 2013, we upgraded the J-PARC linac by adding 972-MHz acceleration sections. The output energy of the J-PARC linac was successfully upgraded to 400 MeV in December 2013, and then the operation of the J-PARC 400-MeV linac started. In the past 8 years of the J-PARC linac operation, no heavy troubles occurred in the RF control systems. Every year we made improvements on the RF control systems, according to the operation experiences. In this paper, the present status of the J-PARC 400-MeV linac RF control systems will be described in details, and an improvement plan for the LLRF systems in the future will also be introduced.

MOPP076	Construction of an Accelerator-based BNCT Facility at yhe Ibaraki Neutron Medical Research Center	target, neutron, rfq, klystron	230
	M. Yoshioka, H. Kobayashi, T. Kurihara, S.-I. Kurokawa, H. Matsumoto, N. Matsumoto KEK, Ibaraki, Japan T. Hashirano, T. Sugano MHI, Hiroshima, Japan F. Hiraga Hokkaido University, Sapporo, Japan H. Kumada, Su. Tanaka Tsukuba University, Graduate School of Comprehensive Human Sciences, Ibaraki, Japan A. Matsumura, H. Sakurai Tsukuba University, Ibaraki, Japan N. Nagura, T. Ohba Nippon Advanced Technology Co. Ltd., Ibaraki-prefecture, Japan T.N. Nakamoto, T. Zagar Cosylab, Ljubljana, Slovenia T. Nakamura JAEA, Ibaraki-ken, Japan T. Ouchi ATOX, Ibaraki, Japan
	An accelerator-based BNCT (Boron Neutron Capture Therapy) facility is being constructed at the Ibaraki Neutron Medical Research Center. It consists of a proton linac of 80kW beam power with 8 MeV energy and 10mA average current, a beryllium target, and a moderator system to provide an epi-thermal neutron flux enough for patient treatment. The technology choices for this present system were driven by the need to site the facility in a hospital and where low residual activity is essential. The maximum neutron energy produced from an 8 MeV-proton is 6 MeV, which is below the threshold energy of the main nuclear reactions which produce radioactive products. The down side of this technology choice is that it produces a high density heat load on the target so that cooling and hydrogen aniti-blistering amelioration prevent sever challenges requiring successful R&D progress. The latest design of the target and moderator system shows that a flux of 4×10⁹ epi-thermal neutrons / cm² / sec can be obtained. This is much higher than the flux from the existing nuclear reactor based BNCT facility at JAEA ( JRR-4).

MOPP077	Electron-Driven Positron Capture Simulation for ILC	positron, electron, target, booster	233
	Y. Seimiya, M. Kuriki HU/AdSM, Higashi-Hiroshima, Japan S. Kashiwagi Tohoku University, Research Center for Electron Photon Science, Sendai, Japan T. Okugi, T. Omori, M. Satoh, J. Urakawa KEK, Ibaraki, Japan T. Takahashi Hiroshima University, Graduate School of Science, Higashi-Hiroshima, Japan
	ILC (International Linear Collider) is a next high-energy physics project to study the Higgs property as detail as possible and new phenomena beyond standard model. In ILC, the positron beam is produced by converting gamma rays from undulator radiations. To obtain gamma rays as undulator radiation, the electron beam for collision (150 GeV or more) is used. This positron generation scheme is a totally new approach. From project point of view, it is desirable to have a technical backup as a replacement of the undulator scheme. We propose an ILC positron source based on the conventional electron driven scheme. In this scheme, positron beam is generated from electromagnetic shower in a heavy target material where electron beam is injected. By manipulating the beam time structure to relax the heat load on the production target, the scheme can be feasible technically. In this study, positron capture in the electron driven scheme is simulated from the positron production to the positron damping ring, to demonstrate that an enough amount of positron can be generated and captured with a controllable heat load on the target.
	Poster MOPP077 [0.879 MB]

MOPP078	RF Power Systems for the FAIR Proton Linac	klystron, proton, electronics, cavity	236
	J. Lesrel, C. Joly IPN, Orsay, France E. Plechov, A. Schnase, G. Schreiber, W. Vinzenz GSI, Darmstadt, Germany
	In the framework of collaboration between the FAIR project, GSI, and CNRS, the IPNO lab is in charge of providing the high power RF components for a cavity test stand and for the planned FAIR proton Linac. This Linac will be connected to the existing GSI synchrotron SIS18 for serving as an injector for the new FAIR facility. The 70 MeV FAIR proton Linac design contains a 3 MeV RFQ, and a DTL based on Cross-bar H-mode cavities (CH). It will operate with pulsed RF at 325.224 MHz with a width of 200 μs and a repetition rate of 4 Hz. The planned RF systems of the proton Linac will be presented as well as the description of the test stand. The first power test results are obtained with a Thales klystron developed jointly with CNRS. Three solid state amplifiers made by Sigmaphi Electronics for the bunchers will also be described in this paper.

MOPP080	Beam Dynamics Study for RAON Superconducting Linac	ion, lattice, proton, quadrupole	239
	H. Jang, H.J. Kim IBS, Daejeon, Republic of Korea J.G. Hwang KNU, Deagu, Republic of Korea B.H. Oh POSTECH, Pohang, Kyungbuk, Republic of Korea
	Rare Isotope Science Project (RISP) in Korea is going to build an ion accelerator, RAON which can generate and accelerate various stable ions such as uranium, proton, xenon and rare isotopes such as tin, nickel. Linear accelerators of RAON adopted superconducting RF cavities and warm quadruple doublet structure. In RAON, there are two low energy linacs which can accelerate the Uranium beam from 0.5MeV/u to 17.5MeV/u, charge stripping sections and one high energy linac which can accelerate the Uranium beam up to 200MeV/u. Due to the diversity of planned ions and isotopes, their A/q range lies widely from 1 to 8. As a result, the research related with linac lattice design and beam dynamics is one of the important topics to build RAON. In this presentation the current status of RAON linac lattice design and the beam dynamics simulation results for acceleration of various ions will be described.

MOPP082	Superconducting Linac for RISP	cavity, cryomodule, ion, quadrupole	245
	H.J. Kim, H.J. Cha, M.O. Hyun, H.C. Jung, Y.J.K. Kim, M. Lee IBS, Daejeon, Republic of Korea
	The RISP (Rare Isotope Science Project) has been proposed as a multi-purpose accelerator facility for providing beams of exotic rare isotopes of various energies. It can deliver ions from proton to Uranium. Proton and Uranium beams are accelerated upto 600 MeV and 200 MeV/u respectively. The facility consists of three superconducting linacs of which superconducting cavities are independently phased. Requirement of the linac design is especially high for acceleration of multiple charge beams. In this paper, we present the RISP linac design, the prototyping of superconducting cavity and cryomodule.

MOPP090	Adjustment of the Coupling Factor of the Input Coupler of the ACS Linac by a Capacitive Iris in J-PARC	cavity, coupling, simulation, ion	264
	J. Tamura, H. Ao, K. Hirano, Y. Nemoto, N. Ouchi JAEA/J-PARC, Tokai-mura, Japan H. Asano Nippon Advanced Technology Co. Ltd., Ibaraki-prefecture, Japan F. Naito, K. Takata KEK, Ibaraki, Japan
	Annular-ring Coupled Structure (ACS) cavities have been installed to increase the beam energy of the Japan Proton Accelerator Research Complex (J-PARC) linac from 181 to 400 MeV in the maintenance period of 2013. Some of the pillbox type input couplers with a ceramic window to the ACS cavity have a larger coupling factor than the target value by an avoidable manufacturing error. To adjust the coupling factor, a capacitive iris was introduced in the rectangular waveguide near the coupler. As a result, it has been confirmed that the iris decreases the coupling factor to a target value without any significant increase in temperature and in a discharge rate during high-power operation. In this paper, the design procedure of the capacitive iris and the result of the coupling factor adjustment are presented.

MOPP091	Beam Test of a New RFQ for the J-PARC Linac	rfq, simulation, emittance, experiment	267
	Y. Kondo, T. Morishita, Y. Sawabe, S. Yamazaki JAEA/J-PARC, Tokai-Mura, Naka-Gun, Ibaraki-Ken, Japan T. Hori JAEA, Ibaraki-ken, Japan A. Takagi KEK, Ibaraki, Japan
	We performed a beam test of a new 324-MHz 3-MeV RFQ (RFQ III) for the beam-current upgrade of the J-PARC linac. RFQ III is the first RFQ developed to meet the requirement of the J-PARC linac. The peak beam current is 50mA, pulse length is 500 micro-sec, and the repetition is 25 Hz. Before the installation to the accelerator tunnel scheduled in summer of 2014, we built a test stand for offline testing of the new ion source and RFQ. Basic performances of RFQ III such as transmission, transverse emittance, and energy spread were measured with short pulse length beams. In this paper, we present the results of the beam test.

MOPP092	Compact Timing System with FPGA for SPring-8 Linac	timing, FPGA, gun, injection	270
	H. Dewa, H. Hanaki, S. Suzuki JASRI/SPring-8, Hyogo-ken, Japan
	Funding: This reserch was supported by TAKUMI project. A new timing system for SPring-8 linac was developed. It is a test system to confirm the possibility of replacing the current NIM module-based system. Although fast logic circuits can be made easily with NIM modules, they become complicated when they are used in a large system. The timing system for SPring-8 linac has been getting larger and larger after several improvements for injection to New SUBARU (NS), top-up injection for storage ring, low repetition operation for saving energy, fast alternative injection and so on. In order to simplify the system, we adopted FPGA technology that can run at a clock over 500 MHz. The new system has 50 NIM inputs and outputs on the front panel, which is installed in an 8U rack-mount box. It only has gun trigger parts of current system, but includes all of the circuit components used in the current system such as and/or logics, counter delay, fan in/out etc. Three clock sources for Synchrotron injection, NS injection, and linac solo use are available in the FPGA, and they can be changed rapidly according to the trigger sources. We describe here the details of test timing system, the results of timing jitter measurements.

MOPP093	Evaluation of Beam Energy Fluctuations Caused by Phase Noises	experiment, timing, electron, cavity	273
	H. Hanaki, H. Dewa, S. Suzuki, K. Yanagida JASRI/SPring-8, Hyogo-ken, Japan T. Asaka, T. Ohshima RIKEN SPring-8 Center, Sayo-cho, Sayo-gun, Hyogo, Japan
	The SSB noises of the RF reference signal dominate the short-term instabilities of the RF phase of the carrier RF. This phase modulation finally results in beam energy fluctuation. This presentation gives a quantitative evaluation of the beam energy fluctuations in an electron linear accelerator caused by phase noises, comparing a theoretical analysis and experimental results. A simple model was introduced to understand how phase noises result in the relative phase difference between a beam bunch and accelerating RF fields. In the experiments, we measured the enhanced beam energy fluctuations by modulating the phase of the reference RF signals with an external signal. The interference between the accelerating RF phase modulation and the timing modulation of a beam bunch was found in the model analysis and also in the experimental results.

MOPP094	Latest Improvements of the SPring-8 Linac for High Reliability	operation, vacuum, electron, injection	276
	S. Suzuki, H. Dewa, H. Hanaki, T. Kobayashi, T. Magome, A. Mizuno, T. Taniuchi, K. Yanagida JASRI/SPring-8, Hyogo-ken, Japan T. Asaka RIKEN SPring-8 Center, Sayo-cho, Sayo-gun, Hyogo, Japan
	In order to perform stable injection to the 8GeV SPring-8 storage ring, which is performing the top-up operation, the high reliability of the linac has been advanced as follows: For reduction of phase variations caused by the waveguide deformation due to the variations of temperature or atmospheric pressure, the waveguide circuit of SF6 enclosure type, which fed RF powers to the bunching section, was replaced with that of vacuum type. And S-band 10MW circulators and isolators of vacuum type were adopted for the first time in the world. The timing system was improved so that the interval time of the beam injection into the 8GeV booster synchrotron and the 1.5 GeV NewSUBARU storage ring has been reduced to 1 sec from 15 seconds, respectively, even in the top-up operation of both storage rings. As a result, the stored current by the top-up operation were further stabilized. The stored current of the NewSUBARU storage ring was stabilized to 0.18% from 0.31%. The electron gun cathode assembly has been developed to reduce the dark emission from a grid plate by the double grid method and the electrolytic polishing.

MOPP095	Emittance Measurement for SPring-8 Linac Using Four Six-Electrode BPMs	emittance, electron, quadrupole, focusing	279
	K. Yanagida, H. Hanaki, S. Suzuki JASRI/SPring-8, Hyogo-ken, Japan
	In the SPring-8 linear accelerator (linac) six-electrode beam position monitors (BPMs) have been installed to measure second-order moments. At the end of the linac where the electron beam energy is 1 GeV four quadrupole magnets are utilized for twiss parameter matching toward the following beam transport line. Last year four six-electrode BPMs were installed at the locations of these four quadrupole magnets for an emittance measurement. The relative second-order moments were obtained changing the magnetic field strength of the quadrupole magnets, then beam sizes, emittances and twiss parameters were deduced or calculated. At this time we applied one pair of beam sizes measured by the screen monitor for a precise determination of emittances but we try to implement non-destructive measurement with no screen monitor. Before the emittance measurement a calibration with fifth-order moment correction was carried out changing beam positions at the BPM locations using upstream steering magnets (the entire calibration).
	Slides MOPP095 [0.984 MB]

MOPP096	Current Status of the Mainz Energy-Recovering Superconducting Accelerator Project	experiment, feedback, operation, diagnostics	282
	M. Dehn, I. Alexander, K. Aulenbacher, J. Diefenbach, R.G. Heine, C. Matejcek, F. Schlander, D. Simon IKP, Mainz, Germany
	Funding: Work supported by the German Federal Ministery of Education and Research (BMBF) and German Research Foundation (DFG) under the Cluster of Excellence "PRISMA" The Mainz Energy-Recovering Superconducting Accelerator (MESA) project at Johannes Gutenberg-Universtitaet Mainz has started in 2012 and is in full swing now. This presentation shows the current status of the project with a glance on cryogenics, superconducting RF, accelerator lattice design and the normal conducting injector.

MOPP098	Physical Starting of the First and Second Section of Accelerator Linac-800	electron, undulator, klystron, gun	288
	V. Kobets, N. Balalykin, I.N. Meshkov, V. Minashkin, G. Shirkov JINR, Dubna, Moscow Region, Russia V. Shabratov JINR/VBLHEP, Moscow, Russia
	In the report discusses the modernization of linear electron accelerator MEA (Medium Energy Accelerator). The aim is to develop a set of MEAs based free-electron lasers, imposed a number of emission wavelengths from infrared to ultraviolet. In work presents the results of the physical starting of the first and second stations accelerating electron linear accelerator LINAC-800, as well as start infrared undulator. We discuss the work program for this accelerator.

MOPP099	Compact Proton Injector for Synchrotrons	rfq, proton, cavity, quadrupole	291
	A.D. Kovalenko, A.V. Butenko JINR, Dubna, Moscow Region, Russia A. Kolomiets, A.S. Plastun ITEP, Moscow, Russia
	Compact linac comprising two sections of different RFQ structures was designed. The first section is conventional RFQ with output energy 3 MeV whereas the second one is RFQ with trapezoidal modulation of vanes. The linac output energy is 8 MeV. The both structures operate at frequency of 352 MHz. The total length of machine is less than 8 m. The output pulsed beam current is of 40 mA. The design is suitable for both as NICA injection complex and proton superconducting medical synchrotron.

MOPP103	Fault Tolerance and Consequences in the MYRRHA Superconducting Linac	cavity, operation, cryomodule, simulation	297
	F. Bouly LPSC, Grenoble Cedex, France J.-L. Biarrotte IPN, Orsay, France D. Uriot CEA/DSM/IRFU, France
	Funding: This work is being supported by the European Atomic Energy Community’s EURATOM) Seventh Framework Programme under grant agreement n°269565(MAX project). The MYRRHA project aims at the construction of new irradiation complex in Mol (Belgium) to demonstrate the transmutation feasibility with an Accelerator Driven System (ADS). In its subcritical configuration, the MYRRHA facility requires a proton flux with a maximum power of 2.4 MW (600 MeV - 4 mA). Such a continuous wave beam will be delivered by a superconducting linac which must fulfil very stringent reliability requirements to ensure the safe ADS operation with a high level of availability. In this purpose, the accelerator design is based on a redundant and fault-tolerant scheme to enable rapid failures mitigations. Beam dynamics studies on the fault tolerance capability of the MYRRHA superconducting linac will be presented. The results will be mainly focused on RF failure compensation scenarios: when one or several superconducting cavities are lost in the linac. The impact on the R&D to enable fast retuning procedures in the linac will also be discussed.

MOPP106	3D Mode Analysis of Full Tanks in Drift-Tube Linacs	DTL, simulation, emittance, drift-tube-linac	300
	S.S. Kurennoy LANL, Los Alamos, New Mexico, USA
	Drift-tube linacs (DTLs) are usually designed and analyzed in axisymmetric approximation, cell by cell, using 2D codes such as Superfish and Parmila. We have developed 3D models of full DTL tanks with CST Studio to accurately calculate the tank modes, their sensitivity to post-coupler positions and tilts, tuner effects, and RF-coupler influence. Such models are important for the LANSCE DTL where each of four tanks contains tens of drift tubes and tank 2 has as much as 66 cells. We perform electromagnetic analysis of the DTL tank models using MicroWave Studio (MWS), mainly with eigensolvers but also in time domain. A similar approach has already been applied for thermal analysis of the LANSCE DTL but only with short tank models [1]. The full-tank analysis allows tuning the field profile of the operating mode and adjusting the frequencies of the neighboring modes within a realistic CST model. The MWS-calculated RF fields can be used for beam dynamics and thermal modeling. Here we present beam dynamics results for the LANSCE DTL from Particle Studio. [1] S.S. Kurennoy, LINAC08, Victoria, BC, 2008, p. 951.

MOPP107	Results from the Installation of a New 201 MHz RF System at LANSCE	DTL, cavity, electronics, controls	303
	J.T.M. Lyles, C.L. Arnold, W.C. Barkley, J. Davis, A.C. Naranjo, M.S. Prokop, D. Rees, G. M. Sandoval, Jr. LANL, Los Alamos, New Mexico, USA D. Baca, R.E. Bratton, R.D. Summers Compa Industries, Inc., Los Alamos, New Mexico, USA
	Funding: Work supported by the United States Department of Energy, National Nuclear Security Agency, under contract DE-AC52-06NA25396. The LANSCE RM project is restoring the linac to it’s original high power capability after the power grid tube manufacturer could no longer provide triodes that could consistently meet our power requirements. High duty factor Diacrodes® now supply RF power to the largest DTL tank. These tetrodes reuse the existing infrastructure including water-cooling systems, coaxial transmission lines, high voltage power supplies and capacitor banks. The power amplifier system uses a combined pair of LANL-designed cavity amplifiers using the TH628L Diacrode® to produce as much as 3.5 MW peak and 420 kW of mean power. A digital low level RF control system was developed to complement these new linear amplifiers. Design and testing was completed in 2012, with commercialization following in 2013. The first installation is commissioned. The two remaining high power RF systems for tanks 3 and 4 will be replaced in subsequent years using a hybrid old/new RF system until the changeover is complete. Features and operating results of the replacement system are summarized, along with observations from the rapid-paced installation project.

MOPP114	SNS Linac Upgrade Plans for the Second Target Station	cryomodule, klystron, cavity, rfq	320
	J. Galambos, D.E. Anderson, M.P. Howell, S.-H. Kim, M.A. Plum, A.P. Shishlo ORNL, Oak Ridge, Tennessee, USA M.E. Middendorf ORNL RAD, Oak Ridge, Tennessee, USA
	Funding: ORNL is managed by UT-Battelle, LLC, under contract DE-AC05-00OR22725 for the U.S. Department of Energy. The Second Target Station (STS) upgrade for the Spallation Neutron Source (SNS) proposes the addition of a short pulse, long wavelength neutron scattering station. In order to provide world-class intensity at the additional station, the SNS linac beam power capability is doubled, to 2.8 MW. This will be accommodated by a 30% increase in the beam energy to 1.3 GeV and a 50% increase in beam current. The beam energy increase will be provided by the addition of 7 additional cyro-modules and supporting RF equipment in space provided during the original SNS construction. The beam current increase will be provided by improved ion source and a reduced chopping fraction, and will require increases in the RF and high voltage modulator systems to accommodate the additional beam loading. Initial plans will be presented. The proposed linac upgrade path will be described.

MOPP119	Measurements and High Power Test of the First C-band Accelerating Structure for SwissFEL	operation, vacuum, FEL, klystron	333
	R. Zennaro, J. Alex, A. Citterio, J.-Y. Raguin PSI, Villigen PSI, Switzerland
	The SwissFEL project is based on a 5.8 GeV C-band Linac which is composed of 10⁴ accelerating structures with a length of 2 m each. Due to the absence of dimple tuning no local frequency correction is possible and hence ultra-precise machining is required. The paper reports on both low level and high power RF test of the first nominal structure produced. The required mechanical precision has been reached and the structure has been successfully power tested to a gradient larger than 50 MV/m, well above the nominal level of 28 MV/m. The measured dark current and break down rates are well in the specifications.

MOPP120	Beam Dynamic Design of a 100 mA, 162.5 Mhz High-Current Linac	rfq, emittance, quadrupole, experiment	336
	F.J. Jia, J.E. Chen, Y.R. Lu, Z. Wang, W.L. Xia, X.Q. Yan, K. Zhu PKU, Beijing, People's Republic of China W.P. Dou, Y. He IMP, Lanzhou, People's Republic of China
	Funding: This work is supported by the 973 program (No. 2014CB845503) and the NSFC (Grants No. 11079001). The beam dynamic design of a 100 mA, 162.5 MHz Radio Frequency Quadrupole (RFQ) is presented in this paper. The RFQ will accelerate protons from 85 keV to 3 MeV under the operation mode of continuous-wave (CW). The code PARMTEQM is used to carry out the beam dynamics design and the transmission efficiency has been optimized and improved to more than 99%. In the design of this high-current linac, the space charge effect is analyzed as it can cause emittance growth, nonuniform particle density distribution and resonance effect. The electrode structure parameters generated by PARMTEQM also be adopted by the code of Toutatis to verify the result’s veracity.

MOPP125	Comparison of Normal Conducting High Energy Accelerating Structures for a Moderate Operating Frequency	coupling, Windows, proton, impedance	348
	V.V. Paramonov RAS/INR, Moscow, Russia
	The progress in the CERN Linac 4 project confirms the very attractive possibility for single frequency high intensity high energy normal conducting hadron linac. The important part of such linac is the accelerating structure for high energy part. Parameters of possible accelerating structures, referring to PIMS, at operating frequency 352 MHz are considered for proton energy up to 600 MeV. The set of parameters, such as dimensions, RF efficiency, field stability, cooling capability, vacuum conductivity, are considered and compared.

MOPP126	Untrapped HOM Radiation Absorption in the LCLS-II Cryomodules	HOM, cryomodule, cavity, impedance	351
	K.L.F. Bane, C. Adolphsen, C.D. Nantista, T.O. Raubenheimer SLAC, Menlo Park, California, USA A. Saini, N. Solyak, V.P. Yakovlev Fermilab, Batavia, Illinois, USA
	Funding: Work supported by Department of Energy contract DE–AC02–76SF00515. The superconducting cavities in the continuous wave (CW) linacs of LCLS-II are designed to operate at 2 K, where cooling costs are very expensive. One source of heat is presented by the higher order mode (HOM) power deposited by the beam. Due to the very short bunch length-especially in L3 the final linac-the LCLS-II beam spectrum extends into the terahertz range. Ceramic absorbers, at 70 K and located between cryomodules, are meant to absorb much of this power. In this report we perform two kinds of calculations to estimate the effectiveness of the absorbers and the amount of beam power that needs to be removed at 2 K.

MOPP130	A Linac-Based Approach to Modelling an Orbit Separated Cyclotron	cavity, cyclotron, simulation, emittance	364
	D.C. Plostinar, G.H. Rees STFC/RAL/ASTeC, Chilton, Didcot, Oxon, United Kingdom
	An orbit separated cyclotron (OSC) is a new type of accelerator intended as a proton driver for Accelerator Driven Subcritical Reactors (ADSRs). A ring has been designed based on the new concept that accelerates a proton beam from 500 MeV to 1 GeV in four turns using multi-cell superconducting cavities in each period. From a beam dynamics point of view, the ring can be considered as a “wrapped-up” linac at four times the ring circumference. In this paper we present beam dynamics modelling details when using 3D linac codes and cavity field maps. We conclude that the versatility of codes such as TraceWin, allows detailed machine modelling and improved design procedures that take into account various aspects including orbit distortion caused by transverse deflecting fields in the cavities.

MOPP134	Superconducting Accelerating Cavity Pressure Sensitivity Analysis and Stiffening	cavity, proton, simulation, vacuum	373
	J. Rodnizki, Y. Ben Aliz, A. Grin, Z. Horvitz, A. Perry, L. Weissman Soreq NRC, Yavne, Israel G.K. Davis JLab, Newport News, Virginia, USA J.R. Delayen ODU, Norfolk, Virginia, USA
	The SARAF Prototype Superconducting Module (PSM) houses six 176 MHz Half Wave Resonators(HWR). The PSM accelerates protons and deuterons from 1.5 MeV/u to 4 and 5.6 MeV. The HWRs are highly sensitive to the coolant liquid Helium pressure fluctuations which limit the available beam power to 2kW per cavity out of 4kW RF amplifier and coupler and so might limit the available beam current to 2mA depending on the output energy. The flat shape of the cavity along the beam line in the area of the high electric field generates the high sensitivity of the Eigen mode frequency to helium pressure. The evaluated cavity sensitivity is full consistent with the measured values. It was explored that the tuning system (the fog structure) has a significant contribution to the cavity sensitivity. By using ribs or by modifying the rigidity of the fog we may reduce the HWR sensitivity by a factor of 3. This analysis is applied to study the stresses on the cavity during cool down and warm up to avoid plastic deformation as the Niobium yield is an order of magnitude lower in room temperature.

MOPP139	Studies of Coherent Synchrotron Radiation in the Jefferson Lab FEL Driver with Implications for Bunch Compression	emittance, acceleration, simulation, FEL	388
	C. Tennant, D. Douglas, R. Li JLab, Newport News, Virginia, USA C.-Y. Tsai Virginia Polytechnic Institute and State University, Blacksburg, Virginia, USA
	Funding: Work supported by the Office of Naval Research and the High Energy Laser Joint Technology. Jefferson Laboratory work is supported under U.S. DOE Contract No. DE-AC05-06OR23177. The Jefferson Laboratory IR FEL Driver provides an ideal test bed for studying a variety of beam dynamical effects. Recent studies focused on characterizing the impact of coherent synchrotron radiation (CSR) with the goal of benchmarking measurements with simulation. Following measurements to characterize the beam, we quantitatively characterized energy extraction via CSR by measuring beam position at a dispersed location as a function of bunch compression. In addition to operating with the beam on the rising part of the linac RF waveform, measurements were also made while accelerating on the falling part. For each, the full compression point was moved along the backleg of the machine and the response of the beam (distribution, extracted energy) measured. Initial results of start-to-end simulations using a 1D CSR algorithm show remarkably good agreement with measurements. A subsequent experiment established lasing with the beam accelerated on the falling side of the RF waveform in conjunction with positive momentum compaction (R56) to compress the bunch. The success of this experiment motivated the design of a modified CEBAF-style arc with control of CSR and microbunching effects.

TUIOA02	R&D Efforts for ERLs	emittance, cavity, operation, SRF	394
	R.G. Eichhorn Cornell University, Ithaca, New York, USA
	The last few years has seen extensive R&D for ERLs, with several prototype facilities now under construction or in operation. The Cornell ERL R&D program has reached major goals, with producing the world’s brightest beam from any photoinjector, reaching CW beam current of greaters than 75 mA, and reaching intrinsic quality factors of 10¹¹ in an SRF cavity installed in a cryomodule. The talk gives an overview of status of ERLs projects, and ERL R&D.
	Slides TUIOA02 [8.803 MB]

TUIOA03	The MAX IV Linac	gun, electron, storage-ring, injection	400
	S. Thorin, J. Andersson, F. Curbis, M. Eriksson, O. Karlberg, D. Kumbaro, E. Mansten, D.F. Olsson, S. Werin MAX-lab, Lund, Sweden
	The MAX IV linac will be used both for injection and top up into two storage rings, and as a high brightness injector for a Short Pulse Facility (SPF). The linac has also been deigned to handle the high demands of an FEL injector. In the storage ring injection mode, the linac is operated at 10 Hz with a thermionic RF gun and the electron bunches are kicked out from the linac at either 3 GeV or 1.5 GeV to reach the respective storage ring. For the Short Pulse mode the linac will operate at 100 Hz with a high brightness photo cathode gun. Compression is done in two double achromats with positive R56 and the natural second order momentum compaction, T566, from the achromats is used together with weak sextupoles to linearise longitudinal phase space, leaving no need for a linearising harmonic cavity. The achromat design for bunch compression produces very short, high peak power electron pulses, while minimizing emittance increase. In this paper we present the MAX IV linac design and the status of commissioning which started in March 2014.
	Slides TUIOA03 [4.202 MB]

TUIOA04	The New LCLS-II Project : Status and Challenges	cryomodule, electron, undulator, operation	404
	J.N. Galayda SLAC, Menlo Park, California, USA
	The LCLS-II was an upgrade of the LCLS which essentially replicated the LCLS in another tunnel using the middle 1/3 of the SLAC S-band linac. In August 2013, the project was doubled in scope and redirected towards providing MHz-rate X-ray pulses from 0.2 to 5.0 keV while still supporting the ongoing program at the LCLS. The accelerator is now based on a 4.0 GeV SCRF linac installed in the front of the SLAC linac tunnel. Status and challenges of LCLS-II in context of July 2013 recommendation of DOE BESAC for a fully coherent, cw, FEL with photon energies up to ~5 keV.
	Slides TUIOA04 [6.386 MB]

TUIOB02	Beam Commissioning of the 100 MeV KOMAC Linac	proton, DTL, operation, klystron	413
	Y.-S. Cho KAERI, Daejon, Republic of Korea
	Funding: This work was supported by the Ministry of Science, ICT & Future Planning of the Korean Government. The operation of the 100MeV proton linear accelerator for multipurpose application started in July, 2013 at KOMAC (Korea Multipurpose Accelerator Complex), KAERI (Korea Atomic Energy Research Institute). Also, the operation of the two beam lines, one is for 20MeV beam and the other for 100MeV beam, started in order to supply proton beams to users. The accumulated operation time was 2,290 hours and the proton beam was supplied to 937 samples in 2013. In addition to the beam service, the effort to increase the beam power is continuing in 2014. Beam commissioning and operation status of the linac will be presented in this talk.
	Slides TUIOB02 [7.200 MB]

TUIOB03	Commissioning of Energy Upgraded Linac of J-PARC	klystron, injection, operation, rfq	417
	K. Hasegawa J-PARC, KEK & JAEA, Ibaraki-ken, Japan
	To realize a full potential of J-PARC facility (1MW at 3 GeV), the J-PARC linac is upgraded from 181 MeV to 400 MeV by using an annular-ring coupled structure linac (ACS). The ACS modules and peripheral system were installed and commissioned in summer to autumn of 2013. Beam commissioning is about to start and results will be expected.
	Slides TUIOB03 [4.905 MB]

TUIOB04	DTL Construction Status of CSNS Project	DTL, vacuum, neutron, ion	423
	H.C. Liu, S. Fu, J. Peng, S. Wang IHEP, Beijing, People's Republic of China
	Linac of Chinese Spallation Neutron Source (CSNS) project is under construction. The ion source is tested and good performance of beam current is obtained. The low level RF tuning is underway of the RFQ and assembling of DTL will start soon. Not only the construction of hardware, but some commissioning software packages have been developed and tested.
	Slides TUIOB04 [4.772 MB]

TUIOC03	Nb3Sn - Present Status and Potential as an Alternative SRF Material	cavity, niobium, SRF, cryogenics	431
	S. Posen, M. Liepe Cornell University (CLASSE), Cornell Laboratory for Accelerator-Based Sciences and Education, Ithaca, New York, USA
	Nb₃Sn is a material that has the potential to have a transformative impact on SRF linacs. Due to its large critical temperature of approximately 18 K, Nb₃Sn cavities can have far smaller surface resistances at a given temperature than standard Nb cavities. This could significantly reduce the costs for infrastructure and power in cryoplants for large CW linacs. In addition, the predicted superheating field of Nb₃Sn is approximately double that of Nb, potentially doubling the maximum energy gradient. This would significantly decrease the size and cost of high energy linacs. In this work, we present recent progress in research and development for this promising material.
	Slides TUIOC03 [3.357 MB]
	Poster TUIOC03 [2.046 MB]

TUPP001	Cryogenic Performance of a New 72 MHz Quarter-Wave Resonator Cryomodule	cryomodule, cavity, cryogenics, solenoid	437
	Z.A. Conway, G.L. Cherry, R.L. Fischer, S.M. Gerbick, M. Kedzie, M.P. Kelly, S.H. Kim, S.W.T. MacDonald, R.C. Murphy, P.N. Ostroumov, C.E. Peters, M.A. Power, T. Reid, J.R. Specht ANL, Argonne, Illinois, USA
	Funding: This material is based upon work supported by the U.S. Department of Energy, Office of Science, Office of Nuclear Physics, under contract number DE-AC02-06CH11357. The Argonne National Laboratory ATLAS accelerator’s Intensity and Efficiency Upgrade project has been successfully finished [1]. This upgrade substantially increases beam currents for experimenters working with the existing stable and in-flight rare isotope beams and for the neutron rich beams from the Californium Rare Isotope Breeder upgrade. A major portion of this project involved the replacement of three existing cryomodules, containing 18 superconducting (SC) accelerator cavities and 9 superconducting solenoids, with a single cryomodule containing 7 SC 72.75 MHz accelerator cavities optimized for ion velocities of 7.7% the speed of light and 4 SC solenoids all operating at 4.5 K. This paper reports the measured thermal load to the 4 K and 80 K coolant streams and compares these results to the pre-upgrade cryogenic system.

TUPP007	Multi Gigawatt High Current Pulsed Electron Accelerator Technology Development Program at BARC	electron, impedance, high-voltage, induction	456
	A. Sharma, R. Agarwal, M. Beg, R. Chandra, H. Choudhary, L.M. Gantayet, S.R. Ghodke, TS. Kolge, R. Kumar, S. Mitra, K.C. Mittal, A.S. Patel, A. Roy, P.C. Saroj, K. Senthil, V.K. Sharma, S.K. Singh BARC, Mumbai, India
	High current intense electron beams were investigated earlier for Flash X-rays and nuclear electromagnetic pulse generation. Starting with moderate parameters of 200 kV, 6 kA, 60 ns pulsed electron beam source from a system named Kilo Ampere Linear Injector (KALI-75) our latest development is KALI-30 GW system rated for 1 MV, 30 kA, 80 ns. First repetitive pulse LINAC without spark gap switching was developed as Linear Induction Accelerator (LIA-200) for technology demonstrations at 100 Hz. Also a repetitive Marx generator coupled reflex triode system to operate at 10 Hz. Next to this series of development LIA-400 has been developed to a capacity of 400 kV, 4 kA, 100 ns, 300 Hz. To make these pulse power systems applicable for big LINAC projects like nToF studies or ADS program, a high current electron gun has also been developed to give 100 A, 2 ns,10 Hz pulses. References [1].Amitava Roy et al, Journal of App. Physics 103, 2008. [2].D. D. P. Kumar, et al. Rev. Sci. Inst., vol. 78, no. 11, 2007. [3].Archana Sharma, et al., IEEE-PS Vol. 39, No. 5, 2011.

TUPP009	Operation and Improvements of the ALBA Linac	klystron, operation, injection, booster	459
	R. Muñoz Horta, J.M. Gómez Cordero, F. Pérez CELLS-ALBA Synchrotron, Cerdanyola del Vallès, Spain
	The ALBA Light Source pre-injector is a 100 MeV electron Linac which started operation in July 2010. Since then, several improvements have been made to the Linac system to enhance the beam stability and the operation reliability with special focus to top-up mode operation requirements. A description of the modifications applied to the RF system and an overview of the different modes of injection are presented. Also operational experience in decay mode and in the recently implemented top-up mode are reported.

TUPP019	Qualification of the Titanium Welds in the E-XFEL Cryomodule and the CE Certification	cryomodule, cavity, operation, quadrupole	468
	S. Barbanotti, H. Hintz, K. Jensch, R. Klos, W. Maschmann, A. Matheisen, A. Schmidt DESY, Hamburg, Germany C. Boulch, C. Cloué, C. Madec, J.L. Perrin, T. Trublet CEA/IRFU, Gif-sur-Yvette, France J.-P. Charrier, O. Napoly CEA/DSM/IRFU, France
	The CE stamping of the one hundred 1.3 GHz cryomodules for the XFEL Linac is a main step in the process of the certification of the entire Linac as a pressure equipment. Stringent requirements on materials and the quality of the welds of the pressurised components need to be satisfied to obtain the stamp. This paper summarizes these requirements, describes the process developed to qualify each module and summarises the rework campaign on the cavity helium vessels made necessary to obtain the required quality for a reliable and safe accelerator.

TUPP022	RF Tuning of a S-band Hybrid Buncher for Injector Upgrade of LINAC II at DESY	electron, simulation, target, experiment	478
	Y.C. Nie, M. Hüning, C. Liebig, M. Schmitz DESY, Hamburg, Germany
	LINACII at DESY currently provides 450 MeV electrons for the synchrotron radiation source PETRAIII. The injector upgrade of it aims to improve its reliability and mitigate the radiological activation due to electron losses at hundreds of MeV. Therefore, a 2.998 GHz hybrid buncher has been developed and will be installed in between a pre-buncher and LINAC II. It comprises a 1-cell standing-wave (SW) section for rapid acceleration and a 13-cells travelling-wave (TW) section for further bunching and acceleration. This paper focuses on its rf tuning procedure. The tuning strategy combines a non-resonant bead-pull measurement of complex electric field and a linear model for local reflection coefficient calculation. The tuning result is satisfying. Field unflatness of the TW section has been improved from ±9% to ±4%, and field in the SW section has been enhanced significantly. By using ASTRA simulation, it has been verified that the residual detuning of the structure is acceptable in view of beam dynamics performance.

TUPP025	Progress on ESS Medium Energy Beam Transport	quadrupole, rfq, cavity, DTL	484
	I. Bustinduy, D. Fernandez-Cañoto, N. Garmendia, A. Ghiglino, O. González, P.J. González, Z. Izaola, I. Madariaga, M. Magan, L. Muguira, J.L. Muñoz, I. Rueda, F. Sordo, S. Varnasseri, R. Vivanco ESS Bilbao, Bilbao, Spain M. Eshraqi, R. Miyamoto, A. Ponton ESS, Lund, Sweden
	The considered versatile ESS MEBT is being designed to achieve four main goals: First, to contain a fast chopper and its correspondent beam dump, that could serve in the commissioning as well as in the ramp up phases. A detailed study of the chopper rise time effects on the loss budget will be presented. Second, to serve as a halo scraping section by means of various adjustable blades. Third, to measure the beam phase and proﬁle between the RFQ and the DTL, along with other beam monitors. And ﬁnally, to match the RFQ output beam characteristics to the DTL input both transversally and longitudinally. For this purpose a set of eleven quadrupoles is used to match the beam characteristics transversally, combined with three 352.2 MHz CCL type buncher cavities, which are used to adjust the beam in order to fulfil the required longitudinal parameters. A thorough study on the optimal input beam parameters will be discussed. Quadrupole design update will be presented along with new RF measurements over the buncher prototype. Finally, updated results will be presented on the chopper and beam-dump system.
	Poster TUPP025 [5.596 MB]

TUPP028	Beam Tests at the CLIC Test Facility, CTF3	experiment, operation, emittance, acceleration	487
	R. Corsini, S. Döbert, W. Farabolini, D. Gamba, J.L. Navarro Quirante, T. Persson, P.K. Skowronski, F. Tecker CERN, Geneva, Switzerland W. Farabolini CEA/DSM/IRFU, France D. Gamba JAI, Oxford, United Kingdom
	The CLIC Test Facility CTF3 has been built at CERN by the Compact Linear Collider (CLIC) International Collaboration, in order to prove the main feasibility issues of the two-beam acceleration technology on which the collider is based. After the successful completion of its initial task, CTF3 is continuing its experimental program in order to give further indications on cost and performance issues, to act as a test bed for the CLIC technology, and to conduct beam experiments aimed at mitigating technological risks. In this paper we discuss the status of the ongoing experiments and present the more recent results, including improvements in beam quality and stability.

TUPP031	Understanding the Error Tolerances Required to Automatically Phase the HIE-ISOLDE Linac	emittance, cavity, software, experiment	496
	M.A. Fraser, J.C. Broere, S. Haastrup, D. Lanaia, D. Valuch, D. Voulot CERN, Geneva, Switzerland
	The broad experimental programme at ISOLDE means that the same radioactive beam species and energy are rarely studied twice and the cavities of the linac must be scaled or re-phased for each experiment. A software application was developed to automatically re-phase the cavities of the HIE-ISOLDE superconducting linac to the beam from computed settings. The application was developed to expedite both machine set-up in normal operation and in scenarios involving cavity failures. A beam dynamics error study will be presented in order to better understand the challenges facing the automatic phasing routine. The effects of a variety of different errors on the efficacy of the phasing application were studied, leading to a specification of the tolerances required for the calibration of the rf system and the accuracy of the survey system that monitors the positions of the cavities.

TUPP033	Effect of Beam-Loading on the Breakdown Rate of High Gradient Accelerating Structures	klystron, beam-loading, experiment, acceleration	499
	J.L. Navarro Quirante, R. Corsini, A. Degiovanni, S. Döbert, A. Grudiev, O. Kononenko, G. McMonagle, S.F. Rey, A. Solodko, I. Syratchev, F. Tecker, L. Timeo, B.J. Woolley, X.W. Wu, W. Wuensch CERN, Geneva, Switzerland O. Kononenko SLAC, Menlo Park, California, USA A. Solodko JINR, Dubna, Moscow Region, Russia J. Tagg National Instruments Switzerland, Ennetbaden, Switzerland B.J. Woolley Cockcroft Institute, Lancaster University, Lancaster, United Kingdom X.W. Wu TUB, Beijing, People's Republic of China
	The Compact Linear Collider (CLIC) is a study for a future room temperature electron-positron collider with a maximum center-of-mass energy of 3 TeV. To efficiently achieve such high energy, the project relies on a novel two beam acceleration concept and on high-gradient accelerating structures working at 100 MV/m. In order to meet the luminosity requirements, the break-down rate in these high-field structures has to be kept below 10 per billion. Such gradients and breakdown rates have been demonstrated by high-power RF testing several 12 GHz structures. However, the presence of beam-loading modifies the field distribution for the structure, such that a higher input power is needed in order to achieve the same accelerating gradient as the unloaded case. The potential impact on the break-down rate was never measured before. In this paper we present an experiment located at the CLIC Test Facility CTF3 recently proposed in order to quantify this effect, layout and hardware status, and discuss its first results.
	Slides TUPP033 [1.970 MB]
	Poster TUPP033 [2.355 MB]

TUPP034	Commissioning of the CERN LINAC4 Wire Scanner, Wire Grid and Slit-Grid Monitors at 3 and 12 MeV	electron, emittance, space-charge, diagnostics	502
	F. Roncarolo, U. Raich, F. Zocca CERN, Geneva, Switzerland
	The CERN LINAC4 has been commissioned up to 12 MeV. The H⁻ beam transverse profile distributions were measured by both wire grids and wire scanners. A slit-grid system located on a temporary diagnostics bench was used to characterize the transverse emittance during the two different stages of commissioning: at the exit of the RFQ (3 MeV) and DTL1 (12 MeV). The wire signal is a balance between the negative charge deposited by the stripped electrons from the H⁻ and the charge lost due to secondary emission. Optimal settings were found for the repelling plates used to suppress secondary emission, which were confirmed by electromagnetic simulations. In addition, suppression of the secondary emission due to the beam space charge was observed. The benefit of changing the wire scanner geometry in order to minimize the cross-talk between horizontal and vertical wires and the observation of thermionic emission on carbon wires are also discussed.

TUPP035	Transverse Profile and Emittance Measurements With a Laser Stripping System During the CERN LINAC4 Commissioning at 3 and 12 MeV	laser, emittance, detector, electron	506
	F. Roncarolo, E. Bravin, T. Hofmann, U. Raich, F. Zocca CERN, Geneva, Switzerland G.E. Boorman, A. Bosco, S.M. Gibson, K.O. Kruchinin Royal Holloway, University of London, Surrey, United Kingdom C. Gabor STFC/RAL/ASTeC, Chilton, Didcot, Oxon, United Kingdom J.K. Pozimski Imperial College of Science and Technology, Department of Physics, London, United Kingdom
	The CERN LINAC4 beam commissioning at 3 and 12 MeV was completed in 2014. A novel system for measuring the transverse beam profile and emittance, based on low power laser stripping and H⁰ detection using a diamond detector, was successfully tested at these two energies. The measurement results agree with the operational slit-grid method within a few percent in terms of both transverse profile and emittance. After describing the general system setup, this remarkable achievement is discussed in detail together with the present limitations, which will be addressed in order to design a laser based emittance monitor for the LINAC4 top energy of 160 MeV.

TUPP036	Space Charge Compensation in the Linac4 LEBT for Three Injected Gas Types	emittance, simulation, ion, space-charge	510
	C.A. Valerio, R. Scrivens CERN, Geneva, Switzerland N. Chauvin CEA/IRFU, Gif-sur-Yvette, France
	The space charge of unbunched, high intensity beams can be compensated by the trapping of charged particles in the potential well of the beam. The source of these secondary charge particles can be the residual gas in the beam line. The effect is important in the Low energy beam transport (LEBT) regions. At CERN’s Linac4, the LEBT transports a pulsed 45keV H⁻ beam, which is compensated by the positive ions, created by collision of the beam with the neutral gas in the beam pipe. The rise time and amount of compensation may be varied by the density of neutral gas and the type of gas used (through the cross-section for ion production and the mass of the resulting ion). In this paper we present measurement results for the transport of the beam at the Linac4 LEBT with the addition of hydrogen, nitrogen and krypton gases into the line, and compare them with simulations of the beam dynamics including the effect of compensating positive ions . The H⁻ beam is provided by a cesiated 2MHz RF ion source with an external solenoidal antenna, operating with 600us pulses at 0.8Hz repetition rate.
	Slides TUPP036 [4.084 MB]
	Poster TUPP036 [1.356 MB]

TUPP037	Transverse Emittance Measurements of the REX-ISOLDE Beams in Preparation for the HIE-ISOLDE Commissioning	emittance, quadrupole, background, ion	513
	D. Voulot, M.A. Fraser, D. Lanaia CERN, Geneva, Switzerland T. Olsson MAX-lab, Lund, Sweden
	The transverse emittance at the output of the REX-ISOLDE normal conducting linac has been measured at different energies in order to characterise the beam at injection to the future HIE-ISOLDE superconducting linac. The measurements were done with low intensity stable beams (~0.5 enA) in order to avoid compensation effects in the EBIS ion source and obtain representative measurements of the radioactive ion beam emittance. Emittances were measured using a slit-grid emittance meter and compared with results obtained with a quadrupole-scan (three-gradient) method. An analysis of the background suppression is presented and possible source of errors for both type of measurements are discussed.
	Poster TUPP037 [2.084 MB]

TUPP038	Transverse Beam Profile Measurements in the Linac4 Medium Energy Beam Transport	emittance, simulation, quadrupole, rfq	516
	M. Yarmohammadi Satri, G. Bellodi, V.A. Dimov, J.-B. Lallement, A.M. Lombardi, U. Raich, F. Roncarolo, F. Zocca CERN, Geneva, Switzerland
	Linac4 is a 160 MeV H⁻ linear accelerator presently under construction at CERN. It will replace the present 50 MeV proton Linac2 as injector of the proton accelerator complex as part of a project to increase the LHC luminosity. The Linac4 front-end, composed of a 45 keV ion source, a Low Energy Beam Transport (LEBT), a 352.2 MHz Radio Frequency Quadrupole (RFQ) which accelerates the beam to 3 MeV and a Medium Energy Beam Transport (MEBT) housing a beam chopper, has been commissioned in the Linac4 tunnel. The MEBT is composed of three buncher cavities and 11 quadrupole magnets to match the beam from the RFQ to the next accelerating structure (DTL) and it includes two wire scanners for beam profile measurement. In this paper we present the results of the profile measurements and we compare them with emittance measurements taken with a temporary slit-and-grid emittance measurement device located after the MEBT line.

TUPP039	Accuracy Determination of the ESS MEBT Emittance Measurements	emittance, scattering, proton, quadrupole	519
	B. Cheymol, A. Ponton ESS, Lund, Sweden
	The European Spallation Source MEBT will be equipped with a full set of diagnostics in order to characterize the bean properties before the injection in the DTL. The 6D phase space of the beam shall be characterize during the commissioning of the normal conducting as well as on regular basis during retuning phase of the machine. In this paper we will discuss the accuracy of the transverse emittance measurement that will be performed with the slit-grid method. The slit geometric parameters have been determined in order to achieve the required resolution and sensitivity. Scattering effects at the slit have been considered to determine the emittance measurement accuracy.

TUPP041	Beam Current Monitor System of the European Spallation Source	FPGA, electronics, EPICS, controls	526
	H. Hassanzadegan, M. Donna, A. Jansson, H. Kocevar, A. Nordt ESS, Lund, Sweden U. Legat Cosylab, Ljubljana, Slovenia M. Werner DESY, Hamburg, Germany
	The Beam Current Monitor system of the ESS will be primarily used for beam current and charge measurements in absolute and differential modes. Moreover, it will provide a fast input to the Beam Interlock System, initiating a trigger to shut the beam off upon high beam loss detection. As the BCM system will be needed at an early stage for Linac commissioning, it needs to work successfully under non-optimal conditions, ex. short pulse and low current beams. It is planned to install in total 20 AC Current Transformers and one Fast Current Transformer along the Linac. The FCT will have a larger bandwidth and it will be used to measure the performance of the fast chopper of the Medium Energy Beam Transport with a rise time of 10 ns. A prototype based on a commercial ACCT and EPICS-integrated MTCA.4 electronics has been set up and successfully tested with an emulated beam. The ACCT signal has been FPGA processed to compensate for the offset and droop as well as filtering and synchronization to an external trigger. This paper gives an overview of the design and test results of the prototype ACCT system with an outlook to future modifications before installation in the ESS Linac.
	Poster TUPP041 [6.113 MB]

TUPP043	Design of the Phase Reference Distribution System at ESS	controls, LLRF, radiation, cavity	529
	R. Zeng, H. Hassanzadegan, M. Jensen, J.M. Jurns, O.A. Persson, A. Sunesson ESS, Lund, Sweden K. Strniša Cosylab, Ljubljana, Slovenia
	PRDS (Phase reference distribution system) at ESS will provide phase reference signals for all LLRF systems and BPM systems with low phase noise and low phase drift. Phase stability requirement is currently 0.1° for short term (during pulse), 1° for long term (days to months). There are 155 LLRF systems and 165 BPM systems in total at current ESS accelerator design.

TUPP045	Beam Physics Challenge in FRIB Driver Linac	ion, proton, focusing, acceleration	532
	Y. Yamazaki, N.K. Bultman, A. Facco, Z.Q. He, M. Ikegami, M.J. Johnson, S.M. Lidia, F. Marti, G. Pozdeyev, K. Saito, J. Wei, X. Wu, Y. Zhang, Q. Zhao FRIB, East Lansing, Michigan, USA
	Funding: *Work supported by the U.S. Department of Energy Office of Science under Cooperative Agreement DE-SC0000661. The Facility for Rare Isotope Beams driver linac provides CW beams of all the stable ions (from protons to uranium) with a beam power of 400 kW and a minimum beam energy of 200 MeV/u in order to produce a wide variety of rare isotopes, mainly for nuclear physics study. The low beam emittances, both transverse and longitudinal, are key performance requirements, together with beam stability. These are required for efficiently separating one isotope from another, the reason for choosing this linac configuration. Multi-charge states (five charge states for the uranium case) are accelerated for maximizing the beam current, while keeping the low emittances. The efficient acceleration of high beam currents from 0.5 MeV/u through the superconducting linac is, needless to say, one of the biggest challenges. The beam power is more than 200 times higher than existing similar SC heavy ion linac. In particular, the SC cavities are difficult to protect from heavy ion beam damage, which can be 30 times larger locally than a proton beam with the same beam power. Other challenges peculiar to the FRIB linac will be presented, together with the solutions.

TUPP054	Study of Beam-Based Alignment for the LCLS-II SC Linac	emittance, alignment, cryomodule, quadrupole	544
	A. Saini, N. Solyak, V.P. Yakovlev Fermilab, Batavia, Illinois, USA T.O. Raubenheimer SLAC, Menlo Park, California, USA
	The Linac Coherent Light Source (LCLS) is an x-ray free electron laser facility. The proposed upgrade of the LCLS facility is based on construction of 4 GeV superconducting (SC) linac. The achievable performance of linac is determined by beam sensitivity to various component errors. In this paper we review misalignment tolerances of LCLS-II SC linac and discuss possible beam-based alignment algorithm to meet these tolerances.

TUPP056	High Current Proton Beam Operation at GSI UNILAC	proton, ion, operation, ion-source	550
	W.A. Barth, A. Adonin, P. Gerhard, M. Heilmann, R. Hollinger, W. Vinzenz, H. Vormann GSI, Darmstadt, Germany
	A significant part of the experimental program at FAIR is dedicated to pbar physics requiring a high number of cooled pbars per hour. The primary proton beam has to be provided by a 70 MeV proton linac followed by two synchrotrons. The new FAIR Proton LINAC will deliver a pulsed proton beam of up to 35 mA of 36 μs duration at a repetition rate of 4 Hz. The current GSI heavy ion linac (UNILAC) is able to deliver world record uranium beam intensities for injection into the synchrotrons, but it is not dedicated for FAIR relevant proton beam operation. In an advanced machine investigation program it could be shown, that the UNILAC is able to provide for sufficient high intensities of CH3-beam, cracked (and stripped) in a supersonic nitrogen gas jet into protons and carbon ions. This advanced operational approach results in up to 2 mA of proton intensity at a maximum beam energy of 20 MeV, 100 μs pulse duration and a rep. rate of 4 Hz. Recent linac beam measurements will be presented, showing that the UNILAC is able to serve as a proton FAIR injector for the first time, while the performance is limited to 17% of the FAIR requirements.

TUPP058	RF System Development for the New 10⁸ MHz Heavy Ion High-Energy Linac at GSI	controls, ion, operation, LLRF	556
	B. Schlitt, M. Hoerr, A. Schnase, G. Schreiber, W. Vinzenz GSI, Darmstadt, Germany
	The GSI UNILAC is in operation successfully since about 40 years. A replacement of the post stripper section is proposed to provide heavy ion beams for the future FAIR facility. Design studies for a new 10⁸ MHz high-energy (HE) linac optimized to accelerate high brilliance and high current ion beams up to U²⁸⁺ for synchrotron injection are in progress. Thus, the UNILAC will be converted into a short-pulse accelerator, the RF duty cycle being reduced from around 30 % to <2 %. To feed the future HE linac and to prepare for the FAIR commissioning, a major modernisation of the existing post stripper RF systems is planned from 2015 to 2017. Besides, the development of a new 1.8 MW cavity amplifier prototype was started recently, based on the widely-used THALES tetrode TH558SC promising an availability for at least 25 years. New 120 - 150 kW solid state driver amplifiers will replace the existing tube drivers. A digital LLRF system designed by industry was integrated into an existing amplifier driving a single gap resonator and was tested including ion beam tests. An overview of the RF system design and of the planned upgrades will be reported including some results of the LLRF tests.

TUPP060	Development of a 217 MHz Superconducting CH Structure	cavity, simulation, operation, accelerating-gradient	563
	M. Basten, M. Amberg, M. Busch, F.D. Dziuba, D. Mäder, H. Podlech IAP, Frankfurt am Main, Germany M. Amberg, K. Aulenbacher, W.A. Barth, S. Mickat HIM, Mainz, Germany W.A. Barth, S. Mickat GSI, Darmstadt, Germany
	Funding: Helmholtz-Institut Mainz, Bundesministerium für Bildung und Forschung contract number 05P12RFRBL To compete in the production of Super Heavy Elements (SHE) in the future a 7.3 AMeV superconducting (sc) continuous wave (cw) LINAC is planned at GSI. The baseline design consists of 9 sc Crossbar-H-mode (CH) cavities operated at 217 MHz. Currently an advanced cw demonstrator is under design at the Institute for Applied Physics (IAP) at Frankfurt University. The purpose of the advanced demonstrator is to investigate a new concept for the superconducting CH structures. It is based on shorter CH-cavities with 8 equidistant gaps without girders and with stiffening brackets at the front and end cap to reduce the pressure sensitivity. One major goal of the advanced demonstrator is to show that the new design leads to higher acceleration gradients and smaller E_p/E_a values. In this contribution first simulation results and technical layouts will be presented.
	Poster TUPP060 [0.593 MB]

TUPP062	A Rebunching CH Cavity for Intense Proton Beams	quadrupole, multipole, cavity, simulation	566
	M. Schwarz, C. Claessens, M. Heilmann, O. Hinrichs, D. Koser, O. Meusel, D. Mäder, H. Podlech, U. Ratzinger, A. Seibel IAP, Frankfurt am Main, Germany
	Funding: Project supported by the EU, FP7 MAX, Contract No. 269565 The Frankfurt Neutron Source at the Stern-Gerlach-Zentrum (FRANZ) will provide ultra short neutron pulses at high intensities and repetition rates. The facility is currently under construction at the Goethe-University in Frankfurt am Main (Germany). A 5-Gap CH rebuncher is installed behind a coupled RFQ/IH-DTL combination at the end of the LINAC section between two magnetic quadrupole triplets. It will be used for varying the final proton energy as well as for focusing the bunch longitudinally to compensate huge space charge forces at currents up to 200 mA at the final stage of extension. High current beam dynamic simulations have been performed. They include benchmarking of different beam dynamic codes like LORASR and TraceWin, as well as validating the results by measurements. Detailed examination of multipole field impact, due to the cavity’s geometry, together with error tolerance studies and thermal simulations are also performed. Furthermore, this CH rebuncher serves as a prototype for rt CH cavities at MYRRHA (Belgium), an Accelerator Driven System for transmutation of high level nuclear waste. After copper plating the cavity, RF conditioning will start soon.
	Poster TUPP062 [6.015 MB]

TUPP063	Improvements of the LORASR Code and their Impact on Current Beam Dynamics Designs	proton, DTL, focusing, quadrupole	569
	R. Tiede, D. Mäder, N.F. Petry, H. Podlech, U. Ratzinger, C. Zhang IAP, Frankfurt am Main, Germany
	LORASR is a multi-particle tracking code optimized for the beam dynamics design of ‘Combined Zero Degree Structure (KONUS)’ lattices, which can benefit from an adapted input file structure and code architecture. Recent code developments focused on the implementation of tools for machine error studies and loss profile investigations, including also steering correction strategies. These tools are a stringent necessity for the design of high intensity linacs. Thus, the abilities of the present LORASR release allow performing a manifold of checks and optimizations before finalizing the layouts of KONUS-based or conventional linacs. Two representative examples are the MAX-MYRRHA Injector and the GSI FAIR Facility Proton Linac, both under development with strong participation of IAP, Frankfurt University. This paper presents the status of the LORASR code development with focus on the new features and illustrates the impact on current designs by examples taken from the above-mentioned projects.

TUPP064	Zero-Current Longitudinal Beam Dynamics	lattice, resonance, damping, cavity	572
	J.-M. Lagniel GANIL, Caen, France
	In linacs, the longitudinal focalization is done by nonlinear forces and the acceleration induces a damping of the phase oscillations. The longitudinal beam dynamics is therefore complex, even when the nonlinear space-charge forces are ignored. The three different ways to study and understand this zero-current longitudinal beam dynamics will be presented and compared.

TUPP065	RF Input Power Couplers for High Current SRF Applications	cavity, booster, SRF, simulation	575
	V.F. Khan, W. Anders, A. Burrill, J. Knobloch, O. Kugeler, A. Neumann HZB, Berlin, Germany H. Wang JLab, Newport News, Virginia, USA
	High current SRF technology is being explored in present day accelerator science. The BERLinPro project is presently being built at the HZB to address the challenges involved in high current SRF machines. A 100 mA electron beam is designed to be accelerated to 50 MeV in continuous wave (cw) mode at 1.3 GHz. One of the main challenges in this project is that of handling high input RF power for the gun as well as booster cavities where there is no energy recovery process. A high power co-axial input coupler is being developed to be used for the booster and gun cavities at the nominal beam current. The coupler is based on the KEK–cERL coupler design. The KEK coupler design has been modified to minimise the penetration of the tip in the beampipe without compromising on beam-power coupling ( Qext ~1 x 105). Herein we report on the RF design for the high power (130 kW) BERLinPro (BP) couplers along with the test stand for conditioning the couplers. We will also report on the RF conditioning of the TTF-III couplers modified for cw operation (low power ~ 10 kW) which will be utilised in a new 4-mA SRF Photoinjector and the BERLinPro main linac cryomodule.
	Slides TUPP065 [2.465 MB]

TUPP067	Chopper Operation for the Tandem Scrapers at the J-PARC Linac	operation, cavity, software, timing	581
	K. Futatsukawa, Z. Fang, Y. Fukui, T. Kobayashi, S. Michizono KEK, Ibaraki, Japan E. Chishiro, K. Hirano, F. Sato, S. Shinozaki JAEA/J-PARC, Tokai-mura, Japan
	In the J-PARC linac, the energy upgrade from 181 MeV to 400 MeV by the installation of annular-ring coupled structure (ACS) cavities was successfully achieved in 2013. In the next stage, we will schedule the intensity upgrade by the increase of the beam current by improving the front-end in this summer. Then, the high heat load of the scraper, which stops the kicked-beam by the RF chopper, is predicted to damage the surface. Therefore, we prepare the tandem scrapers to suppress the heat load. The half of the kicked beam leads to a scraper and the residual is to the other. Its chopping expedient will be achieved by reversing the phase of the RF chopper on the periodic cycle at the low-level RF system. In this paper, I would like to introduce this system and present the result of the low-level test.

TUPP070	Status and Recent Modifications to 324-MHz RF Source in J-PARC LINAC	klystron, operation, high-voltage, cathode	587
	M. Kawamura, Y. Fukui, K. Futatsukawa, F. Naito KEK, Ibaraki, Japan E. Chishiro, K. Hasegawa, F. Sato, S. Shinozaki JAEA/J-PARC, Tokai-mura, Japan T. Hori JAEA, Ibaraki-ken, Japan
	This paper describes the present status of and the recent modifications to the 324-MHz RF source in the J-PARC linac. The recovery from the Great East Japan Earthquake Disaster, the status of the 324-MHz klystrons, the failure of 3 high-voltage transformers (HVTRs), and the discharge suppression for the anode-modulators are described.
	Poster TUPP070 [0.660 MB]

TUPP072	Studies on Wake Field in Annular Coupled Structure	wakefield, impedance, cavity, acceleration	593
	Y. Liu, T. Maruta KEK/JAEA, Ibaraki-Ken, Japan K. Futatsukawa KEK, Ibaraki, Japan A. Miura JAEA/J-PARC, Tokai-mura, Japan
	LINAC injector of J-PARC (Japan Proton Accelerator Research Complex) was recently successfully upgraded from 181 MeV to 400 MeV, applying a type of coupled cavity linac (CCL) structure ACS (Annular Coupled Structure). It was warmly discussed since very beginning on the wake field in the ACS cavities, where there are CCL modes with the same number as that of cells within ~50 MHz, possibly resonating with high intensity proton/H⁻ beams. One of the most important effects from the wake field is the influence on the ACS phase scan. Analytical and simulation studies, as well as the countermeasures were prepared before the energy upgrade. Fortunately we found that detuning of the ACS was unnecessary, which helped to save much work in the commissioning. In addition we got chance to make experiment studies. It was also discussed why the wake field is not so serious as we expected at the very beginning.

TUPP073	Study of the ACS Cavity Without a Bridge Cavity	cavity, coupling, proton, alignment	596
	F. Naito, K. Takata KEK, Ibaraki, Japan H. Ao, K. Hasegawa, K. Hirano, T. Morishita, N. Ouchi JAEA/J-PARC, Tokai-mura, Japan
	J-PARC has installed the Annular-ring Coupled Structure (ACS) linac to increase the beam energy up to 400 MeV. One ACS module is composed of two accelerating tanks which are coupled by the bridge cavity. The bridge cavity simplifies the handling of the multi-tank system. While it is possible to feed the RF power into the each tanks directly with the power divider and the phase shifter instead of the bridge cavity. The rf properties of the ACS linac with the direct rf-power supply system has been measured by using the low power model made of aluminum. The measured results are described in the paper.
	Slides TUPP073 [5.042 MB]

TUPP075	The First Beam Recirculation and Beam Tuning in the Compact ERL at KEK	operation, emittance, recirculation, quadrupole	599
	S. Sakanaka, M. Adachi, S. Adachi, M. Akemoto, D.A. Arakawa, S. Asaoka, K. Enami, K. Endo, S. Fukuda, T. Furuya, K. Haga, K. Hara, K. Harada, T. Honda, Y. Honda, H. Honma, T. Honma, K. Hosoyama, K. Hozumi, A. Ishii, X. Jin, E. Kako, Y. Kamiya, H. Katagiri, H. Kawata, Y. Kobayashi, Y. Kojima, Y. Kondou, O.A. Konstantinova, T. Kume, T. Matsumoto, H. Matsumura, H. Matsushita, S. Michizono, T. Miura, T. Miyajima, H. Miyauchi, S. Nagahashi, H. Nakai, H. Nakajima, N. Nakamura, K. Nakanishi, K. Nakao, K.N. Nigorikawa, T. Nogami, S. Noguchi, S. Nozawa, T. Obina, T. Ozaki, F. Qiu, H. Sagehashi, H. Sakai, S. Sasaki, K. Satoh, M. Satoh, T. Shidara, M. Shimada, K. Shinoe, T. Shioya, T. Shishido, M. Tadano, T. Tahara, T. Takahashi, R. Takai, H. Takaki, T. Takenaka, Y. Tanimoto, M. Tobiyama, K. Tsuchiya, T. Uchiyama, A. Ueda, K. Umemori, K. Watanabe, M. Yamamoto, Y. Yamamoto, Y. Yano, M. Yoshida KEK, Ibaraki, Japan E. Cenni Sokendai, Ibaraki, Japan R. Hajima, S. Matsuba, R. Nagai, N. Nishimori, M. Sawamura, T. Shizuma JAEA, Ibaraki-ken, Japan J.G. Hwang KNU, Deagu, Republic of Korea M. Kuriki, Y. Seimiya HU/AdSM, Higashi-Hiroshima, Japan A. Valloni CERN, Geneva, Switzerland
	Superconducting(SC)-linac-based light sources, which can produce ultra-brilliant photon beams in CW operation, are attracting worldwide attention. In KEK, we have been conducting R&D efforts towards the energy-recovery-linac(ERL)-based light source* since 2006. To demonstrate the key technologies for the ERL, we constructed the Compact ERL (cERL)** from 2009 to 2013. In the cERL, high-brightness CW electron beams are produced using a 500-kV photocathode DC gun. The beams are accelerated using SC cavities, transported through a recirculation loop, decelerated in the SC cavities, and dumped. In the February of 2014, we succeeded in accelerating and recirculating the CW beams of 4.5 micro-amperes in the cERL; the beams were successfully transported from the gun to the beam dump under energy recovery operation in the main linac. Then, precise tuning of beam optics and diagnostics of beam properties are under way. We report our experience on the beam commissioning, as well as the results of initial measurements of beam properties. * N. Nakamura, IPAC2012, TUXB02. ** S. Sakanaka et al., IPAC2013, WEPWA015.

TUPP077	High Precision Manufacturing for LINAC's	extraction, vacuum, controls, laser	603
	F.M. Mirapeix, J. Añel HTS, Mendaro, Spain J. Amores, J. Presa, A. Urzainki DMP, Mendaro, Spain
	A big effort in R&D focused to the LINAC devices together with the know-how already deployed through emblematic projects places DMP in the state of the art of the extreme precision mechanics. This mechanic culture makes of DMP a natural partner in early stages of design or driver of a comprehensive solution, optimizing industrial risks, quality and due date. Surface roughness below 1 nanometer, figure errors better than 50 nanometers in OFE copper enhances lifetime and performance of many devices for LINAC's. Research in joining techniques and combining several alternative technologies to traditional machining improves figure stability and makes complex cooling systems possible.

TUPP082	The MYRRHA Spoke Cryomodule Design	cavity, cryomodule, framework, cryogenics	613
	H. Saugnac, J.-L. Biarrotte, S. Blivet, P. Duchesne, N. Gandolfo, J. Lesrel, G. Olry, E. Rampnoux, D. Reynet IPN, Orsay, France
	In the framework of the MAX project, dedicated to the detailed study of the MYRRHA facility LINAC, the engineering study of the ‘Spoke’ cavities cryomodule, situated in the low energy superconducting section, has been achieved. The beam optics, highly constrained by strong reliability requirements, leads to a modular cryomodule composed of two β=0.37, 352 MHz, single bar ‘Spoke’ cavity cooled at 2K. The power coupler design, not studied in detail under the MAX project, is directly taken from a 20 kW continuous wave 352 MHz coupler designed and successfully tested in the framework of the previous EUROTRANS and EURISOL projects. The cold tuning system is identical to the one designed for the ESS ‘Spoke’ cavities. We present in this paper, the RF, the mechanical and the thermal design of the complete cryomodule as well as the optimization and simulations of its individual components (Cavity, Cryostat, Tuning System…).

TUPP085	RAON Cryomodule Design for QWR, HWR, SSR1 and SSR2	cryomodule, simulation, vacuum, cavity	622
	W.K. Kim, H. Kim, H.J. Kim, Y. Kim, M. Lee, G.-T. Park IBS, Daejeon, Republic of Korea
	The accelerator called RAON which will be built in Korea has four kinds of superconducting cavities such as QWR, HWR, SSR1 and SSR2, operating at 2 K and 4.5 K [1]. The current status of design for the QWR, HWR, SSR1 and SSR2 cryomodules are reported. The issues included in the paper are thermal and structural design results of the components such as supports and thermal shield in the cryomodules. The cryomodule hosts the superconducting cavities in high vacuum and thermally insulated environment in order to maintain the operating temperature of superconducting cavities. It also keeps the cavities in a good alignment to the beam line. It has an interface for supplying RF power to cavities between cold and warm components. The whole configuration of the integrated system is also presented. This paper presents the detailed design of the cryomodule.

TUPP089	Tuning and Field Stabilization of the CERN Linac4 Drift Tube Linac	DTL, cavity, simulation, resonance	631
	M.R. Khalvati IPM, Tehran, Iran S. Ramberger CERN, Geneva, Switzerland
	The Drift Tube Linac (DTL) for the new linear accelerator Linac4 at CERN will accelerate H–beams of up to 40 mA average pulse current from 3 to 50 MeV. The structure consists of three cavities. The first cavity (Tank1) is a 3.9 m long tank containing 38 drift tubes, 10 fixed tuners, 2 movable tuners and 12 post-couplers, operating at a frequency of 352.2 MHz and an average accelerating field of 3.1 MV/m. This paper reports on the results and procedures used for the low–power tuning, stabilization and power coupler tuning carried out on the first Linac4 DTL tank. The upgrade of the bead pull measurement system and twists to the well-known tilt sensitivity technique are discussed.

TUPP090	Spatially Periodic RF Quadrupole LINAC	quadrupole, focusing, ion, lattice	634
	A.S. Plastun, A. Kolomiets ITEP, Moscow, Russia
	Spatially-periodic RF quadrupole structure is proposed as second section of front end of ion linac. It consists of conventional drift tubes and RF quadrupoles. Quadrupoles are 4-vane segments with nonzero electric potential on the longitudinal axis. Thus the accelerating electric field is formed between drift tubes and RF quadrupoles. Moreover accelerating field can be provided even inside the RF quadrupoles. It allows building structures with different focusing lattices and provides high energy gain rate.
	Poster TUPP090 [7.706 MB]

TUPP092	Developmental and Operational Aspects of Nb QWR Based Heavy Ion LINAC System at IUAC Delhi	controls, operation, niobium, ion	640
	S. Ghosh, R. Ahuja, J. Antony, S. Babu, J. Chacko, G.K. Chaudhari, A. Chaudhary, T.S. Datta, R.N. Dutt, R. Joshi, D. Kanjilal, S. Kar, J. Karmakar, M. Kumar, R. Kumar, D.S. Mathuria, K.K. Mistri, A. Pandey, P. Patra, P.N. Potukuchi, A. Rai, J. Sacharias, B.K. Sahu, A. Sarkar, S.S.K. Sonti, S. K. Suman IUAC, New Delhi, India A. Roy VECC, Kolkata, India
	The superconducting linac of IUAC consists of five cryostats containing 27 niobium quarter wave resonators. The prototype and the first 12 resonators were fabricated in collaboration with Argonne National Laboratory. The fabrication of the remaining resonators were carried out using in-house facilities available at IUAC. During the initial period of linac operations, problems were faced to generate higher accelerating fields in the resonators inside the linac cryostat and to reproduce the high fields at the time of beam acceleration. With systemetic efforts, all the major problems are solved and the complete linac is now operational. Since last few years, energized ion beams from linac are being delivered routinely for scheduled experiments. Among the major developmental works related to the linac operation, the vibrational damping mechansim by SS-balls, use of piezo actuator as mechanical tuner and the calculation of optimum phase focussing to control the time width of the beam bunches are noteworthy. Other two developments e.g. automatic phase locking of the resonators and auto beam tuning of the complete linac will be tested during the next beam acceleration.

TUPP094	Recent Progress of Beam Commissioning at J-PARC Linac	operation, acceleration, DTL, cavity	646
	T. Maruta J-PARC, KEK & JAEA, Ibaraki-ken, Japan K. Futatsukawa, T. Miyao KEK, Ibaraki, Japan M. Ikegami FRIB, East Lansing, Michigan, USA Y. Liu KEK/JAEA, Ibaraki-Ken, Japan A. Miura, H. Sako JAEA/J-PARC, Tokai-mura, Japan
	We installed Annular-type Coupled Structure (ACS) linac in year 2013 in present linac downstream to extend the beam energy from 181 to 400 MeV. The beam commissioning had been conducted for one month in last December to January, and then we successfully extract 400 MeV beam. Whereas, we stably operate the linac at peak current of 15 mA, which is equivalent to 300 kW at the extraction of 3 GeV RCS, we observe unexpected residual radiations in ACS section. In this presentation, we review the recent progress in beam commissioning and beam loss study.

TUPP096	LUE-200 Linac. Status & Development	klystron, neutron, electron, beam-loading	653
	A.P. Sumbaev, A.S. Kayukov, V. Kobets, V. Minashkin, V.G. Pyataev, V.A. Shvets JINR, Dubna, Moscow Region, Russia V. Shabratov JINR/VBLHEP, Moscow, Russia V.N. Shvetsov JINR/FLNP, Moscow Region, Russia
	The general scheme and current status of an electron linear accelerator with an S-band travelling wave (f = 2856 MHz) accelerating structure – a driver for a pulsed neutron source (IREN) at the Frank Laboratory of Neutron Physics of the Joint Institute for Nuclear Research - are presented. The parameters of the accelerating system and the measured parameters of the electron beam – pulse-beam current, duration of the current pulse, repetition rate, electron-energy spectrum, and loading characteristics of the accelerating structure - are given. The beginning of the implementation of the project of the second stage of the IREN facility, which forms the basis for the development of the accelerator aimed at increasing its beam power, is reported. Technical solutions underlying the modernization of the accelerator’s electrophysical systems are discussed: accelerating system, RF power supplies,and modulators.

TUPP097	100-MeV Proton Beam Phase Measurement by Using Stripline BPM	proton, DTL, simulation, coupling	656
	H.S. Kim, Y.-S. Cho, H.-J. Kwon KAERI, Daejon, Republic of Korea
	Funding: This work is supported by Ministry of Science, ICT & Future Planning of the Korean Government. In Korea Multipurpose Accelerator Complex (KOMAC), a 100-MeV proton linac, which is composed of a proton injector based on the microwave ion source, 3-MeV RFQ with a four-vane type and 100-MeV DTL with electromagnetic quadrupoles has been developed and currently provides the proton beam to users for various applications. To increase the beam power up to the design value, several improvements are required including the fine adjustment of the RF set-point during the operation. A stripline BPM is used for the beam phase measurement, where the pickup signals from four electrodes are combined by using the RF combiner, then mixed with 300 MHz LO reference signal resulting in 50 MHz IF signal which is processed by digital IQ demodulation method. In this paper, the details of the beam phase measurement setup and results will be presented.

TUPP103	The Beam Envelope Control in SC Linac for the Proton Radiotherapy	controls, proton, cavity, simulation	665
	A.V. Samoshin, I.A. Ashanin, S.M. Polozov MEPhI, Moscow, Russia
	Proton cancer therapy is conventionally based on normal conducting synchrotrons and cyclotrons. The high electrical power consumption and especial devices necessary to energy variation are main problems of such facilities. Superconducting linacs based on short identical independently phased cavities have a seriously progress and it's development allow to propose their using for medical application. High accelerating gradient and small capacity losses nearly 10^-4 Vt/m are main advantages in advance of normal conducting facilities, the energy variation can be realized by means of RF field amplitude and phase variation in a number of cavities. Besides linac structures are lack of unwieldy magnetic system, simplicity of input and output of particles and high current densities. The parameters choose and the optimization for SC linac structure with energy up to 240 MeV and envelope control will discuss in this paper. The simulation was done using BEAMDULAC-SCL code. The study of beam dynamics will direct to realize the energy variation in range 150-240 MeV with beam quality preservation. A.V. Samoshin. Proc. of LINAC2012, Tel-Aviv, Israel, TUPB069, p. 630 - 632

TUPP105	Storage Ring as a Linac Beam Monitor – Its Operation and Contribution to the Stable Top-up Injection	injection, timing, synchrotron, storage-ring	668
	Y. Shoji LASTI, Hyogo, Japan T. Asaka, H. Dewa, H. Hanaki, T. Kobayashi, Y. Minagawa, A. Mizuno, T. Shinomoto, S. Suzuki, Y. Takemura, T. Taniuchi, K. Yanagida JASRI/SPring-8, Hyogo-ken, Japan
	We have used the electron storage ring, NewSUBARU, as a beam monitor of the SPring-8 linac. The time and transverse profiles of the injected linac beam are recorded in a frame of a dual-sweep streak camera. A measurements through synchrotron or betatron oscillation in the ring gives multi-dimensional beam structure. The system functions as a final check of the linac beam. It gives the time profile and energy profile or transverse emittance, which includes Twiss parameters. It measures parameters of one linac bunch in a long macro pulse. A shot-by-shot measurement gives beam fluctuations. We report how we use the system and its contribution to the stable top-up operation. The beam loading effect on the bunch energy was obtained by bunch-by-bunch energy profile measurements. It confirmed the optimization of the ECS (Energy Compression System) parameters. The single shot bunch-by-bunch vertical emittance measurement proved the difference between the front bunch and the following bunches. The same measurement showed a timing jitter of the electron gun pulse although the rf synchronization was perfect. This jittering had made the injection efficiency unstable.

TUPP109	Cryogenic Testing of High-Velocity Spoke Cavities	cavity, cryogenics, acceleration, proton	677
	C.S. Hopper, J.R. Delayen, H. Park ODU, Norfolk, Virginia, USA J.R. Delayen, H. Park JLab, Newport News, Virginia, USA
	Spoke-loaded cavities are being investigated for the high-velocity regime. The relative compactness at low-frequency makes them attractive for applications requiring, or benefiting from, 4 K operation. Additionally, the large velocity acceptance makes them good candidates for the acceleration of high-velocity protons and ions. Here we present the results of cryogenic testing of a 325 MHz, β0 = 0.82 single-spoke cavity and a 500 MHz, β0 = 1 double-spoke cavity.

TUPP119	Design Studies for Medium and High beta SCRF Cavities for Indian Spallation Neutron Source	cavity, HOM, lattice, quadrupole	699
	A.R. Jana, V. Kumar RRCAT, Indore, India
	There is a plan to build a 1 GeV H⁻ linac for the proposed Indian Spallation Neutron Source (ISNS) at Raja Ramanna Centre for Advanced Technology (RRCAT), Indore. The medium and high energy section of the ISNS linac will consist of beta_g=0.61, as well as beta_g = 0.9, 650 MHz, 5-cell superconducting radiofrequency (SCRF) cavities, for which detailed electromagnetic design studies have been performed. During our design study, we have evolved a generalized procedure for the optimization of geometrical parameters of multi-cell SCRF cavities. Studies on higher order modes supported by the cavity and its effect on beam dynamics, as well as on heat load to the cavity have been performed, which constitute an important aspect of the design study. Finally, detailed studies on Lorentz Force Detuning (LFD) have been performed, and design of the cavity has been optimized to minimize the effect due to the LFD. The paper discussed the details of the calculations and the studies that have been performed during the design study.

TUPP121	Limitations for Acceleration of Intermediate Mass Particles with Traveling Wave Structure	operation, acceleration, electron, accelerating-gradient	705
	V.V. Paramonov RAS/INR, Moscow, Russia

Paper

Title

Other Keywords

Page

MOIOA01

Linear Collider Studies

emittance, linear-collider, collider, FEL

1

S. Stapnes
CERN, Geneva, Switzerland

Status and comparison of the two remaining linear collider designs following publication of their CDRs

Slides MOIOA01 [11.279 MB]

MOIOA02

Commissioning of the Low-Energy Part of Linac4

emittance, rfq, DTL, solenoid

6

A.M. Lombardi
CERN, Geneva, Switzerland

The Linac4 front-end (3MeV) was first commissioned in a dedicated test stand and then moved to its final position in the Linac4 tunnel. Accelerating cavities will be added progressively over two years to allow the characterisation of the beam with a dedicated measurement line at several energy stages (3,12,30,50, 100 and finally160MeV). This paper reports about the progress and the commissioning experience up to today.

Slides MOIOA02 [5.339 MB]

MOIOB01

Early Commissioning Experience and Future Plans for the 12 GeV Continuous Electron Beam Accelerator Facility

cryomodule, operation, cavity, SRF

11

M. Spata
JLab, Newport News, Virginia, USA

Jefferson Lab has recently completed the accelerator portion of the 12 GeV Upgrade for the Continuous Electron Beam Accelerator Facility. All 52 SRF cryomodules have been commissioned and operated with beam. The initial beam transport goals of demonstrating 2.2 GeV per pass, greater than 6 GeV in 3 passes to an existing experimental facility and greater than 10 GeV in 5-1/2 passes have all been accomplished. These results along with future plans to commission the remaining beamlines and to increase the performance of the accelerator to achieve reliable, robust and efficient operations at 12 GeV are presented.

Slides MOIOB01 [2.754 MB]

MOIOB02

Optimizing RF Linacs as Drivers for Inverse Compton Sources: the ELI-NP Case

electron, emittance, laser, photon

16

C. Vaccarezza, D. Alesini, M. Bellaveglia, R. Boni, E. Chiadroni, G. Di Pirro, M. Ferrario, A. Gallo, G. Gatti, A. Ghigo, B. Spataro, P. Tomassini
INFN/LNF, Frascati (Roma), Italy
A. Bacci, D.T. Palmer, V. Petrillo, A.R. Rossi, L. Serafini
Istituto Nazionale di Fisica Nucleare, Milano, Italy
A. Cianchi
Università di Roma II Tor Vergata, Roma, Italy
I.V. Drebot
Universita' degli Studi di Milano e INFN, Milano, Italy
A. Giribono, A. Mostacci, L. Palumbo
Rome University La Sapienza, Roma, Italy
C. Ronsivalle
ENEA C.R. Frascati, Frascati (Roma), Italy

The design guide-lines of RF Linacs to fulfill the requirements of high spectral density Inverse Compton Sources for the photo-nuclear science are mostly mutuated from the expertise coming from high brightness electron Linacs driving X-ray FEL's. The main difference is the quest for maximum phase space density (instead of peak brightness), but many common issues and techniques are exploited, in order to achieve an optimum design and lay-out for the machine. A relevant example in this field is the design of the hybrid C-band multi-bunch RF Linacs for the ELI-NP Gamma Beam System, aiming at improving by two orders of magnitude the present state of the art in spectral density available for the gamma-ray beam produced.

Slides MOIOB02 [2.542 MB]

MOIOB04

Current Status of PAL-XFEL

undulator, gun, electron, experiment

26

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

The PAL-XFEL project aims to produce 0.1~nm coherent X-ray laser to photon beam users. In order to produce such photons, there are 10 GeV electron linac based on S-band normal conducting accelerating structures and a 150 m long out-vacuum undulator system. The project was already started in April 2011, and the 1.1 km long building is expected to be completed by December 2014. The injector test facility (ITF) which is for a test of the first 139 MeV section of the main linac has been installed and is in normal operation at the extension of the PLS linac building. In this paper, we introduce the project in general, a brief summary of site preparation and building construction, beam test results of ITF, and test results of subsystems produced by domestic manufacturers

Slides MOIOB04 [9.901 MB]

MOIOC01

Status of Superconducting Electron Linac Driver for Rare Ion Beam Production at TRIUMF

cavity, cryomodule, electron, TRIUMF

31

R.E. Laxdal, F. Ames, R.A. Baartman, I.V. Bylinskii, Y.-C. Chao, D. Dale, K. Fong, E.R. Guetre, P. Kolb, S.R. Koscielniak, A. Koveshnikov, M.P. Laverty, Y. Ma, M. Marchetto, L. Merminga, A.K. Mitra, N. Muller, R.R. Nagimov, T. Planche, W.R. Rawnsley, V.A. Verzilov, Z.Y. Yao, Q. Zheng, V. Zvyagintsev
TRIUMF, Canada's National Laboratory for Particle and Nuclear Physics, Vancouver, Canada

A MW class cw superconducting electron linac is being installed at TRIUMF as a driver for radioactive beam production through photo-fission. The ARIEL e-linac will house five 1.3GHz nine-cell cavities in three cryomodules and accelerate up to 10mA of electrons to 50MeV. A first phase of installation will see three cavities in two cryomodules installed by the end of 2014. Presently the injector cryomodule is installed and undergoing cryogenic and rf characterizations and beam acceleration tests with beam from the 300kV DC gun. The second cryomodule is being prepared for first tests. The linac status including descriptions and operating performance of installed cryogenic and rf systems, electron gun performance, cryomodule performance and the results of first beam acceleration tests will be reported.

Slides MOIOC01 [6.383 MB]

MOIOC03

Model and Beam Based Setup Procedures for a High Power Hadron Superconducting Linac

cavity, simulation, laser, quadrupole

41

A.P. Shishlo
ORNL, Oak Ridge, Tennessee, USA

This presentation will review methods for experimental determination of optimal operational set points in a multi-cavity superconducting high power hadron linac. A typical tuning process, including establishing correct acceleration profile and RMS bunch size matching, is based on comparison between measured data and the results of simulations from envelope, single and multi-particle models. Presence of significant space charge effects requires simulation and measurement of bunch dynamics in 3 dimensions to ensure low loss beam transport. This is especially difficult in a superconducting linac where use of interceptive diagnostics is usually restricted because of the risk of SRF cavity surface contamination. The procedures discussed here are based on non-interceptive diagnostics such as beam position monitors and laser wires, and conventional diagnostics devices such as wire scanners and bunch shape monitors installed outside the superconducting linac. The longitudinal Twiss analysis based on the BPM signals will be described. The superconducting SNS linac tuning experience will be used to demonstrate problems and their solution for real world linac tune-up procedures.

Slides MOIOC03 [1.954 MB]

MOPP002

Design of a Superconducting Quarter-Wave Resonator for eRHIC

cavity, electron, SRF, niobium

49

S.V. Kutsaev, Z.A. Conway, M.P. Kelly, B. Mustapha, P.N. Ostroumov
ANL, Argonne, USA
S.A. Belomestnykh, I. Ben-Zvi
Stony Brook University, Stony Brook, USA
S.A. Belomestnykh, I. Ben-Zvi, Q. Wu, W. Xu
BNL, Upton, Long Island, New York, USA
B. P. Xiao
SBU, Stony Brook, New York, USA

Funding: Work is supported by Brookhaven Science Associates, LLC under contract No. DE-AC02-98CH10886 and by the U.S. Department of Energy, Office of Nuclear Physics, under Contract No. DE-AC02-06CH11357
The electron-ion collider project (eRHIC) at Brookhaven National Laboratory requires a 50 mA 12 MeV electron injector linac for eRHIC main linac and an SRF electron gun for a Coherent electron Cooling (CeC) linac. The necessity to deal with long electron bunches required for both the eRHIC injector and the coherent electron cooler sets the frequency requirement of 84.5 MHz. Quarter wave resonator is a perfect choice for this frequency because of its dimensions, RF parameters and good experience with manufacturing and using them at ANL. Here we present the design and optimization of an 84.5 MHz 2.5 MV superconducting quarter-wave cavity suitable for both machines. One such QWR will be used as a bunching cavity in the injector linac, the other one as the photoemission electron source for the CeC linac. In addition to the optimization of the QWR electromagnetic design we will discuss the tuner design, approaches to cavity fabrication and processing.

MOPP003

A Compact Linac Design for an Accelerator Driven System

cavity, cryomodule, lattice, focusing

52

B. Mustapha, S.V. Kutsaev, J.A. Nolen, 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 compact linac design has been developed for an Accelerator Driven System (ADS). The linac is under 150 meters in length and comprises a radio-frequency quadrupole (RFQ) and 20 superconducting modules. Three types of half-wave cavities and two types of elliptical cavities have been designed and optimized for high performance at frequencies of 162.5, 325 and 650 MHz. The lattice is being designed and optimized for operation with a peak power of 25 MW for a 25 mA – 1 GeV proton beam. The cavities RF design as well as the linac lattice will be presented along with end-to-end beam dynamics simulations for beam currents ranging from 0 to 25 mA.

MOPP004

Design and Development of Pulsed Modulators for RF Electron Linacs

electron, klystron, gun, operation

55

K.P. Dixit, S. Chandan, N. Chaudhary, R.B. Chavan, L.M. Gantayet, S.R. Ghodke, M. Kumar, K.C. Mittal, H.E. Sarukte, A.R. Tillu, H. Tyagi, V. Yadav
BARC, Mumbai, India

Pulsed Modulators required for RF sources, based on klystrons and magnetrons, for RF electron linacs have been designed and developed at Electron Beam Centre, BARC, Mumbai, India. Electron guns in these linacs have also been powered by pulsed modulators. Line-type modulators, as well as IGBT-based solid-state modulators have been developed for these applications. A 150 kV/100 A line-type modulator has been tested on klystron to generate 7 MW peak RF Power. Magnetron modulator has undergone testing up to 40 kV, 165 A on resistive load. Solid-state modulator, using fractional-turn pulse transformer has been designed, developed and tested successfully on magnetron load up to output power of 1.3 MW peak. A transformerless solid-state modulator for electron gun of 6 MeV cargo-scanning linac, uses the Marx adder configuration and has been successfully tested up to 40 kV. In addition, line-type modulators for electron guns up to 85 kV have been successfully commissioned and are in operation in the linac systems. This paper describes the salient design features of these modulators, development of pulse transformers, details of test set-up and discusses the test results of these modulators.

Poster MOPP004 [2.343 MB]

MOPP005

High Power Electron Accelerator Programme at BARC

electron, neutron, experiment, acceleration

58

K.C. Mittal, S. Acharya, R.I. Bakhtsingh, R. Barnwal, D. Bhattacharjee, S. Chandan, N. Chaudhary, R.B. Chavan, S.P. Dewangan, K.P. Dixit, S. Gade, L.M. Gantayet, S.R. Ghodke, S. Gond, D. Jayaprakash, M. Kumar, M.K. Kumar, H.K. Manjunatha, R.L. Mishra, J. Mondal, B. Nayak, S. Nayak, V.T. Nimje, S. Parashar, R. Patel, R.N. Rajan, P.C. Saroj, H.E. Sarukte, D.K. Sharma, V. Sharma, S.K. Srivasatava, N.T. Thakur, A.R. Tillu, R. Tiwari, H. Tyagi, A. Waghmare, V. Yadav
BARC, Mumbai, India

Bhabha Atomic Research Centre in India has taken up the indigenous design & development of high power electron accelerators for industrial, research and cargo-scanning applications. For this purpose, Electron Beam Centre (EBC) has been set up at Navi Mumbai, India. Pulsed RF Linacs, with on-axis coupled cavity configuration, include the 10 MeV Industrial RF linac, as well as 9 MeV linac and compact 6 MeV linac for cargo-scanning applications. Industrial DC accelerators include a 500 keV Cockroft-Walton machine and 3 MeV Dynamitron. Several radiation processing applications, such as material modification, food preservation, flue-gas treatment, etc. have been demonstrated using these accelerators. Cargo-scanning linacs have been successfully commissioned and are being characterized for the required x-ray output. A 30 MeV RF Linac, for research applications, such as shielding studies and n-ToF experiments, is being designed and developed. For ADS studies, a 100 MeV, 100 kW RF Linac system is proposed. This paper presents the details of the design of these accelerators, their development, current status and utilization for various applications.

MOPP011

Reliability and Intensity Upgrade for 200 MeV Linac at Brookhaven National Laboratory

detector, operation, ion, target

67

D. Raparia, J.G. Alessi, B. Briscoe, D.M. Gassner, O. Gould, T. Lehn, V. Lo Destro, J. Ritter, W. Shaffer, A. Zelenski
BNL, Upton, Long Island, New York, USA

Brookhaven 200 MeV H⁻ linac has been operating for last 44 years and providing beam to nuclear physics program and isotope program. Two upgrade programs are in progress to make machine more reliable and to double the intensity. This paper will discuss in detail these upgrade programs.

MOPP015

High Energy Electron Radiography Experiment Research Based on Picosecond Pulse-width Bunch

experiment, electron, proton, quadrupole

76

Q.T. Zhao, S. Cao, R. Cheng, X.K. Shen, Z.M. Zhang, Y.T. Zhao
IMP, Lanzhou, People's Republic of China
Y.-C. Du
TUB, Beijing, People's Republic of China
W. Gai
ANL, Argonne, Illinois, USA

A new scheme is proposed that high energy electron beam as a probe is used for time resolved imaging measurement of high energy density materials, especially for high energy density matter and inertial confinement fusion. The first picosecond pulse-width electron radiography experiment was achieved by Institute of Modern Physics, Chinese Academy of Sciences and Tinghua University (THU), based on THU Linear electron accelerator (LINAC). It is used for principle test and certifying that this kind of LINAC with ultra-short pulse electron bunch can be used for electron radiography. The experiment results, such as magnifying factor and the imaging distortion, are consistent with the beam optical theory well. The 2.5 um RMS spatial resolution has been gotten with magnifying factor 46, with no optimization the imaging lens section. It is found that in the certain range of magnifying factor, the RMS spatial resolution will get better with bigger magnifying factor. The details of experiment set up, results, analysis and discussions are presented here.

Poster MOPP015 [2.866 MB]

MOPP017

Cool Down and Flux Trapping Studies on SRF Cavities

cavity, SRF, cryomodule, operation

84

D. Gonnella, M. Liepe
Cornell University (CLASSE), Cornell Laboratory for Accelerator-Based Sciences and Education, Ithaca, New York, USA

Recent results from Cornell and FNAL have shown that cool down rate can have a strong impact on the residual resistance of a superconducting RF cavity during operation. We have studied the effect of cool down rate, gradient, and external magnetic field during cool down on the residual resistance of an EP, EP+120C baked, and nitrogen-doped cavities. For each cavity, faster cool down and large gradient resulted in lower residual resistance in vertical test. The nitrogen-doped cavities showed the largest improvement with fast cool down, while the EP+120C cavity showed the smallest. The cavities were also placed in a uniform external magnetic field and residual resistance was measured as a function of applied field and cool down rate. We show that the nitrogen-doped cavity was the most susceptible to losses from trapped flux and the EP+120C cavity was least susceptible. These measurements provide new insights into understanding the physics behind the observed impact of cool down rates and gradients on the performance of cavities with differing preparations.

MOPP018

Nitrogen-Doped 9-Cell Cavity Performance in the Cornell Horizontal Test Cryomodule

cavity, cryomodule, SRF, radiation

88

D. Gonnella, R.G. Eichhorn, F. Furuta, G.M. Ge, D.L. Hall, Y. He, G.H. Hoffstaetter, M. Liepe, T.I. O'Connel, S. Posen, P. Quigley, J. Sears, V. Veshcherevich
Cornell University (CLASSE), Cornell Laboratory for Accelerator-Based Sciences and Education, Ithaca, New York, USA
A. Grassellino, A. Romanenko
Fermilab, Batavia, Illinois, USA

Funding: U.S. Department of Energy
Cornell has recently completed construction and qualification of a horizontal cryomodule capable of holding a 9-cell ILC cavity. A nitrogen-doped niobium 9-cell cavity was assembled into the Horizontal Test Cryomodule (HTC) with a high Q input coupler and tested. We report on results from this test of a nitrogen-doped cavity in cryomodule and discuss the effects of cool down rate and thermal cycling on the residual resistance of the cavity.

MOPP020

Input Couplers for Cornell ERL

cryomodule, coupling, cavity, impedance

95

R.G. Eichhorn, P. Quigley, V. Veshcherevich
Cornell University (CLASSE), Cornell Laboratory for Accelerator-Based Sciences and Education, Ithaca, New York, USA
S.A. Belomestnykh
BNL, Upton, Long Island, New York, USA

Cornell has developed two types of input couplers for the Energy Recovery Linac (ERL) Project. Both couplers are 1.3 GHz CW coaxial couplers. The coupler for ERL injector is a 65 kW CW coupler with variable coupling (Qext = 9*E4 to 9*E5). The coupler for ERL main linac is a 5 kW CW coupler with fixed coupling. It can be easily modified for variable coupling operation. Couplers have been tested on test stands and in cryomodules and showed good performance.

MOPP023

X-band Technology for FEL Sources

FEL, emittance, operation, experiment

101

G. D'Auria, S. Di Mitri, C. Serpico
Elettra-Sincrotrone Trieste S.C.p.A., Basovizza, Italy
E. Adli
University of Oslo, Oslo, Norway
A.A. Aksoy, O. Yavaş
Ankara University, Accelerator Technologies Institute, Golbasi / Ankara, Turkey
D. Angal-Kalinin, J.A. Clarke
STFC/DL/ASTeC, Daresbury, Warrington, Cheshire, United Kingdom
C.J. Bocchetta, A.I. Wawrzyniak
Solaris, Kraków, Poland
M.J. Boland, T.K. Charles, R.T. Dowd, G. LeBlanc, Y.E. Tan, K.P. Wootton, D. Zhu
SLSA, Clayton, Australia
G. Burt
Lancaster University, Lancaster, United Kingdom
N. Catalán Lasheras, A. Grudiev, A. Latina, D. Schulte, S. Stapnes, I. Syratchev, W. Wuensch
CERN, Geneva, Switzerland
W. Fang, Q. Gu
SINAP, Shanghai, People's Republic of China
E.N. Gazis
National Technical University of Athens, Athens, Greece
M. Jacewicz, R.J.M.Y. Ruber, V.G. Ziemann
Uppsala University, Uppsala, Sweden
X.J.A. Janssen
VDL ETG, Eindhoven, The Netherlands

As is widely recognized, fourth generation Light Sources are based on FELs driven by Linacs. Soft and hard X-ray FEL facilities are presently operational at several laboratories, SLAC (LCLS), Spring-8 (SACLA), Elettra-Sincrotrone Trieste (FERMI), DESY (FLASH), or are in the construction phase, PSI (SwissFEL), PAL (PAL-XFEL), DESY (European X-FEL), SLAC (LCLS II), or are newly proposed in many laboratories. Most of the above mentioned facilities use NC S-band (3 GHz) or C-band (6 GHz) linacs for generating a multi-GeV low emittance beam. The use of the C-band increases the linac operating gradients, with an overall reduction of the machine length and cost. These advantages, however, can be further enhanced by using X-band (12 GHz) linacs that operate with gradients twice that given by C-band technology. With the low bunch charge option, currently considered for future X-ray FELs, X-band technology offers a low cost and compact solution for generating multi-GeV, low emittance bunches. The paper reports the ongoing activities in the framework of a collaboration among several laboratories for the development and validation of X-band technology for FEL based photon sources.

MOPP024

Perspectives of the S-Band Linac of FERMI

operation, klystron, FEL, electron

105

A. Fabris, P. Delgiusto, M. Milloch, C. Serpico
Elettra-Sincrotrone Trieste S.C.p.A., Basovizza, Italy
A. Grudiev
CERN, Geneva, Switzerland

The S-band linac of FERMI, the seeded Free Electron Laser (FEL) located at the Elettra laboratory in Trieste, has reached the peak on-crest electron energy of 1.55 GeV required for FEL-2 with the present layout. Different ways are being considered to extend the operating energy of the S-band linac up to 1.8 GeV. At the same time upgrades on the existing systems are investigated to address the requirements of operability of a users facility. This paper provides an overview of the developments that are under consideration and discusses the requirements and constraints for their implementation.

MOPP025

Longitudinal Beam Profile Measurements in Linac4 Commissioning

rfq, cavity, electron, emittance

108

G. Bellodi, V.A. Dimov, J.-B. Lallement, A.M. Lombardi, U. Raich, F. Roncarolo, F. Zocca
CERN, Geneva, Switzerland
M. Yarmohammadi Satri
IPM, Tehran, Iran

Linac4, the future 160 MeV H⁻ injector to the CERN Proton Synchrotron Booster, is presently under construction at CERN as a central step of the planned upgrade of the LHC injectors. The Linac front-end, composed of a 45 keV ion source, a Low Energy Beam Transport (LEBT), a 352.2 MHz Radio Frequency Quadrupole (RFQ) and a Medium Energy Beam Transport (MEBT) housing a beam chopper, has been installed and commissioned. Precise measurements of the longitudinalμbunch profiles of ion beams were possible with the help of a Bunch Shape Monitor (BSM) developed at INR Moscow. These were crucial for the successful commissioning of the three RF buncher cavities mounted along the MEBT and well complemented with higher precision the information provided in parallel by spectrometer measurements.

MOPP026

Actively Cooled RF Power Coupler : Theoretical and Experimental Studies

cryomodule, cryogenics, cavity, proton

111

R. Bonomi, V. Parma
CERN, Geneva, Switzerland

In cryostats for Super-conducting Radio Frequency Cavities, the heat loads introduced by the high-power RF couplers represent an important fraction of the overall static thermal budget. Working at low operating temperature benefits from a reduced surface resistance (low dynamic losses) but is penalized by the high refrigeration cost. The external conductor of RF coaxial couplers provides a direct conduction path from ambient to cryogenic temperature plus is heated by resistive power deposition. Heat interception is therefore essential to contain heat in-leaks: a double-walled external conductor with a properly designed gas cooling effectively reduces heat loads to the cold bath by 1 order of magnitude. This paper presents the thermal design of the RF power coupler of the Superconducting Proton Linac (SPL) at CERN, featuring a helium vapour cooling between 4.5 K and ambient temperature. Numerical models, which can be used as design tools for other applications, have been developed to assess efficiency and thermal performance. A full-size mock-up cooled by nitrogen has been built for experimental validation. Comparison between calculations and measurements is presented and discussed.

MOPP029

Overview of the New High Level Software Applications Developed for the HIE-ISOLDE Superconducting Linac

controls, cavity, software, pick-up

117

D. Lanaia, M.A. Fraser, D. Voulot
CERN, Geneva, Switzerland

The High Intensity and Energy (HIE) ISOLDE project consists of an upgrade of the ISOLDE facility. With the installation of 32 independently-phased, superconducting quarter-wave cavities the energy of post-accelerated radioactive beams will be increased from 3 MeV/u to over 10 MeV/u. The large number of cavities will increase the number of parameters to optimise. In order to ensure a fast set-up of the machine during operation and commissioning, new software applications have been developed and an upgrade of the existing software was carried out. Four high level applications have been specifically developed for the SC linac. The first allows the conversion of optics settings into machine settings, and vice versa. The second will aid the phasing of the cavities using beam energy measurements. A third application will provide absolute measurements of the beam energy by means of a time-of-flight system. The last application will automatically generate the phase and voltage settings for the cavities SC linac. In this contribution we will present the new applications and outline how these will be used in the operation of the new SC linac.

Poster MOPP029 [1.568 MB]

MOPP036

Estimation of the Thermal Load and Signal Level of the ESS Wire Scanner

DTL, detector, photon, cryomodule

137

B. Cheymol
ESS, Lund, Sweden

The European Spallation Source (ESS), to be built in the south of Sweden, will use a 2 GeV superconducting linac to produce the worlds most powerful neutron source with a beam power of 5 MW. A number of wire scanners will be used to characterize the beam transverse profile. The design of the wire has to cope with the high power density of the beam and must satisfy the overall measurement robustness, accuracy and sensitivity for the commissioning and the regular retuning phase of the ESS linac. This paper describes the preliminary design of the wire scanner system in the normal conducing linac as well as in the superconducting linac.

MOPP037

Conceptual Design of the ESS DTL Faraday Cup

DTL, simulation, cavity, beam-transport

140

B. Cheymol, E. Lundh
ESS, Lund, Sweden

The DTL section of the ESS linac will accelerate the beam form 3.6 MeV to 90 MeV at a peak current of 62.5 mA. It is foreseen to install after each DTL tank a Faraday cup for beam current and the beam transmission measurements during retuning phase. An energy degrader will be positioned in front of the in order to perform a low resolution phase scan of the DTL tank before injecting the beam in the downstream structure. This paper describes the preliminary studies of the Faraday cup, mainly focus on the energy degrader.

MOPP038

Longitudinal Bunch Profile Monitoring at the ESS Linac

simulation, proton, neutron, target

143

I. Dolenc Kittelmann, B. Cheymol
ESS, Lund, Sweden

The European Spallation Source (ESS), which is currently under construction, will be a neutron source based on 5MW, 2GeV proton linac. This high intensity linac will among other beam instrumentation require longitudinal bunch profile monitors. These shall be used during the commissioning phase and start-up periods for beam dynamics optimization and beam loss reduction. The paper focuses on the preliminary studies concerning the longitudinal bunch profile monitoring at the ESS linac.

MOPP039

Dynamics of Bunches Partially Chopped with the MEBT Chopper in the ESS Linac

DTL, lattice, simulation, quadrupole

146

R. Miyamoto, B. Cheymol, R. De Prisco, M. Eshraqi, A. Ponton, E. Sargsyan
ESS, Lund, Sweden
I. Bustinduy
ESS Bilbao, Bilbao, Spain

The front-end of a hadron linac typically has a transient time during turning on and off and bunches in the head and tail of a pulse from this period likely have wrong parameters and a risk to cause beam losses. A risk of losses must be avoided as possible in a high power machine so these bunches are removed with deflectors called choppers in the ESS Linac. From experiences of other machines, a rise time of a chopper as fast as one RF period (2.84~ns for ESS) is challenging to achieve and not necessarily needed with no ring to inject like ESS, and hence a 10~ns rise time is planned for a chopper in the medium energy beam transport of ESS. This, however, means that several bunches receive intermediate deflections and may propagate with large trajectory excursions. This paper studies dynamics of such partially chopped bunches in detail to ensure no significant loss is caused by them.

MOPP041

Commissioning Plan for the FRIB Driver Linac*

radiation, ion, cryomodule, operation

152

M. Ikegami, L.T. Hoff, S.M. Lidia, F. Marti, G. Pozdeyev, T. Russo, R.C. Webber, J. Wei, Y. Yamazaki
FRIB, East Lansing, Michigan, USA

Funding: * Work supported by the U.S. Department of Energy Office of Science under Cooperative Agreement DE-SC0000661.
The FRIB driver linac accelerates CW beams of all stable ions up to uranium to the energy of 200 MeV/u with the beam power of 400 kW. We plan to start staged beam commissioning in December 2017 in parallel with ongoing installation activities. This allows early recognition of technical issues, which is essential for smooth commissioning and early completion of commissioning goals. As the interlaced nature of commissioning and installation poses both scheduling challenges and special safety issues, it is essential to develop a commissioning plan with focused consideration of each. In this paper, we present a commissioning plan with emphasis on its characteristic features.

MOPP044

MSU RE-Accelerator ReA3 0.085 QWR Cryomodule Status

cryomodule, cavity, solenoid, alignment

155

T. Xu, B. Bird, F. Casagrande, J.L. Crisp, K.D. Davidson, C. Dudley, A. Facco, P.E. Gibson, I. Grender, L. Hodges, K. Holland, M.J. Johnson, S. Jones, B. Laumer, D. Leitner, A. Mccartney, S.J. Miller, D. Morris, S. Nash, J.P. Ozelis, J. Popielarski, L. Popielarski, R. Rosas, R.J. Rose, K. Saito, M. Thrush, R. Walker, J. Wei, W. Wittmer, Y. Xu
FRIB, East Lansing, Michigan, USA
B. Arend, J. Ottarson, D.P. Sanderson, D. Wahlquist, J. Wenstrom
NSCL, East Lansing, Michigan, USA
M. Leitner
LBNL, Berkeley, California, USA

ReA3 β=0.085 QWR cryomodule is the third cryomodule for the superconducting LINAC of ReA3 reaccelerated beam facility, which will bring the maximum beam energy to 3 MeV/u for heavy ions. This cryomodule consists of 8 β=0.085 QWR cavities and 3 9T superconducting solenoids and operates at 4K. Qualification of cavities and FPCs and the construction of cold mass was completed in 2013. The installation of the module was completed this summer. Functioning not only as an important part of the ReA3 facility, cryomodule 3 also serves as a test bed for FRIB driver Linac and demonstrated the technology needed for FRIB CMs. Here we report the construction, installation and testing of the β=0.085 cryomodule and the development of the critical components.
Project funded by Michigan State University

MOPP045

Progress and Plan of Open XAL Physics Application for FRIB

solenoid, cryomodule, database, software

158

Y. Zhang, P. Chu, D.G. Maxwell
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
FRIB driver linac will deliver heavy ion beams with beam energy above 200 MeV/u, and beam power on target up to 400 kW. Commissioning, tuning, and beam power ramping up of the world’s first SRF linac for high-power heavy-ion beams will be challenge, and developments of necessary physics application software tools are very important. In this paper, our major progress and the development plan of physics application software for the FRIB linac within Open XAL frameworks are discussed, which include the FRIB linac online model, MySQL database for physics applications, virtual accelerator application, and several other pilot physics applications. Deploying and initial testing of Open XAL and those pilot applications for FRIB are currently ongoing for a new cryomodule at Michigan State University.

MOPP049

Dipole Kick due to Geometry Asymmetries in HWR for PXIE

cavity, dipole, multipole, cryomodule

165

P. Berrutti, T.N. Khabiboulline, V.A. Lebedev, V.P. Yakovlev
Fermilab, Batavia, Illinois, USA

Funding: Work supported by D.O.E. Contract No. DE-AC02-07CH11359
Project X Injector Experiment (PXIE) will have a family of half wave resonators having frequency=162.5 MHz and beta optimal=0.11. During cavity production, when the niobium parts are assembled and welded together, it is fundamental to control the frequency of the accelerating mode in order to meet the specified operating value. For the HWR of PXIE the tuning will be achieved by trimming one end of the resonator only, this will introduce unwanted asymmetry in the cavity geometry leading to a dipole kick for the particles traveling through the cavity. The cavity geometry will be different from the ideal, once the cavity is assembled, because of small misalignment of the niobium parts and because of the welding shrinkage. Misalignments of the inner conductor and the beam pipes can be expected. The asymmetry due to tuning process along with production misalignments, have been simulated and the equivalent dipole kick has been calculated.

Poster MOPP049 [1.441 MB]

MOPP052

Development of 5-Cell β=0.9 650 MHz Elliptical Cavities for Project X

cavity, HOM, coupling, accelerating-gradient

171

I.V. Gonin, M.H. Awida, M.H. Foley, A. Grassellino, C.J. Grimm, T.N. Khabiboulline, A. Lunin, A.M. Rowe, V.P. Yakovlev
Fermilab, Batavia, Illinois, USA

Several 5-cell 650 MHz elliptical cavities have been fabricated for the PIP-II Project. Two versions of the cavities have been designed to accelerate protons of relative group velocity of β=0.9 and β=0.92 in the high energy region of the linac. In this paper, we report the development status of these cavities, summarize the results of the quality control measurements performed on five initial prototypes, and outline the VTS test results.

MOPP054

Continuous-Wave Horizontal Tests of Dressed 1.3 GHz SRF Cavities for LCLS-II

cavity, HOM, controls, SRF

177

A. Hocker, A.C. Crawford, M. Geynisman, J.P. Holzbauer, A. Lunin, D.A. Sergatskov, N. Solyak, A.I. Sukhanov
Fermilab, Batavia, Illinois, USA

Funding: United States Department of Energy, Contract No. DE-AC02-07CH11359
Fermilab’s Horizontal Test Stand has recently been upgraded to provide CW RF testing capabilities in support of the LCLS-II project at SLAC. Several cavities have been tested in this new configuration in order to validate component designs and processes for meeting the requirements of LCLS-II. Areas of study included gradient and Q0 performance and their dependence on extrinsic factors, thermal performance of the input coupler and HOM feedthroughs, and microphonics and RF control. A description of the testing and the results obtained are presented.

Poster MOPP054 [0.276 MB]

MOPP059

Study and Design of the High Power RF Coupler for the CH-Cavity of the Fair pLINAC

coupling, cavity, proton, resonance

187

F. Maimone, G. Clemente, W. Vinzenz
GSI, Darmstadt, Germany

At GSI a proton Linac has been designed and developed in order to provide a 70 MeV proton beam for the FAIR facility. The pLINAC consists of an RFQ followed by six CH-DTL accelerating cavities and the electromagnetic field inside each cavity is generated by seven Klystrons providing up to 2.8 MW power at 325.224 MHz. The high power RF coupling between the Klystron and the accelerating CH-cavity has been studied and an inductive coupling loop has been designed. The coupler insertion inside the cavity and the rotation angle with respect to the magnetic field lines have been adjusted and the results of the analysis of the coupler positioning are presented. A prototype coupler is under construction and the measurement of RF coupling with the CH-cavity is scheduled within this year.

MOPP060

Status of the GSI Poststripper - HE-Linac

DTL, rfq, ion, simulation

190

S. Mickat, W.A. Barth, G. Clemente, X. Du, L. Groening, A. Orzhekhovskaya, B. Schlitt, H. Vormann, C. Xiao, S.G. Yaramyshev
GSI, Darmstadt, Germany
M. Droba, H. Hähnel, U. Ratzinger, R. Tiede
IAP, Frankfurt am Main, Germany

The High-Energy (HE) Linac is proposed to substitute the existing UNILAC post-stripper section. The post-stripper is an Alvarez DTL, which is in operation over four decades successfully. A quasi Front-to-End simulation along the UNILAC shows, that by taking future upgrade options into account already, with the existing Alvarez section the Fair requirements are not reached. Even by substituting the Alvarez section by the HE Linac the aim is not reached per se regarding the existing boundary conditions. Currently workpackages are defined together with the Institute of Applied Physics at Frankfurt University. Starting from the Ion sources to the SIS18 transfer channel every section is reinvestigated for improvements in beam quality and intensity.

MOPP061

First RF Measurements of the Superconducting 217 MHz CH Cavity for the CW Demonstrator at GSI

cavity, simulation, status, ion

193

F.D. Dziuba, M. Amberg, M. Basten, M. Busch, H. Podlech, U. Ratzinger
IAP, Frankfurt am Main, Germany
M. Amberg, K. Aulenbacher, W.A. Barth, S. Mickat
HIM, Mainz, Germany
K. Aulenbacher
IKP, Mainz, Germany
W.A. Barth, S. Mickat
GSI, Darmstadt, Germany

Funding: Work supported by GSI, HIM, BMBF Contr. No. 05P12RFRBL
Presently, a superconducting (sc) 217 MHz Crossbar-Hmode (CH) cavity is under construction at Research Instruments (RI), Bergisch Gladbach, Germany. Among the horizontal cryomodule and two sc 9.5 T solenoids the cavity is the key component of the cw demonstrator at GSI. To show the operation ability of sc CH cavity technology under a realistic linear accelerator environment is one major goal of the demonstrator project. A successful beam operation of the demonstrator will be a milestone regarding the continuing advanced sc cw linac project at GSI for a competitive production of Super Heavy Elements (SHE) in the future. The fabrication status as well as first rf measurements at room temperature of the 217 MHz CH cavity are presented.

Poster MOPP061 [1.741 MB]

MOPP064

R&D of the 17 MeV MYRRHA Injector

emittance, cavity, proton, rfq

202

D. Mäder, M. Basten, D. Koser, H.C. Lenz, N.F. Petry, H. Podlech, A. Schempp, M. Schwarz, M. Vossberg
IAP, Frankfurt am Main, Germany
C. Zhang
GSI, Darmstadt, Germany

Funding: Project supported by the EU, FP7 MAX, Contract No. 269565
MYRRHA is designed as an accelerator driven system (ADS) for transmutation of long-lived radioactive waste. The challenge of the linac development is the very high reliability of the accelerator to limit the thermal stress inside the reactor. With the concept of parallel redundancy the injector will supply a cw proton beam with 4 mA and 17 MeV to the main linac. The new MYRRHA injector layout consists of a very robust beam dynamics design with low emittance growth rates. Sufficient drift space provides plenty room for diagnostic elements and increases the mountability. Behind a 4-Rod-RFQ and a pair of two-gap QWR rebunchers at 1.5 MeV the protons are matched into the CH cavity section. A focussing triplet between the rebunchers ensures an ideal transversal matching into the doublet lattice. Each of the 7 RT CH structures has a constant phase profile and does not exceed thermal losses of 29 kW/m. The transition to the 5 SC CH cavities with constant beta profile is at 5.9 MeV. For a safe operation of the niobium resonators the electric and magnetic peak fields are defined below 25 MV/m and 57 mT respectively.

Poster MOPP064 [4.024 MB]

MOPP066

High Gradient CH-Type Cavity Development for 10 – 100 AMeV Beams

cavity, quadrupole, ion, heavy-ion

208

A. Almomani, U. Ratzinger
IAP, Frankfurt am Main, Germany

Funding: This work is supported by Federal Ministry of Education and Research - BMBF No. 05P12RFRB9.
The development in pulsed linac activities aims on compact designs and on an increase of the voltage gain per meter. At IAP - Frankfurt, a CH design was developed for these studies, where the mean effective accelerating field is expected to reach well above 10 MV/m at 325 MHz, β=0.164. Within a funded project, this cavity is systematically developed. Currently, the cavity is under construction at NTG GmbH and expected to be ready for copper plating in autumn 2014. The results should give an impact on the rebuilt of the UNILAC - Alvarez section, optimized for achieving the beam intensities specified for the GSI – FAIR project. A mid- and long- term aim is a compact pulsed high current linac. The new GSI 3 MW Thales klystron test stand will be very important for these investigations. Detailed studies on two different types of copper plating can be performed on this cavity. Additionally, operating of normal conducting cavities at cryogenic temperatures will be discussed. In this work, the cavity status will be presented.

MOPP067

Operation of the LINAC and the LINAC RF System for the Ion-Beam Therapy Center Heidelberg

ion, operation, DTL, rfq

211

E. Feldmeier, R. Cee, Th. Haberer
HIT, Heidelberg, Germany

The Heidelberg Ion Therapy Center HIT is in clinical operation since 2009. It is the first dedicated european particle accelerator for medical treatment. Its central location on the campus of the Heidelberg University Hospital fits perfectly in the clinical everyday life. The accelerator complex consists of a linear accelerator and a synchrotron and is designed for protons and carbon ions, but can also provide helium and oxygen ions. The LINAC, build in 2006, operates since 5 years in a 24/7 schema which leads to 60000 operating hours up to now. The performance with an availibility of better than 99% is much higher than expected and is caused by a solid design and a well planned and foresighted maintenance. Unavoidable failures during operation can be solved very fast with the on site experts for each section. The combination of personnel spare parts and permanent ongoing developments is very successful. An upgrade program for parts of the linac and also for the RF system is in planning to keep the uptime high and to improve the performance for further needs.

MOPP070

Final Design for the BERLinPro Main Linac Cavity

HOM, cavity, emittance, dipole

217

A. Neumann, J. Knobloch
HZB, Berlin, Germany
K. Brackebusch, T. Flisgen, T. Galek, U. van Rienen
Rostock University, Faculty of Computer Science and Electrical Engineering, Rostock, Germany
B. Riemann, T. Weis
DELTA, Dortmund, Germany

Funding: This work is partly funded by BMBF contract no. 05K10PEA and 05K10HRC
The Berlin Energy Recovery Linac Project (BERLinPro) is designed to develop and demonstrate CW LINAC technology for 100-mA-class ERLs. High-current operation requires an effective damping of higher-order modes (HOMs) of the 1.3 GHz main-linac cavities. We have studied elliptical 7-cell cavities based on a modified Cornell ERL design combined with JLab's waveguide HOM damping approach. This paper will summarize the final optimization of the end-cell tuning for minimum external Q of the HOMs, coupler kick calculations of the single TTF fundamental power coupler as well as multipole expansion analysis of the given modes and a discussion on operational aspects.

Poster MOPP070 [1.561 MB]

MOPP072

Present Status of J-PARC LINAC LLRF Systems

controls, operation, timing, feedback

224

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

The RF control systems have been developed for the J-PARC proton linac, which consists of 324-MHz and 972-MHz acceleration sections. From October 2006, we started the commissioning of the 324-MHz sections. Then the J-PARC 324-MHz 181-MeV proton linac had been operated nearly for 7 years, until May 2013. In the summer of 2013, we upgraded the J-PARC linac by adding 972-MHz acceleration sections. The output energy of the J-PARC linac was successfully upgraded to 400 MeV in December 2013, and then the operation of the J-PARC 400-MeV linac started. In the past 8 years of the J-PARC linac operation, no heavy troubles occurred in the RF control systems. Every year we made improvements on the RF control systems, according to the operation experiences. In this paper, the present status of the J-PARC 400-MeV linac RF control systems will be described in details, and an improvement plan for the LLRF systems in the future will also be introduced.

MOPP076

Construction of an Accelerator-based BNCT Facility at yhe Ibaraki Neutron Medical Research Center

target, neutron, rfq, klystron

230

M. Yoshioka, H. Kobayashi, T. Kurihara, S.-I. Kurokawa, H. Matsumoto, N. Matsumoto
KEK, Ibaraki, Japan
T. Hashirano, T. Sugano
MHI, Hiroshima, Japan
F. Hiraga
Hokkaido University, Sapporo, Japan
H. Kumada, Su. Tanaka
Tsukuba University, Graduate School of Comprehensive Human Sciences, Ibaraki, Japan
A. Matsumura, H. Sakurai
Tsukuba University, Ibaraki, Japan
N. Nagura, T. Ohba
Nippon Advanced Technology Co. Ltd., Ibaraki-prefecture, Japan
T.N. Nakamoto, T. Zagar
Cosylab, Ljubljana, Slovenia
T. Nakamura
JAEA, Ibaraki-ken, Japan
T. Ouchi
ATOX, Ibaraki, Japan

An accelerator-based BNCT (Boron Neutron Capture Therapy) facility is being constructed at the Ibaraki Neutron Medical Research Center. It consists of a proton linac of 80kW beam power with 8 MeV energy and 10mA average current, a beryllium target, and a moderator system to provide an epi-thermal neutron flux enough for patient treatment. The technology choices for this present system were driven by the need to site the facility in a hospital and where low residual activity is essential. The maximum neutron energy produced from an 8 MeV-proton is 6 MeV, which is below the threshold energy of the main nuclear reactions which produce radioactive products. The down side of this technology choice is that it produces a high density heat load on the target so that cooling and hydrogen aniti-blistering amelioration prevent sever challenges requiring successful R&D progress. The latest design of the target and moderator system shows that a flux of 4×10⁹ epi-thermal neutrons / cm² / sec can be obtained. This is much higher than the flux from the existing nuclear reactor based BNCT facility at JAEA ( JRR-4).

MOPP077

Electron-Driven Positron Capture Simulation for ILC

positron, electron, target, booster

233

Y. Seimiya, M. Kuriki
HU/AdSM, Higashi-Hiroshima, Japan
S. Kashiwagi
Tohoku University, Research Center for Electron Photon Science, Sendai, Japan
T. Okugi, T. Omori, M. Satoh, J. Urakawa
KEK, Ibaraki, Japan
T. Takahashi
Hiroshima University, Graduate School of Science, Higashi-Hiroshima, Japan

ILC (International Linear Collider) is a next high-energy physics project to study the Higgs property as detail as possible and new phenomena beyond standard model. In ILC, the positron beam is produced by converting gamma rays from undulator radiations. To obtain gamma rays as undulator radiation, the electron beam for collision (150 GeV or more) is used. This positron generation scheme is a totally new approach. From project point of view, it is desirable to have a technical backup as a replacement of the undulator scheme. We propose an ILC positron source based on the conventional electron driven scheme. In this scheme, positron beam is generated from electromagnetic shower in a heavy target material where electron beam is injected. By manipulating the beam time structure to relax the heat load on the production target, the scheme can be feasible technically. In this study, positron capture in the electron driven scheme is simulated from the positron production to the positron damping ring, to demonstrate that an enough amount of positron can be generated and captured with a controllable heat load on the target.

Poster MOPP077 [0.879 MB]

MOPP078

RF Power Systems for the FAIR Proton Linac

klystron, proton, electronics, cavity

236

J. Lesrel, C. Joly
IPN, Orsay, France
E. Plechov, A. Schnase, G. Schreiber, W. Vinzenz
GSI, Darmstadt, Germany

In the framework of collaboration between the FAIR project, GSI, and CNRS, the IPNO lab is in charge of providing the high power RF components for a cavity test stand and for the planned FAIR proton Linac. This Linac will be connected to the existing GSI synchrotron SIS18 for serving as an injector for the new FAIR facility. The 70 MeV FAIR proton Linac design contains a 3 MeV RFQ, and a DTL based on Cross-bar H-mode cavities (CH). It will operate with pulsed RF at 325.224 MHz with a width of 200 μs and a repetition rate of 4 Hz. The planned RF systems of the proton Linac will be presented as well as the description of the test stand. The first power test results are obtained with a Thales klystron developed jointly with CNRS. Three solid state amplifiers made by Sigmaphi Electronics for the bunchers will also be described in this paper.

MOPP080

Beam Dynamics Study for RAON Superconducting Linac

ion, lattice, proton, quadrupole

239

H. Jang, H.J. Kim
IBS, Daejeon, Republic of Korea
J.G. Hwang
KNU, Deagu, Republic of Korea
B.H. Oh
POSTECH, Pohang, Kyungbuk, Republic of Korea

Rare Isotope Science Project (RISP) in Korea is going to build an ion accelerator, RAON which can generate and accelerate various stable ions such as uranium, proton, xenon and rare isotopes such as tin, nickel. Linear accelerators of RAON adopted superconducting RF cavities and warm quadruple doublet structure. In RAON, there are two low energy linacs which can accelerate the Uranium beam from 0.5MeV/u to 17.5MeV/u, charge stripping sections and one high energy linac which can accelerate the Uranium beam up to 200MeV/u. Due to the diversity of planned ions and isotopes, their A/q range lies widely from 1 to 8. As a result, the research related with linac lattice design and beam dynamics is one of the important topics to build RAON. In this presentation the current status of RAON linac lattice design and the beam dynamics simulation results for acceleration of various ions will be described.

MOPP082

Superconducting Linac for RISP

cavity, cryomodule, ion, quadrupole

245

H.J. Kim, H.J. Cha, M.O. Hyun, H.C. Jung, Y.J.K. Kim, M. Lee
IBS, Daejeon, Republic of Korea

The RISP (Rare Isotope Science Project) has been proposed as a multi-purpose accelerator facility for providing beams of exotic rare isotopes of various energies. It can deliver ions from proton to Uranium. Proton and Uranium beams are accelerated upto 600 MeV and 200 MeV/u respectively. The facility consists of three superconducting linacs of which superconducting cavities are independently phased. Requirement of the linac design is especially high for acceleration of multiple charge beams. In this paper, we present the RISP linac design, the prototyping of superconducting cavity and cryomodule.

MOPP090

Adjustment of the Coupling Factor of the Input Coupler of the ACS Linac by a Capacitive Iris in J-PARC

cavity, coupling, simulation, ion

264

J. Tamura, H. Ao, K. Hirano, Y. Nemoto, N. Ouchi
JAEA/J-PARC, Tokai-mura, Japan
H. Asano
Nippon Advanced Technology Co. Ltd., Ibaraki-prefecture, Japan
F. Naito, K. Takata
KEK, Ibaraki, Japan

Annular-ring Coupled Structure (ACS) cavities have been installed to increase the beam energy of the Japan Proton Accelerator Research Complex (J-PARC) linac from 181 to 400 MeV in the maintenance period of 2013. Some of the pillbox type input couplers with a ceramic window to the ACS cavity have a larger coupling factor than the target value by an avoidable manufacturing error. To adjust the coupling factor, a capacitive iris was introduced in the rectangular waveguide near the coupler. As a result, it has been confirmed that the iris decreases the coupling factor to a target value without any significant increase in temperature and in a discharge rate during high-power operation. In this paper, the design procedure of the capacitive iris and the result of the coupling factor adjustment are presented.

MOPP091

Beam Test of a New RFQ for the J-PARC Linac

rfq, simulation, emittance, experiment

267

Y. Kondo, T. Morishita, Y. Sawabe, S. Yamazaki
JAEA/J-PARC, Tokai-Mura, Naka-Gun, Ibaraki-Ken, Japan
T. Hori
JAEA, Ibaraki-ken, Japan
A. Takagi
KEK, Ibaraki, Japan

We performed a beam test of a new 324-MHz 3-MeV RFQ (RFQ III) for the beam-current upgrade of the J-PARC linac. RFQ III is the first RFQ developed to meet the requirement of the J-PARC linac. The peak beam current is 50mA, pulse length is 500 micro-sec, and the repetition is 25 Hz. Before the installation to the accelerator tunnel scheduled in summer of 2014, we built a test stand for offline testing of the new ion source and RFQ. Basic performances of RFQ III such as transmission, transverse emittance, and energy spread were measured with short pulse length beams. In this paper, we present the results of the beam test.

MOPP092

Compact Timing System with FPGA for SPring-8 Linac

timing, FPGA, gun, injection

270

H. Dewa, H. Hanaki, S. Suzuki
JASRI/SPring-8, Hyogo-ken, Japan

Funding: This reserch was supported by TAKUMI project.
A new timing system for SPring-8 linac was developed. It is a test system to confirm the possibility of replacing the current NIM module-based system. Although fast logic circuits can be made easily with NIM modules, they become complicated when they are used in a large system. The timing system for SPring-8 linac has been getting larger and larger after several improvements for injection to New SUBARU (NS), top-up injection for storage ring, low repetition operation for saving energy, fast alternative injection and so on. In order to simplify the system, we adopted FPGA technology that can run at a clock over 500 MHz. The new system has 50 NIM inputs and outputs on the front panel, which is installed in an 8U rack-mount box. It only has gun trigger parts of current system, but includes all of the circuit components used in the current system such as and/or logics, counter delay, fan in/out etc. Three clock sources for Synchrotron injection, NS injection, and linac solo use are available in the FPGA, and they can be changed rapidly according to the trigger sources. We describe here the details of test timing system, the results of timing jitter measurements.

MOPP093

Evaluation of Beam Energy Fluctuations Caused by Phase Noises

experiment, timing, electron, cavity

273

H. Hanaki, H. Dewa, S. Suzuki, K. Yanagida
JASRI/SPring-8, Hyogo-ken, Japan
T. Asaka, T. Ohshima
RIKEN SPring-8 Center, Sayo-cho, Sayo-gun, Hyogo, Japan

The SSB noises of the RF reference signal dominate the short-term instabilities of the RF phase of the carrier RF. This phase modulation finally results in beam energy fluctuation. This presentation gives a quantitative evaluation of the beam energy fluctuations in an electron linear accelerator caused by phase noises, comparing a theoretical analysis and experimental results. A simple model was introduced to understand how phase noises result in the relative phase difference between a beam bunch and accelerating RF fields. In the experiments, we measured the enhanced beam energy fluctuations by modulating the phase of the reference RF signals with an external signal. The interference between the accelerating RF phase modulation and the timing modulation of a beam bunch was found in the model analysis and also in the experimental results.

MOPP094

Latest Improvements of the SPring-8 Linac for High Reliability

operation, vacuum, electron, injection

276

S. Suzuki, H. Dewa, H. Hanaki, T. Kobayashi, T. Magome, A. Mizuno, T. Taniuchi, K. Yanagida
JASRI/SPring-8, Hyogo-ken, Japan
T. Asaka
RIKEN SPring-8 Center, Sayo-cho, Sayo-gun, Hyogo, Japan

In order to perform stable injection to the 8GeV SPring-8 storage ring, which is performing the top-up operation, the high reliability of the linac has been advanced as follows: For reduction of phase variations caused by the waveguide deformation due to the variations of temperature or atmospheric pressure, the waveguide circuit of SF6 enclosure type, which fed RF powers to the bunching section, was replaced with that of vacuum type. And S-band 10MW circulators and isolators of vacuum type were adopted for the first time in the world. The timing system was improved so that the interval time of the beam injection into the 8GeV booster synchrotron and the 1.5 GeV NewSUBARU storage ring has been reduced to 1 sec from 15 seconds, respectively, even in the top-up operation of both storage rings. As a result, the stored current by the top-up operation were further stabilized. The stored current of the NewSUBARU storage ring was stabilized to 0.18% from 0.31%. The electron gun cathode assembly has been developed to reduce the dark emission from a grid plate by the double grid method and the electrolytic polishing.

MOPP095

Emittance Measurement for SPring-8 Linac Using Four Six-Electrode BPMs

emittance, electron, quadrupole, focusing

279

K. Yanagida, H. Hanaki, S. Suzuki
JASRI/SPring-8, Hyogo-ken, Japan

In the SPring-8 linear accelerator (linac) six-electrode beam position monitors (BPMs) have been installed to measure second-order moments. At the end of the linac where the electron beam energy is 1 GeV four quadrupole magnets are utilized for twiss parameter matching toward the following beam transport line. Last year four six-electrode BPMs were installed at the locations of these four quadrupole magnets for an emittance measurement. The relative second-order moments were obtained changing the magnetic field strength of the quadrupole magnets, then beam sizes, emittances and twiss parameters were deduced or calculated. At this time we applied one pair of beam sizes measured by the screen monitor for a precise determination of emittances but we try to implement non-destructive measurement with no screen monitor. Before the emittance measurement a calibration with fifth-order moment correction was carried out changing beam positions at the BPM locations using upstream steering magnets (the entire calibration).

Slides MOPP095 [0.984 MB]

MOPP096

Current Status of the Mainz Energy-Recovering Superconducting Accelerator Project

experiment, feedback, operation, diagnostics

282

M. Dehn, I. Alexander, K. Aulenbacher, J. Diefenbach, R.G. Heine, C. Matejcek, F. Schlander, D. Simon
IKP, Mainz, Germany

Funding: Work supported by the German Federal Ministery of Education and Research (BMBF) and German Research Foundation (DFG) under the Cluster of Excellence "PRISMA"
The Mainz Energy-Recovering Superconducting Accelerator (MESA) project at Johannes Gutenberg-Universtitaet Mainz has started in 2012 and is in full swing now. This presentation shows the current status of the project with a glance on cryogenics, superconducting RF, accelerator lattice design and the normal conducting injector.

MOPP098

Physical Starting of the First and Second Section of Accelerator Linac-800

electron, undulator, klystron, gun

288

V. Kobets, N. Balalykin, I.N. Meshkov, V. Minashkin, G. Shirkov
JINR, Dubna, Moscow Region, Russia
V. Shabratov
JINR/VBLHEP, Moscow, Russia

In the report discusses the modernization of linear electron accelerator MEA (Medium Energy Accelerator). The aim is to develop a set of MEAs based free-electron lasers, imposed a number of emission wavelengths from infrared to ultraviolet. In work presents the results of the physical starting of the first and second stations accelerating electron linear accelerator LINAC-800, as well as start infrared undulator. We discuss the work program for this accelerator.

MOPP099

Compact Proton Injector for Synchrotrons

rfq, proton, cavity, quadrupole

291

A.D. Kovalenko, A.V. Butenko
JINR, Dubna, Moscow Region, Russia
A. Kolomiets, A.S. Plastun
ITEP, Moscow, Russia

Compact linac comprising two sections of different RFQ structures was designed. The first section is conventional RFQ with output energy 3 MeV whereas the second one is RFQ with trapezoidal modulation of vanes. The linac output energy is 8 MeV. The both structures operate at frequency of 352 MHz. The total length of machine is less than 8 m. The output pulsed beam current is of 40 mA. The design is suitable for both as NICA injection complex and proton superconducting medical synchrotron.

MOPP103

Fault Tolerance and Consequences in the MYRRHA Superconducting Linac

cavity, operation, cryomodule, simulation

297

F. Bouly
LPSC, Grenoble Cedex, France
J.-L. Biarrotte
IPN, Orsay, France
D. Uriot
CEA/DSM/IRFU, France

Funding: This work is being supported by the European Atomic Energy Community’s EURATOM) Seventh Framework Programme under grant agreement n°269565(MAX project).
The MYRRHA project aims at the construction of new irradiation complex in Mol (Belgium) to demonstrate the transmutation feasibility with an Accelerator Driven System (ADS). In its subcritical configuration, the MYRRHA facility requires a proton flux with a maximum power of 2.4 MW (600 MeV - 4 mA). Such a continuous wave beam will be delivered by a superconducting linac which must fulfil very stringent reliability requirements to ensure the safe ADS operation with a high level of availability. In this purpose, the accelerator design is based on a redundant and fault-tolerant scheme to enable rapid failures mitigations. Beam dynamics studies on the fault tolerance capability of the MYRRHA superconducting linac will be presented. The results will be mainly focused on RF failure compensation scenarios: when one or several superconducting cavities are lost in the linac. The impact on the R&D to enable fast retuning procedures in the linac will also be discussed.

MOPP106

3D Mode Analysis of Full Tanks in Drift-Tube Linacs

DTL, simulation, emittance, drift-tube-linac

300

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

Drift-tube linacs (DTLs) are usually designed and analyzed in axisymmetric approximation, cell by cell, using 2D codes such as Superfish and Parmila. We have developed 3D models of full DTL tanks with CST Studio to accurately calculate the tank modes, their sensitivity to post-coupler positions and tilts, tuner effects, and RF-coupler influence. Such models are important for the LANSCE DTL where each of four tanks contains tens of drift tubes and tank 2 has as much as 66 cells. We perform electromagnetic analysis of the DTL tank models using MicroWave Studio (MWS), mainly with eigensolvers but also in time domain. A similar approach has already been applied for thermal analysis of the LANSCE DTL but only with short tank models [1]. The full-tank analysis allows tuning the field profile of the operating mode and adjusting the frequencies of the neighboring modes within a realistic CST model. The MWS-calculated RF fields can be used for beam dynamics and thermal modeling. Here we present beam dynamics results for the LANSCE DTL from Particle Studio.
[1] S.S. Kurennoy, LINAC08, Victoria, BC, 2008, p. 951.

MOPP107

Results from the Installation of a New 201 MHz RF System at LANSCE

DTL, cavity, electronics, controls

303

J.T.M. Lyles, C.L. Arnold, W.C. Barkley, J. Davis, A.C. Naranjo, M.S. Prokop, D. Rees, G. M. Sandoval, Jr.
LANL, Los Alamos, New Mexico, USA
D. Baca, R.E. Bratton, R.D. Summers
Compa Industries, Inc., Los Alamos, New Mexico, USA

Funding: Work supported by the United States Department of Energy, National Nuclear Security Agency, under contract DE-AC52-06NA25396.
The LANSCE RM project is restoring the linac to it’s original high power capability after the power grid tube manufacturer could no longer provide triodes that could consistently meet our power requirements. High duty factor Diacrodes® now supply RF power to the largest DTL tank. These tetrodes reuse the existing infrastructure including water-cooling systems, coaxial transmission lines, high voltage power supplies and capacitor banks. The power amplifier system uses a combined pair of LANL-designed cavity amplifiers using the TH628L Diacrode® to produce as much as 3.5 MW peak and 420 kW of mean power. A digital low level RF control system was developed to complement these new linear amplifiers. Design and testing was completed in 2012, with commercialization following in 2013. The first installation is commissioned. The two remaining high power RF systems for tanks 3 and 4 will be replaced in subsequent years using a hybrid old/new RF system until the changeover is complete. Features and operating results of the replacement system are summarized, along with observations from the rapid-paced installation project.

MOPP114

SNS Linac Upgrade Plans for the Second Target Station

cryomodule, klystron, cavity, rfq

320

J. Galambos, D.E. Anderson, M.P. Howell, S.-H. Kim, M.A. Plum, A.P. Shishlo
ORNL, Oak Ridge, Tennessee, USA
M.E. Middendorf
ORNL RAD, Oak Ridge, Tennessee, USA

Funding: ORNL is managed by UT-Battelle, LLC, under contract DE-AC05-00OR22725 for the U.S. Department of Energy.
The Second Target Station (STS) upgrade for the Spallation Neutron Source (SNS) proposes the addition of a short pulse, long wavelength neutron scattering station. In order to provide world-class intensity at the additional station, the SNS linac beam power capability is doubled, to 2.8 MW. This will be accommodated by a 30% increase in the beam energy to 1.3 GeV and a 50% increase in beam current. The beam energy increase will be provided by the addition of 7 additional cyro-modules and supporting RF equipment in space provided during the original SNS construction. The beam current increase will be provided by improved ion source and a reduced chopping fraction, and will require increases in the RF and high voltage modulator systems to accommodate the additional beam loading. Initial plans will be presented. The proposed linac upgrade path will be described.

MOPP119

Measurements and High Power Test of the First C-band Accelerating Structure for SwissFEL

operation, vacuum, FEL, klystron

333

R. Zennaro, J. Alex, A. Citterio, J.-Y. Raguin
PSI, Villigen PSI, Switzerland

The SwissFEL project is based on a 5.8 GeV C-band Linac which is composed of 10⁴ accelerating structures with a length of 2 m each. Due to the absence of dimple tuning no local frequency correction is possible and hence ultra-precise machining is required. The paper reports on both low level and high power RF test of the first nominal structure produced. The required mechanical precision has been reached and the structure has been successfully power tested to a gradient larger than 50 MV/m, well above the nominal level of 28 MV/m. The measured dark current and break down rates are well in the specifications.

MOPP120

Beam Dynamic Design of a 100 mA, 162.5 Mhz High-Current Linac

rfq, emittance, quadrupole, experiment

336

F.J. Jia, J.E. Chen, Y.R. Lu, Z. Wang, W.L. Xia, X.Q. Yan, K. Zhu
PKU, Beijing, People's Republic of China
W.P. Dou, Y. He
IMP, Lanzhou, People's Republic of China

Funding: This work is supported by the 973 program (No. 2014CB845503) and the NSFC (Grants No. 11079001).
The beam dynamic design of a 100 mA, 162.5 MHz Radio Frequency Quadrupole (RFQ) is presented in this paper. The RFQ will accelerate protons from 85 keV to 3 MeV under the operation mode of continuous-wave (CW). The code PARMTEQM is used to carry out the beam dynamics design and the transmission efficiency has been optimized and improved to more than 99%. In the design of this high-current linac, the space charge effect is analyzed as it can cause emittance growth, nonuniform particle density distribution and resonance effect. The electrode structure parameters generated by PARMTEQM also be adopted by the code of Toutatis to verify the result’s veracity.

MOPP125

Comparison of Normal Conducting High Energy Accelerating Structures for a Moderate Operating Frequency

coupling, Windows, proton, impedance

348

V.V. Paramonov
RAS/INR, Moscow, Russia

The progress in the CERN Linac 4 project confirms the very attractive possibility for single frequency high intensity high energy normal conducting hadron linac. The important part of such linac is the accelerating structure for high energy part. Parameters of possible accelerating structures, referring to PIMS, at operating frequency 352 MHz are considered for proton energy up to 600 MeV. The set of parameters, such as dimensions, RF efficiency, field stability, cooling capability, vacuum conductivity, are considered and compared.

MOPP126

Untrapped HOM Radiation Absorption in the LCLS-II Cryomodules

HOM, cryomodule, cavity, impedance

351

K.L.F. Bane, C. Adolphsen, C.D. Nantista, T.O. Raubenheimer
SLAC, Menlo Park, California, USA
A. Saini, N. Solyak, V.P. Yakovlev
Fermilab, Batavia, Illinois, USA

Funding: Work supported by Department of Energy contract DE–AC02–76SF00515.
The superconducting cavities in the continuous wave (CW) linacs of LCLS-II are designed to operate at 2 K, where cooling costs are very expensive. One source of heat is presented by the higher order mode (HOM) power deposited by the beam. Due to the very short bunch length-especially in L3 the final linac-the LCLS-II beam spectrum extends into the terahertz range. Ceramic absorbers, at 70 K and located between cryomodules, are meant to absorb much of this power. In this report we perform two kinds of calculations to estimate the effectiveness of the absorbers and the amount of beam power that needs to be removed at 2 K.

MOPP130

A Linac-Based Approach to Modelling an Orbit Separated Cyclotron

cavity, cyclotron, simulation, emittance

364

D.C. Plostinar, G.H. Rees
STFC/RAL/ASTeC, Chilton, Didcot, Oxon, United Kingdom

An orbit separated cyclotron (OSC) is a new type of accelerator intended as a proton driver for Accelerator Driven Subcritical Reactors (ADSRs). A ring has been designed based on the new concept that accelerates a proton beam from 500 MeV to 1 GeV in four turns using multi-cell superconducting cavities in each period. From a beam dynamics point of view, the ring can be considered as a “wrapped-up” linac at four times the ring circumference. In this paper we present beam dynamics modelling details when using 3D linac codes and cavity field maps. We conclude that the versatility of codes such as TraceWin, allows detailed machine modelling and improved design procedures that take into account various aspects including orbit distortion caused by transverse deflecting fields in the cavities.

MOPP134

Superconducting Accelerating Cavity Pressure Sensitivity Analysis and Stiffening

cavity, proton, simulation, vacuum

373

J. Rodnizki, Y. Ben Aliz, A. Grin, Z. Horvitz, A. Perry, L. Weissman
Soreq NRC, Yavne, Israel
G.K. Davis
JLab, Newport News, Virginia, USA
J.R. Delayen
ODU, Norfolk, Virginia, USA

The SARAF Prototype Superconducting Module (PSM) houses six 176 MHz Half Wave Resonators(HWR). The PSM accelerates protons and deuterons from 1.5 MeV/u to 4 and 5.6 MeV. The HWRs are highly sensitive to the coolant liquid Helium pressure fluctuations which limit the available beam power to 2kW per cavity out of 4kW RF amplifier and coupler and so might limit the available beam current to 2mA depending on the output energy. The flat shape of the cavity along the beam line in the area of the high electric field generates the high sensitivity of the Eigen mode frequency to helium pressure. The evaluated cavity sensitivity is full consistent with the measured values. It was explored that the tuning system (the fog structure) has a significant contribution to the cavity sensitivity. By using ribs or by modifying the rigidity of the fog we may reduce the HWR sensitivity by a factor of 3. This analysis is applied to study the stresses on the cavity during cool down and warm up to avoid plastic deformation as the Niobium yield is an order of magnitude lower in room temperature.

MOPP139

Studies of Coherent Synchrotron Radiation in the Jefferson Lab FEL Driver with Implications for Bunch Compression

emittance, acceleration, simulation, FEL

388

C. Tennant, D. Douglas, R. Li
JLab, Newport News, Virginia, USA
C.-Y. Tsai
Virginia Polytechnic Institute and State University, Blacksburg, Virginia, USA

Funding: Work supported by the Office of Naval Research and the High Energy Laser Joint Technology. Jefferson Laboratory work is supported under U.S. DOE Contract No. DE-AC05-06OR23177.
The Jefferson Laboratory IR FEL Driver provides an ideal test bed for studying a variety of beam dynamical effects. Recent studies focused on characterizing the impact of coherent synchrotron radiation (CSR) with the goal of benchmarking measurements with simulation. Following measurements to characterize the beam, we quantitatively characterized energy extraction via CSR by measuring beam position at a dispersed location as a function of bunch compression. In addition to operating with the beam on the rising part of the linac RF waveform, measurements were also made while accelerating on the falling part. For each, the full compression point was moved along the backleg of the machine and the response of the beam (distribution, extracted energy) measured. Initial results of start-to-end simulations using a 1D CSR algorithm show remarkably good agreement with measurements. A subsequent experiment established lasing with the beam accelerated on the falling side of the RF waveform in conjunction with positive momentum compaction (R56) to compress the bunch. The success of this experiment motivated the design of a modified CEBAF-style arc with control of CSR and microbunching effects.

TUIOA02

R&D Efforts for ERLs

emittance, cavity, operation, SRF

394

R.G. Eichhorn
Cornell University, Ithaca, New York, USA

The last few years has seen extensive R&D for ERLs, with several prototype facilities now under construction or in operation. The Cornell ERL R&D program has reached major goals, with producing the world’s brightest beam from any photoinjector, reaching CW beam current of greaters than 75 mA, and reaching intrinsic quality factors of 10¹¹ in an SRF cavity installed in a cryomodule. The talk gives an overview of status of ERLs projects, and ERL R&D.

Slides TUIOA02 [8.803 MB]

TUIOA03

The MAX IV Linac

gun, electron, storage-ring, injection

400

S. Thorin, J. Andersson, F. Curbis, M. Eriksson, O. Karlberg, D. Kumbaro, E. Mansten, D.F. Olsson, S. Werin
MAX-lab, Lund, Sweden

The MAX IV linac will be used both for injection and top up into two storage rings, and as a high brightness injector for a Short Pulse Facility (SPF). The linac has also been deigned to handle the high demands of an FEL injector. In the storage ring injection mode, the linac is operated at 10 Hz with a thermionic RF gun and the electron bunches are kicked out from the linac at either 3 GeV or 1.5 GeV to reach the respective storage ring. For the Short Pulse mode the linac will operate at 100 Hz with a high brightness photo cathode gun. Compression is done in two double achromats with positive R56 and the natural second order momentum compaction, T566, from the achromats is used together with weak sextupoles to linearise longitudinal phase space, leaving no need for a linearising harmonic cavity. The achromat design for bunch compression produces very short, high peak power electron pulses, while minimizing emittance increase. In this paper we present the MAX IV linac design and the status of commissioning which started in March 2014.

Slides TUIOA03 [4.202 MB]

TUIOA04

The New LCLS-II Project : Status and Challenges

cryomodule, electron, undulator, operation

404

J.N. Galayda
SLAC, Menlo Park, California, USA

The LCLS-II was an upgrade of the LCLS which essentially replicated the LCLS in another tunnel using the middle 1/3 of the SLAC S-band linac. In August 2013, the project was doubled in scope and redirected towards providing MHz-rate X-ray pulses from 0.2 to 5.0 keV while still supporting the ongoing program at the LCLS. The accelerator is now based on a 4.0 GeV SCRF linac installed in the front of the SLAC linac tunnel. Status and challenges of LCLS-II in context of July 2013 recommendation of DOE BESAC for a fully coherent, cw, FEL with photon energies up to ~5 keV.

Slides TUIOA04 [6.386 MB]

TUIOB02

Beam Commissioning of the 100 MeV KOMAC Linac

proton, DTL, operation, klystron

413

Y.-S. Cho
KAERI, Daejon, Republic of Korea

Funding: This work was supported by the Ministry of Science, ICT & Future Planning of the Korean Government.
The operation of the 100MeV proton linear accelerator for multipurpose application started in July, 2013 at KOMAC (Korea Multipurpose Accelerator Complex), KAERI (Korea Atomic Energy Research Institute). Also, the operation of the two beam lines, one is for 20MeV beam and the other for 100MeV beam, started in order to supply proton beams to users. The accumulated operation time was 2,290 hours and the proton beam was supplied to 937 samples in 2013. In addition to the beam service, the effort to increase the beam power is continuing in 2014. Beam commissioning and operation status of the linac will be presented in this talk.

Slides TUIOB02 [7.200 MB]

TUIOB03

Commissioning of Energy Upgraded Linac of J-PARC

klystron, injection, operation, rfq

417

K. Hasegawa
J-PARC, KEK & JAEA, Ibaraki-ken, Japan

To realize a full potential of J-PARC facility (1MW at 3 GeV), the J-PARC linac is upgraded from 181 MeV to 400 MeV by using an annular-ring coupled structure linac (ACS). The ACS modules and peripheral system were installed and commissioned in summer to autumn of 2013. Beam commissioning is about to start and results will be expected.

Slides TUIOB03 [4.905 MB]

TUIOB04

DTL Construction Status of CSNS Project

DTL, vacuum, neutron, ion

423

H.C. Liu, S. Fu, J. Peng, S. Wang
IHEP, Beijing, People's Republic of China

Linac of Chinese Spallation Neutron Source (CSNS) project is under construction. The ion source is tested and good performance of beam current is obtained. The low level RF tuning is underway of the RFQ and assembling of DTL will start soon. Not only the construction of hardware, but some commissioning software packages have been developed and tested.

Slides TUIOB04 [4.772 MB]

TUIOC03

Nb3Sn - Present Status and Potential as an Alternative SRF Material

cavity, niobium, SRF, cryogenics

431

S. Posen, M. Liepe
Cornell University (CLASSE), Cornell Laboratory for Accelerator-Based Sciences and Education, Ithaca, New York, USA

Nb₃Sn is a material that has the potential to have a transformative impact on SRF linacs. Due to its large critical temperature of approximately 18 K, Nb₃Sn cavities can have far smaller surface resistances at a given temperature than standard Nb cavities. This could significantly reduce the costs for infrastructure and power in cryoplants for large CW linacs. In addition, the predicted superheating field of Nb₃Sn is approximately double that of Nb, potentially doubling the maximum energy gradient. This would significantly decrease the size and cost of high energy linacs. In this work, we present recent progress in research and development for this promising material.

Slides TUIOC03 [3.357 MB]

Poster TUIOC03 [2.046 MB]

TUPP001

Cryogenic Performance of a New 72 MHz Quarter-Wave Resonator Cryomodule

cryomodule, cavity, cryogenics, solenoid

437

Z.A. Conway, G.L. Cherry, R.L. Fischer, S.M. Gerbick, M. Kedzie, M.P. Kelly, S.H. Kim, S.W.T. MacDonald, R.C. Murphy, P.N. Ostroumov, C.E. Peters, M.A. Power, T. Reid, J.R. Specht
ANL, Argonne, Illinois, USA

Funding: This material is based upon work supported by the U.S. Department of Energy, Office of Science, Office of Nuclear Physics, under contract number DE-AC02-06CH11357.
The Argonne National Laboratory ATLAS accelerator’s Intensity and Efficiency Upgrade project has been successfully finished [1]. This upgrade substantially increases beam currents for experimenters working with the existing stable and in-flight rare isotope beams and for the neutron rich beams from the Californium Rare Isotope Breeder upgrade. A major portion of this project involved the replacement of three existing cryomodules, containing 18 superconducting (SC) accelerator cavities and 9 superconducting solenoids, with a single cryomodule containing 7 SC 72.75 MHz accelerator cavities optimized for ion velocities of 7.7% the speed of light and 4 SC solenoids all operating at 4.5 K. This paper reports the measured thermal load to the 4 K and 80 K coolant streams and compares these results to the pre-upgrade cryogenic system.

TUPP007

Multi Gigawatt High Current Pulsed Electron Accelerator Technology Development Program at BARC

electron, impedance, high-voltage, induction

456

A. Sharma, R. Agarwal, M. Beg, R. Chandra, H. Choudhary, L.M. Gantayet, S.R. Ghodke, TS. Kolge, R. Kumar, S. Mitra, K.C. Mittal, A.S. Patel, A. Roy, P.C. Saroj, K. Senthil, V.K. Sharma, S.K. Singh
BARC, Mumbai, India

High current intense electron beams were investigated earlier for Flash X-rays and nuclear electromagnetic pulse generation. Starting with moderate parameters of 200 kV, 6 kA, 60 ns pulsed electron beam source from a system named Kilo Ampere Linear Injector (KALI-75) our latest development is KALI-30 GW system rated for 1 MV, 30 kA, 80 ns. First repetitive pulse LINAC without spark gap switching was developed as Linear Induction Accelerator (LIA-200) for technology demonstrations at 100 Hz. Also a repetitive Marx generator coupled reflex triode system to operate at 10 Hz. Next to this series of development LIA-400 has been developed to a capacity of 400 kV, 4 kA, 100 ns, 300 Hz. To make these pulse power systems applicable for big LINAC projects like nToF studies or ADS program, a high current electron gun has also been developed to give 100 A, 2 ns,10 Hz pulses.
References
[1].Amitava Roy et al, Journal of App. Physics 103, 2008.
[2].D. D. P. Kumar, et al. Rev. Sci. Inst., vol. 78, no. 11, 2007.
[3].Archana Sharma, et al., IEEE-PS Vol. 39, No. 5, 2011.

TUPP009

Operation and Improvements of the ALBA Linac

klystron, operation, injection, booster

459

R. Muñoz Horta, J.M. Gómez Cordero, F. Pérez
CELLS-ALBA Synchrotron, Cerdanyola del Vallès, Spain

The ALBA Light Source pre-injector is a 100 MeV electron Linac which started operation in July 2010. Since then, several improvements have been made to the Linac system to enhance the beam stability and the operation reliability with special focus to top-up mode operation requirements. A description of the modifications applied to the RF system and an overview of the different modes of injection are presented. Also operational experience in decay mode and in the recently implemented top-up mode are reported.

TUPP019

Qualification of the Titanium Welds in the E-XFEL Cryomodule and the CE Certification

cryomodule, cavity, operation, quadrupole

468

S. Barbanotti, H. Hintz, K. Jensch, R. Klos, W. Maschmann, A. Matheisen, A. Schmidt
DESY, Hamburg, Germany
C. Boulch, C. Cloué, C. Madec, J.L. Perrin, T. Trublet
CEA/IRFU, Gif-sur-Yvette, France
J.-P. Charrier, O. Napoly
CEA/DSM/IRFU, France

The CE stamping of the one hundred 1.3 GHz cryomodules for the XFEL Linac is a main step in the process of the certification of the entire Linac as a pressure equipment. Stringent requirements on materials and the quality of the welds of the pressurised components need to be satisfied to obtain the stamp. This paper summarizes these requirements, describes the process developed to qualify each module and summarises the rework campaign on the cavity helium vessels made necessary to obtain the required quality for a reliable and safe accelerator.

TUPP022

RF Tuning of a S-band Hybrid Buncher for Injector Upgrade of LINAC II at DESY

electron, simulation, target, experiment

478

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

LINACII at DESY currently provides 450 MeV electrons for the synchrotron radiation source PETRAIII. The injector upgrade of it aims to improve its reliability and mitigate the radiological activation due to electron losses at hundreds of MeV. Therefore, a 2.998 GHz hybrid buncher has been developed and will be installed in between a pre-buncher and LINAC II. It comprises a 1-cell standing-wave (SW) section for rapid acceleration and a 13-cells travelling-wave (TW) section for further bunching and acceleration. This paper focuses on its rf tuning procedure. The tuning strategy combines a non-resonant bead-pull measurement of complex electric field and a linear model for local reflection coefficient calculation. The tuning result is satisfying. Field unflatness of the TW section has been improved from ±9% to ±4%, and field in the SW section has been enhanced significantly. By using ASTRA simulation, it has been verified that the residual detuning of the structure is acceptable in view of beam dynamics performance.

TUPP025

Progress on ESS Medium Energy Beam Transport

quadrupole, rfq, cavity, DTL

484

I. Bustinduy, D. Fernandez-Cañoto, N. Garmendia, A. Ghiglino, O. González, P.J. González, Z. Izaola, I. Madariaga, M. Magan, L. Muguira, J.L. Muñoz, I. Rueda, F. Sordo, S. Varnasseri, R. Vivanco
ESS Bilbao, Bilbao, Spain
M. Eshraqi, R. Miyamoto, A. Ponton
ESS, Lund, Sweden

The considered versatile ESS MEBT is being designed to achieve four main goals: First, to contain a fast chopper and its correspondent beam dump, that could serve in the commissioning as well as in the ramp up phases. A detailed study of the chopper rise time effects on the loss budget will be presented. Second, to serve as a halo scraping section by means of various adjustable blades. Third, to measure the beam phase and proﬁle between the RFQ and the DTL, along with other beam monitors. And ﬁnally, to match the RFQ output beam characteristics to the DTL input both transversally and longitudinally. For this purpose a set of eleven quadrupoles is used to match the beam characteristics transversally, combined with three 352.2 MHz CCL type buncher cavities, which are used to adjust the beam in order to fulfil the required longitudinal parameters. A thorough study on the optimal input beam parameters will be discussed. Quadrupole design update will be presented along with new RF measurements over the buncher prototype. Finally, updated results will be presented on the chopper and beam-dump system.

Poster TUPP025 [5.596 MB]

TUPP028

Beam Tests at the CLIC Test Facility, CTF3

experiment, operation, emittance, acceleration

487

R. Corsini, S. Döbert, W. Farabolini, D. Gamba, J.L. Navarro Quirante, T. Persson, P.K. Skowronski, F. Tecker
CERN, Geneva, Switzerland
W. Farabolini
CEA/DSM/IRFU, France
D. Gamba
JAI, Oxford, United Kingdom

The CLIC Test Facility CTF3 has been built at CERN by the Compact Linear Collider (CLIC) International Collaboration, in order to prove the main feasibility issues of the two-beam acceleration technology on which the collider is based. After the successful completion of its initial task, CTF3 is continuing its experimental program in order to give further indications on cost and performance issues, to act as a test bed for the CLIC technology, and to conduct beam experiments aimed at mitigating technological risks. In this paper we discuss the status of the ongoing experiments and present the more recent results, including improvements in beam quality and stability.

TUPP031

Understanding the Error Tolerances Required to Automatically Phase the HIE-ISOLDE Linac

emittance, cavity, software, experiment

496

M.A. Fraser, J.C. Broere, S. Haastrup, D. Lanaia, D. Valuch, D. Voulot
CERN, Geneva, Switzerland

The broad experimental programme at ISOLDE means that the same radioactive beam species and energy are rarely studied twice and the cavities of the linac must be scaled or re-phased for each experiment. A software application was developed to automatically re-phase the cavities of the HIE-ISOLDE superconducting linac to the beam from computed settings. The application was developed to expedite both machine set-up in normal operation and in scenarios involving cavity failures. A beam dynamics error study will be presented in order to better understand the challenges facing the automatic phasing routine. The effects of a variety of different errors on the efficacy of the phasing application were studied, leading to a specification of the tolerances required for the calibration of the rf system and the accuracy of the survey system that monitors the positions of the cavities.

TUPP033

Effect of Beam-Loading on the Breakdown Rate of High Gradient Accelerating Structures

klystron, beam-loading, experiment, acceleration

499

J.L. Navarro Quirante, R. Corsini, A. Degiovanni, S. Döbert, A. Grudiev, O. Kononenko, G. McMonagle, S.F. Rey, A. Solodko, I. Syratchev, F. Tecker, L. Timeo, B.J. Woolley, X.W. Wu, W. Wuensch
CERN, Geneva, Switzerland
O. Kononenko
SLAC, Menlo Park, California, USA
A. Solodko
JINR, Dubna, Moscow Region, Russia
J. Tagg
National Instruments Switzerland, Ennetbaden, Switzerland
B.J. Woolley
Cockcroft Institute, Lancaster University, Lancaster, United Kingdom
X.W. Wu
TUB, Beijing, People's Republic of China

The Compact Linear Collider (CLIC) is a study for a future room temperature electron-positron collider with a maximum center-of-mass energy of 3 TeV. To efficiently achieve such high energy, the project relies on a novel two beam acceleration concept and on high-gradient accelerating structures working at 100 MV/m. In order to meet the luminosity requirements, the break-down rate in these high-field structures has to be kept below 10 per billion. Such gradients and breakdown rates have been demonstrated by high-power RF testing several 12 GHz structures. However, the presence of beam-loading modifies the field distribution for the structure, such that a higher input power is needed in order to achieve the same accelerating gradient as the unloaded case. The potential impact on the break-down rate was never measured before. In this paper we present an experiment located at the CLIC Test Facility CTF3 recently proposed in order to quantify this effect, layout and hardware status, and discuss its first results.

Slides TUPP033 [1.970 MB]

Poster TUPP033 [2.355 MB]

TUPP034

Commissioning of the CERN LINAC4 Wire Scanner, Wire Grid and Slit-Grid Monitors at 3 and 12 MeV

electron, emittance, space-charge, diagnostics

502

F. Roncarolo, U. Raich, F. Zocca
CERN, Geneva, Switzerland

The CERN LINAC4 has been commissioned up to 12 MeV. The H⁻ beam transverse profile distributions were measured by both wire grids and wire scanners. A slit-grid system located on a temporary diagnostics bench was used to characterize the transverse emittance during the two different stages of commissioning: at the exit of the RFQ (3 MeV) and DTL1 (12 MeV). The wire signal is a balance between the negative charge deposited by the stripped electrons from the H⁻ and the charge lost due to secondary emission. Optimal settings were found for the repelling plates used to suppress secondary emission, which were confirmed by electromagnetic simulations. In addition, suppression of the secondary emission due to the beam space charge was observed. The benefit of changing the wire scanner geometry in order to minimize the cross-talk between horizontal and vertical wires and the observation of thermionic emission on carbon wires are also discussed.

TUPP035

Transverse Profile and Emittance Measurements With a Laser Stripping System During the CERN LINAC4 Commissioning at 3 and 12 MeV

laser, emittance, detector, electron

506

F. Roncarolo, E. Bravin, T. Hofmann, U. Raich, F. Zocca
CERN, Geneva, Switzerland
G.E. Boorman, A. Bosco, S.M. Gibson, K.O. Kruchinin
Royal Holloway, University of London, Surrey, United Kingdom
C. Gabor
STFC/RAL/ASTeC, Chilton, Didcot, Oxon, United Kingdom
J.K. Pozimski
Imperial College of Science and Technology, Department of Physics, London, United Kingdom

The CERN LINAC4 beam commissioning at 3 and 12 MeV was completed in 2014. A novel system for measuring the transverse beam profile and emittance, based on low power laser stripping and H⁰ detection using a diamond detector, was successfully tested at these two energies. The measurement results agree with the operational slit-grid method within a few percent in terms of both transverse profile and emittance. After describing the general system setup, this remarkable achievement is discussed in detail together with the present limitations, which will be addressed in order to design a laser based emittance monitor for the LINAC4 top energy of 160 MeV.

TUPP036

Space Charge Compensation in the Linac4 LEBT for Three Injected Gas Types

emittance, simulation, ion, space-charge

510

C.A. Valerio, R. Scrivens
CERN, Geneva, Switzerland
N. Chauvin
CEA/IRFU, Gif-sur-Yvette, France

The space charge of unbunched, high intensity beams can be compensated by the trapping of charged particles in the potential well of the beam. The source of these secondary charge particles can be the residual gas in the beam line. The effect is important in the Low energy beam transport (LEBT) regions. At CERN’s Linac4, the LEBT transports a pulsed 45keV H⁻ beam, which is compensated by the positive ions, created by collision of the beam with the neutral gas in the beam pipe. The rise time and amount of compensation may be varied by the density of neutral gas and the type of gas used (through the cross-section for ion production and the mass of the resulting ion). In this paper we present measurement results for the transport of the beam at the Linac4 LEBT with the addition of hydrogen, nitrogen and krypton gases into the line, and compare them with simulations of the beam dynamics including the effect of compensating positive ions . The H⁻ beam is provided by a cesiated 2MHz RF ion source with an external solenoidal antenna, operating with 600us pulses at 0.8Hz repetition rate.

Slides TUPP036 [4.084 MB]

Poster TUPP036 [1.356 MB]

TUPP037

Transverse Emittance Measurements of the REX-ISOLDE Beams in Preparation for the HIE-ISOLDE Commissioning

emittance, quadrupole, background, ion

513

D. Voulot, M.A. Fraser, D. Lanaia
CERN, Geneva, Switzerland
T. Olsson
MAX-lab, Lund, Sweden

The transverse emittance at the output of the REX-ISOLDE normal conducting linac has been measured at different energies in order to characterise the beam at injection to the future HIE-ISOLDE superconducting linac. The measurements were done with low intensity stable beams (~0.5 enA) in order to avoid compensation effects in the EBIS ion source and obtain representative measurements of the radioactive ion beam emittance. Emittances were measured using a slit-grid emittance meter and compared with results obtained with a quadrupole-scan (three-gradient) method. An analysis of the background suppression is presented and possible source of errors for both type of measurements are discussed.

Poster TUPP037 [2.084 MB]

TUPP038

Transverse Beam Profile Measurements in the Linac4 Medium Energy Beam Transport

emittance, simulation, quadrupole, rfq

516

M. Yarmohammadi Satri, G. Bellodi, V.A. Dimov, J.-B. Lallement, A.M. Lombardi, U. Raich, F. Roncarolo, F. Zocca
CERN, Geneva, Switzerland

Linac4 is a 160 MeV H⁻ linear accelerator presently under construction at CERN. It will replace the present 50 MeV proton Linac2 as injector of the proton accelerator complex as part of a project to increase the LHC luminosity. The Linac4 front-end, composed of a 45 keV ion source, a Low Energy Beam Transport (LEBT), a 352.2 MHz Radio Frequency Quadrupole (RFQ) which accelerates the beam to 3 MeV and a Medium Energy Beam Transport (MEBT) housing a beam chopper, has been commissioned in the Linac4 tunnel. The MEBT is composed of three buncher cavities and 11 quadrupole magnets to match the beam from the RFQ to the next accelerating structure (DTL) and it includes two wire scanners for beam profile measurement. In this paper we present the results of the profile measurements and we compare them with emittance measurements taken with a temporary slit-and-grid emittance measurement device located after the MEBT line.

TUPP039

Accuracy Determination of the ESS MEBT Emittance Measurements

emittance, scattering, proton, quadrupole

519

B. Cheymol, A. Ponton
ESS, Lund, Sweden

The European Spallation Source MEBT will be equipped with a full set of diagnostics in order to characterize the bean properties before the injection in the DTL. The 6D phase space of the beam shall be characterize during the commissioning of the normal conducting as well as on regular basis during retuning phase of the machine. In this paper we will discuss the accuracy of the transverse emittance measurement that will be performed with the slit-grid method. The slit geometric parameters have been determined in order to achieve the required resolution and sensitivity. Scattering effects at the slit have been considered to determine the emittance measurement accuracy.

TUPP041

Beam Current Monitor System of the European Spallation Source

FPGA, electronics, EPICS, controls

526

H. Hassanzadegan, M. Donna, A. Jansson, H. Kocevar, A. Nordt
ESS, Lund, Sweden
U. Legat
Cosylab, Ljubljana, Slovenia
M. Werner
DESY, Hamburg, Germany

The Beam Current Monitor system of the ESS will be primarily used for beam current and charge measurements in absolute and differential modes. Moreover, it will provide a fast input to the Beam Interlock System, initiating a trigger to shut the beam off upon high beam loss detection. As the BCM system will be needed at an early stage for Linac commissioning, it needs to work successfully under non-optimal conditions, ex. short pulse and low current beams. It is planned to install in total 20 AC Current Transformers and one Fast Current Transformer along the Linac. The FCT will have a larger bandwidth and it will be used to measure the performance of the fast chopper of the Medium Energy Beam Transport with a rise time of 10 ns. A prototype based on a commercial ACCT and EPICS-integrated MTCA.4 electronics has been set up and successfully tested with an emulated beam. The ACCT signal has been FPGA processed to compensate for the offset and droop as well as filtering and synchronization to an external trigger. This paper gives an overview of the design and test results of the prototype ACCT system with an outlook to future modifications before installation in the ESS Linac.

Poster TUPP041 [6.113 MB]

TUPP043

Design of the Phase Reference Distribution System at ESS

controls, LLRF, radiation, cavity

529

R. Zeng, H. Hassanzadegan, M. Jensen, J.M. Jurns, O.A. Persson, A. Sunesson
ESS, Lund, Sweden
K. Strniša
Cosylab, Ljubljana, Slovenia

PRDS (Phase reference distribution system) at ESS will provide phase reference signals for all LLRF systems and BPM systems with low phase noise and low phase drift. Phase stability requirement is currently 0.1° for short term (during pulse), 1° for long term (days to months). There are 155 LLRF systems and 165 BPM systems in total at current ESS accelerator design.

TUPP045

Beam Physics Challenge in FRIB Driver Linac

ion, proton, focusing, acceleration

532

Y. Yamazaki, N.K. Bultman, A. Facco, Z.Q. He, M. Ikegami, M.J. Johnson, S.M. Lidia, F. Marti, G. Pozdeyev, K. Saito, J. Wei, X. Wu, Y. Zhang, Q. Zhao
FRIB, East Lansing, Michigan, USA

Funding: *Work supported by the U.S. Department of Energy Office of Science under Cooperative Agreement DE-SC0000661.
The Facility for Rare Isotope Beams driver linac provides CW beams of all the stable ions (from protons to uranium) with a beam power of 400 kW and a minimum beam energy of 200 MeV/u in order to produce a wide variety of rare isotopes, mainly for nuclear physics study. The low beam emittances, both transverse and longitudinal, are key performance requirements, together with beam stability. These are required for efficiently separating one isotope from another, the reason for choosing this linac configuration. Multi-charge states (five charge states for the uranium case) are accelerated for maximizing the beam current, while keeping the low emittances. The efficient acceleration of high beam currents from 0.5 MeV/u through the superconducting linac is, needless to say, one of the biggest challenges. The beam power is more than 200 times higher than existing similar SC heavy ion linac. In particular, the SC cavities are difficult to protect from heavy ion beam damage, which can be 30 times larger locally than a proton beam with the same beam power. Other challenges peculiar to the FRIB linac will be presented, together with the solutions.

TUPP054

Study of Beam-Based Alignment for the LCLS-II SC Linac

emittance, alignment, cryomodule, quadrupole

544

A. Saini, N. Solyak, V.P. Yakovlev
Fermilab, Batavia, Illinois, USA
T.O. Raubenheimer
SLAC, Menlo Park, California, USA

The Linac Coherent Light Source (LCLS) is an x-ray free electron laser facility. The proposed upgrade of the LCLS facility is based on construction of 4 GeV superconducting (SC) linac. The achievable performance of linac is determined by beam sensitivity to various component errors. In this paper we review misalignment tolerances of LCLS-II SC linac and discuss possible beam-based alignment algorithm to meet these tolerances.

TUPP056

High Current Proton Beam Operation at GSI UNILAC

proton, ion, operation, ion-source

550

W.A. Barth, A. Adonin, P. Gerhard, M. Heilmann, R. Hollinger, W. Vinzenz, H. Vormann
GSI, Darmstadt, Germany

A significant part of the experimental program at FAIR is dedicated to pbar physics requiring a high number of cooled pbars per hour. The primary proton beam has to be provided by a 70 MeV proton linac followed by two synchrotrons. The new FAIR Proton LINAC will deliver a pulsed proton beam of up to 35 mA of 36 μs duration at a repetition rate of 4 Hz. The current GSI heavy ion linac (UNILAC) is able to deliver world record uranium beam intensities for injection into the synchrotrons, but it is not dedicated for FAIR relevant proton beam operation. In an advanced machine investigation program it could be shown, that the UNILAC is able to provide for sufficient high intensities of CH3-beam, cracked (and stripped) in a supersonic nitrogen gas jet into protons and carbon ions. This advanced operational approach results in up to 2 mA of proton intensity at a maximum beam energy of 20 MeV, 100 μs pulse duration and a rep. rate of 4 Hz. Recent linac beam measurements will be presented, showing that the UNILAC is able to serve as a proton FAIR injector for the first time, while the performance is limited to 17% of the FAIR requirements.

TUPP058

RF System Development for the New 10⁸ MHz Heavy Ion High-Energy Linac at GSI

controls, ion, operation, LLRF

556

B. Schlitt, M. Hoerr, A. Schnase, G. Schreiber, W. Vinzenz
GSI, Darmstadt, Germany

The GSI UNILAC is in operation successfully since about 40 years. A replacement of the post stripper section is proposed to provide heavy ion beams for the future FAIR facility. Design studies for a new 10⁸ MHz high-energy (HE) linac optimized to accelerate high brilliance and high current ion beams up to U²⁸⁺ for synchrotron injection are in progress. Thus, the UNILAC will be converted into a short-pulse accelerator, the RF duty cycle being reduced from around 30 % to <2 %. To feed the future HE linac and to prepare for the FAIR commissioning, a major modernisation of the existing post stripper RF systems is planned from 2015 to 2017. Besides, the development of a new 1.8 MW cavity amplifier prototype was started recently, based on the widely-used THALES tetrode TH558SC promising an availability for at least 25 years. New 120 - 150 kW solid state driver amplifiers will replace the existing tube drivers. A digital LLRF system designed by industry was integrated into an existing amplifier driving a single gap resonator and was tested including ion beam tests. An overview of the RF system design and of the planned upgrades will be reported including some results of the LLRF tests.

TUPP060

Development of a 217 MHz Superconducting CH Structure

cavity, simulation, operation, accelerating-gradient

563

M. Basten, M. Amberg, M. Busch, F.D. Dziuba, D. Mäder, H. Podlech
IAP, Frankfurt am Main, Germany
M. Amberg, K. Aulenbacher, W.A. Barth, S. Mickat
HIM, Mainz, Germany
W.A. Barth, S. Mickat
GSI, Darmstadt, Germany

Funding: Helmholtz-Institut Mainz, Bundesministerium für Bildung und Forschung contract number 05P12RFRBL
To compete in the production of Super Heavy Elements (SHE) in the future a 7.3 AMeV superconducting (sc) continuous wave (cw) LINAC is planned at GSI. The baseline design consists of 9 sc Crossbar-H-mode (CH) cavities operated at 217 MHz. Currently an advanced cw demonstrator is under design at the Institute for Applied Physics (IAP) at Frankfurt University. The purpose of the advanced demonstrator is to investigate a new concept for the superconducting CH structures. It is based on shorter CH-cavities with 8 equidistant gaps without girders and with stiffening brackets at the front and end cap to reduce the pressure sensitivity. One major goal of the advanced demonstrator is to show that the new design leads to higher acceleration gradients and smaller E_p/E_a values. In this contribution first simulation results and technical layouts will be presented.

Poster TUPP060 [0.593 MB]

TUPP062

A Rebunching CH Cavity for Intense Proton Beams

quadrupole, multipole, cavity, simulation

566

M. Schwarz, C. Claessens, M. Heilmann, O. Hinrichs, D. Koser, O. Meusel, D. Mäder, H. Podlech, U. Ratzinger, A. Seibel
IAP, Frankfurt am Main, Germany

Funding: Project supported by the EU, FP7 MAX, Contract No. 269565
The Frankfurt Neutron Source at the Stern-Gerlach-Zentrum (FRANZ) will provide ultra short neutron pulses at high intensities and repetition rates. The facility is currently under construction at the Goethe-University in Frankfurt am Main (Germany). A 5-Gap CH rebuncher is installed behind a coupled RFQ/IH-DTL combination at the end of the LINAC section between two magnetic quadrupole triplets. It will be used for varying the final proton energy as well as for focusing the bunch longitudinally to compensate huge space charge forces at currents up to 200 mA at the final stage of extension. High current beam dynamic simulations have been performed. They include benchmarking of different beam dynamic codes like LORASR and TraceWin, as well as validating the results by measurements. Detailed examination of multipole field impact, due to the cavity’s geometry, together with error tolerance studies and thermal simulations are also performed. Furthermore, this CH rebuncher serves as a prototype for rt CH cavities at MYRRHA (Belgium), an Accelerator Driven System for transmutation of high level nuclear waste. After copper plating the cavity, RF conditioning will start soon.

Poster TUPP062 [6.015 MB]

TUPP063

Improvements of the LORASR Code and their Impact on Current Beam Dynamics Designs

proton, DTL, focusing, quadrupole

569

R. Tiede, D. Mäder, N.F. Petry, H. Podlech, U. Ratzinger, C. Zhang
IAP, Frankfurt am Main, Germany

LORASR is a multi-particle tracking code optimized for the beam dynamics design of ‘Combined Zero Degree Structure (KONUS)’ lattices, which can benefit from an adapted input file structure and code architecture. Recent code developments focused on the implementation of tools for machine error studies and loss profile investigations, including also steering correction strategies. These tools are a stringent necessity for the design of high intensity linacs. Thus, the abilities of the present LORASR release allow performing a manifold of checks and optimizations before finalizing the layouts of KONUS-based or conventional linacs. Two representative examples are the MAX-MYRRHA Injector and the GSI FAIR Facility Proton Linac, both under development with strong participation of IAP, Frankfurt University. This paper presents the status of the LORASR code development with focus on the new features and illustrates the impact on current designs by examples taken from the above-mentioned projects.

TUPP064

Zero-Current Longitudinal Beam Dynamics

lattice, resonance, damping, cavity

572

J.-M. Lagniel
GANIL, Caen, France

In linacs, the longitudinal focalization is done by nonlinear forces and the acceleration induces a damping of the phase oscillations. The longitudinal beam dynamics is therefore complex, even when the nonlinear space-charge forces are ignored. The three different ways to study and understand this zero-current longitudinal beam dynamics will be presented and compared.

TUPP065

RF Input Power Couplers for High Current SRF Applications

cavity, booster, SRF, simulation

575

V.F. Khan, W. Anders, A. Burrill, J. Knobloch, O. Kugeler, A. Neumann
HZB, Berlin, Germany
H. Wang
JLab, Newport News, Virginia, USA

High current SRF technology is being explored in present day accelerator science. The BERLinPro project is presently being built at the HZB to address the challenges involved in high current SRF machines. A 100 mA electron beam is designed to be accelerated to 50 MeV in continuous wave (cw) mode at 1.3 GHz. One of the main challenges in this project is that of handling high input RF power for the gun as well as booster cavities where there is no energy recovery process. A high power co-axial input coupler is being developed to be used for the booster and gun cavities at the nominal beam current. The coupler is based on the KEK–cERL coupler design. The KEK coupler design has been modified to minimise the penetration of the tip in the beampipe without compromising on beam-power coupling ( Qext ~1 x 105). Herein we report on the RF design for the high power (130 kW) BERLinPro (BP) couplers along with the test stand for conditioning the couplers. We will also report on the RF conditioning of the TTF-III couplers modified for cw operation (low power ~ 10 kW) which will be utilised in a new 4-mA SRF Photoinjector and the BERLinPro main linac cryomodule.

Slides TUPP065 [2.465 MB]

TUPP067

Chopper Operation for the Tandem Scrapers at the J-PARC Linac

operation, cavity, software, timing

581

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

In the J-PARC linac, the energy upgrade from 181 MeV to 400 MeV by the installation of annular-ring coupled structure (ACS) cavities was successfully achieved in 2013. In the next stage, we will schedule the intensity upgrade by the increase of the beam current by improving the front-end in this summer. Then, the high heat load of the scraper, which stops the kicked-beam by the RF chopper, is predicted to damage the surface. Therefore, we prepare the tandem scrapers to suppress the heat load. The half of the kicked beam leads to a scraper and the residual is to the other. Its chopping expedient will be achieved by reversing the phase of the RF chopper on the periodic cycle at the low-level RF system. In this paper, I would like to introduce this system and present the result of the low-level test.

TUPP070

Status and Recent Modifications to 324-MHz RF Source in J-PARC LINAC

klystron, operation, high-voltage, cathode

587

M. Kawamura, Y. Fukui, K. Futatsukawa, F. Naito
KEK, Ibaraki, Japan
E. Chishiro, K. Hasegawa, F. Sato, S. Shinozaki
JAEA/J-PARC, Tokai-mura, Japan
T. Hori
JAEA, Ibaraki-ken, Japan

This paper describes the present status of and the recent modifications to the 324-MHz RF source in the J-PARC linac. The recovery from the Great East Japan Earthquake Disaster, the status of the 324-MHz klystrons, the failure of 3 high-voltage transformers (HVTRs), and the discharge suppression for the anode-modulators are described.

Poster TUPP070 [0.660 MB]

TUPP072

Studies on Wake Field in Annular Coupled Structure

wakefield, impedance, cavity, acceleration

593

Y. Liu, T. Maruta
KEK/JAEA, Ibaraki-Ken, Japan
K. Futatsukawa
KEK, Ibaraki, Japan
A. Miura
JAEA/J-PARC, Tokai-mura, Japan

LINAC injector of J-PARC (Japan Proton Accelerator Research Complex) was recently successfully upgraded from 181 MeV to 400 MeV, applying a type of coupled cavity linac (CCL) structure ACS (Annular Coupled Structure). It was warmly discussed since very beginning on the wake field in the ACS cavities, where there are CCL modes with the same number as that of cells within ~50 MHz, possibly resonating with high intensity proton/H⁻ beams. One of the most important effects from the wake field is the influence on the ACS phase scan. Analytical and simulation studies, as well as the countermeasures were prepared before the energy upgrade. Fortunately we found that detuning of the ACS was unnecessary, which helped to save much work in the commissioning. In addition we got chance to make experiment studies. It was also discussed why the wake field is not so serious as we expected at the very beginning.

TUPP073

Study of the ACS Cavity Without a Bridge Cavity

cavity, coupling, proton, alignment

596

F. Naito, K. Takata
KEK, Ibaraki, Japan
H. Ao, K. Hasegawa, K. Hirano, T. Morishita, N. Ouchi
JAEA/J-PARC, Tokai-mura, Japan

J-PARC has installed the Annular-ring Coupled Structure (ACS) linac to increase the beam energy up to 400 MeV. One ACS module is composed of two accelerating tanks which are coupled by the bridge cavity. The bridge cavity simplifies the handling of the multi-tank system. While it is possible to feed the RF power into the each tanks directly with the power divider and the phase shifter instead of the bridge cavity. The rf properties of the ACS linac with the direct rf-power supply system has been measured by using the low power model made of aluminum. The measured results are described in the paper.

Slides TUPP073 [5.042 MB]

TUPP075

The First Beam Recirculation and Beam Tuning in the Compact ERL at KEK

operation, emittance, recirculation, quadrupole

599

S. Sakanaka, M. Adachi, S. Adachi, M. Akemoto, D.A. Arakawa, S. Asaoka, K. Enami, K. Endo, S. Fukuda, T. Furuya, K. Haga, K. Hara, K. Harada, T. Honda, Y. Honda, H. Honma, T. Honma, K. Hosoyama, K. Hozumi, A. Ishii, X. Jin, E. Kako, Y. Kamiya, H. Katagiri, H. Kawata, Y. Kobayashi, Y. Kojima, Y. Kondou, O.A. Konstantinova, T. Kume, T. Matsumoto, H. Matsumura, H. Matsushita, S. Michizono, T. Miura, T. Miyajima, H. Miyauchi, S. Nagahashi, H. Nakai, H. Nakajima, N. Nakamura, K. Nakanishi, K. Nakao, K.N. Nigorikawa, T. Nogami, S. Noguchi, S. Nozawa, T. Obina, T. Ozaki, F. Qiu, H. Sagehashi, H. Sakai, S. Sasaki, K. Satoh, M. Satoh, T. Shidara, M. Shimada, K. Shinoe, T. Shioya, T. Shishido, M. Tadano, T. Tahara, T. Takahashi, R. Takai, H. Takaki, T. Takenaka, Y. Tanimoto, M. Tobiyama, K. Tsuchiya, T. Uchiyama, A. Ueda, K. Umemori, K. Watanabe, M. Yamamoto, Y. Yamamoto, Y. Yano, M. Yoshida
KEK, Ibaraki, Japan
E. Cenni
Sokendai, Ibaraki, Japan
R. Hajima, S. Matsuba, R. Nagai, N. Nishimori, M. Sawamura, T. Shizuma
JAEA, Ibaraki-ken, Japan
J.G. Hwang
KNU, Deagu, Republic of Korea
M. Kuriki, Y. Seimiya
HU/AdSM, Higashi-Hiroshima, Japan
A. Valloni
CERN, Geneva, Switzerland

Superconducting(SC)-linac-based light sources, which can produce ultra-brilliant photon beams in CW operation, are attracting worldwide attention. In KEK, we have been conducting R&D efforts towards the energy-recovery-linac(ERL)-based light source* since 2006. To demonstrate the key technologies for the ERL, we constructed the Compact ERL (cERL)** from 2009 to 2013. In the cERL, high-brightness CW electron beams are produced using a 500-kV photocathode DC gun. The beams are accelerated using SC cavities, transported through a recirculation loop, decelerated in the SC cavities, and dumped. In the February of 2014, we succeeded in accelerating and recirculating the CW beams of 4.5 micro-amperes in the cERL; the beams were successfully transported from the gun to the beam dump under energy recovery operation in the main linac. Then, precise tuning of beam optics and diagnostics of beam properties are under way. We report our experience on the beam commissioning, as well as the results of initial measurements of beam properties.
* N. Nakamura, IPAC2012, TUXB02.
** S. Sakanaka et al., IPAC2013, WEPWA015.

TUPP077

High Precision Manufacturing for LINAC's

extraction, vacuum, controls, laser

603

F.M. Mirapeix, J. Añel
HTS, Mendaro, Spain
J. Amores, J. Presa, A. Urzainki
DMP, Mendaro, Spain

A big effort in R&D focused to the LINAC devices together with the know-how already deployed through emblematic projects places DMP in the state of the art of the extreme precision mechanics. This mechanic culture makes of DMP a natural partner in early stages of design or driver of a comprehensive solution, optimizing industrial risks, quality and due date. Surface roughness below 1 nanometer, figure errors better than 50 nanometers in OFE copper enhances lifetime and performance of many devices for LINAC's. Research in joining techniques and combining several alternative technologies to traditional machining improves figure stability and makes complex cooling systems possible.

TUPP082

The MYRRHA Spoke Cryomodule Design

cavity, cryomodule, framework, cryogenics

613

H. Saugnac, J.-L. Biarrotte, S. Blivet, P. Duchesne, N. Gandolfo, J. Lesrel, G. Olry, E. Rampnoux, D. Reynet
IPN, Orsay, France

In the framework of the MAX project, dedicated to the detailed study of the MYRRHA facility LINAC, the engineering study of the ‘Spoke’ cavities cryomodule, situated in the low energy superconducting section, has been achieved. The beam optics, highly constrained by strong reliability requirements, leads to a modular cryomodule composed of two β=0.37, 352 MHz, single bar ‘Spoke’ cavity cooled at 2K. The power coupler design, not studied in detail under the MAX project, is directly taken from a 20 kW continuous wave 352 MHz coupler designed and successfully tested in the framework of the previous EUROTRANS and EURISOL projects. The cold tuning system is identical to the one designed for the ESS ‘Spoke’ cavities. We present in this paper, the RF, the mechanical and the thermal design of the complete cryomodule as well as the optimization and simulations of its individual components (Cavity, Cryostat, Tuning System…).

TUPP085

RAON Cryomodule Design for QWR, HWR, SSR1 and SSR2

cryomodule, simulation, vacuum, cavity

622

W.K. Kim, H. Kim, H.J. Kim, Y. Kim, M. Lee, G.-T. Park
IBS, Daejeon, Republic of Korea

The accelerator called RAON which will be built in Korea has four kinds of superconducting cavities such as QWR, HWR, SSR1 and SSR2, operating at 2 K and 4.5 K [1]. The current status of design for the QWR, HWR, SSR1 and SSR2 cryomodules are reported. The issues included in the paper are thermal and structural design results of the components such as supports and thermal shield in the cryomodules. The cryomodule hosts the superconducting cavities in high vacuum and thermally insulated environment in order to maintain the operating temperature of superconducting cavities. It also keeps the cavities in a good alignment to the beam line. It has an interface for supplying RF power to cavities between cold and warm components. The whole configuration of the integrated system is also presented. This paper presents the detailed design of the cryomodule.

TUPP089

Tuning and Field Stabilization of the CERN Linac4 Drift Tube Linac

DTL, cavity, simulation, resonance

631

M.R. Khalvati
IPM, Tehran, Iran
S. Ramberger
CERN, Geneva, Switzerland

The Drift Tube Linac (DTL) for the new linear accelerator Linac4 at CERN will accelerate H–beams of up to 40 mA average pulse current from 3 to 50 MeV. The structure consists of three cavities. The first cavity (Tank1) is a 3.9 m long tank containing 38 drift tubes, 10 fixed tuners, 2 movable tuners and 12 post-couplers, operating at a frequency of 352.2 MHz and an average accelerating field of 3.1 MV/m. This paper reports on the results and procedures used for the low–power tuning, stabilization and power coupler tuning carried out on the first Linac4 DTL tank. The upgrade of the bead pull measurement system and twists to the well-known tilt sensitivity technique are discussed.

TUPP090

Spatially Periodic RF Quadrupole LINAC

quadrupole, focusing, ion, lattice

634

A.S. Plastun, A. Kolomiets
ITEP, Moscow, Russia

Spatially-periodic RF quadrupole structure is proposed as second section of front end of ion linac. It consists of conventional drift tubes and RF quadrupoles. Quadrupoles are 4-vane segments with nonzero electric potential on the longitudinal axis. Thus the accelerating electric field is formed between drift tubes and RF quadrupoles. Moreover accelerating field can be provided even inside the RF quadrupoles. It allows building structures with different focusing lattices and provides high energy gain rate.

Poster TUPP090 [7.706 MB]

TUPP092

Developmental and Operational Aspects of Nb QWR Based Heavy Ion LINAC System at IUAC Delhi

controls, operation, niobium, ion

640

S. Ghosh, R. Ahuja, J. Antony, S. Babu, J. Chacko, G.K. Chaudhari, A. Chaudhary, T.S. Datta, R.N. Dutt, R. Joshi, D. Kanjilal, S. Kar, J. Karmakar, M. Kumar, R. Kumar, D.S. Mathuria, K.K. Mistri, A. Pandey, P. Patra, P.N. Potukuchi, A. Rai, J. Sacharias, B.K. Sahu, A. Sarkar, S.S.K. Sonti, S. K. Suman
IUAC, New Delhi, India
A. Roy
VECC, Kolkata, India

The superconducting linac of IUAC consists of five cryostats containing 27 niobium quarter wave resonators. The prototype and the first 12 resonators were fabricated in collaboration with Argonne National Laboratory. The fabrication of the remaining resonators were carried out using in-house facilities available at IUAC. During the initial period of linac operations, problems were faced to generate higher accelerating fields in the resonators inside the linac cryostat and to reproduce the high fields at the time of beam acceleration. With systemetic efforts, all the major problems are solved and the complete linac is now operational. Since last few years, energized ion beams from linac are being delivered routinely for scheduled experiments. Among the major developmental works related to the linac operation, the vibrational damping mechansim by SS-balls, use of piezo actuator as mechanical tuner and the calculation of optimum phase focussing to control the time width of the beam bunches are noteworthy. Other two developments e.g. automatic phase locking of the resonators and auto beam tuning of the complete linac will be tested during the next beam acceleration.

TUPP094

Recent Progress of Beam Commissioning at J-PARC Linac

operation, acceleration, DTL, cavity

646

T. Maruta
J-PARC, KEK & JAEA, Ibaraki-ken, Japan
K. Futatsukawa, T. Miyao
KEK, Ibaraki, Japan
M. Ikegami
FRIB, East Lansing, Michigan, USA
Y. Liu
KEK/JAEA, Ibaraki-Ken, Japan
A. Miura, H. Sako
JAEA/J-PARC, Tokai-mura, Japan

We installed Annular-type Coupled Structure (ACS) linac in year 2013 in present linac downstream to extend the beam energy from 181 to 400 MeV. The beam commissioning had been conducted for one month in last December to January, and then we successfully extract 400 MeV beam. Whereas, we stably operate the linac at peak current of 15 mA, which is equivalent to 300 kW at the extraction of 3 GeV RCS, we observe unexpected residual radiations in ACS section. In this presentation, we review the recent progress in beam commissioning and beam loss study.

TUPP096

LUE-200 Linac. Status & Development

klystron, neutron, electron, beam-loading

653

A.P. Sumbaev, A.S. Kayukov, V. Kobets, V. Minashkin, V.G. Pyataev, V.A. Shvets
JINR, Dubna, Moscow Region, Russia
V. Shabratov
JINR/VBLHEP, Moscow, Russia
V.N. Shvetsov
JINR/FLNP, Moscow Region, Russia

The general scheme and current status of an electron linear accelerator with an S-band travelling wave (f = 2856 MHz) accelerating structure – a driver for a pulsed neutron source (IREN) at the Frank Laboratory of Neutron Physics of the Joint Institute for Nuclear Research - are presented. The parameters of the accelerating system and the measured parameters of the electron beam – pulse-beam current, duration of the current pulse, repetition rate, electron-energy spectrum, and loading characteristics of the accelerating structure - are given. The beginning of the implementation of the project of the second stage of the IREN facility, which forms the basis for the development of the accelerator aimed at increasing its beam power, is reported. Technical solutions underlying the modernization of the accelerator’s electrophysical systems are discussed: accelerating system, RF power supplies,and modulators.

TUPP097

100-MeV Proton Beam Phase Measurement by Using Stripline BPM

proton, DTL, simulation, coupling

656

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

Funding: This work is supported by Ministry of Science, ICT & Future Planning of the Korean Government.
In Korea Multipurpose Accelerator Complex (KOMAC), a 100-MeV proton linac, which is composed of a proton injector based on the microwave ion source, 3-MeV RFQ with a four-vane type and 100-MeV DTL with electromagnetic quadrupoles has been developed and currently provides the proton beam to users for various applications. To increase the beam power up to the design value, several improvements are required including the fine adjustment of the RF set-point during the operation. A stripline BPM is used for the beam phase measurement, where the pickup signals from four electrodes are combined by using the RF combiner, then mixed with 300 MHz LO reference signal resulting in 50 MHz IF signal which is processed by digital IQ demodulation method. In this paper, the details of the beam phase measurement setup and results will be presented.

TUPP103

The Beam Envelope Control in SC Linac for the Proton Radiotherapy

controls, proton, cavity, simulation

665

A.V. Samoshin, I.A. Ashanin, S.M. Polozov
MEPhI, Moscow, Russia

Proton cancer therapy is conventionally based on normal conducting synchrotrons and cyclotrons. The high electrical power consumption and especial devices necessary to energy variation are main problems of such facilities. Superconducting linacs based on short identical independently phased cavities have a seriously progress and it's development allow to propose their using for medical application. High accelerating gradient and small capacity losses nearly 10^-4 Vt/m are main advantages in advance of normal conducting facilities, the energy variation can be realized by means of RF field amplitude and phase variation in a number of cavities. Besides linac structures are lack of unwieldy magnetic system, simplicity of input and output of particles and high current densities. The parameters choose and the optimization for SC linac structure with energy up to 240 MeV and envelope control will discuss in this paper. The simulation was done using BEAMDULAC-SCL code*. The study of beam dynamics will direct to realize the energy variation in range 150-240 MeV with beam quality preservation.
* A.V. Samoshin. Proc. of LINAC2012, Tel-Aviv, Israel, TUPB069, p. 630 - 632

TUPP105

Storage Ring as a Linac Beam Monitor – Its Operation and Contribution to the Stable Top-up Injection

injection, timing, synchrotron, storage-ring

668

Y. Shoji
LASTI, Hyogo, Japan
T. Asaka, H. Dewa, H. Hanaki, T. Kobayashi, Y. Minagawa, A. Mizuno, T. Shinomoto, S. Suzuki, Y. Takemura, T. Taniuchi, K. Yanagida
JASRI/SPring-8, Hyogo-ken, Japan

We have used the electron storage ring, NewSUBARU, as a beam monitor of the SPring-8 linac. The time and transverse profiles of the injected linac beam are recorded in a frame of a dual-sweep streak camera. A measurements through synchrotron or betatron oscillation in the ring gives multi-dimensional beam structure. The system functions as a final check of the linac beam. It gives the time profile and energy profile or transverse emittance, which includes Twiss parameters. It measures parameters of one linac bunch in a long macro pulse. A shot-by-shot measurement gives beam fluctuations. We report how we use the system and its contribution to the stable top-up operation. The beam loading effect on the bunch energy was obtained by bunch-by-bunch energy profile measurements. It confirmed the optimization of the ECS (Energy Compression System) parameters. The single shot bunch-by-bunch vertical emittance measurement proved the difference between the front bunch and the following bunches. The same measurement showed a timing jitter of the electron gun pulse although the rf synchronization was perfect. This jittering had made the injection efficiency unstable.

TUPP109

Cryogenic Testing of High-Velocity Spoke Cavities

cavity, cryogenics, acceleration, proton

677

C.S. Hopper, J.R. Delayen, H. Park
ODU, Norfolk, Virginia, USA
J.R. Delayen, H. Park
JLab, Newport News, Virginia, USA

Spoke-loaded cavities are being investigated for the high-velocity regime. The relative compactness at low-frequency makes them attractive for applications requiring, or benefiting from, 4 K operation. Additionally, the large velocity acceptance makes them good candidates for the acceleration of high-velocity protons and ions. Here we present the results of cryogenic testing of a 325 MHz, β0 = 0.82 single-spoke cavity and a 500 MHz, β0 = 1 double-spoke cavity.

TUPP119

Design Studies for Medium and High beta SCRF Cavities for Indian Spallation Neutron Source

cavity, HOM, lattice, quadrupole

699

A.R. Jana, V. Kumar
RRCAT, Indore, India

There is a plan to build a 1 GeV H⁻ linac for the proposed Indian Spallation Neutron Source (ISNS) at Raja Ramanna Centre for Advanced Technology (RRCAT), Indore. The medium and high energy section of the ISNS linac will consist of beta_g=0.61, as well as beta_g = 0.9, 650 MHz, 5-cell superconducting radiofrequency (SCRF) cavities, for which detailed electromagnetic design studies have been performed. During our design study, we have evolved a generalized procedure for the optimization of geometrical parameters of multi-cell SCRF cavities. Studies on higher order modes supported by the cavity and its effect on beam dynamics, as well as on heat load to the cavity have been performed, which constitute an important aspect of the design study. Finally, detailed studies on Lorentz Force Detuning (LFD) have been performed, and design of the cavity has been optimized to minimize the effect due to the LFD. The paper discussed the details of the calculations and the studies that have been performed during the design study.

TUPP121

Limitations for Acceleration of Intermediate Mass Particles with Traveling Wave Structure

operation, acceleration, electron, accelerating-gradient

705

V.V. Paramonov
RAS/INR, Moscow, Russia

The Disk Loaded Waveguide (DLW) is the mostly used high frequency structure for acceleration of lightweight particles – electrons in the high energy range. DLW parameters are considered for the lower frequency range and lower particle velocity. Physical and technical restrictions for DLW application for the low particles velocity are analyzed. Basing on particularities of acceleration with traveling wave, deep optimization of DLW cells dimensions, the choice of optimal operating phase advance for each DLW section and combination of forward and backward wave modes, it looks possible to create the simple, cost effective acceleration system for intermediate particles acceleration in the moderate velocity range, in some parameters overcoming accelerating system with RF cavities in the standing wave mode.

TUPP127

R&D of X-band Accelerating Structure for Compact XFEL at SINAP

FEL, simulation, wakefield, radiation

715

W. Fang, Q. Gu, M. Zhang, Z.T. Zhao
SINAP, Shanghai, People's Republic of China
A.A. Aksoy, O. Yavaş
Ankara University, Accelerator Technologies Institute, Golbasi / Ankara, Turkey
D. Angal-Kalinin, J.A. Clarke
Cockcroft Institute, Warrington, Cheshire, United Kingdom
C.J. Bocchetta, A.I. Wawrzyniak
Solaris, Kraków, Poland
M.J. Boland
SLSA, Clayton, Australia
G. D'Auria, S. Di Mitri, C. Serpico
Elettra-Sincrotrone Trieste S.C.p.A., Basovizza, Italy
T.J.C. Ekelöf, R.J.M.Y. Ruber, V.G. Ziemann
Uppsala University, Uppsala, Sweden
E.N. Gazis
National Technical University of Athens, Athens, Greece
A. Grudiev, A. Latina, D. Schulte, S. Stapnes, W. Wuensch
CERN, Geneva, Switzerland

One compact hard X-ray FEL facility is being planned at SINAP, and X-band high gradient accelerating structure is the most competetive scheme for this plan. X-band accelerating structure is designed to switch between 60MV/m and 80MV/m, and carries out 6GeV and 8GeV by 130 meters linac respectively. In this paper, brief layout of compact XFEL will be introduced, and in particular the prototype design of dedicated X-band acceleration RF system is also presented.

TUPP130

Optimization of Beam Parameters in APF Channel

controls, simulation, emittance, rfq

722

V.V. Altsybeyev, D.A. Ovsyannikov
St. Petersburg State University, St. Petersburg, Russia

A new approach based on mathematical optimization methods to obtain a synchronous phase sequence in APF linacs is suggested. The optimization problem of intensity deuteron beam parameters is discussed. As an example, the results of beam dynamics simulations are presented.

TUPP133

Optimization of the RF Cavity of the Medical Purpose Electron Linac by Using Genetic Algorithm

cavity, electron, impedance, acceleration

726

S. Shin, J.-S. Chai
SKKU, Suwon, Republic of Korea

A compact electron linear accelerator for the medical application has been developing at Sungkyunkwan University. Due to this electron linac is attached on the robot arm or gantry, it should be compact enough to be held by the structure. An X-band technology has been used to meet the requirements for the compact linac. Because the particle accelerator is complex and sensitive machine to design it takes a lot of time to get a good performance accelerator. In this research, a special technique named single-objective genetic algorithm for the optimization process has been applied to achieve a better RF cavity design by changing various geometric parameters.

TUPP135

Beam Dynamics Calculations and Magnet Design for Future Measurements of Transverse Beam Break-Up at the S-DALINAC*

electron, experiment, recirculation, sextupole

729

F. Hug, M. Arnold, L.E. Jürgensen, T. Kürzeder, N. Pietralla, M. Schilling
TU Darmstadt, Darmstadt, Germany

Funding: *Work supported by the BMBF through 05K13RDA
The superconducting electron accelerator S-DALINAC at TU Darmstadt produces c.w. electron beams of up to 90 MeV. The S-DALINAC consists of a SC 14-MeV injector linac, a SC main linac and two recirculation paths. Currently a third recirculation is in its final design phase and will be constructed end 2014 in order to achieve an energy of 130 MeV in future. The main linac houses eight 20-cell SRF cavities operated at 3 GHz and 2 K. Due to the occurance of transverse beam break-up, the highest stable beam current obtained so far amounts to 5 μA only, which is below the design beam current of 20 μA but sufficient for the nuclear physics experiments carried out at Darmstadt since 1991. In this work we will present beam-dynamics calculations and newly designed magnets for planned experiments at the S-DALINAC in order to benchmark different strategies of increasing the threshold current for beam break-up.

WEIOA01

Construction and RF Conditioning of the Cell-Coupled Drift Tube Linac (CCDTL) for Linac4 at CERN

vacuum, coupling, cavity, quadrupole

746

A.G. Tribendis, Y.A. Biryuchevsky, E. Kendjebulatov, Ya.G. Kruchkov, E. Rotov, A.A. Zhukov
BINP SB RAS, Novosibirsk, Russia
Y. Cuvet, A. Dallocchio, J.-F. Fuchs, F. Gerigk, J.-M. Giguet, J. Hansen, T. Muranaka, E. Page, B. Riffaud, N. Thaus, M. Tortrat, M. Vretenar, R. Wegner
CERN, Geneva, Switzerland
M.Y. Naumenko
RFNC-VNIITF, Snezhinsk, Chelyabinsk region, Russia

This paper reports on the construction experience of the Linac4 CCDTL, which took place in two Russian institutes in the framework of three ISTC projects in close collaboration with CERN. The tanks were constructed at VNIITF, Snezhinsk, while the drift tubes and supports were made at BINP, Novosibirsk. All structures were then assembled and tuned at BINP before shipment to CERN where the high-power conditioning took place. The tuning principles, quality checks and conditioning results are presented.

Slides WEIOA01 [4.909 MB]

WEIOA05

High Power RF Sources for the ESS RF Systems

klystron, operation, DTL, rfq

756

M. Jensen, G. Göransson, C. Marrelli, C. Martins, R. Montaño, A. Sunesson, R.A. Yogi, R. Zeng
ESS, Lund, Sweden
A.J. Johansson
Lund University, Lund, Sweden

The RF system for ESS will consist of around 150 high power RF sources and will deliver 125 MW peak power to the proton beam during the 2.86 ms pulse with an average power of 5 MW. The two RF frequencies, 352 and 704 MHz, the different power requirements along the linac and the sources currently available strongly influence the choice of RF technology. This talk will focus on the high power RF solutions for the main parts of the linac. We present an overview of the available technology along with the first test results of the main sources. Additionally, we will present the preliminary design of a new 1.2 MW multi-beam super power IOT being designed together with industry for the high beta section of the linac.

Slides WEIOA05 [5.090 MB]

WEIOB03

Status of RAON Heavy Ion Accelerator Project

ion, rfq, cavity, target

775

D. Jeon, H.J. Kim
IBS, Daejeon, Republic of Korea

Funding: This work was supported by the Institute for Basic Science funded by the Ministry of Science, ICT and Future Planning (MSIP) and the NRF of Korea under Contract 2013M7A1A1075764.
Construction of the RAON heavy ion accelerator facility is under way in Korea to build the In-flight Fragment (IF) and Isotope Separation On-Line (ISOL) facilities to support cutting-edge researches in various science fields. At present prototyping of major components are proceeding including 28 GHz ECR ion source, RFQ, superconducting cavities, magnets and cryomodules. Superconducting magnets of 28 GHz ECR ion source are fabricated and tested. First article of prototype superconducting cavities are delivered that were fabricated through domestic vendors. Prototype HTS quadrupole is under development. Progress report of the RAON accelerator systems is presented.

Slides WEIOB03 [6.228 MB]

WEIOB04

CW Heavy Ion Accelerator With Adjustable Energy for Material Science

ion, cavity, rfq, heavy-ion

780

S.V. Kutsaev, B. Mustapha, J.A. Nolen, 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
The proposed eXtreme MATerial (XMAT) research facility at ANL’s Advanced Photon Source (APS) combines medium-energy heavy-ion accelerator capability with the high-energy X-ray analysis to enable rapid in situ mesoscale bulk analysis of ion radiation damage in advanced materials and nuclear fuels. The XMAT facility requires CW heavy ion accelerator with adjustable beam energy in the range of 300 keV/u to 1.25 MeV/u. Such an accelerator has been developed and based on ECR, normal conducting RFQ and multi-gap quarter wave resonators (QWR) operating at 60 MHz. This talk will present complete 3D beam dynamics studies and multi-physics design of both RFQ and QWRs. The design includes a beam transport system capable to focus ions into 20-micron diameter spot on the target.

Slides WEIOB04 [1.159 MB]

THIOA01

Cost Optimized Design of High Power Linacs

cavity, neutron, emittance, acceleration

785

M. Eshraqi
ESS, Lund, Sweden

The research accelerators are growing in energy and power which translates to an increase in their cost, and also size if the conventional acceleration techniques are used. On the other hand, handling megawatts of power requires a design that is robust, respects the known criteria in beam physics to avoid losses in the order of less than one part in million. Traditionally cost increases with power and quality of the accelerator and beam. In this paper, using the ESS linac as an example, this tradition is challenged and ways to reduce the cost while neither quality nor power is compromised are presented.

Slides THIOA01 [8.363 MB]

THIOA03

Status of the HIE-ISOLDE Linac

cryomodule, cavity, solenoid, vacuum

795

W. Venturini Delsolaro, L. Alberty, L. Arnaudon, K. Artoos, J. Bauche, A.P. Bernardes, J.A. Bousquet, E. Bravin, S. Calatroni, E.D. Cantero, O. Capatina, N. Delruelle, D. Duarte Ramos, M. Elias, F. Formenti, M.A. Fraser, J. Gayde, S. Giron, N.M. Jecklin, Y. Kadi, G. Kautzmann, Y. Leclercq, P. Maesen, V. Mertens, E. Montesinos, V. Parma, G.J. Rosaz, K.M. Schirm, E. Siesling, D. Smekens, A. Sublet, M. Therasse, D. Valuch, G. Vandoni, E. Vergara Fernandez, D. Voulot, L.R. Williams, P. Zhang
CERN, Geneva, Switzerland

The HIE-ISOLDE project aims at increasing the energy of the radioactive beams (RIB) of REX-ISOLDE from the present 3 MeV/u up to 10 MeV/u for A/q up to 4.5. This will be accomplished by means of a new superconducting linac, based on independently phased quarter wave resonators using the Nb sputtering on copper technology, and working at 101.28 MHz. The focusing elements are superconducting solenoids providing 13.5 T2m field integral. These active elements are contained in a common vacuum cryostat. The presentation will cover the status of advancement of the HIE-ISOLDE linac technical systems. The performance of the superconducting elements will be presented, together with the assembly work of the cryomodule in clean room and the planned qualification tests in the horizontal test facility at CERN

Slides THIOA03 [24.692 MB]

THIOA04

Superconducting Cavities and Cryomodules for Proton and Deuteron Linacs

cavity, cryomodule, vacuum, cryogenics

801

G. Devanz
CEA/IRFU, Gif-sur-Yvette, France

We review the recent advances in the design plans and test results of the superconducting structures for proton (ESS) and deuteron linacs (SPIRAL2, IFMIF). A variety of RF resonators are used for this purposes, from multicell elliptical cavities for the acceleration of pulsed proton beams to half and quarter wave resonators for CW deuteron beams. The increase in beam power with respect to previous generations of linacs brings new challenges to cavities and RF couplers. Test results of the available SRF prototypes and cryomodules of the aforementioned projects will be presented.

Slides THIOA04 [6.785 MB]

THIOA05

An 800 MeV Superconducting Linac to Support Megawatt Proton Operations at Fermilab

cryomodule, booster, cavity, operation

807

V.A. Lebedev, P. Derwent, S.D. Holmes
Fermilab, Batavia, Illinois, USA

Funding: Operated by Fermi Research Alliance, LLC under Contract No. DE-AC02-07CH11359 with the United States Department of Energy
Active discussion on the high energy physics priorities in the US carried out since summer of 2013 resulted in changes in Fermilab plans for future development of the existing accelerator complex. In particular, the scope of Project X was reduced to the support of the Long Base Neutrino Facility (LBNF) at the project first stage. The name of the facility was changed to the PIP-II (Proton Improvement Plan). This new facility is a logical extension of the existing Proton Improvement Plan aimed at doubling average power of the Fermilab’s Booster and Main Injector (MI). Its design and required R&D are closely related to the Project X. The paper discusses the goals of this new facility and changes to the Project X linac introduced to support the goals.

Slides THIOA05 [1.597 MB]

THIOB01

Cryogenic Plants for SRF Linacs

vacuum, SRF, cryomodule, cryogenics

811

D. Arenius
JLab, Newport News, Virginia, USA

Review of the types of considerations that go into cryo-plant design. Arenius is a world expert on this topic and has led the completion of the upgraded cryo-plant at Jefferson Lab, and has recently provided substantial input on this question to the new LCLS II project.

Slides THIOB01 [4.382 MB]

THIOB02

SPIRAL2 Cryomodule Production Result and Analysis

cryomodule, cavity, operation, cryogenics

814

P.-E. Bernaudin, R. Ferdinand
GANIL, Caen, France
P. Bosland, C. Marchand
CEA/IRFU, Gif-sur-Yvette, France
Y. Gómez Martínez
LPSC, Grenoble Cedex, France
D. Longuevergne, G. Olry
IPN, Orsay, France

The production and qualification of the SPIRAL2 cryomodules are close to the end. Their performances are now well established. This paper will explain the path followed to the good achievements, and show some statistical analyses to be used for future projects. How far can we push the performances? What cryogenics consumption shall we take as design values?

Slides THIOB02 [2.864 MB]

THIOC01

SPIRAL2 Bunch Extension Monitor

cryomodule, detector, cavity, background

824

R.V. Revenko, J.L. Vignet
GANIL, Caen, France

Funding: The work is funded in frame of CRISP WP3T1
Superconducting linacs require beam diagnostics to quantify the time extension of the bunch for a proper beam adaptation. Bunch extension monitor (BEM) should provide measurements with required resolution and minimal disturbance of beam properties, have a broad dynamic range of beam intensity and should be easy to use for accelerator routine operation. The design of BEM should take into account operation at the vicinity of cryomodules and satisfy imposed requirements for this. BEM measures the x-rays resulting of the bunch interaction with a tungsten wire. Developed prototype of detector was successfully tested with ions beams. Test for detector background conditions at vicinity of cryomodule was carried out and results are presented.

Slides THIOC01 [7.054 MB]

THPP005

A New High Current and Single Bunch Injector at ELSA

booster, electron, injection, timing

847

M. Schedler, P. Hänisch, W. Hillert, D. Proft
ELSA, Bonn, Germany
J. Zappai
Uni Bonn, Bonn, Germany

At the Electron Stretcher Facility ELSA of Bonn University, an increase of the maximum stored beam current from 20 mA to 200 mA is planned for the stretcher ring. In order to keep the desired duty cycle of the post acceleration mode at about 80 \% a new high current injector operating at 3 GHz has been built. It provides an electron beam with an energy of 20 MeV and a beam current of 800 mA in pulsed operation. A prebuncher, travelling wave buncher system and an energy compressing system are installed in order to enhance the beam acceptance of the linac and to reduce the energy spread in order to achieve an improved injection efficiency into the booster synchrotron. For studying accelerators impedances and beam instabilities the linac is able to produce single bunches with a pulse current of 2 A which will be accumulated in the stretcher ring.

THPP007

Uniform Current Density for BLIP Target at Brookhaven 200 MeV Linac

target, octupole, dipole, isotope-production

850

D. Raparia, B. Briscoe, P. Cerniglia, R. Connolly, C. Cullen, D.M. Gassner, R.L. Hulsart, R.F. Lambiase, V. Lo Destro, L.F. Mausner, R.J. Michnoff, P. Thieberger, M. Wilinski
BNL, Upton, Long Island, New York, USA

Bulk of the beam from the linac is used for Brookhaven linac isotope producer (BLIP). The average current from the linac is up 125 uA. At this current BLIP has several target failures and yield uncertainty due to partially melted target salt. To reduce current density, we have tried octupoles in the past but did not produce uniform beam as calculated due to the x-y coupling present in the linac. A beam painting scheme with help of one x and y steers with 90 phase leg at 5 kHz will provide desire current density at the target. This paper discuss beam optics of the blip transport line and beam footprint on the target with given constrains.

THPP012

A Prototype 1 Mev X-Band Linac for Aviation Cargo Inspection

cavity, electron, simulation, accelerating-gradient

853

M. Jenkins, P.K. Ambattu, G. Burt
Cockcroft Institute, Lancaster University, Lancaster, United Kingdom
S. Andrews, T.A. Cross, C.R. Weatherup
e2v, Chelmsford, Essex, United Kingdom
P.A. Corlett, P. Goudket, A.R. Goulden, P.A. McIntosh, K.J. Middleman, Y.M. Saveliev, R.J. Smith, A.E. Wheelhouse
STFC/DL/ASTeC, Daresbury, Warrington, Cheshire, United Kingdom
S.A. Griffiths, M.D. Hancock, T. Hartnett, C. Hill, J.P. Hindley, B.G. Martlew, N. Templeton
STFC/DL, Daresbury, Warrington, Cheshire, United Kingdom

Aviation cargo Unit Load Device (ULD) containers are typically much smaller than standard shipping containers, with a volume of around 1m3. Standard 3-6 MeV X-ray screening linacs have too much energy to obtain sufficient contrast when inspecting ULD’s, hence a lower 1 MeV linac is required. In order to obtain a small physical footprint, which can be adapted to mobile platform applications a compact design is required, hence X-band technology is the ideal solution. A prototype 1 MeV linac cavity has been designed by Lancaster University, manufactured by Comeb (Italy) and tested at STFC Daresbury Laboratory using an e2v magnetron, modulator and electron gun. The cavity is a bi-periodic π/2 structure, with beam-pipe aperture coupling to simplify the manufacture at the expense of shunt impedance. The design, manufacture and testing of this linac structure is presented.

THPP015

Status of the FAIR Proton Source and LEBT

ion, diagnostics, proton, ion-source

863

N. Chauvin, O. Delferrière, Y. Gauthier, P. Girardot, J.L. Jannin, A. Lotode, N. Misiara, J. Neyret, F. Senée, C.S. Simon, O. Tuske
CEA/IRFU, Gif-sur-Yvette, France
R. Berezov, J. Fils, P. Forck, R. Hollinger, V. Ivanova, C. Ullmann, W. Vinzenz
GSI, Darmstadt, Germany
A. Maugueret
CEA/DSM/IRFU, France

The unique Facility for Antiproton and Ion Research – FAIR will deliver stable and rare isotope beams covering a huge range of intensities and beam energies. A significant part of the experimental program at FAIR is dedicated to antiproton physics that requires an ultimate number 7x10¹⁰ cooled pbar/h. The high-intensity proton beam that is necessary for antiproton production will be deliver by a dedicated 75 mA/70 MeV proton linac. The injector section of this accelerator is composed by an ECR source, delivering a pulsed 100 mA H⁺ beam (4 Hz) at 95 keV and a low energy beam transport (LEBT) line required to match the beam for the RFQ injection. The proposed design for the LEBT is based on a dual solenoids focusing scheme. A dedicated chamber containing several diagnostics (Alisson scanner, Wien filter, SEM grid, Iris, Faraday Cup) will be located between the two solenoids. At the end of the beam line, an electrostatic chopper system is foreseen to inject up to 50μseconds long beam pulses into the RFQ. The status of LEBT simulations, design and fabrication of the FAIR proton injector will be presented.

THPP016

Nitrogen-Treated Cavity Testing at Cornell

cavity, SRF, niobium, vacuum

866

D. Gonnella, F. Furuta, G.M. Ge, M. Liepe
Cornell University (CLASSE), Cornell Laboratory for Accelerator-Based Sciences and Education, Ithaca, New York, USA

Funding: U.S. Department of Energy
Recent results from Cornell, FNAL, and TJNAF have shown that superconducting RF cavities given a heat treatment in a nitrogen atmosphere show higher Q₀ at operating gradients at 2.0 K than standard SRF cavities. Here we present on recent results at Cornell in which five single cell cavities and three 9-cell cavities were tested after receiving various nitrogen-doping treatments. Cavity performance was correlated with treatment, and samples treated with the cavities were analyzed with SIMS. These results provide new insights into the science behind the excellent performance that is observed in these cavities.

THPP017

Beam-Based HOM Studies of the Cornell Energy Recovery Linac 7-Cell SRF Cavity

HOM, cavity, cryomodule, experiment

869

D.L. Hall, A.C. Bartnik, M.G. Billing, R.G. Eichhorn, G.H. Hoffstaetter, M. Liepe, C.E. Mayes, P. Quigley, V. Veshcherevich
Cornell University (CLASSE), Cornell Laboratory for Accelerator-Based Sciences and Education, Ithaca, New York, USA

Funding: NSF Grant DMR-0807731
The 1.3 GHz 7-cell SRF cavity for the Cornell ERL main linac is optimized for high beam current ERL operation with injected CW beam currents of 100 mA. Beam stability at 100 mA requires very strong damping of the Higher-Order-Modes (HOM) in the cavity by HOM beamline absorbers at the ends of the cavity. To verify the optimized design of the cavity and the HOM damping scheme, a prototype 7-cell main linac cavity was installed into the Cornell Horizontal Test Cryomodule (HTC), and inserted into the beamline of the Cornell ERL high current photo-injector. A beam-based method was then used to search for the presence of dangerous HOMs. Individual HOMs were excited using a charge-modulated beam, after which their effect upon an unmodulated beam was observed using a BPM. Data collected was used to calculate loaded Q of observed HOMs. Results show that it is very unlikely that HOMs will cause BBU in the Cornell ERL. In addition, measurements of the temperature rise of the HOM absorber rings during high current CW beam tests were consistent with simulations, indicating that the optimized main linac cavity is capable of operating at the specified current of 100mA in an ERL configuration.

THPP019

Low Kick Coupler for Superconducting Cavities

cavity, emittance, dipole, resonance

876

R.G. Eichhorn, C. Egerer, V. Veshcherevich
Cornell University (CLASSE), Cornell Laboratory for Accelerator-Based Sciences and Education, Ithaca, New York, USA

Results from the high current, low emittance photo injector at Cornell revealed that even with two opposing input couplers, the beam emittance is affected by the coupler kick. As a result, a coupler with low transverse kick is proposed for use in superconducting accelerating cavities. In this coupler, a rectangular waveguide transforms into a coaxial line inside the beam pipe. The geometry of the coupler is tuned to minimize the transverse kick that is important for linear accelerators with low emittance. The coupler can be used in ERL injectors or other linacs for high brightness light sources.

THPP021

Analysis of the RF Test Results from the On-going Accelerator Cavity Production for the European XFEL

cavity, superconductivity, SRF, operation

879

D. Reschke, S. Aderhold, V. Gubarev, J. Schaffran, N.J. Walker
DESY, Hamburg, Germany
L. Monaco
INFN/LASA, Segrate (MI), Italy
Y. Yamamoto
KEK, Ibaraki, Japan

Funding: The research leading to these results has received funding from the European Union Seventh Framework Programme (FP7/2007-2013) under grant agreement no 283745 (CRISP)
The main Linac of the European XFEL will consist of 100 superconducting accelerator modules, operated at an average design gradient of 23.6 MV/m. The fabrication by industry (which includes chemical surface preparation) of the required 800 superconducting cavities is now in full swing, with approximately 400 cavities having been delivered to date. In this interim report, we present an analysis of the RF acceptance tests amassed so far.

THPP022

Efficiency of High Order Modes Extraction in the European XFEL Linac

HOM, cavity, damping, dipole

883

A.A. Sulimov, J. Iversen, D. Kostin, W.-D. Möller, D. Reschke, J.K. Sekutowicz, J.H. Thie
DESY, Hamburg, Germany
D. Karolczyk, K. Kasprzak, S. Myalski, M. Wiencek, A. Zwozniak
IFJ-PAN, Kraków, Poland

The serial production of components for the European XFEL linac was started in 2011 and reached the planned level of 8 cavities (1 module) per week in 2013. The measurements of High Order Modes (HOM) characteristics under cryogenic conditions (2K) are being done at the Accelerating Module Test Facility (AMTF) by the IFJ-PAN Team in collaboration with DESY groups. More than 50 % of the cavities have been already produced and 30 % of the whole amount were measured during either cavity vertical tests or module tests. We present first statistics of these measurements and analyze the efficiency of HOM extraction.

Poster THPP022 [0.801 MB]

THPP027

Commissioning of the Linac4 Low Level RF and Future Plans

cavity, LLRF, klystron, DTL

892

P. Baudrenghien, J. Galindo, G. Hagmann, J. Noirjean, D. Stellfeld, D. Valuch
CERN, Geneva, Switzerland

Linac4 is a new 86-m long normal-conducting linear accelerator that will provide 160 MeV H⁻ to the CERN PS Booster (PSB), and replace the present 50 MeV proton Linac2. The Low Level RF (LLRF) system has to control the RFQ, two choppers, three bunching cavities, twenty two accelerating cavities and one debuncher in the transfer line to the PSB. To optimize the transfer into the 1 MHz PSB bucket, the machine includes fast choppers (synchronized with the PSB RF) and a voltage modulation of the last two cavities that will provide Longitudinal Painting for optimum filling. The commissioning in the tunnel with beam has started in October 2013. So far the part consisting of the RFQ, the three bunching cavities, and the first DTL is operational. The rest of the machine will be progressively commissioned till end 2015. The paper presents the LLRF system. First results from the commissioning (with a prototype regulation system) are shown and the more sophisticated algorithms under development are presented.

THPP030

Status of the Design Study for 10 MHz Post-accelerated Radioactive Ion Beams at HIE-ISOLDE

rfq, emittance, bunching, ion

901

M.A. Fraser, R. Calaga
CERN, Geneva, Switzerland

A ten-fold increase in the bunch spacing of post-accelerated radioactive ion beams has been requested by several research groups at ISOLDE, CERN in order for experiments to use time-of-flight particle identification and background suppression techniques. It is proposed to bunch externally into the existing REX-ISOLDE RFQ at a sub-harmonic frequency of 10.128 MHz to produce the desired 100 ns bunch separation with minimal loss in transmission. The status of a beam dynamics design study carried out to meet this request will be presented in the framework of the HIE-ISOLDE linac upgrade at CERN.

THPP031

Plans for an ERL Test Facility at CERN

cavity, cryomodule, electron, SRF

905

E. Jensen, O.S. Brüning, R. Calaga, K.M. Schirm, R. Torres-Sanchez, A. Valloni
CERN, Geneva, Switzerland
K. Aulenbacher
IKP, Mainz, Germany
S.A. Bogacz, A. Hutton
JLab, Newport News, Virginia, USA
M. Klein
The University of Liverpool, Liverpool, United Kingdom

The baseline electron accelerator for LHeC and one option for FCC-he is an Energy Recovery Linac. To prepare and study the necessary key technologies, CERN has started – in collaboration with JLAB and Mainz University – the conceptual design of an ERL Test Facility (ERL-TF). Staged construction will allow the study under different conditions with up to 3 passes, beam energies of up to about 1 GeV and currents of up to 50 mA. The design and development of superconducting cavity modules, including coupler and HOM damper designs, are also of central importance for other existing and future accelerators and their tests are at the heart of the current ERL-TF goals. The ERL-TF could also provide a unique infrastructure for several applications that go beyond developing and testing the ERL technology at CERN. In addition to experimental studies of beam dynamics, operational and reliability issues in an ERL, it could equally serve for quench tests of superconducting magnets, as physics experimental facility on its own right or as test stand for detector developments. This contribution will describe the goals and the concept of the facility and the status of the R&D.

THPP032

Magnetic Characterization of Fast-Pulsed Quadrupole Magnets for Linac4

quadrupole, flattop, power-supply, target

909

S. Kasaei, M.C.L. Buzio, O. Crettiez, V. Della Selva, L. Fiscarelli, J. Garcia Perez, J.-B. Lallement
CERN, Geneva, Switzerland

Linac4, currently being built at CERN, includes 24 quadrupole magnets characterized by narrow apertures and fast excitation cycles which make accurate magnetic measurements challenging. This paper describes the method used for the measurement, which is a combination of techniques based on stretched wire, rotating and fixed search coils. We show how these different instruments can be used in a complementary way to derive information on different aspects of the magnetic behaviour, such as the impact of hysteresis and dynamic eddy current effects. We summarize the results of the series measurement campaign, which include field strength, harmonic components, and the offset and orientation of the magnetic axis. Finally, we discuss the relevance of these measurements as their impact to the operation of the linac.

THPP033

Linac4 Transverse and Longitudinal Emittance Reconstruction in the Presence of Space Charge

emittance, quadrupole, simulation, rfq

913

J.-B. Lallement, G. Bellodi, V.A. Dimov, A.M. Lombardi, M. Yarmohammadi Satri
CERN, Geneva, Switzerland
M. Yarmohammadi Satri
IPM, Tehran, Iran

Linac4 is a pulsed, normal-conducting 160 Mev H⁻ linear accelerator presently under construction at CERN. It will replace the present 50 MeV Linac2 as injector of the proton accelerator complex as part of a project to increase the LHC luminosity. The 3 MeV front end, composed of a 45 keV ion source, a Low Energy Beam transport (LEBT), a 352 MHz Radio Frequency Quadrupole (RFQ) at 3 MeV and Medium Energy Beam Transport (MEBT) housing a beam chopper, and the first Drift Tube Linac (DTL) tank at 12 MeV have been commissioned during the first half of 2014. The transverse and longitudinal emittance reconstruction technique in the presence of space charge, that will be used for the next commissioning stages and permanently during the Linac operation, was successfully tested and validated. The reconstruction method and the results obtained at 3 and 12 MeV are presented in this paper.

THPP034

Toolbox for Applying Beam-Based Alignment to Linacs

wakefield, emittance, interface, controls

916

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

Tests of Beam-Based Alignment have been performed at FACET, at SLAC in the USA, and at Fermi, at Elettra in Trieste, Italy, with very promising results. Dispersion-Free Steering and Wakefield-free steering have been successfully applied to both machines. In order to make the correction process as automatic as possible, a set of robust tools has been developed, which allowed to span a large set of parameters. These tools and some of the experimental results performed at both machines are presented in this paper.

THPP036

CERN Linac4 Drift Tube Linac Manufacturing and Assembly

vacuum, DTL, alignment, interface

923

S. Ramberger, P. Bourquin, A. Cherif, Y. Cuvet, A. Dallocchio, G. Favre, J.-F. Fuchs, J.-M. Geisser, F. Gerigk, J.-M. Giguet, J. Hansen, M. Polini, S. Sgobba, N. Thaus, M. Vretenar
CERN, Geneva, Switzerland

The manufacturing of the Linac4 Drift Tube Linac (DTL) components has been completed and the assembly of the structures is in its final stages. 3 tanks of 3.9m, 7.3m, and 7.3m, designed to accelerate a 40mA average pulse current H–beam from 3 to 50MeV, are being assembled from 2, 4 and 4 segments of about 2.0m length, containing each from 22 drift tubes at the low energy end, down to only 6 at the high energy end. Due to its peculiar design avoiding adjustment mechanisms on the drift tube, tight tolerances have to be maintained in the production. This paper discusses the assembly stages that are used to achieve the tolerances over the full length of the structures. Metrology results on the assembled DTL Tank1 confirm the required precision.

THPP037

Commissioning and Operational Experience Gained with the Linac4 RFQ at CERN

rfq, cavity, emittance, ion

926

C. Rossi, L. Arnaudon, P. Baudrenghien, G. Bellodi, O. Brunner, J. Hansen, J.-B. Lallement, A.M. Lombardi, J. Noirjean
CERN, Geneva, Switzerland
M. Desmons, A. France, O. Piquet
CEA/DSM/IRFU, France

The installation of Linac4 has started in 2013 with the 3 MeV Front End, aiming at delivering a fully commissioned 160 MeV H⁻ beam by 2016. During summer 2013 the H⁻ ion source, a clone of the first prototype, and the Low Energy Beam Transport lines have been installed in the Linac4 tunnel followed shortly by the Radiofrequency Quadrupole accelerator (RFQ), operating at the RF frequency of 352.2 MHz and which accelerates the ion beam to the energy of 3 MeV. The RFQ, which had already been commissioned at the 3 MeV Test Stand, was this time driven by a fully digital LLRF system. This paper reports the result of the bead-pull field check performed after the installation in the tunnel, the experience gained during recommissioning and the results of field characterization as a function of the water temperature in the RFQ cooling channels, showing how the accelerating field can be adjusted by simply tuning the different cavity modules.

THPP038

The Drift Tube Welding Assembly for the Linac4 Drift Tube Linac at CERN

operation, drift-tube-linac, electron, DTL

929

I. Sexton, A. Cherif, Y. Cuvet, G. Favre, J.-M. Geisser, S. Ramberger, S. Sgobba, T. Tardy
CERN, Geneva, Switzerland
F.M. Mirapeix
DMP, Mendaro, Spain

The fabrication of the Linac4 Drift Tube Linac (DTL) required the welding assembly of 10⁸ drift tubes (DT) which has been undertaken at the CERN workshop. The design of the DTL is particular in that it was purposely simplified to avoid any position adjustment mechanism for drift tubes in the tank. In consequence, drift tubes have been designed with tight tolerances and parts have been assembled with an optimised welding procedure. Two re-machining stages have been introduced in order to compensate for welding distortions. This paper discusses the various assembly stages with a view on the final precision that has been achieved.

Poster THPP038 [8.665 MB]

THPP040

A Compact High-Frequency RFQ for Medical Applications

rfq, proton, cavity, quadrupole

935

M. Vretenar, A. Dallocchio, V.A. Dimov, M. Garlaschè, A. Grudiev, A.M. Lombardi, S.J. Mathot, E. Montesinos, M.A. Timmins
CERN, Geneva, Switzerland

In the frame of a new program for medical applications, CERN has designed and is presently constructing a compact 750 MHz Radio Frequency Quadrupole to be used as injector for hadron therapy linacs. The RFQ reaches an energy of 5 MeV in only 2 meters; it is divided into four standardized modules of 500 mm, each equipped with 12 tuner ports and one RF input. The inner quadrant radius is 46 mm and the RFQ has an outer diameter of 134 mm; its total weight is only 220 kg. The beam dynamics and RF design have been optimized for reduced length and minimum RF power consumption; construction techniques have been adapted for future industrial production. The multiple RF ports are foreseen for using either 4 solid-state units or 4 IOT’s as RF power sources. Although hadron therapy requires only a low duty cycle, the RFQ has been designed for 5% duty cycle in view of other uses. This extremely compact and economical RFQ design opens several new perspectives for medical applications, in particular for PET isotopes production in hospitals with two coupled high-frequency RFQs reaching 10 MeV and for Technetium production for SPECT tomography with two RFQs followed by a DTL.

THPP041

The Accelerator Cryoplant at ESS

controls, operation, cryogenics, cryomodule

939

P. Arnold, J. Fydrych, W. Hees, J.M. Jurns, X. Wang, J.G. Weisend
ESS, Lund, Sweden

The European Spallation Source (ESS) is a neutron science facility funded by a collaboration of 17 European countries currently under design and construction in Lund, Sweden. Cryogenic cooling is vital particularly for the linear accelerator, producing a 5 MW beam of 2.0 GeV protons to strike a rotating tungsten target. The cryogenic section of the linac comprises cryomodules with superconducting RF cavities that require helium cooling at 2.0 K, shield cooling at ~40 K and liquid helium for power coupler cooling. An extensive cryogenic distribution system connects the cryomodules with the linac cryoplant. With estimated electricity consumption of up to 3 MW this plant will be one of the major power consumers at ESS. Turndown modes and the intrinsic uncertainties regarding heat loads drive the need for high plant efficiency not only during full load operation but also at reduced performance. Together with flexibility and reliability over a long operation period these are the key challenges that will be addressed in this paper.

Poster THPP041 [4.141 MB]

THPP042

Error Study on the Normal Conducting ESS Linac

emittance, DTL, rfq, quadrupole

942

R. De Prisco, M. Eshraqi, R. Miyamoto, E. Sargsyan
ESS, Lund, Sweden
A.R. Karlsson
Lund University, Lund, Sweden

One of the preliminary, but important test to evaluate the robustness of the accelerator design is performing the statistical error study by introducing realistic tolerances on the machine components. In this paper the guidelines to define the tolerances and the correction system are summarized in order to validate the design. Firstly statistical studies have been performed in order to define the sensitivity to single errors and to fix the tolerances. Then all errors, within the previous defined tolerances, are applied with the correction system to evaluate the beam quality and to check if the system guarantees a radiologically safe operation.

THPP043

Benchmark of the Beam Dynamics Code DYNAC Using the ESS Proton Linac

simulation, rfq, space-charge, DTL

945

E. Tanke, R. De Prisco, M. Eshraqi, R. Miyamoto, A. Ponton, E. Sargsyan
ESS, Lund, Sweden
S. Valero
CEA, Gif-sur-Yvette, France

The beam dynamics code DYNAC is benchmarked using the ESS Proton Linac. Recent work on improvements in the code, including of the RFQ model, is discussed. The three space charge routines contained in DYNAC, including a 3D version, have remained unchanged. The code contains a numerical method, capable of simulating a multi-charge state ion beam in accelerating elements. In addition, protons, single charge state heavy ions and non-relativistic electrons in accelerating elements can be modeled using an analytical method. The benchmark will include comparisons of both methods with the beam dynamics models in use at ESS: TraceWin and Toutatis. As this analytical method used in DYNAC is fast, it is a prime candidate for use as an online beam simulation tool.

THPP044

ESS Normal Conducting Linac Status and Plans

rfq, proton, DTL, vacuum

948

A. Ponton, B. Cheymol, R. De Prisco, M. Eshraqi, R. Miyamoto, E. Sargsyan
ESS, Lund, Sweden
G. Bourdelle, M. Desmons, A. France, O. Piquet, B. Pottin
CEA/DSM/IRFU, France
I. Bustinduy, P.J. González, J.L. Muñoz, I. Rueda, F. Sordo
ESS Bilbao, Bilbao, Spain
L. Celona, S. Gammino, L. Neri
INFN/LNS, Catania, Italy
M. Comunian, F. Grespan, A. Pisent, C. R. Roncolato
INFN/LNL, Legnaro (PD), Italy
P. Mereu
INFN-Torino, Torino, Italy

The ESS Normal Conducting (NC) linac is composed of an ion source, a Low Energy Beam Transport line, a Radio Frequency Quarupole (RFQ), a Medium Energy Beam Transport Line (MEBT) and a Drift Tube Linac (DTL). It creates, bunches and accelerates the proton beam up to 90 MeV before injecting into the superconducting linac which will deliver a 5 MW beam onto the neutron production target. The construction of the NC linac is part of a broad collaboration involving experts of various Labs in Europe. The technical chalenges and the collaboration strategy for the NC linac will be presented.

THPP045

ESS Linac Beam Modes

rfq, emittance, quadrupole, DTL

951

E. Sargsyan, R. Miyamoto
ESS, Lund, Sweden

The ESS Linac will ultimately deliver 5 MW of beam power to the target with a long-pulse structure of 2.86 ms and 14 Hz repetition rate, which is essential for the production of long-wavelength neutrons [1]. Ten different beam power levels are requested for the operation. In order to preserve the required time structure of the beam, different beam power levels will be produced by reducing the beam current in ten regular steps using an iris with an adjustable aperture in the LEBT. Low current and low emittance beams may as well be useful for the beam commissioning of the Linac. This paper describes the generation and the beam dynamics of different beam modes in the ESS Linac.

THPP054

Study of Coupler's Effect in Third Harmonic Section of LCLS-II SC Linac

cavity, cryomodule, emittance, HOM

969

A. Saini, A. Lunin, N. Solyak, V.P. Yakovlev
Fermilab, Batavia, Illinois, USA
T.O. Raubenheimer
SLAC, Menlo Park, California, USA

The Linac Coherent Light Source (LCLS) is an x-ray free electron laser facility. The proposed upgrade of the LCLS facility is based on construction of 4 GeV superconducting (SC) linac which will use two stage bunch compression scheme in order to achieve short bunches with high peak current. In order to reduce non-linear effects in first bunch compressor, third harmonic section is utilized to linearize longitudinal phase space of the beam. However, transverse phase space of beam may get distorted due to coupler RF kicks and coupler wake kicks resulting from the asymmetry of input and HOM couplers in 3.9 GHz cavity. In this paper, we discuss coupler's effects and estimate resulting emittance dilution in third harmonic section. Local compensation of coupler kicks using different orientation of cavities are also addressed.

THPP059

Z-Shaper: A Picosecond UV Laser Pulse Shaping Channel at the Advanced Superconducting Test Accelerator

laser, experiment, electron, controls

986

J.C.T. Thangaraj, D.R. Edstrom, A.H. Lumpkin, J. Ruan
Fermilab, Batavia, Illinois, USA
B. Beaudoin
UMD, College Park, Maryland, USA

Many accelerator applications require a longitudinally shaped electron beam profile for studies ranging from THz generation to dielectric wakefield acceleration. An electron beam profile can be shaped through many techniques in both electron beam generation, such as with a DAZZLER or in ellipsoidal pulse generation, and beam transport, using an emittance exchanger or linearizing harmonic cavity. In this paper, shaping of a UV pulse with length on the order of picoseconds is examined using alpha-BBO crystals in the Advanced Superconducting Test Accelerator (ASTA) drive laser. A relatively economical solution to effect a predictable and tunable longitudinal bunch shape, profiles have been generated and observed using a Hamamatsu C5680 streak camera, and the results are compared with the analytical theory.

THPP061

RF Design of a Novel S-Band Backward Traveling Wave Linac for Proton Therapy

coupling, accelerating-gradient, proton, impedance

992

S. Benedetti, U. Amaldi
TERA, Novara, Italy
A. Degiovanni, A. Grudiev, W. Wuensch
CERN, Geneva, Switzerland

Proton therapy is a rapidly developing technique for tumour treatment, thanks to the physical and dosimetric advantages of charged particles in the dose distribution. Here the RF design of a novel high gradient accelerating structure for proton Linacs is discussed. The choice of a linear accelerator lies mainly in its advantage over cyclotron and synchrotron in terms of fast energy modulation of the beam, which allows the implementation of active spot scanning technique without need of passive absorbers. The design discussed hereafter represents a unicum thanks to the accelerating mode chosen, a 2.9985 GHz backward traveling wave mode with 150° phase advance, and to the RF design approach. The prototype has been designed to reach an accelerating gradient of 50 MV/m, which is more than twice that obtained before. This would allow a shorter Linac potentially reducing cost. The complete 3D RF design of the full structure for beta equal to 0.38 is presented. A prototype will be soon produced and tested at high power. This structure is part of the TULIP project, a proton therapy single-room facility based on high gradient linear accelerators.

Slides THPP061 [1.537 MB]

THPP063

Beam Diagnostics Layout for the FAIR Proton Linac

proton, diagnostics, emittance, beam-diagnostic

998

T. Sieber, M.H. Almalki, C. Dorn, J. Fils, P. Forck, R. Haseitl, W. Kaufmann, W. Vinzenz, M. Witthaus, B. Zwicker
GSI, Darmstadt, Germany
C.S. Simon
CEA/DSM/IRFU, France

The planned proton Linac for FAIR (Facility of Antiproton an Ion Research) will be - additionally to the existing GSI UNILAC - a second injector for the FAIR accelerator chain. It will inject a 70 MeV, (up to) 70 mA proton beam with a nominal pulse length of 30 us into the SIS18. The beam diagnostics system for the proton Linac comprises nine current transformers for pulse current determination and fourteen BPMs for position, mean beam energy and relative current measurement. SEM-Grids and stepping motor driven slits will be used for profile as well as for emittance measurements. A wire-based bunch shape monitor is foreseen, additionally a bending magnet for longitudinal emittance determination during commissioning. Presently, main efforts are conducted concerning the BPM system. Detailed signal simulations with the finite element code CST are performed. An electronics board using digital signal processing is evaluated by detailed lab-based characterization and beam-based measurements at the UNILAC. In this paper we present the general layout and the status of the diagnostics systems as well as key results from our measurements and simulations.

THPP068

Cold Power Tests of the SC 325 MHz CH-Cavity

cavity, controls, ion, heavy-ion

1007

M. Busch, M. Amberg, F.D. Dziuba, H. Podlech, U. Ratzinger
IAP, Frankfurt am Main, Germany
M. Amberg
HIM, Mainz, Germany

Funding: Work supported by GSI, BMBF Contr. No. 06FY7102
At the Institute for Applied Physics (IAP), Frankfurt University, a superconducting 325 MHz CH-Cavity has been designed, built and first tests have successfully been performed. The cavity is determined for a 11.4 AMeV, 10 mA ion beam at the GSI UNILAC. Consisting of 7 gaps this resonator is envisaged to deliver a gradient of 5 MV/m. Novel features of this structure are a compact design, low peak fields, improved surface processing and power coupling. Furthermore a tuner system based on bellow tuners driven by a stepping motor and a piezo actuator and attached inside the resonator will control the frequency. In this contribution measurements executed at 4 K and 2 K at the cryo lab in Frankfurt will be presented.

Poster THPP068 [1.449 MB]

THPP072

BERLinPro Booster Cavity Design, Fabrication and Test Plans

cavity, cryomodule, booster, SRF

1019

A. Burrill, W. Anders, A. Frahm, J. Knobloch, A. Neumann
HZB, Berlin, Germany
G. Ciovati, P. Kneisel, L. Turlington
JLab, Newport News, Virginia, USA

The BERLinPro project, a 100 mA, 50 MeV superconducting RF (SRF) Energy Recovery Linac (ERL) is under construction at Helmholtz-Zentrum Berlin for the purpose of studying the technical challenges and physics of operating a high current, c.w., 1.3 GHz ERL. This machine will utilize three unique SRF cryomodules for the injector, booster and linac module respectively. The booster cryomodule will contain three 2-cell SRF cavities, based on the original design by Cornell University, and will be equipped with twin 115 kW RF power couplers in order to provide the appropriate acceleration to the high current electron beam. This paper will review the status of the fabrication of the 4 booster cavities that have been built for this project by Jefferson Laboratory and look at the challenges presented by the incorporation of fundamental power couplers capable of delivering 115 kW. The test plan for the cavities and couplers will be given along with a brief overview of the cryomodule design.

THPP073

Cavity Excitation of the Chopped Beam at the J-PARC Linac

DTL, pick-up, operation, injection

1023

K. Futatsukawa
KEK, Ibaraki, Japan

In the J-PARC linac, the beam energy at the injection of the rapid-cycle synchrotron (RCS) was upgraded up to 400 MeV by the installation of 25 additional cavities, annular-ring coupled structure (ACS), in 2013. The initial frequency of RCS was shifted to 1.227 MHz because of the change the injection-beam velocity. At the linac, the beam is chopped as the comb-like structure with this frequency (intermediate-pulse) by the RF deflector. The component of this RCS frequency excited the PC1 mode of DTL2 and was the cause of the RF-control difficulty. Additionally, it could be confirmed that other chopping operations, which does not have specific intermediate-pulses for example, drove other modes. In this paper, I would like to introduce this phenomena and the counterplan as the RF control.

THPP086

ESS DTL Error Study

emittance, DTL, multipole, dipole

1047

M. Comunian, F. Grespan, A. Pisent
INFN/LNL, Legnaro (PD), Italy

The Drift Tube Linac (DTL) of the European Spallation Source (ESS) is designed to operate at 352.2 MHz with a duty cycle of 4% (3 ms pulse length, 14 Hz repetition period) and will accelerate a proton beam of 62.5 mA pulse peak current from 3.62 to 90 MeV. The error study is decisive to define the DTL manufacturing tolerances and to evaluate its robustness. In this paper the DTL performances are shown.

THPP087

ESS DTL Design and Drift Tube Prototypes

DTL, coupling, vacuum, quadrupole

1050

F. Grespan, M. Comunian, A. Pisent, M. Poggi, C. R. Roncolato
INFN/LNL, Legnaro (PD), Italy
P. Mereu
INFN-Torino, Torino, Italy

The Drift Tube Linac (DTL) for the ESS accelerator will accelerate protons up to 62.5 mA average pulse current from 3.62 to 90 MeV. The 5 tanks composing the DTL are designed to operate at 352.2 MHz in pulses of 2.86 ms long with a repetition rate of 14 Hz. The accelerating field is around 3.1 MV/m, constant in each tank. Permanent magnet quadrupoles (PMQs) are used as focusing element in a FODO lattice. The empty drift tubes accommodate Electro Magnetic Dipoles (EMDs) and Beam Position Monitors (BPMs) in order to implement beam corrective schemes. A complete set of Drift Tubes is under construction that is BPM, EMD and PMQ types. These prototypes are aimed to validate the design with the involved integration issues of the various components, as well as the overall technological and assembly process. This paper presents the main mechanical choices and the status of the prototyping program of the Drift Tubes.

THPP089

High Power Conditioning of Annular-Ring Coupled Structures for the J-PARC Linac

vacuum, operation, cavity, coupling

1053

H. Ao, T. Ito, Y. Nemoto, H. Oguri, N. Ouchi, J. Tamura
JAEA/J-PARC, Tokai-mura, Japan
H. Asano
Nippon Advanced Technology Co. Ltd., Ibaraki-prefecture, Japan
Z. Fang, K. Futatsukawa, K. Nanmo, T. Sugimura
KEK, Ibaraki, Japan

The linac of Japan Proton Accelerator Research Complex (J-PARC), which is an injector to a 3-GeV synchrotron, comprised a 3-MeV RFQ, 50-MeV DTLs and 181-MeV Separated-type DTLs. From September 2013, 25 annular-ring coupled structure (ACS) cavities were additionally installed to increase the linac beam energy up to 400 MeV and achieve 1-MW beam power of the 3-GeV synchrotron. After installation work the high power conditioning was started from December 2013 and most of the ACS cavities were conditioned within three weeks. We passed through some troubles and finally finished conditioning all the cavities until the middle of January 2014. In this paper, we present the conditioning results and how to handle the issue in the conditioning process.

Slides THPP089 [7.756 MB]

THPP090

Longitudinal Measurement of Annular-Ring Coupled Structure Linac in J-PARC

injection, simulation, distributed, rfq

1056

T. Maruta, Y. Liu
KEK/JAEA, Ibaraki-Ken, Japan
A. Miura
JAEA/J-PARC, Tokai-mura, Japan

In the J-PARC linac, Annular-type Coupled Structure (ACS) linac was introduced for the beam energy extension to 400 MeV in year 2013. To measure the longitudinal property of the ACS, we measured acceptance in phase direction by synchronous phase scan method and confirm that the acceptance is consistent with that by 3D PIC simulation. Simultaneously, the output beam energy from ACS was measured by orbit displacement where the dispersion is large. In this presentation, we discuss the measurement method and results.

THPP091

Installation and Performance Check of Beam Monitors for Energy Upgraded J-PARC Linac

operation, quadrupole, cavity, acceleration

1059

A. Miura, K. Hasegawa, H. Oguri, N. Ouchi
JAEA/J-PARC, Tokai-mura, Japan
M. Ikegami
FRIB, East Lansing, Michigan, USA
Y. Liu
KEK/JAEA, Ibaraki-Ken, Japan
T. Maruta
J-PARC, KEK & JAEA, Ibaraki-ken, Japan
T. Miyao
KEK, Ibaraki, Japan

An energy upgrade project has started to achieve the design beam power of 1 MW at the exit of the downstream synchrotron in the J-PARC Linac since 2009. In the upgraded project, a beam energy in the Linac has increased from present 181 MeV to 400 MeV using the additional 21 annular-ring coupled structure (ACS) cavities. The new beam monitors as the beam current monitors, the phase monitors, the beam position monitors, the transverse profile monitors (wire scanner monitors) and the longitudinal profile monitors (bunch shape monitors) for the part where the ACS cavities were installed were designed, fabricated and calibrated. Till the end of November, 2013, all beam monitors were completed to be installed. From the middle of December, we started the beam commissioning to achieve the beam energy as 400 MeV, as well as to confirm the beam monitor functioning. We achieved the 400 MeV beam acceleration at the middle of January, 2014 using newly installed beam monitors. This paper describes the beam monitor installation, calibration and the beam commissioning results of beam monitor functioning.

THPP094

The Heavy Ion Injector at the NICA Project

ion, rfq, heavy-ion, ion-source

1068

A.V. Butenko, D.E. Donets, E.E. Donets, A.D. Kovalenko, A.O. Sidorin, A. Tuzikov
JINR/VBLHEP, Moscow, Russia
V. Aleksandrov, E.D. Donets, A. Govorov, V. Kobets, K.A. Levterov, I.N. Meshkov, V.A. Mikhaylov, V. Monchinsky, G.V. Trubnikov
JINR, Dubna, Moscow Region, Russia
H. Hoeltermann, H. Podlech, U. Ratzinger, A. Schempp
BEVATECH, Frankfurt, Germany
T. Kulevoy, D.A. Liakin
ITEP, Moscow, Russia

The general goals of the Nuclotron-based Ion Collider fAcility (NICA) project at JINR (Dubna) are providing of colliding beams for experimental studies of both hot and dense strongly interacting baryonic matter and spin physics. The experiments will be performed in collider mode and at fixed target. The first part of the project program requires the collisions of heavy nuclei up to 197Au⁷⁹⁺ to be studied. The new heavy ion linac – HILac (Heavy Ion Linear Accelerator) will accelerate ions with q/A – values above 0.16 to 3.2 MeV/u is under manufacturing presently. The main features of HILac are described.

THPP095

Design Study of Superconducting Linear Accelerator for Unstable Ion Beams in RISP

emittance, ion, simulation, ISOL

1071

J.G. Hwang, C. Kim, E.-S. Kim
Kyungpook National University, Daegu, Republic of Korea
B.H. Choi, H. Jang, D. Jeon, H.J. Kim, H.J. Kim, I. Shin
IBS, Daejeon, Republic of Korea
L. Lee
KNU, Deagu, Republic of Korea

The post accelerator of RAON can accelerate the unstable and stable ion beams up to 15 MeV/u for 132Sn¹⁶⁺ and 58Ni⁸⁺ for 16.5 MeV/u, which has the ratio of mass to charge, A/q, of 8.3. The unstable ion beam such as 132Sn¹⁶⁺ produced by an ISOL system has the large transverse and longitudinal emittances. The post-accelerator consists of post-LEBT, RFQ, MEBT and superconduction linac(SCL3 and we optimized acceptance and beam envelope based on the beam dynamics in the linac. The accelerated beam by post accelerator was transported by the post-to-driver transport (P2DT) line which consists of a charge stripper, two charge selection sections and a telescope section with the bunching cavities to the high energy linac(SCL2) and accelerated up to 200 MeV/u. In this presentation, we will show the criteria for the design of the post accelerator and result of beam tracking simulation from post-LEBT to end of high energy linac.

THPP100

Result of MHI 2-Cell Seamless Dumb-Bell Cavity Vertical Test

cavity, superconducting-cavity, vacuum, electron

1087

K. Okihira, H. Hara, N. Ikeda, F. Inoue, K. Sennyu
MHI, Kobe, Japan
R.L. Geng, R.A. Rimmer
JLab, Newport News, Virginia, USA
E. Kako
KEK, Ibaraki, Japan

MHI have supplied several 9-cell cavities for STF (R&D of ILC project at KEK) and have been considering production method for stable quality and cost reduction, seamless dumb-bell cavity was one of them. We had fabricated a 2 cell seamless dumb-bell cavity for cost reduction and measured RF performance in collaboration with JLab, KEK and MHI. Surface treatment recipe for ILC was applied for MHI 2-cell cavity and vertical test was performed at JLab. The cavity reached Eacc=32.4MV/m after BCP and EP. Details of the result are reported.

THPP105

Beam Dynamics Simulation for the 1 GeV High Power Proton Linac

focusing, rfq, proton, simulation

1099

S.M. Polozov, V.S. Dyubkov, T. Kulevoy, A.V. Samoshin
MEPhI, Moscow, Russia
G. Kropachev, T. Kulevoy
ITEP, Moscow, Russia

Funding: This work is supported in part by the Ministry of Science and Education of Russian Federation under contract No. 14.516.11.0084
The design of high energy and high power proton linacs for accelerating driven systems (ADS) is one of the accelerator technology frontiers. Such linacs are under developing in EU, Japan, PRC but not discussed in Russia previous fifteen years. The driver linac and the breeder conceptual designs were funded by the Ministry of Science and Education of Russian Federation in 2013. The 2 MeV RFQ linac was proposed as the first accelerating section. A number of RF focusing sections types (by RF crossed lenses, modified electrode profile RFQ, axi-symmetrical RF focusing) were discussed for medium energies. The conventional modular scheme linac based on spoke-cavities and 5-cell elliptical cavities was designed for higher energies. The results of beam dynamics simulation in this linac will present.

THPP109

History of Cryomodule Repairs at SNS

cryomodule, HOM, cavity, operation

1108

M.P. Howell, M. Doleans, D.L. Douglas, S.-H. Kim
ORNL, Oak Ridge, Tennessee, USA
R. Afanador, B. DeGraff, B.S. Hannah, C.J. McMahan, T.S. Neustadt, S.W. Ottaway, J. Saunders, P.V. Tyagi, D.M. Vandygriff
ORNL RAD, Oak Ridge, Tennessee, USA

The operation of the Superconducting linear accelerator (SCL) has matured and now averages less than one trip per day. The availability of the SCL including radiofrequency systems, high voltage converter modulators, controls, vacuum and other support systems over the last three years is approximately 98%. The SNS has been in operation for ten years including the commissioning period. In support of achieving the stability of operation, multiple cryomodule repairs have been performed. Repairs to cryomodules have included instruments, helium leaks, valve actuators, cavity tuners, insulating vacuum repairs and upgrades, power supplies, higher order mode (HOM) feedthroughs, coupler windows, and coupler cooling components. Performance degradation has been experienced in multiple cavities. This has been corrected by thermal cycling the cryomodules with the affected cavities. Only two cavities have displayed slight permanent degradation that could not be corrected by thermal cycling. Repairs made to the SNS cryomodule will be detailed in this paper.

THPP118

Design of a New Superconducting Linac for the RIBF Upgrade

cyclotron, acceleration, ion, emittance

1127

K. Yamada, O. Kamigaito, N. Sakamoto, K. Suda
RIKEN Nishina Center, Wako, Japan

An upgrade plan for the RIKEN RI-Beam Factory[1] is under discussion, the objective being to significantly increase the uranium beam intensity. In the upgrade plan, the existing ring cyclotron called RRC[2] will be replaced by a new linac, mainly consisting of superconducting (SC) cavities. The new linac is designed to accelerate heavy ions with a mass-to-charge ratio of ~7, such as 238U³⁵⁺, up to an energy of 11 MeV/u in the cw mode. The present injector linac, RILAC2[3], will be used for the low-energy end, and a short room-temperature (RT) section will be added to RILAC2, which will boost the beam energy up to 1.4 MeV/u. The succeeding SC section consists of 14 cryomodules, each of which contains four quater-wavelength resonators (QWRs) with two gaps operated at 73 MHz. A RT quadrupole doublet is placed in each gap between the cryomodules. The modular configuration of the SC section was optimized based on the first-order approximation for the transverse and longitudinal motions. The designs of SC QWR were carried out using CST Microwave Studio 2013. Further study is under way on the SC QWR including the mechanical considerations, and we also start a design of cryostats.
[1] Y. Yano, Nucl. Instr. Meth. B 261, 1009 (2007).
[2] Y. Yano, Proc. 13th Int. Cyclo. Conf., 102 (1992).
[3] K. Yamada et al., Proc. of IPAC'12, TUOBA02, 1071 (2012).

THPP121

Injector System for the IR-FEL at RRCAT

beam-loading, electron, FEL, cavity

1137

L. Faillace, R.B. Agustsson
RadiaBeam, Santa Monica, California, USA
A. Kumar, K.K. Pant
RRCAT, Indore (M.P.), India

An infrared (IR) free-electron laser (FEL) has been proposed to be built at the Raja Ramanna Centre for Advanced Technology (RRCAT). RadiaBeam is currently involved in the design of the RRCAT FEL's injector system. The injector will deliver an electron beam with a variable energy (from 15 up to 40 MeV) and 1.5 nC at 36.6 MHz repetition rate. We show here the beam dynamics of the beam transport through the injector as well as the RF design and mechanical model of the system.
* S. Krishnagopal et al., PRELIMINARY DESIGN OF THE PROPOSED IR-FEL IN INDIA, RRCAT, Indore, M.P. 452013, India

THPP122

Development of Superconducting Cavities and Related Infrastructure for High Intensity Proton Linac for Spallation Neutron Source

cavity, niobium, laser, proton

1140

S.C. Joshi, J. Dwivedi, P.D. Gupta, P.R. Hannurkar, V. Jain, P. Khare, P.K. Kush, G. Mundra, A. Puntambekar, S. Raghvendra, S.B. Roy, P. Shrivastava
RRCAT, Indore (M.P.), India

Raja Ramanna Centre for Advanced Technology has taken up a program on R&D activities of a 1 GeV, high intensity superconducting proton linac for a spallation neutron source. The proton linac will require a large number of superconducting Radio Frequency cavities ranging from low beta spoke resonators to medium and high beta multi-cell elliptical cavities at different RF frequencies. A dedicated facility is being set up for development of multi-cell superconducting cavities and their performance characterization. 1.3 GHz single-cell niobium cavities have been developed to establish the fabrication procedure. These cavities has exhibited high quality factor with an accelerating gradients up to 37 MV/m. A novel technique of laser welding of 1.3 GHz niobium cavity has been developed and demonstrated performance comparable to electron beam welded cavity. A dedicated facility for SCRF cavity forming, machining, electron beam welding, RF characterization, cavity tuning and cavity processing is being set up. To characterize a SCRF cavity at 2K, a vertical test stand has been developed and a horizontal test stand has been designed.

THPP124

Wakefields in the Superconducting RF Cavities of LCLS-II

cavity, wakefield, electron, niobium

1147

K.L.F. Bane, T.O. Raubenheimer
SLAC, Menlo Park, California, USA
A. Romanenko, V.P. Yakovlev
Fermilab, Batavia, Illinois, USA

Funding: Work supported by Department of Energy contract DE–AC02–76SF00515.
The superconducting cavities in the linacs of LCLS-II are designed to operate at 2K, where cooling costs are very expensive. In addition to an unavoidable static load and the dynamic load of the fundamental 1.3 GHz accelerating rf, there will be higher order mode (HOM) power deposited by the beam. Due to the very short bunch length the LCLS-II beam spectrum extends into the THz range. Ceramic absorbers, cooled to 70K and located between cryomodules, are meant to absorb much of this power; understanding their effectiveness, however, is a challenging task. In this report we calculate the amount of power radiated by the beam in the different portions of the linac as the bunch length is changed by the bunch compressors. We consider both the steady state radiation as well as transients that arise at the beginning of the linac structures. In addition, transitions due to changes in the vacuum chamber aperture at the ends of the linacs are also considered. Finally, under the assumption that all the wake power ends up in the SRF cavity walls, we estimate the wall heating and the possibility of breaking the Cooper pairs and quenching the cavities.

THPP132

Warming Rate Reduction of the SARAF RF Couplers by Application of a High Voltage Dc Bias

operation, experiment, proton, cavity

1168

B. Kaizer, Y. Ben Aliz, I. Fishman, J. Rodnizki, L. Weissman
Soreq NRC, Yavne, Israel

Warming up of the coupler region of the SARAF Half Wave Resonator (HWR) cavities was one of the main limiting factors for long operation at high RF field values. The warming effect is, most likely, associated with multipacting in the coupler region. We have tried to suppress the multipacting discharge in the couplers by application a DC bias to their inner conductors. A bias-T, element that conducts up to 4 kW of 176 MHz RF power and provides DC insulation of the coupler inner conductor, was designed and built for this purpose. First on-line operation showed that the DC bias indeed reduces dramatically the warming rates of most of the cavities by an order of magnitude. Today, coupler warming is no longer the main factor hindering accelerator operation.

THPP135

Recent Improvements to Software Used for Optimization of SRF Linacs

cryomodule, cavity, cryogenics, SRF

1174

T. Powers
JLab, Newport News, Virginia, USA

Funding: Notice: Authored by Jefferson Science Associates, LLC under U.S. DOE Contract No. DE-AC05-06OR23177.
This work describes a software tool that allows one to vary parameters and understand the effects on the optimized costs of construction plus 10 year operations of an SRF linac. The program includes estimates for the associated cryogenic facility, and controls hardware, where operation costs includes the cost of the electrical utilities but not the labor or other costs. The software interface provides the ability to vary the cost of the different aspects of the machine as well as to change the cryomodule and cavity types. Additionally, this work will describe the recent improvements to the software that allow one to estimate the costs of energy recovery based linacs and to enter arbitrary values of the low field Qo and Qo slope. The initial goal was to convert a spreadsheet format to a graphical interface to allow the ability to sweep different parameter sets. The tools also allow one to compare the cost of the different facets of the machine design and operations so as to better understand the tradeoffs. An example of how it was used to investigate the cost optimization tradeoffs for the LCLS 2 linac will also be presented.

THPP137

Present Status of the 3 MeV Proton Linac at Tsinghua University

rfq, proton, status, target

1182

Q.Z. Xing, C. Cheng, C.T. Du, L. Du, T. Du, X. Guan, C. Jiang, C.-X. Tang, X.W. Wang, H.Y. Zhang, S.X. Zheng
TUB, Beijing, People's Republic of China
W.Q. Guan, Y. He, J. Li
NUCTECH, Beijing, People's Republic of China
B.C. Wang
NINT, Xi'an, People's Republic of China

We present, in this paper, the present status of the 3 MeV high current proton Linac for the Compact Pulsed Hadron Source (CPHS) at Tsinghua University. The ECR ion source produces 50 keV proton beam which is accelerated to 3 MeV by the downstream RFQ accelerator. The RFQ accelerator has been conditioned to 50 Hz/500 μs with the input power of 442 kW. Proton beam with the peak current of 30 mA, pulse length of 100 μs and repetition rate of 50 Hz has been delivered to the Beryllium target to produce the neutron since July 2013. The status of the development of the Drift Tube Linac is also presented in this paper. The beam energy will be enhanced to 13 MeV after the DTL is ready in 2015.

THPP139

800MeV Linear Accelerator Development for HLS Upgrade

electron, klystron, operation, injection

1189

K. Jin, Y. Hong, G. Huang, D. Jia, S.C. Zhang
USTC/NSRL, Hefei, Anhui, People's Republic of China

Hefei Light Source (HLS) was mainly composed of an 800 MeV electron storage ring and a 200 MeV constant-impedance Linac functioning as its injector in NSRL PhaseⅠ. A new Linac has been developed successfully in view of the Full Energy Injection and the Top-up Injection scheme will be adopted in the HLS upgrade. In this paper, an 800MeV linear accelerating system construction, the constant-gradient structure with the symmetry couplers will be described in detail. The microwave system, the manufacture technology, the RF measurement, the high power testing and the accelerating system operation with beam currents are presented.

THPP140

High Transparent Matched Window for Standing Wave Linear Accelerators

electron, vacuum, network, coupling

1192

A. Leggieri, F. Di Paolo, D. Passi
Università degli Studi di Roma "Tor Vergata", Roma, Italy
A. Ciccotelli, G. Felici
S.I.T., Aprilia, Italy

This paper proposes a particular Dielectric Window (DW) for Standing Wave (SW) Linear Accelerators (LINAC’s). This study investigates the in-frequency return loss behavior of the LINAC, in order to improve matching and transmitting conditions while maintaining the optimum coupling between LINAC and High Power Microwave (HPMW) source. Device design is single-frequency based and considers the DW interface as an Input Matching Network (IMN) at the LINAC Normal Mode (NM) working frequency. Thus, design formulas are provided and Computer Aided Design (CAD) techniques are proposed. A prototype has been made and tested by performing cold S-parameter and Percentage Depth Dose (PDD) measurements of a LINAC with the proposed DW and with a traditional DW. The proposed device offers more energy transport attitude over the traditional DW, as shown by a return loss increase of 167% and an output electron energy increase of 5.5% while maintaining the same LINAC input power settings. This solution can offer a decrease of power line size, weight and cost. An after brazing global improvement of the accelerator figures of merit is also possible, as this study have demonstrated.
[1]Hiroyuki Arai, 1986
[2]K. Hirano, 1995
[3]Y. Otake, 1995
[5]A. Leggieri, 2014
[6]A. C. Ugural, 2003
[7]A. Leggieri, 2014
[8]F. Di Paolo, 2000
[9]N. Marcuvitz, 1951

FRIOB01

Positive Trends in Radiation Risk Assessment and Consequent Opportunities for Linac Applications

radiation, FEL, controls, simulation

1202

Y. Socol
Falcon Analytics, Netanya, Israel

Ionizing radiation, an unavoidable by-product of high-energy LINACs, makes them subject to strict regulation and severe public concerns. During the last two decades the attitude to ionizing radiation hazards has been becoming more balanced, as opposed to the historical "radiophobia". The linear no-threshold hypothesis (LNTH), based on the assumption that every radiation dose increment constitutes increased cancer risk for humans, is more and more debated. In particular, the recent memorandum of the International Commission on Radiological Protection admits that the LNTH predictions at low doses are "speculative, unproven, undetectable and "phantom'." Moreover, numerous experimental, ecological, and epidemiological studies show that low doses of ionizing radiation may be beneficial to human health. While these advances in scientific understanding have not yet given fruit regarding radiation regulation and policy, we are hopeful these may happen in near to middle term. The presentation reviews the present status of the low-dose radiation-hazard debate. It also outlines anticipated opportunities for LINAC applications, especially in the prospective field of low-dose radiation therapy.

Slides FRIOB01 [1.890 MB]

FRIOB02

Proton and Carbon Linacs for Hadron Therapy

proton, hadron, ion, hadrontherapy

1207

A. Degiovanni, U. Amaldi
TERA, Novara, Italy
A. Degiovanni
CERN, Geneva, Switzerland

Beams of 200 MeV protons and 400 MeV/u fully stripped carbon ions are used for the treatment of solid tumours seated at a maximum depth of 27 cm. More than 100’000 patients have been treated with proton beams and more than 10’000 with carbon ions. Very low proton currents - of the order of 1 nA - are enough to deliver the typical dose of 2 Gy/l in one minute. In the case of carbon ions the currents are of the order of 0.1-0.2 nA. For this reason 3 GHz linacs are well suited in spite of the small apertures and low duty cycle. The main advantage of linacs, pulsing at 200-400 Hz, is that the output energy can be continuously varied pulse-by-pulse and in 2-3 min a moving tumour target can be covered about 10 times by deposing the dose in many thousands of ‘spots’. High frequency hadron therapy linacs have been studied in the last 20 years and are now being built as hearts of proton therapy centres, while carbon ion linacs are still in the designing stage. At present the main challenges are the reduction of the footprint of compact ‘single-room’ proton machines and the power efficiency of dual proton and carbon ions ‘multi-room’ facilities.

Slides FRIOB02 [14.013 MB]