IPAC2012 - List of Keywords (ion)

Paper	Title	Other Keywords	Page
MOXBP01	The First Two Years of LHC Operation	luminosity, proton, emittance, dipole	1
	S. Myers CERN, Geneva, Switzerland
	The operational performance of the LHC machine both for proton and lead ion operation are reviewed for the period 2010 and up the present. The beam parameter path allowing the very high rate of collider performance is presented and discussed. The accelerator issues encountered and those somewhat surprisingly not encountered are also discussed. The short and longer term plans for the LHC are also briefly presented.
	Slides MOXBP01 [17.468 MB]

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

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

MOEPPB005	Initial Commissioning of NDCX-II	induction, diagnostics, solenoid, beam-transport	85
	S.M. Lidia, D. Arbelaez, W.G. Greenway, J.-Y. Jung, J.W. Kwan, T.M. Lipton, A. Pekedis, P.K. Roy, P.A. Seidl, J.H. Takakuwa, W.L. Waldron LBNL, Berkeley, California, USA A. Friedman, D.P. Grote, W. M. Sharp LLNL, Livermore, California, USA E.P. Gilson PPPL, Princeton, New Jersey, USA
	Funding: This work was performed under the auspices of the U.S Department of Energy by LLNL under contract DE AC52 07NA27344, and by LBNL under contract. DE-AC02-05CH11231. The Neutralized Drift Compression Experiment-II (NDCX-II) will generate ion beam pulses for studies of Warm Dense Matter and heavy-ion-driven Inertial Fusion Energy. The machine will accelerate 20-50 nC of Li+ to 1.2-3 MeV energy, starting from a 10.9-cm alumino-silicate ion source. At the end of the accelerator the ions are focused to a sub-mm spot size onto a thin foil (planar) target. The pulse duration is compressed from ~500 ns at the source to sub-ns at the target following beam transport in a neutralizing plasma. We first describe the injector, accelerator, transport, final focus and diagnostic facilities. We then report on the results of early commissioning studies that characterize beam quality and beam transport, acceleration waveform shaping and beam current evolution. We present WARP simulation results to benchmark against the experimental measurements.

MOEPPB006	Formation of Beams in the Ion Accelerator Complex of the Medium Energy Electron Ion Collider Facility at JLab	booster, proton, acceleration, collider	88
	S.L. Manikonda, P.N. Ostroumov ANL, Argonne, USA B. Erdelyi Northern Illinois University, DeKalb, Illinois, USA
	Funding: This work was supported by the U.S. Department of Energy, Office of Nuclear Physics, under Contract No. DE-AC02-06CH11357. At the interaction point of the Medium Energy Electron Ion Collider (MEIC) facility the luminosity of 10³³cm^-2s^-1 will be achieved through the collision of counter rotating beams of 0.5A ions and 3A electrons at 750MHz frequency. Formation of ion beams at MEIC is carried out in the Ion Accelerator Complex (IAC) comprising of a linac, pre-booster ring, booster ring, and a collider ring. We will describe the scheme proposed for the formation of ion beams at MEIC facility from the point of view of longitudinal beam dynamics. The proposed scheme minimizes losses due to space charge effects at low energies and needs moderate RF requirements already achieved at other existing facilities. Simulation studies have been conducted to verify the proposed scheme. We will present the results of these simulation studies.

MOEPPB010	Measurement of Satellite Bunches at the LHC	photon, emittance, synchrotron, coupling	97
	A. Jeff, M. Andersen, A. Boccardi, S. Bozyigit, E. Bravin, T. Lefèvre, A. Rabiller, F. Roncarolo CERN, Geneva, Switzerland A.S. Fisher SLAC, Menlo Park, California, USA C.P. Welsch Cockcroft Institute, Warrington, Cheshire, United Kingdom
	Funding: Adam Jeff is a DITANET fellow, supported by the EU's Marie Curie actions contract PITN-GA-2008-215080. The RF gymnastics involved in the delivery of proton and lead ion bunches to the LHC can result in satellite bunches of varying intensity occupying the nominally empty RF buckets. Quantification of these satellites is crucial for bunch-by-bunch luminosity normalization as well as for machine protection. We present an overview of the longitudinal density monitor (LDM) which is the principal instrument for the measurement of satellite bunches in the LHC. The LDM uses single photon counting of synchrotron light. The very high energies reached in the LHC, combined with a dedicated undulator for diagnostics, allow synchrotron light measurements to be made with both protons and heavy ions. The arrival times of photons are collected over a few million turns, with the resulting histogram corrected for the effects of the detector’s deadtime and afterpulsing in order to reconstruct the longitudinal profile of the entire LHC ring. The LDM has achieved a dynamic range in excess of 10⁵ and a time resolution of 90 ps. Example results are presented and the measurements are benchmarked against satellite distributions based on collision data from the LHC experiments.

MOPPC013	Optics and Lattice Optimizations for the LHC Upgrade Project	optics, luminosity, lattice, insertion	151
	B. Dalena CEA/IRFU, Gif-sur-Yvette, France R. Appleby UMAN, Manchester, United Kingdom A.V. Bogomyagkov BINP SB RAS, Novosibirsk, Russia A. Chancé, J. Payet CEA/DSM/IRFU, France R. De Maria, B.J. Holzer CERN, Geneva, Switzerland A. Faus-Golfe, J. Resta-López IFIC, Valencia, Spain K.M. Hock, M. Korostelev, L.N.S. Thompson, A. Wolski Cockcroft Institute, Warrington, Cheshire, United Kingdom C. Milardi INFN/LNF, Frascati (Roma), Italy
	The luminosity upgrade of the LHC collider at CERN is based on a strong focusing scheme to reach lowest values of the beta function at the collision points. Several issues have to be addressed in this context, that are considered as mid term goals for the optimisation of the lattice and beam optics: Firstly a number of beam optics have been developed to establish a baseline for the hardware R&D, and to define the specifications for the new magnets that will be needed, in Nb3Sn and in NbTi technology. Secondly, the need for sufficient flexibility of the beam optics especially for smallest β^* values has to be investigated as well as the need for a smooth transition between the injection and the collision optics. Finally the performance of the optics based on flat and round beams has to be compared and different ways have to be studied to optimise the chromatic correction, including the study of local correction schemes. This paper presents the status of this work, which is a result of an international collaboration, and summarises the main parameters that are foreseen to reach the HL-LHC luminosity goal.

MOPPC022	Off-momentum Dynamic Aperture for Lattices in the RHIC Heavy Ion Runs	lattice, luminosity, heavy-ion, emittance	175
	Y. Luo, M. Bai, M. Blaskiewicz, W. Fischer, X. Gu, A. Marusic, T. Roser, S. Tepikian, S.Y. Zhang BNL, Upton, Long Island, New York, USA
	Funding: Work supported by Brookhaven Science Associates, LLC under Contract No. DE-AC02-98CH10886 with the U.S. Department of Energy. In this article we calculate and compare the off-momentum dynamic aperture for lattices with different phase advances per FODO cell in the RHIC heavy ion runs. A lattice with an increased phase advance was adopted in 2008-2011 to reduce transverse emittance growth rates from intra-beam scattering. However, during these runs, a large beam loss was observed with longitudinal RF re-bucketing which increased the momentum spread. With operational transverse stochastic cooling in the 2011 RHIC heavy ion run, the transverse intra-beam scattering emittance growth was eliminated, and the beam loss during stores was determined by the off-momentum aperture and burn-off from luminosity. We investigate the possibilities to increase the off-momentum dynamic aperture that would lead to an increase in the integrated luminosity.

MOPPC039	Electron Recombination in a Dense Hydrogen Plasma	cavity, electron, collider, plasma	217
	B.T. Freemire, P.M. Hanlet IIT, Chicago, Illinois, USA M. Chung Handong Global University, Pohang, Republic of Korea M.G. Collura Politecnico di Torino, Torino, Italy M.R. Jana, C. Johnstone, T. Kobilarcik, G.M. Koizumi, M.A. Leonova, A. Moretti, M. Popovic, T.A. Schwarz, A.V. Tollestrup, Y. Torun, K. Yonehara Fermilab, Batavia, USA R.P. Johnson Muons, Inc, Batavia, USA
	Funding: US DOE under contract DE-AC02-07CH11359. A high pressure hydrogen gas filled RF cavity was subjected to an intense proton beam to study the evolution of the beam induced plasma inside the cavity. The electron recombination rate with the dense ionized hydrogen plasma has been measured under varying conditions. Recombination rates as high as 10^-7 cm³/s have been recorded. This technique shows promise in the R&D program for a muon accelerator. The use of hydrogen, both as a way to prevent breakdown in an RF cavity and as a mechanism for cooling a beam of muons, will be discussed.

MOPPC040	Study of Electronegative Gas Effect in Beam-Induced Plasma	cavity, plasma, electron, proton	220
	M.A. Leonova, M.R. Jana, A. Moretti, M. Popovic, T.A. Schwarz, A.V. Tollestrup, K. Yonehara Fermilab, Batavia, USA M. Chung Handong Global University, Pohang, Republic of Korea M.G. Collura Politecnico di Torino, Torino, Italy B.T. Freemire, P.M. Hanlet, Y. Torun IIT, Chicago, Illinois, USA R.P. Johnson Muons, Inc, Batavia, USA
	Funding: This research was supported by US DOE under contract DE-AC02-07CH11359. Muon Colliders and Neutrino Factories call for R&D for a high-gradient RF system capable of operating in a high magnetic field. Adding a high pressure gas inside an RF cavity (HPRF) prevents cavity breakdown, allowing higher gradients in a magnetic field. A high-energy beam passing through an HPRF cavity ionizes the gas, producing plasma. Plasma electrons absorb cavity’s energy, reducing the energy available for beam acceleration. Doping cavity gas with electronegative gas (gas that tends to attract and bond electrons) reduces the number of plasma electrons. The experiments were carried out at the MuCool Test Area (MTA) facility at Fermilab. Different concentrations of an electronegative gas SF6 were added to hydrogen gas. The results of room-temperature tests showing a great reduction in power drop in the cavity will be presented. However, a realistic cavity would operate at liquid nitrogen temperature, where SF6 freezes. Thus, a search for a better electronegative gas candidate is underway; we plan to test oxygen-doping next.

MOPPC058	Eigenmode Computation for Ferrite-loaded Cavity Resonators	cavity, resonance, heavy-ion, acceleration	265
	K. Klopfer, W. Ackermann, T. Weiland TEMF, TU Darmstadt, Darmstadt, Germany
	The GSI Helmholtzzentrum für Schwerionenforschung in Darmstadt is operating the heavy-ion synchrotron SIS18 for fundamental research. Within the ring two ferrite-loaded cavity resonators are installed. During the acceleration phase their resonance frequency has to be adjusted to the revolution frequency of the heavy-ions to reflect their increasing velocity. Within the resonator structures dedicated biased ferrite rings are installed. In the whole setup a properly chosen bias current is used to modify the differential permeability of the ferrite material which consequently enables to adjust the eigenfrequency of the resonator system. The goal of the current study is to numerically determine the lowest eigensolutions of accelerating ferrite-loaded cavities based on the Finite Integration Technique. Since the underlying eigenmodes depend on the differential permeability, the static magnetic field generated by the bias current has to be computed in a first step. The eigenmodes can then be determined with the help of a dedicated Jacobi-Davidson eigensolver. Particular emphasis is put on the implementation to enable high performance computations based on distributed memory machines.

MOPPC060	Investigations into Beam Life Time in Low Energy Storage Rings	target, storage-ring, electron, antiproton	271
	A.I. Papash, A.V. Smirnov MPI-K, Heidelberg, Germany A.I. Papash JINR, Dubna, Moscow Region, Russia C.P. Welsch Cockcroft Institute, Warrington, Cheshire, United Kingdom
	Funding: Work supported by the Helmholtz Association of National Research Centers and GSI under contract VH-NG-328. In low energy storage rings, beam life time critically depends on the residual gas pressure, scattering effects caused by in-ring experiments and the available machine acceptance. A comprehensive simulation study into these effects has been realized with a focus on the TSR storage ring in Heidelberg and the electrostatic rings ELISA, the AD recycler and the ultra-low energy storage ring (USR). This was done by using the computer code BETACOOL in combination with the OPERA-3D and MAD-X programs. In this contribution, the results from these studies are presented and compared to available experimental data. Based on these simulations, criteria for stable ring operation are then presented.

MOPPC061	An Antiproton Recycler for Atom-Antiproton Collision Experiments	antiproton, injection, acceleration, target	274
	M.R.F. Siggel-King, C.P. Welsch Cockcroft Institute, Warrington, Cheshire, United Kingdom O. Karamyshev, A.I. Papash MPI-K, Heidelberg, Germany M.R.F. Siggel-King The University of Liverpool, Liverpool, United Kingdom
	Funding: Work supported by the Helmholtz Association and GSI under contract VH-NG-328, the EU under contract PITN-GA-2008-215080 and STFC. Collision experiments with low energy antiprotons and different gas jet targets on the level of differential cross sections would be very desirable to use to investigate the details of this fundamental process. At present, such experiments are, however, not feasible, since the only source of antiprotons in the world, the AD at CERN, cannot provide beams of the required energy and quality. A small electrostatic ring has been designed and developed by the QUASAR Group. Serving at the same time as a prototype for the future ultra-low energy storage ring (USR), to be integrated at the facility for low-energy antiproton and ion research (FLAIR), this small accelerator is unique due to its combination of size, electrostatic nature, and energy of the circulating particles. In this contribution, the design of the ring is described in detail and possible operation scenarios in the ASACUSA beam line and behind the ELENA ring are compared with each other.

MOPPC064	Simulation of the Behavior of Ionized Residual Gas in the Field of Electrodes	simulation, electron, emittance, vacuum	283
	G. Pöplau, U. van Rienen Rostock University, Faculty of Computer Science and Electrical Engineering, Rostock, Germany A. Meseck HZB, Berlin, Germany
	Funding: Work supported by BMBF under contract number 05K10HRC Light sources of the next generation such as ERLs require minimal beam losses as well as a stable beam position and emittance over the time. Instabilities caused by ionized residual gas have to be avoided. In this paper we present simulations of the behavior of ionized residual gas in the field of clearing electrodes and investigate e.g. clearing times. For these simulations we apply MOEVE PIC Tracking developed at Rostock University. We demonstrate numerical results with parameters planed for the ERL BERLinPro.

MOPPD002	Ultra-low Energy Storage Ring at FLAIR	extraction, antiproton, storage-ring, lattice	367
	C.P. Welsch, D. Newton, M.R.F. Siggel-King Cockcroft Institute, Warrington, Cheshire, United Kingdom O.E. Gorda, O. Karamyshev, G.A. Karamysheva, M. Panniello, A.I. Papash, A.V. Smirnov MPI-K, Heidelberg, Germany J. Harasimowicz, M. Putignano, C.P. Welsch The University of Liverpool, Liverpool, United Kingdom
	Funding: The support of the HGF and GSI under contract VH-NG-328, the EU under contract PITN-GA-2008-215080, the Max Planck Institute for Nuclear Physics and the STFC Grant ST/G008248/1 is acknowledged. The Ultra-low energy electrostatic Storage Ring (USR) at the future Facility for Low-energy Antiproton and Ion Research (FLAIR) will provide cooled beams of antiprotons in the energy range between 300 keV down to 20 keV. Based on the original design concept developed in 2005, the USR has been completely redesigned over the past few years. The ring structure is now based on a 'split achromat' lattice. This ensures compact ring dimensions of 10 x 10 m, whilst allowing both, in-ring experiments with gas jet targets and studies with extracted beams. In the USR, a wide range of beam parameters will be provided, ranging from very short pulses in the nanosecond regime to a coasting beam. In addition, a combined fast and slow extraction scheme was developed that allows for providing external experiments with cooled beams of different time structure. Furthermore, studies into beam diagnostics methods for the monitoring of ultra-low energy ions at beam intensities less than 10⁶ were carried out. Here, we present the USR design with an emphasis on the expected beam parameters available to the experiments at FLAIR.

MOPPD005	Stochastic Cooling of Antiprotons in the Collector Ring at FAIR	pick-up, antiproton, kicker, simulation	376
	C. Dimopoulou, A. Dolinskii, F. Nolden, C. Peschke, M. Steck GSI, Darmstadt, Germany
	In order to reach the required luminosities for the experiments at FAIR, the hot secondary beams (antiprotons or rare isotopes) emerging from the production targets will be efficiently collected and phase-space cooled in the large-acceptance Collector Ring (CR), which is equipped with pertinent stochastic cooling systems. Simulations of the system performance are underway in parallel with the finalization of the system design. After an overview of the CR stochastic cooling systems, simulation results for antiproton cooling in the bandwidth 1-2 GHz are presented. The CERN Fokker-Planck code is used for momentum cooling and an analytical model based on "rms" theory for the simultaneous betatron cooling. In the focus is the comparison between the time of flight and the notch filter momentum cooling methods. The results are essential for system optimization as well as input for the users of the CR-precooled beams i.e. the HESR.

MOPPD009	Stochastic Cooling Developments for HESR at FAIR	target, heavy-ion, emittance, scattering	388
	H. Stockhorst, R. Maier, D. Prasuhn, R. Stassen FZJ, Jülich, Germany C. Dimopoulou, A. Dolinskii, T. Katayama, Yu.A. Litvinov, M. Steck, T. Stöhlker GSI, Darmstadt, Germany
	The High-Energy Storage Ring (HESR) is part of the upcoming International Facility for Antiproton and Ion Research (FAIR) at GSI in Darmstadt. The HESR is planned to dedicate to the field of high-energy antiproton physics to explore the research areas of charmonium spectroscopy, hadronic structure, and quark-gluon dynamics with high-quality beams over a broad momentum range from 1.5 to 15 GeV/c. The new facility provides the combination of powerful phase-space cooled antiproton beams and internal Pellet and gas jet targets to achieve the requirements of the experiment PANDA in terms of beam quality and luminosity. Detailed theoretical analyses have been carried out to design the stochastic cooling system for accumulation and stochastic cooling of antiprotons with target operation. Recently it is proposed to utilize the HESR also for the atomic and nuclear physics with highly charged heavy ions such as 132Sn⁵⁰⁺ in the dedicated experiments at high energies 0.74-3 GeV/u. In this contribution the feasibility of stochastic cooling of heavy ions with internal targets is in detail investigated under the constraint of the cooling system hardware as foreseen for anti-proton cooling.

MOPPD011	Analysis of Frequency Spectrum of Bunched Beam Related to Transverse Laser Cooling*	synchrotron, laser, betatron, coupling	391
	K. Jimbo Kyoto University, Institute for Advanced Energy, Kyoto, Japan Z.Q. He TUB, Beijing, People's Republic of China M. Nakao, A. Noda, H. Souda, H. Tongu Kyoto ICR, Uji, Kyoto, Japan
	Using synchro-betatron coupling, transverse laser cooling is pursued at an ion storage/cooler ring, S-LSR, Kyoto University. A bunched 40 keV 24Mg+ beam was cooled by a co-propagating laser of 280 nm wavelength. Synchrotron oscillation in the longitudinal direction and betatron oscillation in the horizontal direction were intentionally coupled by an RF drift tube located at the finite dispersive section (D =1.1 m) where longitudinal cooling force was transmitted to the horizontal direction.* Analyzing bunched Schottky signals, which represents longitudinal physical quantities of the beam, we try to obtain an evidence of synchro-betatron coupling and accordingly laser cooling of the beam in the transverse direction. * H. Okamoto, Phys. Rev. E 50, 4982 (1994)

MOPPD012	Challenge for More Efficient Transverse Laser Cooling for Beam Crystallization	laser, synchrotron, simulation, betatron	394
	A. Noda, M. Nakao, H. Souda, H. Tongu Kyoto ICR, Uji, Kyoto, Japan M. Grieser MPI-K, Heidelberg, Germany Z.Q. He TUB, Beijing, People's Republic of China K. Ito, H. Okamoto, K. Osaki HU/AdSM, Higashi-Hiroshima, Japan K. Jimbo Kyoto University, Institute for Advanced Energy, Kyoto, Japan Y. Yuri JAEA/TARRI, Gunma-ken, Japan
	Funding: Work supported by Advanced Compact Accelerator Development project by MEXT. Also supported by GCOE project at Kyoto University, The next generation of Physics-Spun from Universality and Emergency. At S-LSR in ICR, Kyoto University, Mg ion beam has been successfully laser cooled both in longitudinal* and transverse** directions. The cooling rate, however, is not strong enough to realize the crystalline beam due to the heating because of intra-beam scattering (IBS) effect. So as to suppress this IBS, reduction of the beam intensity is inevitable, which however, had resulted in poor S/N ratio for observation of the transverse beam size. In the present paper, we would like to describe a new beam scraping scheme, which selects out the beams in the distribution tail of the transverse phase space keeping the beam density in the core part by simultaneous application of multi-dimensional laser cooling and beam scraping. The strategy to reduce the beam intensity and hence beam heating due to IBS by a controlled scraping of the outskirt beam keeping the beam density at core part almost the same, has been searched by combination of the beam experiments and computer simulations. * M. Tanabe et al., Applied Physics Express 1, 028001 (2008). ** M. Nakao et al., submitted to PRST-AB.

MOPPD013	Observation of 2-Component Bunched Beam Signal with Laser Cooling	laser, betatron, coupling, injection	397
	H. Souda, M. Nakao, A. Noda, H. Tongu Kyoto ICR, Uji, Kyoto, Japan M. Grieser MPI-K, Heidelberg, Germany Z.Q. He TUB, Beijing, People's Republic of China K. Ito, H. Okamoto HU/AdSM, Higashi-Hiroshima, Japan K. Jimbo Kyoto University, Institute for Advanced Energy, Kyoto, Japan Y. Yuri JAEA/TARRI, Gunma-ken, Japan
	Funding: Work supported by Advanced Compact Accelerator Development Project of MEXT, Global COE program "The Next Generation of Physics, Spun from Universality and Emergence" and Grant-in-Aid for JSPS Fellows. Longitudinal beam temperature during a laser cooling was measured through bunch length measurement at S-LSR. 40keV 24Mg+ beams were bunched by an RF voltage with a harmonic number of 5 and were cooled by a co-propagating laser with a wavelength of 280nm. Bunch length was measured by time-domain signal from a pair of parallel-plate electrostatic pickups with a length of 140mm. Injected non-cooled beams gave a bunch length of 2.5m (2-σ) and cooled beam has a 2-component of broad and sharp distribution. Broad distribution had a longitudinal length of 2.2m, which is close to that of initial beam. The length of the sharp distribution shrunk to 0.25m and is considered as a cooled part. Capture efficiency of cooling, which represents the ratio of the particle numbers of cooled part and the total particle number, varies by the change of the detuning of the laser (fixed frequency or scanning). With scanning range of 2GHz, capture efficiency was improved from 66% to 92%, whereas the bunch became longer by 10% with scanning. Approach to improve the number of cooled particle and cut uncooled part* will be applied to attain a strong signal with a low-current beam with a low temperature. * J. S. Hangst et al., Phys. Rev. Lett. 74, 4432 (1995). ** A. Noda et al., these proceedings.

MOPPD016	Status of Proof-of-principle Experiment for Coherent Electron Cooling	electron, gun, wiggler, FEL	400
	I. Pinayev, S.A. Belomestnykh, I. Ben-Zvi, J. Bengtsson, A. Elizarov, A.V. Fedotov, D.M. Gassner, Y. Hao, D. Kayran, V. Litvinenko, G.J. Mahler, W. Meng, T. Roser, B. Sheehy, R. Than, J.E. Tuozzolo, G. Wang, S.D. Webb, V. Yakimenko BNL, Upton, Long Island, New York, USA G.I. Bell, D.L. Bruhwiler, V.H. Ranjbar, B.T. Schwartz Tech-X, Boulder, Colorado, USA A. Hutton, G.A. Krafft, M. Poelker, R.A. Rimmer JLAB, Newport News, Virginia, USA M.A. Kholopov, P. Vobly BINP SB RAS, Novosibirsk, Russia
	Funding: US DOE Office of Science, DE-FC02-07ER41499, DE-FG02-08ER85182; NERSC DOE contract No. DE-AC02-05CH11231. Coherent electron cooling (CEC) has a potential to significantly boost luminosity of high-energy, high-intensity hadron colliders. To verify the concept we conduct proof-of-the-principle experiment at RHIC. In this paper, we describe the current experimental setup to be installed into 2 o’clock RHIC interaction regions. We present current design, status of equipment acquisition and estimates for the expected beam parameters.

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

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

MOPPD036	Gabor Lens Focusing for Medical Applications	laser, proton, space-charge, focusing	442
	J.K. Pozimski, M. Aslaninejad Imperial College of Science and Technology, Department of Physics, London, United Kingdom
	The widespread introduction of Hadron therapy for cancer treatment is inhibited by the large costs for the accelerator and treatment facility and the subsequent maintenance costs which reflects into the cost per treatment. In the long term future (laser) plasma wakefield accelerated hadrons could offer compact treatment devices with significantly reduced treatment costs. In the moment the particle distributions produced by such accelerators do not fulfill the medical requirements by far. Never the less steady progress on the field might change the situation in the future. Beside the reliable production of a sufficient number of ions at the required energy the formation of a particle beam suitable for treatment from the burst of ions created in the acceleration process is one of the major challenges. While conventional optical systems will be operating at the technical limits which would be contradictory to the cost argument, space charge lenses of the Gabor type might be a cost effective alternative. In this paper a beam line consisting of such lenses will be presented together with particle transport simulations.

MOPPD037	Investigation of Space Charge Compensation at FETS	space-charge, emittance, ion-source, rfq	445
	J.K. Pozimski, S.M.H. Alsari, P. Savage Imperial College of Science and Technology, Department of Physics, London, United Kingdom D.C. Faircloth, A.P. Letchford STFC/RAL/ISIS, Chilton, Didcot, Oxon, United Kingdom
	In order to contribute to the development of high power proton accelerators in the MW range, to prepare the way for an ISIS upgrade and to contribute to the UK design effort on neutrino factories, a front end test stand (FETS) is being constructed at the Rutherford Appleton Laboratory (RAL) in the UK. The aim of the FETS is to demonstrate the production of a 60 mA, 2 ms, 50 pps chopped beam at 3 MeV with sufficient beam quality. The ion source and LEBT are operational with the RFQ under manufacture. In the LEBT a high degree of space charge compensation (~90%) and a rise time of space charge compensation around ~ 50 μs could be concluded indirectly from measurements . As a more detailed knowledge is of interest also for other projects like ESS the FETS LEBT was updated to perform a detailed experimental analysis of space charge compensation. In this paper the results of the experimental work will be presented together with discussion of the findings in respect to beam transport.

MOPPD038	Simulation Study of Electron Response Amplification in Coherent Electron Cooling	electron, bunching, FEL, undulator	448
	Y. Hao, V. Litvinenko BNL, Upton, Long Island, New York, USA
	Funding: Work supported by Brookhaven Science Associates, LLC under Contract No. DE-AC02-98CH10886 with the U.S. Department of Energy. In Coherent Electron Cooling (CEC), it is essential to study the amplification of electron response to a single ion in the FEL process, in order to proper align the electron beam and the ion beam in the kicker to maximize the cooling effect. In this paper, we use Genesis to simulate the amplified electron beam response of single ion in FEL amplification process, which acts as 'Green function' of the FEL amplifier.

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

MOPPD046	Lifetime of the Highly Efficient H⁻ Ion Sources	cathode, plasma, extraction, electron	466
	V.G. Dudnikov Muons, Inc, Batavia, USA D.S. Bollinger Fermilab, Batavia, USA D.C. Faircloth, S.R. Lawrie STFC/RAL/ISIS, Chilton, Didcot, Oxon, United Kingdom
	Funding: Work supported by grant DE-SC0006267, and STFC JAI grant ST/G008531 Factors limiting operating lifetime of Compact Surface Plasma Sources (CSPS) are analyzed and possible treatments for lifetime enhancement are considered. CSPSs have high plasma density (up to 10¹⁴ cm^-3), high emission current density of negative ions (up to 8 A/cm²), small (1–5 mm) gap between cathode emitter, and a small extraction aperture in the anode. They are very simple, have high energy efficiency up to 100 mA/kW of discharge (~100 times higher then modern large Volume RF SPS) and have a high gas efficiency (up to 30%) using pulsed valves. CSPSs are very good for pulsed operation but electrode power density is often too high for dc operation. However, CSPSs were successfully adopted for DC operation with emission current density ~300 mA/cm² in Hollow cathode Penning Discharge and up to 1 A/cm² in Spherical focusing semiplanotron. Flakes from electrodes sputtering and blistering induced by back accelerated positive ions are the main reasons of ion source failure. Suppression of back accelerated positive ions, flakes explosion by pulsed discharges, and flakes gasification by discharge in NF₃ (or XeF₂) can be used for significant increase of operating lifetime of CSPSs.

MOPPD047	Progress of Surface Plasma H⁻ Ion Source with Saddle RF Antenna Plasma Generator	plasma, ion-source, gun, electron	469
	V.G. Dudnikov, R.P. Johnson Muons, Inc, Batavia, USA S.N. Murray, T.R. Pennisi, C. Piller, M. Santana, M.P. Stockli, R.F. Welton ORNL, Oak Ridge, Tennessee, USA
	Funding: Supported in part by SBIR Grant 4729 · 09SC02690. Progress in development of RF H⁻ surface plasma source (SPS) with saddle (SA) RF antenna which will provide better power efficiency for high pulsed and average current, higher brightness with longer lifetime and higher reliability will be considered. Several versions of new plasma generators with a small Al2O3chamber and different antennas and magnetic field configurations were tested in the SNS small Test Stand. A prototype SA SPS was installed in the Test Stand with a larger, normal-sized SNS AlN chamber that achieved unanalyzed peak currents of up to 67 mA with an apparent efficiency of 1.6 mA/kW. Control experiments with H⁻ beam produced by SNS SPS with internal and external antennas in the similar conditions were conducted. A new version of the RF triggering plasma source (TPS) has been designed and fabricated. A Saddle antenna SPS with water cooling is being fabricated for high duty factor testing

MOPPD048	Ribbon Electron Beam Profile Monitor for Bunched Beam Tomography	electron, cathode, proton, diagnostics	472
	V.G. Dudnikov Muons, Inc, Batavia, USA A.V. Aleksandrov ORNL, Oak Ridge, Tennessee, USA
	Funding: Work supported by Contract DE-AC05-00OR22725 and by STTR grant DE-SC0007559 Advanced beam diagnostics are essential for high performance accelerator beam production and for reliable accelerator operation. It is important to have noninvasive diagnostics which can be used continuously with intense beams of accelerated particles. Recently, an electron probe was successfully used to determine accelerated particle density distributions. However, the apparatus used for this diagnostic is large and complex which restricts its wider use for tomography of accelerated bunches. We propose to use a strip cathode is for ribbon electron beam formation instead of a scanning of pencil beam used in the previous electron probe bunch profile monitors. The apparatus with the strip cathode is smaller, has simpler design and less expensive manufacturing, can have better magnetic shielding, higher sensitivity, higher resolution, can have better measurement accuracy and better time resolution. With this device it is possible to develop almost ideal tomography diagnostics of bunches in linear accelerators and in circular accelerators and storage rings.

MOPPD070	A SVD-based Orbit Steering Algorithm for RHIC Injection	injection, heavy-ion, proton, controls	523
	C. Liu, A. Marusic, M.G. Minty, V. Ptitsyn BNL, Upton, Long Island, New York, USA
	Funding: Work supported by Brookhaven Science Associates, LLC under Contract No. DE-AC02-98CH10886 with the U.S. Department of Energy. The RHIC physics programs involve experiments with polarized proton and several species of ion beams. In the past, when switching between physics programs, first turn and circulating beam in RHIC was established manually by adjustments to the corrector dipoles for minimum beam loss. In this report, we introduce a new steering scheme based on an SVD algorithm which uses a single-pass orbit response matrix for first turn steering. The new scheme was implemented into the controls system and demonstrated successfully in Run-11. Establishing circulating beam using this automated approach has been shown to dramatically reduce the beam setup time.

MOPPR012	Beam Induced Fluorescence Monitors for FAIR	vacuum, electron, target, antiproton	798
	F. Becker, C.A. Andre, C. Dorn, P. Forck, R. Haseitl, B. Walasek-Höhne GSI, Darmstadt, Germany T. Dandl, T. Heindl, A. Ulrich TUM/Physik, Garching bei München, Germany
	Online profile diagnostic is preferred to monitor intense hadron beams at the Facility of Antiproton and Ion Research (FAIR). One instrument for beam profile measurement is the gas based Beam Induced Fluorescence (BIF)-monitor. It relies on the optical fluorescence of residual gas, excited by beam particles. Depending on the beam parameters and vacuum constraints, BIF monitors can be operated at base pressure or in dedicated local pressure bumps. Spectroscopic data in nitrogen and rare gases confirms an exploitable dynamic range from UHV to atmospheric pressure. Optical transitions and corresponding beam profiles are discussed for gas pressures from 10^-3 to 30 mbar. Fundamental limitations for some application scenarios will be addressed as well.

MOPPR013	Beam Loss and Transmission Control at FAIR	controls, synchrotron, proton, extraction	801
	M. Schwickert, T. Hoffmann, F. Kurian, H. Reeg, A. Reiter GSI, Darmstadt, Germany W. Vodel HIJ, Jena, Germany
	FAIR, the Facility for Antiproton and Ion Research, is presently entering the final layout phase at GSI. The injector chain consists of the existing linear accelerator UNILAC and synchrotron SIS18, plus a new dedicated 70 MeV high-intensity proton Linac. Along the injector chain to the main synchrotron SIS100 as well as in the beam transport lines, which connect synchrotrons, storage rings and experimental areas, beam transmission or vice versa beam loss have to be controlled very precisely. To supply a maximum intensity of 5·10¹¹ U²⁸⁺/spill to experiments and to prevent machine damages by intense beams, an integrated system for transmission and loss control is mandatory. While various kinds of beam current transformers control transmission online, intercepting Particle Detector Combinations (scintillators, ionization chambers, secondary electron monitors) are foreseen for optimization runs. External Beam Loss Monitors indirectly detect loss positions by measuring secondary particles. This contribution summarizes the requirements for the related detector systems and presents basic concepts for beam loss and transmission control at FAIR.

MOPPR020	An Improved Cryogenic Current Comparator for FAIR	pick-up, shielding, cryogenics, niobium	822
	R. Geithner, W. Vodel HIJ, Jena, Germany R. Geithner, R. Neubert, P. Seidel FSU Jena, Jena, Germany F. Kurian, H. Reeg, M. Schwickert GSI, Darmstadt, Germany
	Online monitoring of low intensity (below 1 μA) charged particle beams without disturbing the beam and its environment is crucial for any accelerator facility. For the upcoming FAIR project a beam monitor based on the Cryogenic Current Comparator principle with an enhanced resolution was developed. The main focus of research was on the low temperature properties of the ferromagnetic core material of the superconducting pickup coil. The pickup coil transforms the magnetic field of the beam into a current that is detected by a high performance low temperature dc Superconducting QUantum Interference Device (LTS-DC-SQUID). The penetration of the pickup coil by interfering magnetic fields is highly attenuated by a meander shaped superconducting shielding. The Cryogenic Current Comparator is able to measure DC beam currents, e.g. as required for slow extraction from a synchrotron, as well as bunched beams. In this contribution we present first results of the improved Cryogenic Current Comparator working in a laboratory environment.

MOPPR028	Upgrade Plan of BLM System of J-PARC MR	extraction, injection, proton, monitoring	837
	K. Satou, T. Toyama J-PARC, KEK & JAEA, Ibaraki-ken, Japan
	The upgrade plan of BLM system of J-PARC Main Ring synchrotron (MR) will be described. Existing proportional chamber beam loss monitors (P-BLMs) have fast signal rise time of about 100ns and high gas gain of about 2·10⁴ at the maximum. These abilities were quite advantageous for the early beam commissioning stage. On the other hand, the gas gain is degraded with increasing output current. The P-BLM is suitable for a measurement of a low level beam loss event, however, vulnerable to a measurement of an accidental beam loss event (fast loss) causing high radiation. To enhance the dynamic range of the system, 1m long Air Ionization Chambers (AICs) will be installed and operated with the P-BLM. Experiments using the real beam loss at collimator area and at the Co60 radiation facility have demonstrated the stable operations up to the radiation level activated by the maximum beam loss power of the collimator area. A new data taking system is now under development, and its performances will also be presented.

MOPPR029	Upgrade of Ionization Profile Monitor (IPM) in the J-PARC 3-GeV RCS	electron, vacuum, status, space-charge	840
	H. Harada, K. Yamamoto, M. Yoshimoto JAEA/J-PARC, Tokai-Mura, Naka-Gun, Ibaraki-Ken, Japan
	Ionization Profile Monitors (IPM) were installed and operated in the J-PARC 3-GeV RCS for the observation of circulating beam profile. In IPM system, ions produced by the beam passing through beam chamber lead to Multi Channel Plate (MCP) by electric field, and the signals from the MCP are observed as the beam profile. The IPM system has an upgrade plan for the optimization of the electric fields. This will be reported the upgrade status of the IPM.

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

MOPPR055	A Two-dimensional Wire Scanner for a Low Energy Ion Beam	diagnostics, ion-source, acceleration, vacuum	909
	C. Gabor STFC/RAL/ASTeC, Chilton, Didcot, Oxon, United Kingdom G.E. Boorman Royal Holloway, University of London, Surrey, United Kingdom A.P. Letchford STFC/RAL/ISIS, Chilton, Didcot, Oxon, United Kingdom
	The Front End Test Stand (FETS) at the Rutherford Appleton Laboratory (RAL) is intended to demonstrate the early stages of acceleration for future high power proton applications. So far, the H⁻ ion source and the low energy beam transport (LEBT) are operational. The commissioning of the LEBT is carried out with a multipurpose diagnostics vessel. On the other hand, the present status of the LEBT does not provide any permanent installed beam diagnostics beyond current measurement. Possible diagnostics need to be compact and rigid in a way that it can survive an area with potentially high beam losses and not suffering to much of beam noise. Furthermore, minimal invasive diagnostics is preferred. It is intended to present first results of a wire scanner where the geometry has been changed in a way that the two dimensional xy-space is accessible.

MOPPR056	Experimental and Theoretical Studies of a Low Energy H⁻ beam	rfq, acceleration, ion-source, solenoid	912
	C. Gabor STFC/RAL/ASTeC, Chilton, Didcot, Oxon, United Kingdom G.E. Boorman Royal Holloway, University of London, Surrey, United Kingdom A.P. Letchford STFC/RAL/ISIS, Chilton, Didcot, Oxon, United Kingdom
	The Front End Test Stand (FETS) at the Rutherford Appleton Laboratory (RAL) is intended to demonstrate the early stages of acceleration (0-3 MeV) and beam chopping required for high power proton accelerators. At the moment, the RFQ is under construction and there is a need to understand the matching of the Low Energy Beam Transport (LEBT) into the RFQ as conclusive as possible. The parameter of interest may include solenoid settings, steering effects but also the influence of the post acceleration of the ion source and potential effects of space charge compensation. Two emittance scanner are installed and can be combined with scintillator acting as a beam profile monitor and auxiliaries like current measurement.

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

TUYA02	Overview of Asymmetric Electron Hadron Colliders	electron, collider, hadron, proton	1025
	V. Ptitsyn BNL, Upton, Long Island, New York, USA
	The first lepton-proton collider HERA at DESY completed its operation in 2007. Presently, several accelerator proposals for future electron-hadron colliders are under consideration in several laboratories from all over the world. The future accelerators intend to exceed the HERA luminosity by 2-3 orders of magnitude, as well as to cover the different ranges of center-of-mass collision energies. The research capabilities will be extended by including the collisions of electrons with heavy ions, as well as, in some designs, with polarized protons and polarized ions. The future electron-hadron colliders would serve as high-resolution microscopes able to reveal unprecedented details of the structure of nucleons and ions, including their spin content and the state of high gluon density matter. The colliders will provide us with ultimate tools to test both the ways Quantum Chromodynamics works as well as to look for new physics beyond the Standard Model. All proposed electron-hadron colliders are based on the extension of existing accelerators to accommodate the electron-hadron collisions. Advanced accelerator technologies are utilized in order to achieve the desired high luminosity.
	Slides TUYA02 [6.002 MB]

TUYB01	Proton Beam Acceleration with Circular Polarized Laser Pulses	laser, proton, electron, plasma	1045
	X.Q. Yan, J.E. Chen, C. Lin, Y.R. Lu, H. Wang PKU/IHIP, Beijing, People's Republic of China Z.Y. Guo IHEP, Beijing, People's Republic of China
	This presentation should describe the use of circular polarized laser pulses for phase-stable acceleration of proton beams. The principles of the technique should be explained, with comparisons and contrasts made with similar techniques. The potential for production of high-intensity, mono-energetic proton beams should be discussed, and the results of analytical, simulation, and experimental studies presented.
	Slides TUYB01 [7.922 MB]

TUOBA01	Summary of Fermilab’s Recycler Electron Cooler Operation and Studies	electron, antiproton, emittance, extraction	1068
	L.R. Prost, A.V. Shemyakin Fermilab, Batavia, USA
	Funding: Operated by Fermi Research Alliance, LLC under Contract No. DE-AC02-07CH11359 with the United States Department of Energy. Fermilab’s Recycler ring was used as a storage ring for accumulation and subsequent manipulations of 8 GeV antiprotons destined for the Tevatron collider. To satisfy these missions, a unique electron cooling system was designed, developed and successfully implemented. The most important features that distinguish the Recycler cooler from other existing electron coolers are its relativistic energy (it employs a 4.3 MeV, 0.1 A DC electron beam), a weak continuous longitudinal magnetic field in the cooling section (~100 G), and lumped focusing elsewhere. With the termination of the collider operation at Fermilab, the cooler operation was also terminated. In this article, we will summarize the experience of commissioning, optimizing and running this unique machine over the 6 years of its existence.
	Slides TUOBA01 [2.503 MB]

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

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

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

TUPPC007	Electron Cloud Dynamics in a Gabor Space Charge Lens	electron, space-charge, plasma, focusing	1164
	K. Schulte, M. Droba, B. Glaeser, S. Klaproth, O. Meusel, U. Ratzinger IAP, Frankfurt am Main, Germany
	Inside Gabor space charge lenses, external fields confine electrons forming a homogeneously distributed electron cloud. Its linear electric space charge field enables the focusing of high intensity heavy ion beams without aberrations. The focusing performance depends on the properties of the non-neutral plasma. In a small-scale table top experiment, different types of space charge lenses are used to characterize the collective behavior of the confined electron cloud using new non-interceptive diagnostic methods. The plasma parameters, e.g. electron temperature and density, are important to an improved understanding of loss and production mechanisms as well as the electron cloud dynamics. In this context, the evolution of instabilities caused by the enclosing fields has been investigated in detail. Experimental results will be presented and compared to numerical simulations.

TUPPC012	Optics of Extraction Lines at CNAO	proton, dipole, extraction, septum	1179
	E. Bressi, L. Falbo, C. Priano, M. Pullia CNAO Foundation, Milan, Italy C. Biscari INFN/LNF, Frascati (Roma), Italy
	The CNAO (National Center for Oncological Hadrontherapy), is the first Italian center for deep hadrontherapy with proton and carbon ion beams, treating patients since fall 2011. The beam is delivered to the patient through a high energy transfer line (HEBT). The line is equipped with a horizontal switching dipole that carries the beam in three treatment rooms and a vertical switching dipole that allows a vertical delivery of the beam in the central treatment room. The CNAO HEBT commissioning has been carried out using proton and Carbon beams in the full range of energies: 60 to 250 MeV/u for protons, 120 to 400 MeV/u for Carbon ions. Optimization of the beam lines setup has been carried out for few energies, applying beam magnetic rigidity scaling for the full range in steps of the order of 1 MeV. The scaling has proven to be satisfactory for most elements, and only minor adjustments in the initial part of the line were needed to fulfill tolerances in all the range. Repeatability of magnetic settings is supported by measurements along the lines. Finally the results in terms of beam dimensions, beam transmission and beam position at the patient position are presented.

TUPPC030	Status of the Ion Sources at ESS-Bilbao	controls, ion-source, plasma, extraction	1227
	J. Feuchtwanger, I. Arredondo, F.J. Bermejo, I. Bustinduy, J. Corres, M. Eguiraun, P.J. González, J.L. Muñoz ESS Bilbao, Bilbao, Spain V. Etxebarria, J. Jugo, J. Portilla University of the Basque Country, Faculty of Science and Technology, Bilbao, Spain R. Miracoli ESS-Bilbao, Zamudio, Spain
	Currently there are two types of ion sources under development and testing at ESS-Bilbao, the first one is a Penning type source based on the ISIS/RAL source, modified to use permanent magnets to generate the Penning field. The second source is an off-resonance ECR source that is being developed in-house. The Penning source is in the late stages of commissioning, and a beam has been extracted from it. Currently the main work on that source is in the optimization of the operating parameters. The ECR source on the other hand is in the early stages of the commissioning, all parts have been fabricated, and Vacuum tests are underway. Testing of the RF and control systems will follow, and finally the whole system will be tested. The control system for both ion sources was developed under LabView, and runs on a real time system. While for testing the timing sequences run locally, the system is being developed so that it can run using a central timing system.

TUPPC062	Transfer of Polarized 3He Ions in the AtR Beam Transfer Line	injection, extraction, dipole, proton	1317
	N. Tsoupas, W.W. MacKay, F. Méot, T. Roser, D. Trbojevic BNL, Upton, Long Island, New York, USA
	Funding: Work supported by the US Department of Energy In addition to collisions of electrons with various unpolarized ion species as well as polarized protons, the proposed electron-hadron collider (eRHIC) will also facilitate the collisions of electrons with polarized 3He ions. The AGS is the last acceleration stage of ions before injection into one RHIC for final acceleration. The AtR (AGS to RHIC) transfer line will be utilized to transport the polarized 3He ions from AGS into one of the RHIC’s collider rings. In this paper we investigate the extraction energy of the polarized 3He ions from the AGS which will optimize the polarization of 3He ions injected into RHIC. Some of the peculiarities (interleaved horizontal and vertical bends) of the AtR line's layout may degrade this spin matching of the polarized 3He ions. We will also discuss possible simple modifications of the AtR line to accomplish a perfect “spin matching” of the injected 3He beam with that of the stable spin direction at the injection point of the RHIC ring.

TUPPC097	Computational Modeling of Electron Cloud For MEIC	electron, simulation, collider, emittance	1383
	S. Ahmed, J.D. Dolph, G.A. Krafft, T. Satogata, B.C. Yunn JLAB, Newport News, Virginia, USA
	Funding: Authored by Jefferson Science Associates, LLC under U.S. DOE Contract No. DE-AC05-06OR23177. This work is the continuation of our earlier studies on electron cloud (EC) simulations reported in IPAC'11 for the medium energy electron-ion collider (MEIC) envisioned at JLab beyond the 12 GeV upgrade of CEBAF. In this paper, we will study the EC saturation density in various MEIC operations scenarios to calculate details of the EC-induced wakefield to establish more stringent bounds on instability thresholds and determine whether EC mitigation, such as NEG coatings or solenoid fields, should be considered in the MEIC design.

TUPPC099	Optimization of Chromaticity Compensation and Dynamic Aperture in MEIC Collider Rings	sextupole, dynamic-aperture, octupole, collider	1389
	F. Lin, Y.S. Derbenev, V.S. Morozov, Y. Zhang JLAB, Newport News, Virginia, USA K.B. Beard Muons, Inc, Batavia, USA
	Funding: Authored by Jefferson Science Associates, LLC under U.S. DOE Contract No. DE-AC05-06OR23177. Supported in part by US DOE STTR grant DE-SC0006272. The conceptual design of the Medium-energy Electron-Ion Collider (MEIC) at Jefferson Lab relies on an ultra-small beta-star to achieve high luminosities of up to 10³⁴ cm^-2s⁻¹. A low-beta insertion for interaction regions unavoidably induces large chromatic effects that demand a proper compensation. The present approach of chromatic compensation in the MEIC collider rings is based on a local correction scheme using two symmetric chromatic compensation blocks that includes families of sextupoles, and are placed in a beam extension area on both sides of a collision point. It can simultaneously compensate the first order chromaticity and chromatic beam smear at the IP without inducing significant second order aberrations. In this paper, we investigate both the momentum acceptance and dynamic aperture in the MEIC ion collider ring by considering the aberration effects up to the third order, such as amplitude dependent tune shift. We also explore the compensation of the third order effects by introducing families of octupoles in the extended beam area. Authored by Jefferson Science Associates, LLC under U.S. DOE Contract No. DE-AC05-06OR23177. Supported in part by US DOE STTR grant DE-SC0006272.

TUPPC103	Ion Bunch Length Effects on the Beam-beam Interaction and its Compensation in a High-luminosity Ring-ring Electron-ion Collider	electron, proton, luminosity, simulation	1401
	C. Montag, W. Fischer, A. Oeftiger BNL, Upton, Long Island, New York, USA
	Funding: Work supported by Brookhaven Science Associates, LLC under Contract No. DE-AC02-98CH10886 with the U.S. Department of Energy. One of the luminosity limits in a ring-ring electron-ion collider is the beam-beam effect on the electrons. In the limit of short ion bunches, simulation studies have shown that this limit can be significantly increased by head-on beam-beam compensation with an electron lens. However, with an ion bunch length comparable to the beta-function at the IP in conjunction with a large beam-beam parameter, the electrons perform a sizeable fraction of a betatron oscillation period inside the long ion bunches. We present recent simulation results on the compensation of this beam-beam interaction with multiple electron lenses.

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

TUPPD026	Study of the RFQ Beam Cooler for SPES project	rfq, quadrupole, emittance, extraction	1467
	M.M. Maggiore, A.M. Porcellato, S. Stark INFN/LNL, Legnaro (PD), Italy
	The SPES project is the new Radioactive Ion Beam facility under construction at Laboratori Nazionali of Legnaro, Italy. In this framework in order to improve the beam quality in terms of emittance and energy spread, a study of a new RFQ beam cooler device is accomplishing. The electromagnetic design of the RFQ section and the electrostatic layout of the injection and extraction regions have been done. The study about the beam dynamic is going on by means of dedicated codes which allow to take into account the interaction of the ions with the buffer gas needed to cool the beams. The status of the project and the results will be shown in this report.

TUPPD031	Novel Techniques for Isotope Harvesting at FRIB	simulation, optics, target, resonance	1470
	M.A.C. Cummings Muons, Inc, Batavia, USA L.L. Bandura FRIB, East Lansing, Michigan, USA
	Exotic isotopes have applications in medicine, industry, and national security. Historically, the U.S. has relied on foreign sources for these isotopes. FRIB will be a domestic source of these isotopes. While FRIB is mainly focused on producing exotic isotopes for basic nuclear physics experiments, it also offers an opportunity to harvest unused isotopes for other applications. It is critical that isotope harvesting take place in a synergistic manner that does not adversely affect experiments that will be simultaneously taking place at the facility. Beam optics schemes will be calculated to determine the best locations and methods of separation. These calculations will use COSY Monte Carlo and G4beamline in conjunction with other state of the art ion optical codes that simulate isotope dynamics in magnetic fields and in matter. The results of these simulations will be used to determine the best beam-target combinations to produce the isotopes that are most in-demand and calculate purities of these isotopes in multiple locations in the fragment separators. Trapping and extraction schemes will also be described to maximally recover pure isotope samples.

TUPPD042	Design of Transmission Line at 28 GHz, 10 kW for ECR Ion Source in KBSI	ion-source, ECRIS, plasma, vacuum	1494
	M. Won, S. Choi, B.C. Kim, B.S. Lee, J.W. Ok, J.Y. Park, J.H. Yoon Korea Basic Science Institute, Busan, Republic of Korea
	The 28 GHz gyrotron system was designed to deliver the microwave power from gyrotron oscillator to an electron cyclotron resonance ion source (ECRIS) for simultaneously producing high current and highly charged ions. The microwave power from 28 GHz gyrotron were measured from the range between 0.5 kW and 10 kW with frequency variation from 27.9740 to 27.9893 GHz. The gyrotron oscillator of transmission system operates in continuous wave regime with the smoothly regulated output microwave power. A transmission line was designed for the transport of microwaves to an ion source. For the electrical insulation between gyrotron system and ion source chamber applied to high voltage, we installed a DC break. In order to evaluate gyrotron operation, a dummy load was developed to consume such high microwave power.

TUPPD044	Conceptual Gas Jet as a Stripping Target for Charge Exchange Injection	target, injection, laser, proton	1500
	V.G. Dudnikov, C.M. Ankenbrandt Muons, Inc, Batavia, USA
	Stripping targets for charge exchange injection now uses thin carbon or Al2O3 foils. During long time injection for high intense beam accumulation by low current injection a foil life time can be compromised by overheating and alternative stripping targets need be developed. A pulsed supersonic gas jet was used as a stripping target in first realization of charge exchange injection with H⁻ ion energy 1.5 MeV and stationary gas jets are used as internal targets in experiments with super high vacuum. A stripper target thickness is proportional to the injection energy and for energy 1GeV should be ~0.3 mg/cm² of carbon. The pulsed gas target with such thickness acceptable for long time charge exchange injection can be produced with using of heavy hydrocarbon molecules used in the diffusion or booster vacuum pumps. Formation of the pulsed gas jet stripping targets will be considered.

TUPPD045	Efficient Plasma Generation by Positive Circulating Beams	electron, proton, vacuum, plasma	1503
	V.G. Dudnikov, C.M. Ankenbrandt Muons, Inc, Batavia, USA
	Performances of high brightness circulating beams are affected by development of strong “electron-proton” (e-p) instabilities connected with generation of an electron cloud (EC). For suppression of the EC generation it is proposed a coating of vacuum chambers by compounds with low secondary electron emission, which is very complex and expensive for large systems like LHC or RHIC. Threshold beam intensity for EC generation can be increased during the vacuum chamber bombarding by plasma particles generating by EC. Vacuum chamber processing (scrubbing) by EC is conducted by bunched beam with a highest possible intensity and with shortest gaps between bunches. Highly efficient plasma generation can be produced in the coasting circulating beam of positive particles with relative low intensity and energy. With the coasting positive beam the plasma particles are generating by low energy electrons trapped by a positive beam space charge. Dynamics of electrons and ions generation will be estimated and simulated. The rate of plasma generation and surface scrubbing can be increase by decrease of pumping and injection of selected gases.

TUPPD046	Characterization of Li⁺ Alumino-Silicate Ion Source for Target Heating Experiments	extraction, ion-source, space-charge, brightness	1506
	P.K. Roy, W.G. Greenway, J.W. Kwan, S.M. Lidia, P.A. Seidl, W.L. Waldron LBNL, Berkeley, California, USA D.P. Grote LLNL, Livermore, California, USA
	Funding: *This work was performed under the auspices of the U.S Department of Energy by LLNL under contract DE AC52 07NA27344, and by LBNL under contract. DE-AC02-05CH11231. The Heavy Ion Fusion Sciences (HIFS) program at Lawrence Berkeley National Laboratory will carry out warm dense matter experiments using Li⁺ ion beam with energy 1.2–3 MeV to achieve uniform heating up to 0.1–1 eV. Experiments will be done using the Neutralized Drift Compression Experiment-II (NDCX-II) facility. The NDCX-II accelerator has been designed to use a large diameter (10.9 cm) Li⁺ doped alumino-silicate source to produce short pulses of ≈93 mA beam current. Fabrication of a lithium source is complex, it is necessary to apply a higher temperature (>1200-degC) for thermionic emission, and the beam current density of this source is ~1mA/cm² in the space-charge limited regime. Li⁺ emission is lower than the other alkaline ions sources (K⁺, Cs⁺). The lifetime of this source is roughly 50 hours, when pulsed. Characterization of an operational lithium alumino-silicate ion source, including beam emittance, is presented.

TUPPD047	Injection Sequence for High-power Isochronous Cyclotrons for ADS Fission	cyclotron, rfq, ion-source, emittance	1509
	S. Assadi, K.E. Badgley, C. Collins, J. Comeaux, R. Garrison, P.M. McIntyre, A. Sattarov Texas A&M University, College Station, Texas, USA
	Funding: This work is supported by grants from the State of Texas (ASE) and the Mitchell Family Foundation. A high-current injector sequence is being developed for use in a flux-coupled stack of high-current cyclotrons for accelerator-driven subcritical (ADS) fission. The design includes an ECR ion source, LEBT, RF quadrupole, and multi-stage chopper. A first cyclotron then accelerates the beams to 100 MeV for injection to the sector isochronous cyclotron. Provisions for control of emittance and bunch tails are described.

TUPPD048	Optical Emission Spectroscopy Studies of the Spallation Netron Source (SNS) H⁻ Ion Source	ion-source, plasma, neutron, background	1512
	B. Han, S.N. Murray ORNL RAD, Oak Ridge, Tennessee, USA T.R. Pennisi, M. Santana, M.P. Stockli, R.F. Welton ORNL, Oak Ridge, Tennessee, USA
	A Cs enhanced, RF-driven H⁻ ion source feeds the SNS accelerator with a 65 keV H⁻ beam at 60 Hz with a pulse length of up to 1.0 ms. The ion source beam intensity and reliability are critical to the SNS operational power level and availability. The 1-MW level routine operation of the SNS requires ~38 mA beam in the linac. This requirement is normally met by the ion source in a persistent manner for a 4-5 weeks service-cycle of the ion source. But, in some occasions, the ion source either falls short of the beam current or fails to keep the beam current persistent. The key factor in achieving high current, persistent H⁻ beam is to have a proper coverage of Cs on the ion converter surface near the source outlet. To quantify the amount of Cs put into the system during cesiation(s) and to monitor the Cs migration during the source operation, an experimental study is under way with an optical spectrometer monitoring the emission lights from the ion source plasma. Another possible use of this emission spectroscopy study is to detect the indication of the ion source antenna deterioration before it develops into a total failure. The progress and some preliminary results are presented.

TUPPD052	A New Load Lock System for the Source of Polarized Electrons at ELSA	electron, vacuum, polarization, laser	1521
	D. Heiliger, W. Hillert, B. Neff ELSA, Bonn, Germany
	Funding: supported by DFG (SFB/TR16) Since 2000, an inverted source of polarized electrons at the electron stretcher accelerator ELSA routinely provides a pulsed beam with a current of 100 mA and a polarization degree of about 80%. One micro-second long pulses with 100 nC charge are produced by irradiating a GaAs strained-layer superlattice photocathode (8 mm in diameter) with laser light. Future accelerator operation requires a significantly higher beam intensity, which can be achieved by using photocathodes with sufficiently high quantum efficiency. Therefore, and in order to enhance the reliability and up time of the source, a new extreme high-vacuum (XHV) load lock system was installed and commissioned at the beginning of this year. It consists of three chambers: The activation chamber for heat cleaning of the photocathodes and activation with cesium and oxygen. The storage chamber in which up to five different types of photocathodes with various diameters of the emitting surface can be stored under XHV conditions. The loading chamber in which an atomic hydrogen source is used to remove any remaining surface oxidation. Additionally, tests of the photocathodes’ properties can be performed during operation.

TUPPR079	Ion Polarization in the MEIC Figure-8 Ion Collider Ring	polarization, proton, resonance, collider	2008
	V.S. Morozov, Y.S. Derbenev, Y. Zhang JLAB, Newport News, Virginia, USA P. Chevtsov Paul Scherrer Institut, Villigen, Switzerland Y. Filatov MIPT, Dolgoprudniy, Moscow Region, Russia A.M. Kondratenko, M.A. Kondratenko Science and Technique Laboratory Zaryad, Novosibirsk, Russia
	Funding: Authored by Jefferson Science Associates, LLC under U.S. DOE Contract No. DE-AC05-06OR23177. The nuclear physics program envisaged at the Medium-energy Electron-Ion Collider (MEIC) currently being developed at the Jefferson Lab calls for collisions of 3-11 GeV/c longitudinally polarized electrons and 20-100 GeV/c, in equivalent proton momentum, longitudinally or transversely polarized light ions. In this paper, we present a scheme based on figure-8 shaped booster and collider rings that provides the required ion polarization arrangement in the MEIC's ion collider ring. The U.S. Government retains a non-exclusive, paid-up, irrevocable, world-wide license to publish or reproduce this manuscript for U.S. Government purposes.

TUPPR080	Integration of Detector into Interaction Region at MEIC	dipole, solenoid, optics, electron	2011
	V.S. Morozov, R. Ent, P. Nadel-Turonski JLAB, Newport News, Virginia, USA C. Hyde Old Dominion University, Norfolk, Virginia, USA
	Funding: Notice: Authored by Jefferson Science Associates, LLC under U.S. DOE Contract No. DE-AC05-06OR23177. The Jefferson Lab's Medium-energy Electron Ion Collider (MEIC) is proposed as a next-generation facility for the study of strong interaction (QCD). Accessing the relevant physics requires a full-acceptance detector with a dedicated small-angle high-resolution detection system capable of covering a wide range of momenta (and charge-to-mass ratios) with respect to the original ion beam. We present a design of such a detection system integrated into the collider's interaction region, in which full acceptance is attained by letting small-angle collision products pass through the nearest elements of the machine final-focusing system for further detection. The proposed design is consistent with the current collider optics and demonstrates an excellent performance in terms of detector acceptance and resolution. The U.S. Government retains a non-exclusive, paid-up, irrevocable, world-wide license to publish or reproduce this manuscript for U.S. Government purposes.

TUPPR082	MEIC Design Progress	electron, collider, booster, polarization	2014
	Y. Zhang, Y.S. Derbenev, D. Douglas, A. Hutton, G.A. Krafft, R. Li, F. Lin, V.S. Morozov, E.W. Nissen, F.C. Pilat, T. Satogata, C. Tennant, B. Terzić, B.C. Yunn JLAB, Newport News, Virginia, USA D.P. Barber DESY, Hamburg, Germany Y. Filatov JINR, Dubna, Russia C. Hyde Old Dominion University, Norfolk, Virginia, USA A.M. Kondratenko Science and Technique Laboratory Zaryad, Novosibirsk, Russia S.L. Manikonda, P.N. Ostroumov ANL, Argonne, USA M.K. Sullivan SLAC, Menlo Park, California, USA
	Funding: Supported by the U.S. Department of Energy, Office of Nuclear Physics, under Contract No. DE-AC05-06OR23177 and No. DE-AC02-06CH11357. This paper will report the recent progress in the conceptual design of MEIC, a high luminosity medium energy polarized ring-ring electron-ion collider at Jefferson lab. The topics and achievements that will be covered are design of the ion large booster and the ERL-circulator-ring-based electron cooling facility, optimization of chromatic corrections and dynamic aperture studies, schemes and tracking simulations of lepton and ion polarization in the figure-8 collider ring, and the beam-beam and electron cooling simulations. A proposal of a test facility for the MEIC electron cooler will also be discussed.

TUPPR083	Kink Instability Suppression with Stochastic Cooling Pickup and Kicker	electron, feedback, pick-up, kicker	2017
	Y. Hao, M. Blaskiewicz, V. Litvinenko, V. Ptitsyn BNL, Upton, Long Island, New York, USA
	Funding: Work supported by Brookhaven Science Associates, LLC under Contract No. DE-AC02-98CH10886 with the U.S. Department of Energy. The kink instability is one of the major beam dynamics issues of the linac-ring based electron ion collider. This head-tail type instability arises from the oscillation of the electron beam inside the opposing ion beam. It must be suppressed to achieve the desired luminosity. There are various ways to suppress the instability, such as tuning the chromaticity in the ion ring or by a dedicated feedback system of the electron beam position at IP, etc. However, each method has its own limitation. In this paper, we will discuss an alternative opportunity of suppressing the kink instability of the proposed eRHIC at BNL using the existing pickup-kicker system of the stochastic cooling system in RHIC.

TUPPR087	Status of NSCL Cyclotron Gas Stopper	cyclotron, extraction, injection, emittance	2029
	N.S. Joshi, G. Bollen, M. Brodeur, D.J. Morrissey, S. Schwarz NSCL, East Lansing, Michigan, USA
	A gas-filled reverse cyclotron for the thermalization of energetic beams is under construction at NSCL/MSU. Rare isotopes produced via projectile fragmentation after in-flight separation will be injected into the device and converted into low-energy beams through buffer gas interactions as they spiral towards the center of the device. The extracted thermal beams will be used for low energy experiments such as precision mass measurements with traps or laser spectroscopy, and further transport for reacceleration. Detailed calculations have been performed to optimize the magnetic field design as well as the transport and stopping of ions inside the gas. An RF-carpet will be used to transport the thermal ions to the axial extraction point. The calculations indicate that the cyclotron gas stopper will be much more efficient for the thermalization of light and medium mass ions compared to linear gas cells. In this contribution we will discuss simulations of the overall performance and acceptance of machine, the beam matching calculations to the fragment separator emittance, and the construction status.

WEXA02	Development of Electron Coolers in Novosibirsk	electron, gun, acceleration, proton	2068
	V.V. Parkhomchuk BINP SB RAS, Novosibirsk, Russia S. Nagaitsev Fermilab, Batavia, USA
	An electron cooling method was proposed by G. Budker aproximately 50 years ago. Since the first demonstrations of strong cooling in 1972, the Novosibirsk Institute of Nuclear Physics has continued to develop this technique for various machines with increasingly higher energy beams. Recent application of the e-cooling method at LEIR appeared as a crucial application for a high luminosity achieved in lead-lead ion beam collisions at LHC. This talk should describe the fundamental mechanism of strong cooling, describe historical progress at the BINP and present recent results achieved at the LHC. New 2MeV cooler for COSY ring under commissioning just now at BINP.
	Slides WEXA02 [7.872 MB]

WEOBA03	Beam Tests of a High Pressure Gas-Filled Cavity for a Muon Collider	cavity, electron, pick-up, collider	2131
	T.A. Schwarz, M.A. Leonova, A. Moretti, M. Popovic, A.V. Tollestrup, K. Yonehara Fermilab, Batavia, USA M. Chung Handong Global University, Pohang, Republic of Korea B.T. Freemire, P.M. Hanlet, Y. Torun IIT, Chicago, Illinois, USA R.P. Johnson Muons, Inc, Batavia, USA
	Funding: US DOE under contract DE-AC02-07CH11359. One of the greatest challenges in constructing a Muon Collider is cooling the hot muons into a focused beam after their production. Because the beam must be cooled quickly before the muons decay, compact cooling designs require high gradient cavities inside strong magnetic fields. Unfortunately, due to focused field emission, an external magnetic field degrades the performance of the cavity below what is required for a muon collider. High-pressure gas inside the cavity has been proposed to both mitigate this effect, as well as serve as an absorber for transversely cooling the muon beam. A prototype of a high pressure gas-filled cavity is currently being studied at the Muon Test Area at Fermilab. The experimental setup as well as several measurements of the physics and performance of the apparatus while operating in a 400-MeV proton beam will be discussed.
	Slides WEOBA03 [6.912 MB]

WEPPC018	Design of a Spoke Cavity for RIKEN RI-beam Factory	cavity, vacuum, simulation, heavy-ion	2245
	L. Lu RIKEN, Saitama, Japan O. Kamigaito, N. Sakamoto, K. Suda, K. Yamada RIKEN Nishina Center, Wako, Japan
	Designs of a CW superconducting rebuncher tri-spoke cavity for uranium beams with β = 0.303 has been studied. The estimated peak voltage is rather high as 3 mega-voltages (MV). The resonator frequency was chose as 219MHz which is 12 times of the foundational frequency. The buncher would be settled in a location between two booster cyclotrons (RRC: K = 540MeV, fRC: K = 570 MeV). In this cavity design, a flat E field distribution on beam axis was designed based on the Microwave Studio (MWS) simulations. The cavity parameters, detail designs and some simulated results will be reported in this paper.

WEPPC034	LA³NET - An International Network on Laser Applications at Accelerators	laser, acceleration, diagnostics, electron	2281
	C.P. Welsch Cockcroft Institute, Warrington, Cheshire, United Kingdom C.P. Welsch The University of Liverpool, Liverpool, United Kingdom
	Funding: This project is funded by the European Union under contract PITN-GA-2011-289191. Lasers have become increasingly important for the successful operation and continuous optimization of particle accelerators: Laser-based particle sources are well suited for delivering the highest quality ion and electron beams, laser acceleration has demonstrated unprecedented accelerating gradients and might be an alternative for conventional particle accelerators in the future, and without laser-based beam diagnostics it would not be possible to unravel the characteristics of many complex particle beams. The LA³NET project will bring together research centers, universities, and industry partners to jointly train 17 early stage researchers. In addition, the consortium will also organize a number of international training events, such as schools, topical workshops and conferences. This contribution gives examples from the network's broad research program and summarizes planned training events.

WEPPC037	A Ring-shaped Center Conductor Geometry for a Half-wave Resonator	quadrupole, impedance, cavity, linac	2289
	B. Mustapha, Z.A. Conway, P.N. Ostroumov ANL, Argonne, USA
	Funding: This work was supported by the U.S. Department of Energy, Office of Nuclear Physics, under Contract DE-AC02-06CH11357. Half-wave resonators (HWR) are used and being proposed for the acceleration of high-intensity proton and heavy-ion beams in the 0.1 < β < 0.5 velocity range. The highest performing half-wave resonator geometries use a center conductor with a race-track shaped cross section in the high-electric field region; a feature shared with spoke cavities which are also being proposed for the same velocity regime. We here propose a ring-shaped center conductor instead of the race-track shape. Preliminary studies show that the ring geometry has a similar peak surface electric field as the race-track one, but has several other advantages. In particular, the ring-shaped geometry has: a lower peak surface magnetic field, a much higher Shunt impedance for the same peak fields, and no quadrupole electric field asymmetry which has been observed in the race-track geometry. In a solenoid-based symmetric focusing, the quadrupole component may lead to unnecessary emittance growth which is not acceptable in high-intensity ion linacs. We will present a detailed comparison and a discussion of the two geometries.

WEPPC039	Development of a Half-Wave Resonator for Project X	cavity, linac, SRF, cryomodule	2295
	P.N. Ostroumov, Z.A. Conway, R.L. Fischer, S.M. Gerbick, M. Kedzie, M.P. Kelly, B. Mustapha ANL, Argonne, USA I.V. Gonin, S. Nagaitsev Fermilab, Batavia, USA
	Funding: This work was supported by the U.S. Department of Energy, Office of High Energy Physics and Nuclear Physics, under Contract DE-AC02-76CH03000 and DE-AC02-06CH11357. We have developed an optimized electromagnetic and mechanical design of a 162.5 MHz half-wave resonator (HWR) suitable for acceleration of high-intensity proton or H-minus beams in the energy range from 2 MeV to 10 MeV. The cavity design is based on recent advances in SRF technology for TEM-class structures being developed at ANL. Highly optimized EM parameters were achieved by adjusting the shapes of both inner and outer conductors. This new design will be processed with a new HWR horizontal electropolishing system after all mechanical work on the cavity including the welding of the helium jacket is complete. The prototype HWR is being fabricated by domestic vendors under ANL’s supervision.

WEPPC095	Evaluation of Silicon Diodes as In-situ Cryogenic Field Emission Detectors for SRF Cavity Development	cavity, radiation, SRF, cryogenics	2438
	A.D. Palczewski, R.L. Geng JLAB, Newport News, Virginia, USA
	Funding: This work is authored by Jefferson Science Associates, LLC under U.S. DOE Contract No. DE-AC05-06OR23177. We performed in-situ cryogenic testing of five silicon diodes as possible candidates for field emission monitor of SRF cavities in vertical testing dewars and in cryo-modules. We evaluated diodes from 2 companies - from Hamamatsu corporation model S5821-02 (used at KEK)* and S1223-02; and from OSI Optoelectronics models OSD35-LR-A, XUV-50C, and FIL-UV20. The measurements were done by placing the diodes in superfluid liquid helium near a field emitting 9-cell cavity during its vertical test. For each diode, we will discuss their viability as a 2K cryogenic detector for FE mapping of SRF cavities and their directionality in such environments. We will also present calibration curves between the diodes and JLab’s standard radiation detector placed above the dewar top plate and within radiation shielding. * H. Sakai et al., Proc of IPAC10, WEPEC028 p. 2950 (2010).

WEPPC097	Development of Nb and Alternative Material Thin Films Tailored for SRF Applications	SRF, ECR, vacuum, plasma	2444
	A-M. Valente-Feliciano, H.L. Phillips, C.E. Reece, J.K. Spradlin, X. Zhao JLAB, Newport News, Virginia, USA B. Xiao The College of William and Mary, Williamsburg, USA
	Funding: *Authored by Jefferson Science Associates LLC under U.S. DOE Contract No. DE-AC05-06OR23177. Avenues for the production of thin films tailored for Superconducting RF (SRF) applications are showing promise with recent developments in vacuum deposition techniques using energetic ions. JLab is using energetic condensation via Electron Cyclotron Resonance and High Power Impulse Magnetron Sputtering (HiPIMS) for the development of Nb films and multilayer SIS (superconductor-insulator-superconductor) structures to reach bulk Nb performance and beyond. Nb films with RRR comparable to bulk values are readily produced. The influence of the deposition energy on the material and RF properties of the Nb thin film is investigated with the characterization of their surface, structure, superconducting properties and RF response. Nucleation studies are investigating the best conditions to create a favorable template for growing the final SRF surface. This paper presents results on surface impedance measurements correlated with surface and material characterization for Nb and multilayered SIS films produced on a variety of substrates.

WEPPC100	Design of Electron and Ion Crabbing Cavities for an Electron-Ion Collider	cavity, HOM, electron, damping	2447
	A. Castilla, J.R. Delayen, G.A. Krafft ODU, Norfolk, Virginia, USA A. Castilla JLAB, Newport News, Virginia, USA
	Beyond the 12 GeV upgrade at the Jefferson Lab a Medium Energy Electron-Ion Collider (MEIC) has been considered. In order to achieve the desired high luminosities at the Interaction Points (IP), the use of crabbing cavities is under study. In this work, we will present to-date designs of superconducting cavities, considered for crabbing both ion and electron bunches. A discussion of properties such as peak surface fields and higher-order mode separation will be presented.

WEPPD008	Recondenser Performance: Impact on the Superconducting Undulator Magnet at Argonne National Laboratory	undulator, cryogenics, background, factory	2513
	J.M. Pfotenhauer, D.M. Schick UW-Madison/EP, Madison, Wisconsin, USA
	Funding: This work is supported by Argonne National Laboratory, subcontract number 9F-31982. The current sharing temperature of 6.5 K for the superconducting undulator magnet being developed at Argonne National Laboratory drives the thermal design of the magnet’s cooling system. In order to remain below the current sharing temperature, a thermo-siphon cooling loop is being developed to sweep the anticipated heat load away from the magnet windings and deposit it in the associated liquid helium reservoir located above the magnet. Performance of the magnet’s cooling system is crucially dependent on the ability of the re-condenser to maintain the reservoir’s saturation temperature near 4 K, despite thermal stratification and slowly varying thermal profiles within the vapor region above the liquid in the reservoir. Here we report the results of an experimental investigation of the impact of various geometric configurations for the re-condenser and the thermal resistance associated with the film layer at the re-condensing surface, on the time-varying saturation temperature within the helium reservoir. The resulting temporal thermal variations in the superconducting winding are highlighted as well as the impact they have on the magnet’s stability.

WEPPD011	Study of the Pressure Profile Inside the NEG Coated Chambers of the SIS 18	vacuum, dipole, simulation, quadrupole	2519
	M.C. Bellachioma, H. Kollmus, A. Krämer, J. Kurdal, H. Reich-Sprenger, L. Urban, M. Wengenroth GSI, Darmstadt, Germany
	In the context of the technical developments for the construction of FAIR at GSI, an intensive programme for the vacuum upgrade of the existing SIS 18 was started in 2005, with the aim to improve the beam lifetime and intensity. To reach these purposes also the installation of NEG coated dipole and quadrupole chambers is foreseen. During the upgrade shutdowns performed between 2006 and 2009 the vacuum chambers of approximately 65% of the SIS18 circumference were replaced by NEG coated pipes. To evaluate in detail the pressure profile inside the coated chambers mounted into the accelerator a dedicated experimental set-up, which reproduces a vacuum environment similar to the one of the SIS 18, was built. Using three gauges, mounted in different positions of a coated chamber, it was possible to measure the pressure in the range of 10^-12 mbar inside the activated NEG pipe and 10^-11 mbar outside the pipe at the pumping posts. Additionally, a modelling of a SIS18 vacuum sector was realised and the pressure variation values obtained by a Monte-Carlo simulation were compared with those measured. In this paper the experimental results and the vacuum simulations are described and discussed.

WEPPD013	Status of the Vacuum System in J-PARC RCS	vacuum, proton, site, electron	2522
	J. Kamiya, Y. Hikichi, M. Kinsho, M. Nishikawa, N. Ogiwara, T. Yanagibashi JAEA/J-PARC, Tokai-Mura, Naka-Gun, Ibaraki-Ken, Japan
	In the vacuum system of J-PARC Rapid cycling synchrotron (RCS), we use beam pipes and bellows whose materials are vacuum fired at 700~850 oC in order to eliminate atoms in their bulk who are origin of outgassing. Until now, beam power has been increased up to 300 kW. Pressure in synchrotron beam line increased when the high power beam was accelerated. However, increment of pressure has reduced during the continuous beam operation. It is because the molecules, which adsorb on surface of the wall of the vacuum chambers, desorb by an ion bombardment and a heat generation due to an eddy current. Because the atoms in the bulk is eliminated, desorption of the molecules, which adsorb on the surface, means the reduction of the outgassing from the wall. In this presentation, we will report the past situation of the vacuum system during the beam operation. In addition, we also show the status after the Great East Japan Earthquake.

WEPPD020	Vacuum System for TPS Booster	vacuum, booster, lattice, electron	2540
	C.M. Cheng, C.K. Chan, C.L. Chen, J.-R. Chen, G.-Y. Hsiung, S-N. Hsu, H.P. Hsueh NSRRC, Hsinchu, Taiwan
	The TPS booster is designed for lower beam emittance and 3GeV full energy injection ramped up from 150MeV. It is a synchrotron accelerator of 496.8m in circumference and located concentric with the electron storage ring in the same tunnel. The vacuum system for the booster is divided into six super periods and each has nine bending magnet chambers. The beam duct is made of thin stainless steel tube extruded to the elliptical cross section with inner diameters of 35 mm×20 mm and thickness of 0.7 mm. All the chambers will be supported on the inner wall of the tunnel. The straightness of the extruded thin chambers is controlled within 2.5 mm in 4 m length. The bending chamber is made by mechanical bending from the straight tube. All the beam ducts will be chemical cleaned prior to welding, with flanges or BPM chambers, to form the long chambers in the clean room before installation. The arrangement of vacuum pumps are distributed to fulfill an average pressure of ＜1×10^-6 Pa. The detailed design and the construction status will be described in the paper.

WEPPD025	LHC Detector Vacuum System Consolidation for Long Shutdown 1 (LS1) in 2013-2014	vacuum, background, radiation, electron	2555
	M.A. Gallilee, J. Chaure, P. Cruikshank, J.E. Gallagher, C. Garion, J.M. Jimenez, R. Kersevan, H. Kos, L. Leduc, P. Lepeule, N. Provot, H. Rambeau, R. Veness CERN, Geneva, Switzerland
	The LHC has ventured into unchartered territory for Particle Physics accelerators. A dedicated consolidation program is required between 2013 and 2014 to ensure optimal physics performance. The experiments, ALICE, ATLAS, CMS, and LHCb, will utilise this shutdown, along with the gained experience of three years of physics running, to make optimisations to the detectors. New vacuum technologies have been developed for the experimental areas, to be integrated during this first phase shutdown. These technologies include bellows, vacuum chambers and ion pumps in aluminium, new beryllium vacuum chambers, and composite mechanical supports. An overview of this first phase consolidation program for the LHC experiments is presented.

WEPPD027	Global and Local Loss Suppression in the UA9 Crystal Collimation Experiment	collimation, proton, simulation, collider	2561
	W. Scandale LAL, Orsay, France S. Montesano CERN, Geneva, Switzerland
	UA9 was operated in the CERN-SPS for some years in view of investigating the feasibility of the halo collimation assisted by bent crystals. Two-millimeter-long silicon crystals, with bending angles of about 150 mirrored, are used as primary collimators. The crystal collimation process is obtained consistently through channeling with high efficiency. The loss profiles in the area of the crystal-collimator setup and in the downstream dispersion suppressor area show a steady reduction of slightly less than one order of magnitude at the onset of the channeling process. This result holds both for protons and for lead-ions. The corresponding loss map in the accelerator ring is accordingly reduced. These observations strongly support our expectation that the coherent deflection of the beam halo by a bent crystal should enhance the collimation efficiency in hadron colliders, such as LHC. for the UA9 Collaboration

WEPPD028	Collimators and Materials for High Intensity Heavy Ion Synchrotrons	heavy-ion, simulation, proton, collimation	2564
	J. Stadlmann, H. Kollmus, P.J. Spiller, I. Strašík, N.A. Tahir, M. Tomut, C. Trautmann GSI, Darmstadt, Germany L.H.J. Bozyk TU Darmstadt, Darmstadt, Germany
	Funding: Funded by EU FP7 WP8 ColMat and Federal Republic of Germany The operation of high power high brightness accelerators requires huge efforts for beam cleaning and machine protection. Within the WP 8 (ColMat)of the EU research framework EuCARD we investigate new materials and methods for beam collimation and machine protection. TWe present an overview of these activities at the GSI Helmholtzzentrum für Schwerioneforschung in Darmstadt. Simulations of accidental beam losses in LHC and SIS100 have been performed. Scenarios for halo collimation of heavy ions and protons in SIS100 routine operation have been investigated. A prototype of a cryogenic collimator for charge exchange losses during intermediate charge state heavy ion operation in SIS100 has been build and tested with beam. Several candidates of advances composite materials for collimation system upgrades of present and construction of future high power accelerators have been irradiated and their properties are being characterized. Most deliverables and milestones of the R&D programm have already been reached before the end of the funding period. A summary of the obtained results will be presented.

WEPPD031	A Transverse Electron Target for Heavy Ion Storage Rings	electron, target, interaction-region, simulation	2573
	S. Geyer, O. Meusel IAP, Frankfurt am Main, Germany O.K. Kester GSI, Darmstadt, Germany
	Funding: supported by HIC for FAIR A transverse electron target is a well suited concept for storage rings to investigate electron-ion interactions processes relevant for heavy ion accelerators. In comparison with an internal gas target, it promises a better energy resolution but still has the advantage, in contrast to an electron cooler, of access to the interaction region for photon and electron spectroscopy under large solid angles. The new electron target is suited for the use under the UHV requirements of a storage ring and realizes an open geometry for spectroscopy. A simple design based on electrostatic fields was chosen. The sheet beam application provides a higher perveance limit and a smaller potential depression than a cylindrical gun arrangement. The adjustable electron energy ranges between several 10eV and a few keV. The setup will be installed applying the so-called animated beam technique. The electron target is dedicated to the NESR at the new FAIR facility. First measurements are planned at a test bench and subsequent tests at the Frankfurt Low Energy Storage Ring (FLSR) are envisaged. An overview of the progress in the development of the transverse electron target will be given.

WEPPD035	Design Considerations for an MEBT Chopper Absorber of 2.1MeV H⁻ at the Project X Injector Experiment at Fermilab	vacuum, cryomodule, radiation, neutron	2585
	C.M. Baffes, M.H. Awida, A.Z. Chen, Y.I. Eidelman, V.A. Lebedev, L.R. Prost, A.V. Shemyakin, N. Solyak, V.P. Yakovlev Fermilab, Batavia, USA
	Funding: Operated by Fermi Research Alliance, LLC, under Contract No. DE-AC02-07CH11359 with the United States Department of Energy The Project X Injector Experiment (PXIE) will be a prototype of the Project X front end that will be used to validate the design concept and decrease technical risks. One of the most challenging components of PXIE is the wide-band chopping system of the Medium Energy Beam Transport (MEBT) section, which will form an arbitrary bunch pattern from the initially CW 162.5 MHz 5mA beam. The present scenario assumes diverting 80% of the beam to an absorber to provide a beam with the average current of 1mA to SRF linac. This absorber must withstand a high level of energy deposition and high ion fluence, while being positioned in proximity of the superconductive cavities. This paper discusses design considerations for the absorber, including specific challenges as spreading of energy deposition, management of temperatures and temperature-induced mechanical stresses, radiation effects, surface effects (sputtering and blistering), and maintaining vacuum quality. Thermal and mechanical analyses of a conceptual design are presented, and future plans for the fabrication and testing of a prototype are described.

WEPPD044	Machine Protection System for the SPIRAL2 Facility	controls, beam-losses, diagnostics, target	2612
	M.H. Moscatello, C. Berthe, C. Jamet, G. Normand GANIL, Caen, France
	The phase 1 of the SPIRAL2 facility, extension project of the GANIL laboratory, is under construction. The accelerator is based on a linear solution, mainly composed of a normal conducting RFQ and a superconducting linac. One of its specificities is to be designed to accelerate high power deuteron and heavy ion beams (40-200kW), and medium intensity heavy ion beams as well (a few kW). The associated Machine Protection System, has thus to be able to control and protect the accelerator for a very large range in terms of beam intensities and beam powers. This paper presents the technical solutions chosen for this system and the present status of its construction.

WEPPD058	The Project-X 3 GeV Beam Distribution System	cavity, cryogenics, kaon, linac	2651
	D.E. Johnson, M.H. Awida, M.S. Champion, I.V. Gonin, A.L. Klebaner, N. Solyak, V.P. Yakovlev Fermilab, Batavia, USA
	In the Project X facility, a 3 GeV H⁻ CW beam is delivered to three users simultaneously. This will be accomplished by selectively filling appropriate RF buckets at the front end of the linac and then utilizing a RF splitter to transversely separate bunches to three different target halls. A compact TE113 squashed-wall superconducting RF cavity has been proposed to produce the initial vertical deflection. The transport line optics, cavity design parameters, and cryogenic system requirements will be presented.

WEPPD070	Automatic Tuner Unit Operation for the Microwave System of the ESS-Bilbao H⁺ Ion Source	impedance, plasma, ion-source, controls	2684
	L. Muguira, I. Arredondo, D. Belver, M. Eguiraun, F.J. Fernandez Huerta, J. Feuchtwanger, N. Garmendia, O. González, P.J. González ESS Bilbao, LEIOA, Spain V. Etxebarria, J. Jugo, J. Portilla University of the Basque Country, Faculty of Science and Technology, Bilbao, Spain J. Verdu EPFL, Lausanne, Switzerland
	Funding: The present work is supported by the Basque Government and Spanish Ministry of Science and Innovation. The operation of the waveguide automatic tuner unit (ATU) for optimizing the impedance matching and the RF power coupling in the ESS-Bilbao H⁺ Ion Source (ISHP) is presented. Since the plasma chamber can be considered as a time varying load impedance for the pulsed RF 2.7 GHz high power generator, several approaches have been studied for accurately measuring the load impedance. In the later case, a set of power detectors connected to electric field probes, IQ demodulators and gain/phase detectors connected to dual directional couplers have been integrated. An experimental comparison of these approaches is presented, showing their accuracy, limitations and error-correction methods. Finally, the control system developed for the automatic operation of the triple capacitive post tuner is described, as well as illustrative results.

WEPPD082	Characterization of Photocathode Damage during High Current Operation of the Cornell ERL Photoinjector	gun, site, vacuum, linac	2717
	J.M. Maxson, S.S. Karkare Cornell University, Ithaca, New York, USA I.V. Bazarov, S.A. Belomestnykh, L. Cultrera, D.S. Dale, J. Dobbins, B.M. Dunham, K. Finkelstein, R.P.K. Kaplan, V.O. Kostroun, Y. Li, X. Liu, F. Löhl, B. Pichler, P. Quigley, D.H. Rice, K.W. Smolenski, M. Tigner, V. Veshcherevich, Z. Zhao CLASSE, Ithaca, New York, USA
	The Cornell ERL Photoinjector prototype has recently demonstrated successful operation at 20 mA for 8 hours using a bi-alkali photocathode grown on a Si substrate. The photocathode film was grown off center, and remained relatively undamaged; however, upon removal from the gun, the substrate at the gun electrostatic center displayed significant visible damage. Here we will describe not only the parameters of that particular high current run, but a suite of post-operation surface morphology and crystallographic measurements, including X-ray fluorescence, X-ray diffraction, contact profilometry, scanning electron microscopy, performed about the damage site and photocathode film. The data indicate violent topological changes to the substrate surface, as well as significant induced crystallographic strain. Ion back-bombardment is proposed as a possible mechanism for damage, and a simple model for induced crystal strain is proposed (as opposed to ion induced sputtering), and is shown to have good qualitative agreement with the spatial distribution of damage.

WEPPP029	Quasi-Monoenergetic Ion Bunch Generating by Two-Stage Laser Acceleration	laser, acceleration, target, light-ion	2787
	G. Dudnikova UMD, College Park, Maryland, USA D. Gorpinchenko ICM&MG SB RAS, Novosibirsk, Russia
	Experiments carried out in recent years on the laser-plasma interaction show the possibility of ions acceleration to high energy. The energy spectrum of these ions is typically broad. Practical applications require that the beams of accelerated ions be monoenergetic. A scheme is proposed for producing a quasi-monoenergetic ion bunch by irradiating a foil with two subsequent laser pulses–a prepulse followed by a stronger main pulse. We have demonstrated a possible mechanism for generating a quasi-monoenergetic ion bunch from a homogeneous target consisting of atoms of the same species by the two-stage acceleration. Results are presented from 2D and 3D PIC simulation that illustrate the scheme and determine the space–time and energy characteristics of the accelerated ions. Investigation was made by varying such control parameters as the duration and amplitude of the main laser pulse and the prepulse, the time lag between the pulses, and the thickness and density of the foil.

WEPPP061	A Method to Obtain the Frequency of the Longitudinal Dipole Oscillation for Modeling and Control in Synchrotrons with Single or Double Harmonic RF Systems	synchrotron, controls, dipole, emittance	2846
	J. Grieser, J. Adamy, D.E.M. Lens TU Darmstadt, RTR, Darmstadt, Germany H. Klingbeil TEMF, TU Darmstadt, Darmstadt, Germany
	Funding: This work was partly funded by GSI Helmholtzzentrum für Schwerionenforschung GmbH In a heavy-ion synchrotron the bunched beam can perform longitudinal oscillations around the synchronous particle (single bunch dipole oscillation, SBDO). If disturbances/instabilities exciting the SBDO exceed the rate of Landau damping, the beam can become unstable. Furthermore, Landau damping is accompanied by an increase of the beam emittance which may be undesired. Thus, control efforts are taken to stabilize the beam and to keep the emittance small. It is known that for a single harmonic cavity and a small bunch the SBDO oscillates with the synchrotron frequency* if the oscillation amplitudes are small. For a larger bunch or a double harmonic RF systems that introduces nonlinearities*, this is no longer valid. This work shows how the frequency of the SBDO can be determined in general. As a result, the SBDO can again be modeled as a harmonic oscillator with an additional damping term to account for Landau damping. This model can be used for feedback designs which is shown by means of a simple example. As the frequency of the SBDO and the damping rate depend on the size of the bunch in phase space, it is shown how this information can be obtained from the measured beam current. F. Pedersen and F. Sacherer, IEEE Transactions on Nuclear Science, 24:1296–1398, 1977 ** A. Hofmann and S. Myers, Proc. of the 11th International Conference on High Energy Acceleration, 1980

WEPPP084	Weighted SVD Algorithm for Close-Orbit Correction and 10 Hz Feedback in RHIC	feedback, electron, proton, closed-orbit	2906
	C. Liu, R.L. Hulsart, A. Marusic, R.J. Michnoff, M.G. Minty, V. Ptitsyn BNL, Upton, Long Island, New York, USA
	Funding: Work supported by Brookhaven Science Associates, LLC under Contract No. DE-AC02-98CH10886 with the U.S. Department of Energy. Measurements of the beam position along an accelerator are typically treated equally using standard SVD-based orbit correction algorithms so distributing the residual errors, modulo the local beta function, equally at the measurement locations. However, sometimes a more stable orbit at select locations is desirable. In this paper, we introduce an algorithm for weighting the beam position measurements to achieve a more stable local orbit. The results of its application to close-orbit correction and 10-Hz orbit feedback will be shown and analyzed.

WEPPR001	Experimental Observation of Space Charge Effects in Transverse Bunch Oscillations in the SIS18 Synchrotron	space-charge, synchrotron, simulation, damping	2931
	V. Kornilov, O. Boine-Frankenheim GSI, Darmstadt, Germany
	Coherent signals from transverse bunch oscillations in the heavy-ion synchrotron SIS18 are used for direct measurements of the space charge effect. The bunch oscillations are excited by a transverse kick and the resulting decoherence is observed. The transverse coherent motion in the SIS18 experiments is strongly affected by space charge. The bunches are long, thus the nonlinear motion in the rf bucket plays an important role and must be taken into account. The signals from the measurements are analyzed and explained using analytical and numerical models.

WEPPR003	Longitudinal Dynamics of Intense Heavy-Ion Bunches in SIS-100	impedance, space-charge, heavy-ion, beam-loading	2937
	M. Mehler, O. Boine-Frankenheim, O. Chorniy, O.K. Kester GSI, Darmstadt, Germany
	In the SIS-100 highest heavy-ion intensities have to be accelerated to deliver beam to the FAIR experiments. In the projected SIS-100 synchrotron the heavy ion bunches will be strongly affected by the longitudinal space charge force. Due to the limited RF bucket area all mechanisms which might cause longitudinal phase space dilution must be understood and controlled. Space charge effects, like the reduction in the RF voltage and the loss of Landau damping, have already been part of elaborate studies. It has been shown that cavity beam loading can deform the flattened bunch shape in the dual rf bucket. Among the different counter measures an inductive insert has been proposed in order to partially compensate the longitudinal space charge impedance. Optimized settings for the difference between the two rf phases in a dual rf bucket might be an option to reduce the effect of beam loading. In this contribution we will analyse the matched bunch distribution for SIS-100 parameters in single and dual rf buckets. Analytical and numerical studies of the interplay of longitudinal space charge, cavity beam loading and an inductive insert will be presented.

WEPPR016	Potential for Luminosity Improvement for Low-energy RHIC Operation	luminosity, space-charge, electron, emittance	2973
	A.V. Fedotov BNL, Upton, Long Island, New York, USA
	Funding: Work supported by Brookhaven Science Associates, LLC under Contract No. DE-AC02-98CH10886 with the U.S. Department of Energy. At the Brookhaven National Laboratory, a physics program, motivated by the search of the QCD phase transition critical point, requires operation of the Relativistic Heavy Ion Collider (RHIC) with heavy ions at very low beam energies corresponding to 2.5-20 GeV/n. Several physics runs were already successfully performed at these low energies. However, the luminosity is very low at lowest energies of interest (< 10 GeV/n) limited by the intra-beam scattering and space-charge, as well as by machine nonlinearities. At these low energies, electron cooling is very effective in counteracting luminosity degradation due to the IBS, while it is less effective against other limitations. Overall potential luminosity improvement for low-energy RHIC operation from cooling is summarized for various energies, taking into account all these limitations as well as beam lifetime measured during the low-energy RHIC runs. We also explore a possibility of further luminosity improvement under the space-charge limitation.

WEPPR049	The Impact of Fill Patterns on the Fast Ion Instability in the ILC Damping Ring	damping, emittance, feedback, electron	3036
	G.X. Xia MPI-P, München, Germany
	The ions produced via collisional ionization of the residual gas molecules in vacuum pipe with the circulating electron beam have deleterious effect on the beam properties and may become a limiting factor in the machine’s performance. In this paper, the various beam fill patterns are investigated and their effects on the fast ion instability are discussed. The simulations show that an optimal fill pattern can reduce growth rate of the fast ion instability significantly.

WEPPR059	The Simulation of Ion Cloud Build-up in Electron Storage Ring	electron, simulation, space-charge, storage-ring	3060
	X.L. Yu, W. Li, L. Wang USTC/NSRL, Hefei, Anhui, People's Republic of China
	In electron storage rings, positive ions are created by the ionization of the residual gas. Three main collision types including elastic collision, excitation collision and ionization collision are considered in this paper. In order to calculate the probability of the gas ionization using DSMC method, the total cross section, total inelastic cross section, elastic cross section, excitation cross section and ionization cross section are deduced separately. Once ions are created，PIC is adopted to trace the ion，s motion under the combined action due to externally applied field and self-field. The purpose of all study is to present how ion cloud gets to equilibrium little by little.

WEPPR092	Beam Ion Instability in ILC Damping Ring with Multi-gas Species	vacuum, damping, simulation, lattice	3150
	L. Wang, M.T.F. Pivi SLAC, Menlo Park, California, USA
	Ion induced beam instability is one critical issue for the electron damping ring of the International Linear Collider (ILC) due to its ultra small emittance of 2 pm. The beam ion instability with various beam filling patterns for the latest lattice DTC02 is studied using code IONCLOUD. The code has been benchmarked with SPEAR3 experimental data and there is a good agreement between the simulation and observations. It uses the optics from MAD and can handle arbitrary beam filling pattern and vacuum. Different from previous studies, multi-gas species have been used simultaneously in the simulation. This feature makes it more accurate.

WEPPR093	Impedance Budget for Crab Cavity in MEIC Electron Ring	impedance, electron, cavity, collider	3153
	S. Ahmed, G.A. Krafft, B.C. Yunn JLAB, Newport News, Virginia, USA
	Funding: Authored by Jefferson Science Associates, LLC under U.S. DOE Contract No. DE-AC05-06OR23177. The Medium Energy Electron-Ion Collider (MEIC) at Jefferson Lab has been envisioned as a first stage high energy particle accelerator beyond the 12 GeV upgrade of CEBAF. The estimate of impedance budget is important from the view point of beam stability and matching with other accelerator components driving currents. The detailed study of impedance budget for electron ring has been performed by considering the current design parameters of the e-ring. A comprehensive picture of the calculations involved in this study has been illustrated in the paper.

THXA02	Operation and Patient Treatments at CNAO Facility	proton, synchrotron, extraction, acceleration	3180
	E. Bressi CNAO Foundation, Milan, Italy
	The CNAO (National Centre for Oncological Hadrontherapy) has been realized in Pavia. It is a clinical facility created and financed by the Italian Ministry of Health and conceived to supply hadrontherapy treatments to patients recruited all over the Country. A qualified network of clinical and research Institutes, the CNAO Collaboration, has been created to build and to run the centre. Three treatment rooms (three horizontal and one vertical) are installed. Beams of protons with kinetic energies up to 250 MeV and beams of carbon ions with maximum kinetic energy of 400 MeV/u are transported and delivered by active scanning systems. CNAO commissioning concerning the high technology started in 2009. First patient was treated with Proton beam in September 2011, the 22nd. This presentation presents the features of the system, together with the results of the first treatments.
	Slides THXA02 [14.843 MB]

THYA03	Critical Technologies and Future Directions in High Intensity ISOL RIB Production	target, ion-source, ISOL, proton	3195
	P.G. Bricault, F. Ames, M. Dombsky, P. Kunz, J. Lassen, G. Minor, A. Mjøs, B. Moss, M. Nozar TRIUMF, Canada's National Laboratory for Particle and Nuclear Physics, Vancouver, Canada
	This presentation should review the technology challenges and future directions in the production of high intensity RIBs, including the operation of targets/ion sources in high radiation environment, high efficiency charge stripping, and high reliability.
	Slides THYA03 [5.010 MB]

THYB02	Influence of Electron Beam Parameters on Coherent Electron Cooling	electron, FEL, acceleration, radiation	3213
	G. Wang, Y. Hao BNL, Upton, Long Island, New York, USA V. Litvinenko Stony Brook University, Stony Brook, USA S.D. Webb Tech-X, Boulder, Colorado, USA
	Coherent electron cooling (CeC) is promising to revolutionize the cooling of high energy hadron beams. The intricate dynamics of the CeC depends both on the local density and energy distribution of the beam. This talk should present a rigorous analytical model of the 3D processes (including diffraction) in the modulator and the FEL and describe how the theory is applied to electron beams with inhomogeneous longitudinal density- and energy distributions in the process of CeC. The SPC would like you to describe the influence of electron beam energy and current variations along the bunch length.
	Slides THYB02 [0.878 MB]

THEPPB002	High-Fidelity 3D Modulator Simulations of Coherent Electron Cooling Systems	electron, plasma, simulation, shielding	3231
	G.I. Bell, D.L. Bruhwiler, I.V. Pogorelov, B.T. Schwartz Tech-X, Boulder, Colorado, USA Y. Hao, V. Litvinenko, G. Wang BNL, Upton, Long Island, New York, USA
	Funding: This work is supported by the US DOE Office of Science, Office of Nuclear Physics, grant numbers DE-SC0000835 and DE-FC02-07ER41499. Resources of NERSC were used under contract No. DE-AC02-05CH11231. Next generation electron-hadron colliders will require effective cooling of high-energy, high-intensity hadron beams. Coherent electron cooling (CeC) can in principle cool relativistic hadron beams on orders-of-magnitude shorter time scales than other techniques. The parallel VORPAL framework is used for 3D delta-f PIC simulations of anisotropic Debye shielding in a full longitudinal slice of the co-propagating electron beam, choosing parameters relevant to the proof-of-principle experiment under development at BNL. The transverse density conforms to an exponential Vlasov equilibrium for Gaussian velocities, with no longitudinal density variation. Comparison with 1D1V Vlasov/Poisson simulations shows good agreement in 1D. Parallel 3D simulations at NERSC show 3D effects for ions moving longitudinally and transversely. Simulation results are compared with the constant-density theory of Wang and Blaskiewicz. V.N. Litvinenko and Y.S. Derbenev, Phys. Rev. Lett. 10², 114801 (2009). ** Wang and Blaskiewicz, Phys Rev E 78, 026413 (2008).

THEPPB004	Development of a Cryocatcher-System for SIS100	vacuum, heavy-ion, simulation, cryogenics	3237
	L.H.J. Bozyk, H. Kollmus, P.J. Spiller GSI, Darmstadt, Germany
	Funding: Work supported by EU (FP7 workpackage COLMAT) and GP-HIR – Graduate Program for Hadron and Ion Research at GSI. The main accelerator SIS100 of the FAIR-facility will provide heavy ion beams of highest intensities using intermediate charge state heavy ions. Ionization beam loss is the most important loss mechanism, therefore, a special synchrotron layout has been developed, which includes a dedicated cold ion catcher system which provides almost hundred percent catching efficiency. Dynamic vacuum effects are suppressed effectively by means of special low desorption yield surfaces. A prototype of the cryocatcher system has been developed, constructed and tested with heavy ion beam from SIS18. It is a work package of the EU-FP-7 project COLMAT. Results from these tests are presented as well as implications for the production of the 60 SIS100 cryocatchers.

THEPPB006	Improving the Synchrotron Performance of the Heidelberg Ionbeam Therapy Center	synchrotron, controls, extraction, dipole	3243
	Th. Haberer HIT, Heidelberg, Germany
	The HIT linac-synchrotron-system routinely delivers pencil beams to the dose delivering rasterscanning devices at 3 treatment rooms, including the worldwide first scanning ion gantry, and 1 experimental cave. At HIT the quality-assured library of pencil beam parameters covers roughly 100.000 combinations of the ion, energy, intensity and beam size. Each patient-specific treatment plan defines a subset of these pencil beams being subsequently requested during the dose delivery. Aiming at shortened irradiation times an upgrade program making heavy use of feed-back mechanisms is under way. Driven by patient-specific data out of the scanning beam dose delivery process central synchrotron components are coupled to the therapy control system in order to tailor the beam characteristics in real-time to the clinical requirements. The paper will discuss the functional upgrades and report about the impact on the medical application at HIT.

THEPPB009	The CRISP Project – Building Synergies between Research Infrastructures	neutron, electron, laser, ion-source	3248
	P. Antici INFN/LNF, Frascati (Roma), Italy
	Recently, the European Commission granted 12 M€ for a project aiming at the implementation of common solutions in infrastructures on the ESFRI* roadmap in the fields of physics, astronomy and analytical sciences. The objective of this initiative is to generate synergies in the development of components of interest for several infrastructures and thus promote efficiency and optimisation in the use of resources. The project, called "CRISP (Cluster of Research Infrastructures for Synergies in Physics) and started October 2011, gathers many major European large-scale infrastructures (CERN, XFEL, ESRF, ESS, FAIR, ILL, SKA, SLHC, SPIRAL-2, ELI, EuroFEL, ILC-Higrade etc). The generated synergies will be crucial to stimulate scientific and technological progress and to respond to the rapidly evolving user community. A brief overview of the different activities that are part of the project will be given, presenting the innovative approach of crossing boundaries between scientific disciplines and thus generating synergies. *ESFRI stands for European Strategy Forum on Research Infrastructures

THEPPB011	Apparatus and Experimental Procedures to Test Crystal Collimation	collimation, alignment, instrumentation, proton	3254
	S. Montesano CERN, Geneva, Switzerland W. Scandale LAL, Orsay, France
	UA9 is an experimental setup operated in the CERN-SPS in view of investigating the feasibility of halo collimation assisted by bent crystals. The UA9 collimation system is composed only of one crystal acting as primary halo deflector and one single absorber. Different crystals are tested in turn using two-arm goniometers with an angular reproducibility of better than 10 microrad. The performance of the system are assessed through the study of the secondary and tertiary halo in critical areas, by using standard machine instrumentation and few customized equipments. The alignment of the crystal is verified by measuring the loss rate close to the crystal position. The collimation efficiency is computed by intercepting the deflected halo with a massive collimator or with an imaging device installed into a Roman Pot. The leakage of the system is evaluated in the dispersion suppressor by means of movable aperture restrictions. In this contribution the setup and the experimental methods in use are revisited in a critical way and thoroughly discussed. Particular emphasis is given on feasibility, reproducibility and effectiveness of the operational procedures. For the UA9 Collaboration

THEPPB013	Progress in Modeling Arcs	plasma, electron, cavity, simulation	3260
	J. Norem, Z. Insepov ANL, Argonne, USA S. Mahalingam, S.A. Veitzer Tech-X, Boulder, Colorado, USA A. Moretti Fermilab, Batavia, USA I. Morozov, G.E. Norman JIHT RAS, Moscow, Russia
	Funding: DOE Office of High Energy Physics. We are continuing to extend and simplify our understanding of vacuum arcs. We believe that all the breakdown phenomena we see (with and without B fields) can be explained by: 1) fracture due to electrostatic forces at surface crack junctions, 2) the development of a unipolar arc driven by the cavity electric field, and 3) cooling, and cracking of the surface after the event is finished. Recent progress includes the evaluation of non-Debye sheaths using Molecular Dynamics, studies of sheath driven instabilities, a model of degradation of gradient limits in strong B fields, analysis of the variety of arcs that can occur in cavities and their damage and further studies of breakdown triggers.

THPPC003	Development of a Broad-band Magnetic Alloy Cavity at GSI	cavity, impedance, coupling, storage-ring	3275
	T.S. Mohite, U. Ratzinger IAP, Frankfurt am Main, Germany R. Balß, P. Hülsmann GSI, Darmstadt, Germany
	FINEMET, a Magnetic Alloy material, is often used to build a broad-band cavity for an accelerator or a storage ring. A research on the broad-band FINEMET cavity is of prime importance not only for the present accelerator facility but also for the future storage rings and synchrotron in upcoming FAIR facility alongside the GSI, Darmstadt. In several measurements, high intensity rare-isotope beams, with lower life time, are demanded at injection energy in Experimental Storage Ring (ESR) at GSI. A longitudinal beam stacking of such beams by means of using a special barrier-bucket RF cavity is found appropriate to serve this purpose. Additionally, this cavity is supposed to provide the compressed bunches at lower energies for HITRAP, an ion-trap facility for experiments with highly charged ions, in FAIR. Several measurements are being performed, along with the theoretical analysis, to achieve the designed parameters for the planned barrier-bucket cavity. 60 FINEMET ring cores have been tested to confirm their designed electrical properties. Some of these ring cores are then loaded, in steps, in a test cavity, which will further be used as the barrier-bucket cavity for the ESR. C. Dimopoulou et al., JACoW Proceedings of COOL 2007, Bad Kreuznach, Germany

THPPC013	Progress on Coupled RFQ-SFRFQ Accelerator for Materials Irradiation Research	rfq, cavity, ion-source, ECR	3302
	Z. Wang, J.E. Chen, S.L. Gao, Z.Y. Guo, Y.R. Lu, S.X. Peng, W.L. Xia, X.Q. Yan, J. Zhao, K. Zhu PKU/IHIP, Beijing, People's Republic of China
	Funding: Project supported by the National Natural Science Foundation of China (Grant No.10905003) and China Postdoctoral Science Foundation. There is always high interest to study material irradiation damage effects based on accelerators. The bombardment of solids with high energy particles causes some changes in many important engineering properties. By implanting helium ions, it may be possible to simulate the damage process occurs in vessels and unravel the complexμstructural andμchemical evolutions that are expected in advanced nuclear energy systems. A materials irradiation facility based on coupled RFQ-SFRFQ accelerator will be built in Peking University, attribute to the commissioning of prototype SFRFQ accelerator, we have coupled the SFRFQ electrodes and the traditional RFQ electrodes in one cavity to form a more compact accelerator which can provide helium beam with energy of 0.8MeV for materials irradiation research.

THPPC014	Commissioning Status of the 3 MeV RFQ for the Compact Pulsed Hadron Source (CPHS) at Tsinghua University	rfq, proton, vacuum, status	3305
	Q.Z. Xing, Y.J. Bai, D.T. Bin, J.C. Cai, C. Cheng, L. Du, Q. Du, C. Jiang, Q. Qiang, D. Wang, X.W. Wang, Z.F. Xiong, S.Y. Yang, H.Y. Zhang, S.X. Zheng TUB, Beijing, People's Republic of China J.H. Billen TechSource, Santa Fe, New Mexico, USA W.Q. Guan, Y. He, J. Li NUCTECH, Beijing, People's Republic of China X.L. Guan Tsinghua University, Beijing, People's Republic of China J. Stovall CERN, Geneva, Switzerland L.M. Young AES, Medford, NY, USA
	Funding: Work supported by the “985 Project” of the Ministry of Education of China. We present, in this paper, the commissioning status of a Radio Frequency Quadrupole (RFQ) accelerator for the Compact Pulsed Hadron Source (CPHS) at Tsinghua University. In 2012 the 3-meter-long RFQ will deliver 3 MeV protons to the downstream High Energy Beam Transport (HEBT) with the peak current of 50 mA, pulse length of 0.5 ms and beam duty factor of 2.5%. Braze of the vanes was completed in September, 2011. The final field tuning of the whole cavity was completed in October, 2011. Initial commissioning will be underway at the beginning of 2012.

THPPC040	Improved RF Design for an 805 MHz Pillbox Cavity for the US MuCool Program	cavity, coupling, simulation, multipactoring	3371
	Z. Li, C. Adolphsen, L. Ge SLAC, Menlo Park, California, USA D.L. Bowring, D. Li LBNL, Berkeley, California, USA
	Funding: Work supported by US DOE under contract number DE-AC02-05CH11231, and DE-AC02-76SF00515. Normal conducting RF cavities are required to operate at high gradient in the presence of strong magnetic field in muon ionization cooling channels for a Muon Collider. Experimental studies using an 805 MHz pillbox cavity at MTA of Fermilab has shown significant degradation in gradient performance and damage in the regions that are correlated with high RF fields in magnetic field up to 4 Tesla. These effects are believed to be related to the dark current and/or multipacting activities in the presence of external magnetic field. To improve the performance of the cavity, a new RF cavity with significantly lower surface field enhancement was designed, and will be built and tested in the near future. Numerical analyses of multipacting and dark current were performed using the 3D parallel code Track3P for both the original and new improved cavity profiles in order to gain more insight in understanding of the gradient issues under strong external magnetic field. In this paper, we will present the improved RF design and the dark current and multipacting analyses for the 805 MHz cavity.

THPPD045	High Temperature Superconducting Magnets for Efficient Low Energy Beam Transport Systems	solenoid, rfq, emittance, vacuum	3614
	J.H. Nipper, G. Flanagan, R.P. Johnson Muons, Inc, Batavia, USA M. Popovic Fermilab, Batavia, USA
	Modern ion accelerators and ion implantation systems need very short, highly versatile, Low Energy Beam Transport (LEBT) systems. The need for reliable and continuous operation requires LEBT designs to be simple and robust. The energy efficiency of available high temperature superconductors (HTS), with efficient and simple cryocooler refrigeration, is an additional attraction. Innovative, compact LEBT systems based on solenoids designed and built with high-temperature superconductor will be developed using computer models and prototyped. The parameters will be chosen to make this type of LEBT useful in a variety of ion accelerators, ion implantation systems, cancer therapy synchrotrons, and research accelerators, including the ORNL SNS. The benefits of solenoids made with HTS will be evaluated with analytical and numerical calculations for a two-solenoid configuration, as will be used in the SNS prototype LEBT that will replace the electrostatic one at SNS, and a single solenoid configuration, as was proposed for the Fermilab proton driver that will be most applicable to ion implantation applications.

THPPD049	Conceptual Design of a Superconducting Septum for FFAGs	septum, extraction, proton, simulation	3620
	H. Witte BNL, Upton, Long Island, New York, USA M. Aslaninejad, J. Pasternak Imperial College of Science and Technology, Department of Physics, London, United Kingdom K.J. Peach, T. Yokoi JAI, Oxford, United Kingdom
	Funding: This work was supported by STFC grant ST/G008531/1 and EPSRC Grant EP/E032869/1. The fixed magnetic field in FFAG (Fixed Field Alternating Gradient) accelerators means that particles can be accelerated very rapidly. This makes them attractive candidates for many applications, for example for accelerating muons for a neutrino factory or for charged particle therapy (CPT). To benefit fully from this the particles have to be extracted at the same rate. In combination with the high magnetic rigidity of the particles this represents a significant challenge, especially where variable energy extraction is required, which implies extraction at variable radius. This paper presents a conceptual design of a 4T superconducting septum for the PAMELA accelerator, which is an FFAG for a combined proton/carbon ion therapy facility. The field in the septum is varied as a function of the horizontal position, which allows variable energy extraction without the need for sweeping of the magnetic field.

THPPD074	Effect of a Metallized Chamber upon the Field Response of a Kicker Magnet: Simulation Results and Analytical Calculations	kicker, simulation, vacuum, booster	3686
	M.J. Barnes, M.G. Atanasov, T. Fowler, T. Kramer, T. Stadlbauer CERN, Geneva, Switzerland
	Metallized racetrack vacuum chambers will be used in the pulsed magnets of the Austrian cancer therapy and research facility, MedAustron. It is important that the metallization does not unduly degrade field rise and fall times or the flattop of the field pulse in the pulsed magnets. This was of particular concern for a tune kicker magnet, which has a specified rise and fall time of 100 ns. The impact of the metallization, upon the transient field response, has been determined by finite element method (FEM) simulations: the dependency of the field response to the metallization thickness and resistivity are presented. Formulae for the field response, which permit the use of a ramped transient excitation current, are presented: thus the coating thickness and resistivity can be determined which result in a maximum permissible field attenuation and delay for a given current rise time. In addition, results of simulations of the effect of a magnetic brazing collar, located between the ceramic vacuum chamber and flange, are reported.

THPPP001	High Intensity Intermediate Charge State Heavy Ions in Synchrotrons	injection, septum, emittance, heavy-ion	3719
	P.J. Spiller, U. Blell, L.H.J. Bozyk, H. Reich-Sprenger, J. Stadlmann GSI, Darmstadt, Germany Y. El-Hayek FIAS, Frankfurt am Main, Germany
	In order to reach the desired FAIR intensities for heavy ions, SIS18 and SIS100 have to be operated with intermediate charge states. Operation with intermediate charge state heavy ions at the intensity level of about 1011 ions per cycle has never been demonstrated elsewhere and requires a dedicated machine design. After partially completing the upgrade program of SIS18, the number of intermediate charge state heavy ions accelerated to the FAIR booster energy of 200 MeV/u, could be increased by a factor of 70. The specific challenge for the SIS18 and SIS100 booster operation is the high cross section for ionization of the intermediate charge state heavy ions, in combination with gas desorption processes and the dynamic vacuum pressure. The achieved progress in minimizing the ionization beam loss underlines that the chosen technical strategies described in this report are appropriate. The latest intensity records and results from the machine development programs are presented.

THPPP002	Operation of the HESR Storage Ring of the FAIR Project with Ions and Rare Isotopes	target, electron, antiproton, storage-ring	3722
	M. Steck, C. Dimopoulou, A. Dolinskii, T. Katayama, Yu.A. Litvinov, T. Stöhlker GSI, Darmstadt, Germany R. Maier, D. Prasuhn, H. Stockhorst FZJ, Jülich, Germany
	The HESR storage ring of the FAIR project is designed for experiments with cooled antiprotons. The HESR receives pre-cooled antiprotons from the Collector Ring CR which is also designed for cooling of rare isotope beams. The magnetic rigidity of 13 Tm is the same for the pre-cooling of antiprotons and rare isotopes in the CR. Therefore the transfer of ions or rare isotopes from the CR to the HESR can be performed under similar condition, except the different polarity of the magnetic components. This is an option for the first stage of the FAIR project when no other storage ring is available for experiments with stored ions. In the HESR the ions can be decelerated or accelerated, like the antiprotons, to energies corresponding to the magnetic rigidity range from 5 to 50 Tm. The planned beam cooling systems of the HESR, stochastic and electron cooling, can be applied to improve the quality of the ion beams in the HESR and support experiments using an internal target or the accumulation of rare isotope beams in the HESR. Scenarios for operating the HESR with ions and rare isotopes as well as achievable performance, beam intensity and quality for internal experiments will be discussed.

THPPP012	Performance of the CERN Heavy Ion Production Complex	target, injection, proton, luminosity	3752
	D. Manglunki, M. E. Angoletta, H. Bartosik, G. Bellodi, A. Blas, T. Bohl, C. Carli, E. Carlier, S. Cettour Cave, K. Cornelis, H. Damerau, I. Efthymiopoulos, A. Findlay, S.S. Gilardoni, S. Hancock, J.M. Jowett, D. Kuchler, S. Maury, M. O'Neil, Y. Papaphilippou, S. Pasinelli, R. Scrivens, G. Tranquille, B. Vandorpe, U. Wehrle, J. Wenninger CERN, Geneva, Switzerland
	The second LHC ion run took place at 1.38 A TeV/c per beam in autumn 2011; more than 100 inverse microbarns was accumulated by each of the experiments. In addition, the LHC injector chain delivered primary Pb and secondary Be ion beams to fixed target experiments in the North Area. This paper presents the current performance of the heavy ion production complex, and prospects to further improve it in the near future.

THPPP027	The Design of a Large Booster Ring for the Medium Energy Electron-Ion Collider at JLab	booster, collider, dipole, electron	3791
	E.W. Nissen, T. Satogata, Y. Zhang JLAB, Newport News, Virginia, USA
	Funding: Notice: Authored by Jefferson Science Associates, LLC under U.S. DOE Contract No. DE-AC05-06OR23177. In this paper, we present the current design of the large booster ring for the Medium Energy Electron-Ion Collder (MEIC) at JLab. The booster ring takes 3 GeV protons or ions of equivalent energy from a pre-booster ring, and accelerates them to 20 GeV for protons or equivalent energy for light to heavy ions before sending them to the ion collider ring. The present design calls for a figure-8 shape of the ring for superior preservation of ion polarization. The ring is made of warm magnets and shares a tunnel with the two collider rings. Acceleration is achieved by warm RF systems. A linear optics has been designed with the transition energy above the highest beam energy in the ring so crossing of transition energy will be avoided. Preliminary beam dynamics studies including chromaticity compensation, analyses of dynamic aperture, working point and high order effects are also presented in this paper.

THPPP032	Advanced Layout Studies for the GSI CW-Linac	linac, solenoid, cavity, heavy-ion	3803
	W.A. Barth, S. Mickat GSI, Darmstadt, Germany S. Jacke HIM, Mainz, Germany
	Beam dynamics studies were made with the LORASR code for the planned superconducting (sc)continuous wave (cw) linear accelerator. It comprises a fixed accelerating part with an output energy of 3.5 MeV/u at a design mass/charge ratio of 6 and an energy variable part with an output energy of up to 7.3 MeV/u. The general layout, which provides for nine cavities combined with seven separate solenoids for a total length of 12.7 m, is based on a basic design by A. Minaev. The recent studies show the parameter study for output energy variation. The statistical rotational and transverse offset error calculations illuminate the tolerances for acceptable errors. These are particularly relevant in the beam dynamics within a superconducting environment. Further calculations focus on varying the charge-to-mass ratio to reach linac energies up to 10 MeV/u, meeting the requirements of future UNILAC experiments. A. Minaev et al., “Superconducting, energy variable heavy ion linac with constant beta, multicell cavities of CH-type,” PRST-AB 12, 120101 (2009).

THPPP033	New Developments for the Present and Future GSI Linacs	linac, cavity, emittance, proton	3806
	L. Groening, W.A. Barth, G. Clemente, V. Gettmann, B. Schlitt GSI, Darmstadt, Germany M. Amberg, K. Aulenbacher, S. Mickat HIM, Mainz, Germany F.D. Dziuba, H. Podlech, U. Ratzinger, C. Xiao IAP, Frankfurt am Main, Germany

Paper

Title

Other Keywords

Page

MOXBP01

The First Two Years of LHC Operation

luminosity, proton, emittance, dipole

1

S. Myers
CERN, Geneva, Switzerland

The operational performance of the LHC machine both for proton and lead ion operation are reviewed for the period 2010 and up the present. The beam parameter path allowing the very high rate of collider performance is presented and discussed. The accelerator issues encountered and those somewhat surprisingly not encountered are also discussed. The short and longer term plans for the LHC are also briefly presented.

Slides MOXBP01 [17.468 MB]

MOOBA02

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

linac, cryomodule, cryogenics, solenoid

34

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

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

Slides MOOBA02 [7.044 MB]

MOOAC03

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

linac, cavity, cryomodule, SRF

61

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

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

Slides MOOAC03 [4.009 MB]

MOEPPB005

Initial Commissioning of NDCX-II

induction, diagnostics, solenoid, beam-transport

85

S.M. Lidia, D. Arbelaez, W.G. Greenway, J.-Y. Jung, J.W. Kwan, T.M. Lipton, A. Pekedis, P.K. Roy, P.A. Seidl, J.H. Takakuwa, W.L. Waldron
LBNL, Berkeley, California, USA
A. Friedman, D.P. Grote, W. M. Sharp
LLNL, Livermore, California, USA
E.P. Gilson
PPPL, Princeton, New Jersey, USA

Funding: This work was performed under the auspices of the U.S Department of Energy by LLNL under contract DE AC52 07NA27344, and by LBNL under contract. DE-AC02-05CH11231.
The Neutralized Drift Compression Experiment-II (NDCX-II) will generate ion beam pulses for studies of Warm Dense Matter and heavy-ion-driven Inertial Fusion Energy. The machine will accelerate 20-50 nC of Li+ to 1.2-3 MeV energy, starting from a 10.9-cm alumino-silicate ion source. At the end of the accelerator the ions are focused to a sub-mm spot size onto a thin foil (planar) target. The pulse duration is compressed from ~500 ns at the source to sub-ns at the target following beam transport in a neutralizing plasma. We first describe the injector, accelerator, transport, final focus and diagnostic facilities. We then report on the results of early commissioning studies that characterize beam quality and beam transport, acceleration waveform shaping and beam current evolution. We present WARP simulation results to benchmark against the experimental measurements.

MOEPPB006

Formation of Beams in the Ion Accelerator Complex of the Medium Energy Electron Ion Collider Facility at JLab

booster, proton, acceleration, collider

88

S.L. Manikonda, P.N. Ostroumov
ANL, Argonne, USA
B. Erdelyi
Northern Illinois University, DeKalb, Illinois, USA

Funding: This work was supported by the U.S. Department of Energy, Office of Nuclear Physics, under Contract No. DE-AC02-06CH11357.
At the interaction point of the Medium Energy Electron Ion Collider (MEIC) facility the luminosity of 10³³cm^-2s^-1 will be achieved through the collision of counter rotating beams of 0.5A ions and 3A electrons at 750MHz frequency. Formation of ion beams at MEIC is carried out in the Ion Accelerator Complex (IAC) comprising of a linac, pre-booster ring, booster ring, and a collider ring. We will describe the scheme proposed for the formation of ion beams at MEIC facility from the point of view of longitudinal beam dynamics. The proposed scheme minimizes losses due to space charge effects at low energies and needs moderate RF requirements already achieved at other existing facilities. Simulation studies have been conducted to verify the proposed scheme. We will present the results of these simulation studies.

MOEPPB010

Measurement of Satellite Bunches at the LHC

photon, emittance, synchrotron, coupling

97

A. Jeff, M. Andersen, A. Boccardi, S. Bozyigit, E. Bravin, T. Lefèvre, A. Rabiller, F. Roncarolo
CERN, Geneva, Switzerland
A.S. Fisher
SLAC, Menlo Park, California, USA
C.P. Welsch
Cockcroft Institute, Warrington, Cheshire, United Kingdom

Funding: Adam Jeff is a DITANET fellow, supported by the EU's Marie Curie actions contract PITN-GA-2008-215080.
The RF gymnastics involved in the delivery of proton and lead ion bunches to the LHC can result in satellite bunches of varying intensity occupying the nominally empty RF buckets. Quantification of these satellites is crucial for bunch-by-bunch luminosity normalization as well as for machine protection. We present an overview of the longitudinal density monitor (LDM) which is the principal instrument for the measurement of satellite bunches in the LHC. The LDM uses single photon counting of synchrotron light. The very high energies reached in the LHC, combined with a dedicated undulator for diagnostics, allow synchrotron light measurements to be made with both protons and heavy ions. The arrival times of photons are collected over a few million turns, with the resulting histogram corrected for the effects of the detector’s deadtime and afterpulsing in order to reconstruct the longitudinal profile of the entire LHC ring. The LDM has achieved a dynamic range in excess of 10⁵ and a time resolution of 90 ps. Example results are presented and the measurements are benchmarked against satellite distributions based on collision data from the LHC experiments.

MOPPC013

Optics and Lattice Optimizations for the LHC Upgrade Project

optics, luminosity, lattice, insertion

151

B. Dalena
CEA/IRFU, Gif-sur-Yvette, France
R. Appleby
UMAN, Manchester, United Kingdom
A.V. Bogomyagkov
BINP SB RAS, Novosibirsk, Russia
A. Chancé, J. Payet
CEA/DSM/IRFU, France
R. De Maria, B.J. Holzer
CERN, Geneva, Switzerland
A. Faus-Golfe, J. Resta-López
IFIC, Valencia, Spain
K.M. Hock, M. Korostelev, L.N.S. Thompson, A. Wolski
Cockcroft Institute, Warrington, Cheshire, United Kingdom
C. Milardi
INFN/LNF, Frascati (Roma), Italy

The luminosity upgrade of the LHC collider at CERN is based on a strong focusing scheme to reach lowest values of the beta function at the collision points. Several issues have to be addressed in this context, that are considered as mid term goals for the optimisation of the lattice and beam optics: Firstly a number of beam optics have been developed to establish a baseline for the hardware R&D, and to define the specifications for the new magnets that will be needed, in Nb3Sn and in NbTi technology. Secondly, the need for sufficient flexibility of the beam optics especially for smallest β^* values has to be investigated as well as the need for a smooth transition between the injection and the collision optics. Finally the performance of the optics based on flat and round beams has to be compared and different ways have to be studied to optimise the chromatic correction, including the study of local correction schemes. This paper presents the status of this work, which is a result of an international collaboration, and summarises the main parameters that are foreseen to reach the HL-LHC luminosity goal.

MOPPC022

Off-momentum Dynamic Aperture for Lattices in the RHIC Heavy Ion Runs

lattice, luminosity, heavy-ion, emittance

175

Y. Luo, M. Bai, M. Blaskiewicz, W. Fischer, X. Gu, A. Marusic, T. Roser, S. Tepikian, S.Y. Zhang
BNL, Upton, Long Island, New York, USA

Funding: Work supported by Brookhaven Science Associates, LLC under Contract No. DE-AC02-98CH10886 with the U.S. Department of Energy.
In this article we calculate and compare the off-momentum dynamic aperture for lattices with different phase advances per FODO cell in the RHIC heavy ion runs. A lattice with an increased phase advance was adopted in 2008-2011 to reduce transverse emittance growth rates from intra-beam scattering. However, during these runs, a large beam loss was observed with longitudinal RF re-bucketing which increased the momentum spread. With operational transverse stochastic cooling in the 2011 RHIC heavy ion run, the transverse intra-beam scattering emittance growth was eliminated, and the beam loss during stores was determined by the off-momentum aperture and burn-off from luminosity. We investigate the possibilities to increase the off-momentum dynamic aperture that would lead to an increase in the integrated luminosity.

MOPPC039

Electron Recombination in a Dense Hydrogen Plasma

cavity, electron, collider, plasma

217

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

Funding: US DOE under contract DE-AC02-07CH11359.
A high pressure hydrogen gas filled RF cavity was subjected to an intense proton beam to study the evolution of the beam induced plasma inside the cavity. The electron recombination rate with the dense ionized hydrogen plasma has been measured under varying conditions. Recombination rates as high as 10^-7 cm³/s have been recorded. This technique shows promise in the R&D program for a muon accelerator. The use of hydrogen, both as a way to prevent breakdown in an RF cavity and as a mechanism for cooling a beam of muons, will be discussed.

MOPPC040

Study of Electronegative Gas Effect in Beam-Induced Plasma

cavity, plasma, electron, proton

220

M.A. Leonova, M.R. Jana, A. Moretti, M. Popovic, T.A. Schwarz, A.V. Tollestrup, K. Yonehara
Fermilab, Batavia, USA
M. Chung
Handong Global University, Pohang, Republic of Korea
M.G. Collura
Politecnico di Torino, Torino, Italy
B.T. Freemire, P.M. Hanlet, Y. Torun
IIT, Chicago, Illinois, USA
R.P. Johnson
Muons, Inc, Batavia, USA

Funding: This research was supported by US DOE under contract DE-AC02-07CH11359.
Muon Colliders and Neutrino Factories call for R&D for a high-gradient RF system capable of operating in a high magnetic field. Adding a high pressure gas inside an RF cavity (HPRF) prevents cavity breakdown, allowing higher gradients in a magnetic field. A high-energy beam passing through an HPRF cavity ionizes the gas, producing plasma. Plasma electrons absorb cavity’s energy, reducing the energy available for beam acceleration. Doping cavity gas with electronegative gas (gas that tends to attract and bond electrons) reduces the number of plasma electrons. The experiments were carried out at the MuCool Test Area (MTA) facility at Fermilab. Different concentrations of an electronegative gas SF6 were added to hydrogen gas. The results of room-temperature tests showing a great reduction in power drop in the cavity will be presented. However, a realistic cavity would operate at liquid nitrogen temperature, where SF6 freezes. Thus, a search for a better electronegative gas candidate is underway; we plan to test oxygen-doping next.

MOPPC058

Eigenmode Computation for Ferrite-loaded Cavity Resonators

cavity, resonance, heavy-ion, acceleration

265

K. Klopfer, W. Ackermann, T. Weiland
TEMF, TU Darmstadt, Darmstadt, Germany

The GSI Helmholtzzentrum für Schwerionenforschung in Darmstadt is operating the heavy-ion synchrotron SIS18 for fundamental research. Within the ring two ferrite-loaded cavity resonators are installed. During the acceleration phase their resonance frequency has to be adjusted to the revolution frequency of the heavy-ions to reflect their increasing velocity. Within the resonator structures dedicated biased ferrite rings are installed. In the whole setup a properly chosen bias current is used to modify the differential permeability of the ferrite material which consequently enables to adjust the eigenfrequency of the resonator system. The goal of the current study is to numerically determine the lowest eigensolutions of accelerating ferrite-loaded cavities based on the Finite Integration Technique. Since the underlying eigenmodes depend on the differential permeability, the static magnetic field generated by the bias current has to be computed in a first step. The eigenmodes can then be determined with the help of a dedicated Jacobi-Davidson eigensolver. Particular emphasis is put on the implementation to enable high performance computations based on distributed memory machines.

MOPPC060

Investigations into Beam Life Time in Low Energy Storage Rings

target, storage-ring, electron, antiproton

271

A.I. Papash, A.V. Smirnov
MPI-K, Heidelberg, Germany
A.I. Papash
JINR, Dubna, Moscow Region, Russia
C.P. Welsch
Cockcroft Institute, Warrington, Cheshire, United Kingdom

Funding: Work supported by the Helmholtz Association of National Research Centers and GSI under contract VH-NG-328.
In low energy storage rings, beam life time critically depends on the residual gas pressure, scattering effects caused by in-ring experiments and the available machine acceptance. A comprehensive simulation study into these effects has been realized with a focus on the TSR storage ring in Heidelberg and the electrostatic rings ELISA, the AD recycler and the ultra-low energy storage ring (USR). This was done by using the computer code BETACOOL in combination with the OPERA-3D and MAD-X programs. In this contribution, the results from these studies are presented and compared to available experimental data. Based on these simulations, criteria for stable ring operation are then presented.

MOPPC061

An Antiproton Recycler for Atom-Antiproton Collision Experiments

antiproton, injection, acceleration, target

274

M.R.F. Siggel-King, C.P. Welsch
Cockcroft Institute, Warrington, Cheshire, United Kingdom
O. Karamyshev, A.I. Papash
MPI-K, Heidelberg, Germany
M.R.F. Siggel-King
The University of Liverpool, Liverpool, United Kingdom

Funding: Work supported by the Helmholtz Association and GSI under contract VH-NG-328, the EU under contract PITN-GA-2008-215080 and STFC.
Collision experiments with low energy antiprotons and different gas jet targets on the level of differential cross sections would be very desirable to use to investigate the details of this fundamental process. At present, such experiments are, however, not feasible, since the only source of antiprotons in the world, the AD at CERN, cannot provide beams of the required energy and quality. A small electrostatic ring has been designed and developed by the QUASAR Group. Serving at the same time as a prototype for the future ultra-low energy storage ring (USR), to be integrated at the facility for low-energy antiproton and ion research (FLAIR), this small accelerator is unique due to its combination of size, electrostatic nature, and energy of the circulating particles. In this contribution, the design of the ring is described in detail and possible operation scenarios in the ASACUSA beam line and behind the ELENA ring are compared with each other.

MOPPC064

Simulation of the Behavior of Ionized Residual Gas in the Field of Electrodes

simulation, electron, emittance, vacuum

283

G. Pöplau, U. van Rienen
Rostock University, Faculty of Computer Science and Electrical Engineering, Rostock, Germany
A. Meseck
HZB, Berlin, Germany

Funding: Work supported by BMBF under contract number 05K10HRC
Light sources of the next generation such as ERLs require minimal beam losses as well as a stable beam position and emittance over the time. Instabilities caused by ionized residual gas have to be avoided. In this paper we present simulations of the behavior of ionized residual gas in the field of clearing electrodes and investigate e.g. clearing times. For these simulations we apply MOEVE PIC Tracking developed at Rostock University. We demonstrate numerical results with parameters planed for the ERL BERLinPro.

MOPPD002

Ultra-low Energy Storage Ring at FLAIR

extraction, antiproton, storage-ring, lattice

367

C.P. Welsch, D. Newton, M.R.F. Siggel-King
Cockcroft Institute, Warrington, Cheshire, United Kingdom
O.E. Gorda, O. Karamyshev, G.A. Karamysheva, M. Panniello, A.I. Papash, A.V. Smirnov
MPI-K, Heidelberg, Germany
J. Harasimowicz, M. Putignano, C.P. Welsch
The University of Liverpool, Liverpool, United Kingdom

Funding: The support of the HGF and GSI under contract VH-NG-328, the EU under contract PITN-GA-2008-215080, the Max Planck Institute for Nuclear Physics and the STFC Grant ST/G008248/1 is acknowledged.
The Ultra-low energy electrostatic Storage Ring (USR) at the future Facility for Low-energy Antiproton and Ion Research (FLAIR) will provide cooled beams of antiprotons in the energy range between 300 keV down to 20 keV. Based on the original design concept developed in 2005, the USR has been completely redesigned over the past few years. The ring structure is now based on a 'split achromat' lattice. This ensures compact ring dimensions of 10 x 10 m, whilst allowing both, in-ring experiments with gas jet targets and studies with extracted beams. In the USR, a wide range of beam parameters will be provided, ranging from very short pulses in the nanosecond regime to a coasting beam. In addition, a combined fast and slow extraction scheme was developed that allows for providing external experiments with cooled beams of different time structure. Furthermore, studies into beam diagnostics methods for the monitoring of ultra-low energy ions at beam intensities less than 10⁶ were carried out. Here, we present the USR design with an emphasis on the expected beam parameters available to the experiments at FLAIR.

MOPPD005

Stochastic Cooling of Antiprotons in the Collector Ring at FAIR

pick-up, antiproton, kicker, simulation

376

C. Dimopoulou, A. Dolinskii, F. Nolden, C. Peschke, M. Steck
GSI, Darmstadt, Germany

In order to reach the required luminosities for the experiments at FAIR, the hot secondary beams (antiprotons or rare isotopes) emerging from the production targets will be efficiently collected and phase-space cooled in the large-acceptance Collector Ring (CR), which is equipped with pertinent stochastic cooling systems. Simulations of the system performance are underway in parallel with the finalization of the system design. After an overview of the CR stochastic cooling systems, simulation results for antiproton cooling in the bandwidth 1-2 GHz are presented. The CERN Fokker-Planck code is used for momentum cooling and an analytical model based on "rms" theory for the simultaneous betatron cooling. In the focus is the comparison between the time of flight and the notch filter momentum cooling methods. The results are essential for system optimization as well as input for the users of the CR-precooled beams i.e. the HESR.

MOPPD009

Stochastic Cooling Developments for HESR at FAIR

target, heavy-ion, emittance, scattering

388

H. Stockhorst, R. Maier, D. Prasuhn, R. Stassen
FZJ, Jülich, Germany
C. Dimopoulou, A. Dolinskii, T. Katayama, Yu.A. Litvinov, M. Steck, T. Stöhlker
GSI, Darmstadt, Germany

The High-Energy Storage Ring (HESR) is part of the upcoming International Facility for Antiproton and Ion Research (FAIR) at GSI in Darmstadt. The HESR is planned to dedicate to the field of high-energy antiproton physics to explore the research areas of charmonium spectroscopy, hadronic structure, and quark-gluon dynamics with high-quality beams over a broad momentum range from 1.5 to 15 GeV/c. The new facility provides the combination of powerful phase-space cooled antiproton beams and internal Pellet and gas jet targets to achieve the requirements of the experiment PANDA in terms of beam quality and luminosity. Detailed theoretical analyses have been carried out to design the stochastic cooling system for accumulation and stochastic cooling of antiprotons with target operation. Recently it is proposed to utilize the HESR also for the atomic and nuclear physics with highly charged heavy ions such as 132Sn⁵⁰⁺ in the dedicated experiments at high energies 0.74-3 GeV/u. In this contribution the feasibility of stochastic cooling of heavy ions with internal targets is in detail investigated under the constraint of the cooling system hardware as foreseen for anti-proton cooling.

MOPPD011

Analysis of Frequency Spectrum of Bunched Beam Related to Transverse Laser Cooling*

synchrotron, laser, betatron, coupling

391

K. Jimbo
Kyoto University, Institute for Advanced Energy, Kyoto, Japan
Z.Q. He
TUB, Beijing, People's Republic of China
M. Nakao, A. Noda, H. Souda, H. Tongu
Kyoto ICR, Uji, Kyoto, Japan

Using synchro-betatron coupling, transverse laser cooling is pursued at an ion storage/cooler ring, S-LSR, Kyoto University. A bunched 40 keV 24Mg+ beam was cooled by a co-propagating laser of 280 nm wavelength. Synchrotron oscillation in the longitudinal direction and betatron oscillation in the horizontal direction were intentionally coupled by an RF drift tube located at the finite dispersive section (D =1.1 m) where longitudinal cooling force was transmitted to the horizontal direction.* Analyzing bunched Schottky signals, which represents longitudinal physical quantities of the beam, we try to obtain an evidence of synchro-betatron coupling and accordingly laser cooling of the beam in the transverse direction.
* H. Okamoto, Phys. Rev. E 50, 4982 (1994)

MOPPD012

Challenge for More Efficient Transverse Laser Cooling for Beam Crystallization

laser, synchrotron, simulation, betatron

394

A. Noda, M. Nakao, H. Souda, H. Tongu
Kyoto ICR, Uji, Kyoto, Japan
M. Grieser
MPI-K, Heidelberg, Germany
Z.Q. He
TUB, Beijing, People's Republic of China
K. Ito, H. Okamoto, K. Osaki
HU/AdSM, Higashi-Hiroshima, Japan
K. Jimbo
Kyoto University, Institute for Advanced Energy, Kyoto, Japan
Y. Yuri
JAEA/TARRI, Gunma-ken, Japan

Funding: Work supported by Advanced Compact Accelerator Development project by MEXT. Also supported by GCOE project at Kyoto University, The next generation of Physics-Spun from Universality and Emergency.
At S-LSR in ICR, Kyoto University, Mg ion beam has been successfully laser cooled both in longitudinal* and transverse** directions. The cooling rate, however, is not strong enough to realize the crystalline beam due to the heating because of intra-beam scattering (IBS) effect. So as to suppress this IBS, reduction of the beam intensity is inevitable, which however, had resulted in poor S/N ratio for observation of the transverse beam size. In the present paper, we would like to describe a new beam scraping scheme, which selects out the beams in the distribution tail of the transverse phase space keeping the beam density in the core part by simultaneous application of multi-dimensional laser cooling and beam scraping. The strategy to reduce the beam intensity and hence beam heating due to IBS by a controlled scraping of the outskirt beam keeping the beam density at core part almost the same, has been searched by combination of the beam experiments and computer simulations.
* M. Tanabe et al., Applied Physics Express 1, 028001 (2008).
** M. Nakao et al., submitted to PRST-AB.

MOPPD013

Observation of 2-Component Bunched Beam Signal with Laser Cooling

laser, betatron, coupling, injection

397

H. Souda, M. Nakao, A. Noda, H. Tongu
Kyoto ICR, Uji, Kyoto, Japan
M. Grieser
MPI-K, Heidelberg, Germany
Z.Q. He
TUB, Beijing, People's Republic of China
K. Ito, H. Okamoto
HU/AdSM, Higashi-Hiroshima, Japan
K. Jimbo
Kyoto University, Institute for Advanced Energy, Kyoto, Japan
Y. Yuri
JAEA/TARRI, Gunma-ken, Japan

Funding: Work supported by Advanced Compact Accelerator Development Project of MEXT, Global COE program "The Next Generation of Physics, Spun from Universality and Emergence" and Grant-in-Aid for JSPS Fellows.
Longitudinal beam temperature during a laser cooling was measured through bunch length measurement at S-LSR. 40keV 24Mg+ beams were bunched by an RF voltage with a harmonic number of 5 and were cooled by a co-propagating laser with a wavelength of 280nm*. Bunch length was measured by time-domain signal from a pair of parallel-plate electrostatic pickups with a length of 140mm. Injected non-cooled beams gave a bunch length of 2.5m (2-σ) and cooled beam has a 2-component of broad and sharp distribution. Broad distribution had a longitudinal length of 2.2m, which is close to that of initial beam. The length of the sharp distribution shrunk to 0.25m and is considered as a cooled part. Capture efficiency of cooling, which represents the ratio of the particle numbers of cooled part and the total particle number, varies by the change of the detuning of the laser (fixed frequency or scanning). With scanning range of 2GHz, capture efficiency was improved from 66% to 92%, whereas the bunch became longer by 10% with scanning. Approach to improve the number of cooled particle and cut uncooled part** will be applied to attain a strong signal with a low-current beam with a low temperature.
* J. S. Hangst et al., Phys. Rev. Lett. 74, 4432 (1995).
** A. Noda et al., these proceedings.

MOPPD016

Status of Proof-of-principle Experiment for Coherent Electron Cooling

electron, gun, wiggler, FEL

400

I. Pinayev, S.A. Belomestnykh, I. Ben-Zvi, J. Bengtsson, A. Elizarov, A.V. Fedotov, D.M. Gassner, Y. Hao, D. Kayran, V. Litvinenko, G.J. Mahler, W. Meng, T. Roser, B. Sheehy, R. Than, J.E. Tuozzolo, G. Wang, S.D. Webb, V. Yakimenko
BNL, Upton, Long Island, New York, USA
G.I. Bell, D.L. Bruhwiler, V.H. Ranjbar, B.T. Schwartz
Tech-X, Boulder, Colorado, USA
A. Hutton, G.A. Krafft, M. Poelker, R.A. Rimmer
JLAB, Newport News, Virginia, USA
M.A. Kholopov, P. Vobly
BINP SB RAS, Novosibirsk, Russia

Funding: US DOE Office of Science, DE-FC02-07ER41499, DE-FG02-08ER85182; NERSC DOE contract No. DE-AC02-05CH11231.
Coherent electron cooling (CEC) has a potential to significantly boost luminosity of high-energy, high-intensity hadron colliders. To verify the concept we conduct proof-of-the-principle experiment at RHIC. In this paper, we describe the current experimental setup to be installed into 2 o’clock RHIC interaction regions. We present current design, status of equipment acquisition and estimates for the expected beam parameters.

MOPPD029

Recent Achievements and Upgrade Programs at RIKEN Radioactive Isotope Beam Factory

cyclotron, ECRIS, electron, linac

430

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

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

MOPPD030

Present Status of RIKEN Ring Cyclotron

heavy-ion, cyclotron, linac, vacuum

433

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

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

MOPPD036

Gabor Lens Focusing for Medical Applications

laser, proton, space-charge, focusing

442

J.K. Pozimski, M. Aslaninejad
Imperial College of Science and Technology, Department of Physics, London, United Kingdom

The widespread introduction of Hadron therapy for cancer treatment is inhibited by the large costs for the accelerator and treatment facility and the subsequent maintenance costs which reflects into the cost per treatment. In the long term future (laser) plasma wakefield accelerated hadrons could offer compact treatment devices with significantly reduced treatment costs. In the moment the particle distributions produced by such accelerators do not fulfill the medical requirements by far. Never the less steady progress on the field might change the situation in the future. Beside the reliable production of a sufficient number of ions at the required energy the formation of a particle beam suitable for treatment from the burst of ions created in the acceleration process is one of the major challenges. While conventional optical systems will be operating at the technical limits which would be contradictory to the cost argument, space charge lenses of the Gabor type might be a cost effective alternative. In this paper a beam line consisting of such lenses will be presented together with particle transport simulations.

MOPPD037

Investigation of Space Charge Compensation at FETS

space-charge, emittance, ion-source, rfq

445

J.K. Pozimski, S.M.H. Alsari, P. Savage
Imperial College of Science and Technology, Department of Physics, London, United Kingdom
D.C. Faircloth, A.P. Letchford
STFC/RAL/ISIS, Chilton, Didcot, Oxon, United Kingdom

In order to contribute to the development of high power proton accelerators in the MW range, to prepare the way for an ISIS upgrade and to contribute to the UK design effort on neutrino factories, a front end test stand (FETS) is being constructed at the Rutherford Appleton Laboratory (RAL) in the UK. The aim of the FETS is to demonstrate the production of a 60 mA, 2 ms, 50 pps chopped beam at 3 MeV with sufficient beam quality. The ion source and LEBT are operational with the RFQ under manufacture. In the LEBT a high degree of space charge compensation (~90%) and a rise time of space charge compensation around ~ 50 μs could be concluded indirectly from measurements . As a more detailed knowledge is of interest also for other projects like ESS the FETS LEBT was updated to perform a detailed experimental analysis of space charge compensation. In this paper the results of the experimental work will be presented together with discussion of the findings in respect to beam transport.

MOPPD038

Simulation Study of Electron Response Amplification in Coherent Electron Cooling

electron, bunching, FEL, undulator

448

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

Funding: Work supported by Brookhaven Science Associates, LLC under Contract No. DE-AC02-98CH10886 with the U.S. Department of Energy.
In Coherent Electron Cooling (CEC), it is essential to study the amplification of electron response to a single ion in the FEL process, in order to proper align the electron beam and the ion beam in the kicker to maximize the cooling effect. In this paper, we use Genesis to simulate the amplified electron beam response of single ion in FEL amplification process, which acts as 'Green function' of the FEL amplifier.

MOPPD045

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

ion-source, high-voltage, proton, linac

463

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

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

MOPPD046

Lifetime of the Highly Efficient H⁻ Ion Sources

cathode, plasma, extraction, electron

466

V.G. Dudnikov
Muons, Inc, Batavia, USA
D.S. Bollinger
Fermilab, Batavia, USA
D.C. Faircloth, S.R. Lawrie
STFC/RAL/ISIS, Chilton, Didcot, Oxon, United Kingdom

Funding: Work supported by grant DE-SC0006267, and STFC JAI grant ST/G008531
Factors limiting operating lifetime of Compact Surface Plasma Sources (CSPS) are analyzed and possible treatments for lifetime enhancement are considered. CSPSs have high plasma density (up to 10¹⁴ cm^-3), high emission current density of negative ions (up to 8 A/cm²), small (1–5 mm) gap between cathode emitter, and a small extraction aperture in the anode. They are very simple, have high energy efficiency up to 100 mA/kW of discharge (~100 times higher then modern large Volume RF SPS) and have a high gas efficiency (up to 30%) using pulsed valves. CSPSs are very good for pulsed operation but electrode power density is often too high for dc operation. However, CSPSs were successfully adopted for DC operation with emission current density ~300 mA/cm² in Hollow cathode Penning Discharge and up to 1 A/cm² in Spherical focusing semiplanotron. Flakes from electrodes sputtering and blistering induced by back accelerated positive ions are the main reasons of ion source failure. Suppression of back accelerated positive ions, flakes explosion by pulsed discharges, and flakes gasification by discharge in NF₃ (or XeF₂) can be used for significant increase of operating lifetime of CSPSs.

MOPPD047

Progress of Surface Plasma H⁻ Ion Source with Saddle RF Antenna Plasma Generator

plasma, ion-source, gun, electron

469

V.G. Dudnikov, R.P. Johnson
Muons, Inc, Batavia, USA
S.N. Murray, T.R. Pennisi, C. Piller, M. Santana, M.P. Stockli, R.F. Welton
ORNL, Oak Ridge, Tennessee, USA

Funding: Supported in part by SBIR Grant 4729 · 09SC02690.
Progress in development of RF H⁻ surface plasma source (SPS) with saddle (SA) RF antenna which will provide better power efficiency for high pulsed and average current, higher brightness with longer lifetime and higher reliability will be considered. Several versions of new plasma generators with a small Al2O3chamber and different antennas and magnetic field configurations were tested in the SNS small Test Stand. A prototype SA SPS was installed in the Test Stand with a larger, normal-sized SNS AlN chamber that achieved unanalyzed peak currents of up to 67 mA with an apparent efficiency of 1.6 mA/kW. Control experiments with H⁻ beam produced by SNS SPS with internal and external antennas in the similar conditions were conducted. A new version of the RF triggering plasma source (TPS) has been designed and fabricated. A Saddle antenna SPS with water cooling is being fabricated for high duty factor testing

MOPPD048

Ribbon Electron Beam Profile Monitor for Bunched Beam Tomography

electron, cathode, proton, diagnostics

472

V.G. Dudnikov
Muons, Inc, Batavia, USA
A.V. Aleksandrov
ORNL, Oak Ridge, Tennessee, USA

Funding: Work supported by Contract DE-AC05-00OR22725 and by STTR grant DE-SC0007559
Advanced beam diagnostics are essential for high performance accelerator beam production and for reliable accelerator operation. It is important to have noninvasive diagnostics which can be used continuously with intense beams of accelerated particles. Recently, an electron probe was successfully used to determine accelerated particle density distributions. However, the apparatus used for this diagnostic is large and complex which restricts its wider use for tomography of accelerated bunches. We propose to use a strip cathode is for ribbon electron beam formation instead of a scanning of pencil beam used in the previous electron probe bunch profile monitors. The apparatus with the strip cathode is smaller, has simpler design and less expensive manufacturing, can have better magnetic shielding, higher sensitivity, higher resolution, can have better measurement accuracy and better time resolution. With this device it is possible to develop almost ideal tomography diagnostics of bunches in linear accelerators and in circular accelerators and storage rings.

MOPPD070

A SVD-based Orbit Steering Algorithm for RHIC Injection

injection, heavy-ion, proton, controls

523

C. Liu, A. Marusic, M.G. Minty, V. Ptitsyn
BNL, Upton, Long Island, New York, USA

Funding: Work supported by Brookhaven Science Associates, LLC under Contract No. DE-AC02-98CH10886 with the U.S. Department of Energy.
The RHIC physics programs involve experiments with polarized proton and several species of ion beams. In the past, when switching between physics programs, first turn and circulating beam in RHIC was established manually by adjustments to the corrector dipoles for minimum beam loss. In this report, we introduce a new steering scheme based on an SVD algorithm which uses a single-pass orbit response matrix for first turn steering. The new scheme was implemented into the controls system and demonstrated successfully in Run-11. Establishing circulating beam using this automated approach has been shown to dramatically reduce the beam setup time.

MOPPR012

Beam Induced Fluorescence Monitors for FAIR

vacuum, electron, target, antiproton

798

F. Becker, C.A. Andre, C. Dorn, P. Forck, R. Haseitl, B. Walasek-Höhne
GSI, Darmstadt, Germany
T. Dandl, T. Heindl, A. Ulrich
TUM/Physik, Garching bei München, Germany

Online profile diagnostic is preferred to monitor intense hadron beams at the Facility of Antiproton and Ion Research (FAIR). One instrument for beam profile measurement is the gas based Beam Induced Fluorescence (BIF)-monitor. It relies on the optical fluorescence of residual gas, excited by beam particles. Depending on the beam parameters and vacuum constraints, BIF monitors can be operated at base pressure or in dedicated local pressure bumps. Spectroscopic data in nitrogen and rare gases confirms an exploitable dynamic range from UHV to atmospheric pressure. Optical transitions and corresponding beam profiles are discussed for gas pressures from 10^-3 to 30 mbar. Fundamental limitations for some application scenarios will be addressed as well.

MOPPR013

Beam Loss and Transmission Control at FAIR

controls, synchrotron, proton, extraction

801

M. Schwickert, T. Hoffmann, F. Kurian, H. Reeg, A. Reiter
GSI, Darmstadt, Germany
W. Vodel
HIJ, Jena, Germany

FAIR, the Facility for Antiproton and Ion Research, is presently entering the final layout phase at GSI. The injector chain consists of the existing linear accelerator UNILAC and synchrotron SIS18, plus a new dedicated 70 MeV high-intensity proton Linac. Along the injector chain to the main synchrotron SIS100 as well as in the beam transport lines, which connect synchrotrons, storage rings and experimental areas, beam transmission or vice versa beam loss have to be controlled very precisely. To supply a maximum intensity of 5·10¹¹ U²⁸⁺/spill to experiments and to prevent machine damages by intense beams, an integrated system for transmission and loss control is mandatory. While various kinds of beam current transformers control transmission online, intercepting Particle Detector Combinations (scintillators, ionization chambers, secondary electron monitors) are foreseen for optimization runs. External Beam Loss Monitors indirectly detect loss positions by measuring secondary particles. This contribution summarizes the requirements for the related detector systems and presents basic concepts for beam loss and transmission control at FAIR.

MOPPR020

An Improved Cryogenic Current Comparator for FAIR

pick-up, shielding, cryogenics, niobium

822

R. Geithner, W. Vodel
HIJ, Jena, Germany
R. Geithner, R. Neubert, P. Seidel
FSU Jena, Jena, Germany
F. Kurian, H. Reeg, M. Schwickert
GSI, Darmstadt, Germany

Online monitoring of low intensity (below 1 μA) charged particle beams without disturbing the beam and its environment is crucial for any accelerator facility. For the upcoming FAIR project a beam monitor based on the Cryogenic Current Comparator principle with an enhanced resolution was developed. The main focus of research was on the low temperature properties of the ferromagnetic core material of the superconducting pickup coil. The pickup coil transforms the magnetic field of the beam into a current that is detected by a high performance low temperature dc Superconducting QUantum Interference Device (LTS-DC-SQUID). The penetration of the pickup coil by interfering magnetic fields is highly attenuated by a meander shaped superconducting shielding. The Cryogenic Current Comparator is able to measure DC beam currents, e.g. as required for slow extraction from a synchrotron, as well as bunched beams. In this contribution we present first results of the improved Cryogenic Current Comparator working in a laboratory environment.

MOPPR028

Upgrade Plan of BLM System of J-PARC MR

extraction, injection, proton, monitoring

837

K. Satou, T. Toyama
J-PARC, KEK & JAEA, Ibaraki-ken, Japan

The upgrade plan of BLM system of J-PARC Main Ring synchrotron (MR) will be described. Existing proportional chamber beam loss monitors (P-BLMs) have fast signal rise time of about 100ns and high gas gain of about 2·10⁴ at the maximum. These abilities were quite advantageous for the early beam commissioning stage. On the other hand, the gas gain is degraded with increasing output current. The P-BLM is suitable for a measurement of a low level beam loss event, however, vulnerable to a measurement of an accidental beam loss event (fast loss) causing high radiation. To enhance the dynamic range of the system, 1m long Air Ionization Chambers (AICs) will be installed and operated with the P-BLM. Experiments using the real beam loss at collimator area and at the Co60 radiation facility have demonstrated the stable operations up to the radiation level activated by the maximum beam loss power of the collimator area. A new data taking system is now under development, and its performances will also be presented.

MOPPR029

Upgrade of Ionization Profile Monitor (IPM) in the J-PARC 3-GeV RCS

electron, vacuum, status, space-charge

840

H. Harada, K. Yamamoto, M. Yoshimoto
JAEA/J-PARC, Tokai-Mura, Naka-Gun, Ibaraki-Ken, Japan

Ionization Profile Monitors (IPM) were installed and operated in the J-PARC 3-GeV RCS for the observation of circulating beam profile. In IPM system, ions produced by the beam passing through beam chamber lead to Multi Channel Plate (MCP) by electric field, and the signals from the MCP are observed as the beam profile. The IPM system has an upgrade plan for the optimization of the electric fields. This will be reported the upgrade status of the IPM.

MOPPR048

Beam Instrumentation for the HIE-ISOLDE Linac at CERN

diagnostics, linac, cryomodule, emittance

891

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

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

MOPPR055

A Two-dimensional Wire Scanner for a Low Energy Ion Beam

diagnostics, ion-source, acceleration, vacuum

909

C. Gabor
STFC/RAL/ASTeC, Chilton, Didcot, Oxon, United Kingdom
G.E. Boorman
Royal Holloway, University of London, Surrey, United Kingdom
A.P. Letchford
STFC/RAL/ISIS, Chilton, Didcot, Oxon, United Kingdom

The Front End Test Stand (FETS) at the Rutherford Appleton Laboratory (RAL) is intended to demonstrate the early stages of acceleration for future high power proton applications. So far, the H⁻ ion source and the low energy beam transport (LEBT) are operational. The commissioning of the LEBT is carried out with a multipurpose diagnostics vessel. On the other hand, the present status of the LEBT does not provide any permanent installed beam diagnostics beyond current measurement. Possible diagnostics need to be compact and rigid in a way that it can survive an area with potentially high beam losses and not suffering to much of beam noise. Furthermore, minimal invasive diagnostics is preferred. It is intended to present first results of a wire scanner where the geometry has been changed in a way that the two dimensional xy-space is accessible.

MOPPR056

Experimental and Theoretical Studies of a Low Energy H⁻ beam

rfq, acceleration, ion-source, solenoid

912

C. Gabor
STFC/RAL/ASTeC, Chilton, Didcot, Oxon, United Kingdom
G.E. Boorman
Royal Holloway, University of London, Surrey, United Kingdom
A.P. Letchford
STFC/RAL/ISIS, Chilton, Didcot, Oxon, United Kingdom

The Front End Test Stand (FETS) at the Rutherford Appleton Laboratory (RAL) is intended to demonstrate the early stages of acceleration (0-3 MeV) and beam chopping required for high power proton accelerators. At the moment, the RFQ is under construction and there is a need to understand the matching of the Low Energy Beam Transport (LEBT) into the RFQ as conclusive as possible. The parameter of interest may include solenoid settings, steering effects but also the influence of the post acceleration of the ion source and potential effects of space charge compensation. Two emittance scanner are installed and can be combined with scintillator acting as a beam profile monitor and auxiliaries like current measurement.

MOPPR077

ION CHAMBERS AND HALO RINGS FOR LOSS DETECTION AT FRIB

radiation, linac, cryomodule, simulation

969

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

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

TUYA02

Overview of Asymmetric Electron Hadron Colliders

electron, collider, hadron, proton

1025

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

The first lepton-proton collider HERA at DESY completed its operation in 2007. Presently, several accelerator proposals for future electron-hadron colliders are under consideration in several laboratories from all over the world. The future accelerators intend to exceed the HERA luminosity by 2-3 orders of magnitude, as well as to cover the different ranges of center-of-mass collision energies. The research capabilities will be extended by including the collisions of electrons with heavy ions, as well as, in some designs, with polarized protons and polarized ions. The future electron-hadron colliders would serve as high-resolution microscopes able to reveal unprecedented details of the structure of nucleons and ions, including their spin content and the state of high gluon density matter. The colliders will provide us with ultimate tools to test both the ways Quantum Chromodynamics works as well as to look for new physics beyond the Standard Model. All proposed electron-hadron colliders are based on the extension of existing accelerators to accommodate the electron-hadron collisions. Advanced accelerator technologies are utilized in order to achieve the desired high luminosity.

Slides TUYA02 [6.002 MB]

TUYB01

Proton Beam Acceleration with Circular Polarized Laser Pulses

laser, proton, electron, plasma

1045

X.Q. Yan, J.E. Chen, C. Lin, Y.R. Lu, H. Wang
PKU/IHIP, Beijing, People's Republic of China
Z.Y. Guo
IHEP, Beijing, People's Republic of China

This presentation should describe the use of circular polarized laser pulses for phase-stable acceleration of proton beams. The principles of the technique should be explained, with comparisons and contrasts made with similar techniques. The potential for production of high-intensity, mono-energetic proton beams should be discussed, and the results of analytical, simulation, and experimental studies presented.

Slides TUYB01 [7.922 MB]

TUOBA01

Summary of Fermilab’s Recycler Electron Cooler Operation and Studies

electron, antiproton, emittance, extraction

1068

L.R. Prost, A.V. Shemyakin
Fermilab, Batavia, USA

Funding: Operated by Fermi Research Alliance, LLC under Contract No. DE-AC02-07CH11359 with the United States Department of Energy.
Fermilab’s Recycler ring was used as a storage ring for accumulation and subsequent manipulations of 8 GeV antiprotons destined for the Tevatron collider. To satisfy these missions, a unique electron cooling system was designed, developed and successfully implemented. The most important features that distinguish the Recycler cooler from other existing electron coolers are its relativistic energy (it employs a 4.3 MeV, 0.1 A DC electron beam), a weak continuous longitudinal magnetic field in the cooling section (~100 G), and lumped focusing elsewhere. With the termination of the collider operation at Fermilab, the cooler operation was also terminated. In this article, we will summarize the experience of commissioning, optimizing and running this unique machine over the 6 years of its existence.

Slides TUOBA01 [2.503 MB]

TUOBA02

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

cyclotron, linac, DTL, ECRIS

1071

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

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

Slides TUOBA02 [9.947 MB]

TUOBA03

H⁻ and Proton Beam Loss Comparison at SNS Superconducting Linac

proton, linac, quadrupole, DTL

1074

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

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

Slides TUOBA03 [0.772 MB]

TUOAB03

Five Years of Accelerator Operation Experience at HIT

controls, ion-source, synchrotron, linac

1083

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

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

Slides TUOAB03 [7.526 MB]

TUPPC007

Electron Cloud Dynamics in a Gabor Space Charge Lens

electron, space-charge, plasma, focusing

1164

K. Schulte, M. Droba, B. Glaeser, S. Klaproth, O. Meusel, U. Ratzinger
IAP, Frankfurt am Main, Germany

Inside Gabor space charge lenses, external fields confine electrons forming a homogeneously distributed electron cloud. Its linear electric space charge field enables the focusing of high intensity heavy ion beams without aberrations. The focusing performance depends on the properties of the non-neutral plasma. In a small-scale table top experiment, different types of space charge lenses are used to characterize the collective behavior of the confined electron cloud using new non-interceptive diagnostic methods. The plasma parameters, e.g. electron temperature and density, are important to an improved understanding of loss and production mechanisms as well as the electron cloud dynamics. In this context, the evolution of instabilities caused by the enclosing fields has been investigated in detail. Experimental results will be presented and compared to numerical simulations.

TUPPC012

Optics of Extraction Lines at CNAO

proton, dipole, extraction, septum

1179

E. Bressi, L. Falbo, C. Priano, M. Pullia
CNAO Foundation, Milan, Italy
C. Biscari
INFN/LNF, Frascati (Roma), Italy

The CNAO (National Center for Oncological Hadrontherapy), is the first Italian center for deep hadrontherapy with proton and carbon ion beams, treating patients since fall 2011. The beam is delivered to the patient through a high energy transfer line (HEBT). The line is equipped with a horizontal switching dipole that carries the beam in three treatment rooms and a vertical switching dipole that allows a vertical delivery of the beam in the central treatment room. The CNAO HEBT commissioning has been carried out using proton and Carbon beams in the full range of energies: 60 to 250 MeV/u for protons, 120 to 400 MeV/u for Carbon ions. Optimization of the beam lines setup has been carried out for few energies, applying beam magnetic rigidity scaling for the full range in steps of the order of 1 MeV. The scaling has proven to be satisfactory for most elements, and only minor adjustments in the initial part of the line were needed to fulfill tolerances in all the range. Repeatability of magnetic settings is supported by measurements along the lines. Finally the results in terms of beam dimensions, beam transmission and beam position at the patient position are presented.

TUPPC030

Status of the Ion Sources at ESS-Bilbao

controls, ion-source, plasma, extraction

1227

J. Feuchtwanger, I. Arredondo, F.J. Bermejo, I. Bustinduy, J. Corres, M. Eguiraun, P.J. González, J.L. Muñoz
ESS Bilbao, Bilbao, Spain
V. Etxebarria, J. Jugo, J. Portilla
University of the Basque Country, Faculty of Science and Technology, Bilbao, Spain
R. Miracoli
ESS-Bilbao, Zamudio, Spain

Currently there are two types of ion sources under development and testing at ESS-Bilbao, the first one is a Penning type source based on the ISIS/RAL source, modified to use permanent magnets to generate the Penning field. The second source is an off-resonance ECR source that is being developed in-house. The Penning source is in the late stages of commissioning, and a beam has been extracted from it. Currently the main work on that source is in the optimization of the operating parameters. The ECR source on the other hand is in the early stages of the commissioning, all parts have been fabricated, and Vacuum tests are underway. Testing of the RF and control systems will follow, and finally the whole system will be tested. The control system for both ion sources was developed under LabView, and runs on a real time system. While for testing the timing sequences run locally, the system is being developed so that it can run using a central timing system.

TUPPC062

Transfer of Polarized 3He Ions in the AtR Beam Transfer Line

injection, extraction, dipole, proton

1317

N. Tsoupas, W.W. MacKay, F. Méot, T. Roser, D. Trbojevic
BNL, Upton, Long Island, New York, USA

Funding: Work supported by the US Department of Energy
In addition to collisions of electrons with various unpolarized ion species as well as polarized protons, the proposed electron-hadron collider (eRHIC) will also facilitate the collisions of electrons with polarized 3He ions. The AGS is the last acceleration stage of ions before injection into one RHIC for final acceleration. The AtR (AGS to RHIC) transfer line will be utilized to transport the polarized 3He ions from AGS into one of the RHIC’s collider rings. In this paper we investigate the extraction energy of the polarized 3He ions from the AGS which will optimize the polarization of 3He ions injected into RHIC. Some of the peculiarities (interleaved horizontal and vertical bends) of the AtR line's layout may degrade this spin matching of the polarized 3He ions. We will also discuss possible simple modifications of the AtR line to accomplish a perfect “spin matching” of the injected 3He beam with that of the stable spin direction at the injection point of the RHIC ring.

TUPPC097

Computational Modeling of Electron Cloud For MEIC

electron, simulation, collider, emittance

1383

S. Ahmed, J.D. Dolph, G.A. Krafft, T. Satogata, B.C. Yunn
JLAB, Newport News, Virginia, USA

Funding: Authored by Jefferson Science Associates, LLC under U.S. DOE Contract No. DE-AC05-06OR23177.
This work is the continuation of our earlier studies on electron cloud (EC) simulations reported in IPAC'11 for the medium energy electron-ion collider (MEIC) envisioned at JLab beyond the 12 GeV upgrade of CEBAF. In this paper, we will study the EC saturation density in various MEIC operations scenarios to calculate details of the EC-induced wakefield to establish more stringent bounds on instability thresholds and determine whether EC mitigation, such as NEG coatings or solenoid fields, should be considered in the MEIC design.

TUPPC099

Optimization of Chromaticity Compensation and Dynamic Aperture in MEIC Collider Rings

sextupole, dynamic-aperture, octupole, collider

1389

F. Lin, Y.S. Derbenev, V.S. Morozov, Y. Zhang
JLAB, Newport News, Virginia, USA
K.B. Beard
Muons, Inc, Batavia, USA

Funding: Authored by Jefferson Science Associates, LLC under U.S. DOE Contract No. DE-AC05-06OR23177. Supported in part by US DOE STTR grant DE-SC0006272.
The conceptual design of the Medium-energy Electron-Ion Collider (MEIC) at Jefferson Lab relies on an ultra-small beta-star to achieve high luminosities of up to 10³⁴ cm^-2s⁻¹. A low-beta insertion for interaction regions unavoidably induces large chromatic effects that demand a proper compensation. The present approach of chromatic compensation in the MEIC collider rings is based on a local correction scheme using two symmetric chromatic compensation blocks that includes families of sextupoles, and are placed in a beam extension area on both sides of a collision point. It can simultaneously compensate the first order chromaticity and chromatic beam smear at the IP without inducing significant second order aberrations. In this paper, we investigate both the momentum acceptance and dynamic aperture in the MEIC ion collider ring by considering the aberration effects up to the third order, such as amplitude dependent tune shift. We also explore the compensation of the third order effects by introducing families of octupoles in the extended beam area.
Authored by Jefferson Science Associates, LLC under U.S. DOE Contract No. DE-AC05-06OR23177. Supported in part by US DOE STTR grant DE-SC0006272.

TUPPC103

Ion Bunch Length Effects on the Beam-beam Interaction and its Compensation in a High-luminosity Ring-ring Electron-ion Collider

electron, proton, luminosity, simulation

1401

C. Montag, W. Fischer, A. Oeftiger
BNL, Upton, Long Island, New York, USA

Funding: Work supported by Brookhaven Science Associates, LLC under Contract No. DE-AC02-98CH10886 with the U.S. Department of Energy.
One of the luminosity limits in a ring-ring electron-ion collider is the beam-beam effect on the electrons. In the limit of short ion bunches, simulation studies have shown that this limit can be significantly increased by head-on beam-beam compensation with an electron lens. However, with an ion bunch length comparable to the beta-function at the IP in conjunction with a large beam-beam parameter, the electrons perform a sizeable fraction of a betatron oscillation period inside the long ion bunches. We present recent simulation results on the compensation of this beam-beam interaction with multiple electron lenses.

TUPPD023

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

rfq, plasma, laser, linac

1458

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

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

TUPPD026

Study of the RFQ Beam Cooler for SPES project

rfq, quadrupole, emittance, extraction

1467

M.M. Maggiore, A.M. Porcellato, S. Stark
INFN/LNL, Legnaro (PD), Italy

The SPES project is the new Radioactive Ion Beam facility under construction at Laboratori Nazionali of Legnaro, Italy. In this framework in order to improve the beam quality in terms of emittance and energy spread, a study of a new RFQ beam cooler device is accomplishing. The electromagnetic design of the RFQ section and the electrostatic layout of the injection and extraction regions have been done. The study about the beam dynamic is going on by means of dedicated codes which allow to take into account the interaction of the ions with the buffer gas needed to cool the beams. The status of the project and the results will be shown in this report.

TUPPD031

Novel Techniques for Isotope Harvesting at FRIB

simulation, optics, target, resonance

1470

M.A.C. Cummings
Muons, Inc, Batavia, USA
L.L. Bandura
FRIB, East Lansing, Michigan, USA

Exotic isotopes have applications in medicine, industry, and national security. Historically, the U.S. has relied on foreign sources for these isotopes. FRIB will be a domestic source of these isotopes. While FRIB is mainly focused on producing exotic isotopes for basic nuclear physics experiments, it also offers an opportunity to harvest unused isotopes for other applications. It is critical that isotope harvesting take place in a synergistic manner that does not adversely affect experiments that will be simultaneously taking place at the facility. Beam optics schemes will be calculated to determine the best locations and methods of separation. These calculations will use COSY Monte Carlo and G4beamline in conjunction with other state of the art ion optical codes that simulate isotope dynamics in magnetic fields and in matter. The results of these simulations will be used to determine the best beam-target combinations to produce the isotopes that are most in-demand and calculate purities of these isotopes in multiple locations in the fragment separators. Trapping and extraction schemes will also be described to maximally recover pure isotope samples.

TUPPD042

Design of Transmission Line at 28 GHz, 10 kW for ECR Ion Source in KBSI

ion-source, ECRIS, plasma, vacuum

1494

M. Won, S. Choi, B.C. Kim, B.S. Lee, J.W. Ok, J.Y. Park, J.H. Yoon
Korea Basic Science Institute, Busan, Republic of Korea

The 28 GHz gyrotron system was designed to deliver the microwave power from gyrotron oscillator to an electron cyclotron resonance ion source (ECRIS) for simultaneously producing high current and highly charged ions. The microwave power from 28 GHz gyrotron were measured from the range between 0.5 kW and 10 kW with frequency variation from 27.9740 to 27.9893 GHz. The gyrotron oscillator of transmission system operates in continuous wave regime with the smoothly regulated output microwave power. A transmission line was designed for the transport of microwaves to an ion source. For the electrical insulation between gyrotron system and ion source chamber applied to high voltage, we installed a DC break. In order to evaluate gyrotron operation, a dummy load was developed to consume such high microwave power.

TUPPD044

Conceptual Gas Jet as a Stripping Target for Charge Exchange Injection

target, injection, laser, proton

1500

V.G. Dudnikov, C.M. Ankenbrandt
Muons, Inc, Batavia, USA

Stripping targets for charge exchange injection now uses thin carbon or Al2O3 foils. During long time injection for high intense beam accumulation by low current injection a foil life time can be compromised by overheating and alternative stripping targets need be developed. A pulsed supersonic gas jet was used as a stripping target in first realization of charge exchange injection with H⁻ ion energy 1.5 MeV and stationary gas jets are used as internal targets in experiments with super high vacuum. A stripper target thickness is proportional to the injection energy and for energy 1GeV should be ~0.3 mg/cm² of carbon. The pulsed gas target with such thickness acceptable for long time charge exchange injection can be produced with using of heavy hydrocarbon molecules used in the diffusion or booster vacuum pumps. Formation of the pulsed gas jet stripping targets will be considered.

TUPPD045

Efficient Plasma Generation by Positive Circulating Beams

electron, proton, vacuum, plasma

1503

V.G. Dudnikov, C.M. Ankenbrandt
Muons, Inc, Batavia, USA

Performances of high brightness circulating beams are affected by development of strong “electron-proton” (e-p) instabilities connected with generation of an electron cloud (EC). For suppression of the EC generation it is proposed a coating of vacuum chambers by compounds with low secondary electron emission, which is very complex and expensive for large systems like LHC or RHIC. Threshold beam intensity for EC generation can be increased during the vacuum chamber bombarding by plasma particles generating by EC. Vacuum chamber processing (scrubbing) by EC is conducted by bunched beam with a highest possible intensity and with shortest gaps between bunches. Highly efficient plasma generation can be produced in the coasting circulating beam of positive particles with relative low intensity and energy. With the coasting positive beam the plasma particles are generating by low energy electrons trapped by a positive beam space charge. Dynamics of electrons and ions generation will be estimated and simulated. The rate of plasma generation and surface scrubbing can be increase by decrease of pumping and injection of selected gases.

TUPPD046

Characterization of Li⁺ Alumino-Silicate Ion Source for Target Heating Experiments

extraction, ion-source, space-charge, brightness

1506

P.K. Roy, W.G. Greenway, J.W. Kwan, S.M. Lidia, P.A. Seidl, W.L. Waldron
LBNL, Berkeley, California, USA
D.P. Grote
LLNL, Livermore, California, USA

Funding: *This work was performed under the auspices of the U.S Department of Energy by LLNL under contract DE AC52 07NA27344, and by LBNL under contract. DE-AC02-05CH11231.
The Heavy Ion Fusion Sciences (HIFS) program at Lawrence Berkeley National Laboratory will carry out warm dense matter experiments using Li⁺ ion beam with energy 1.2–3 MeV to achieve uniform heating up to 0.1–1 eV. Experiments will be done using the Neutralized Drift Compression Experiment-II (NDCX-II) facility. The NDCX-II accelerator has been designed to use a large diameter (10.9 cm) Li⁺ doped alumino-silicate source to produce short pulses of ≈93 mA beam current. Fabrication of a lithium source is complex, it is necessary to apply a higher temperature (>1200-degC) for thermionic emission, and the beam current density of this source is ~1mA/cm² in the space-charge limited regime. Li⁺ emission is lower than the other alkaline ions sources (K⁺, Cs⁺). The lifetime of this source is roughly 50 hours, when pulsed. Characterization of an operational lithium alumino-silicate ion source, including beam emittance, is presented.

TUPPD047

Injection Sequence for High-power Isochronous Cyclotrons for ADS Fission

cyclotron, rfq, ion-source, emittance

1509

S. Assadi, K.E. Badgley, C. Collins, J. Comeaux, R. Garrison, P.M. McIntyre, A. Sattarov
Texas A&M University, College Station, Texas, USA

Funding: This work is supported by grants from the State of Texas (ASE) and the Mitchell Family Foundation.
A high-current injector sequence is being developed for use in a flux-coupled stack of high-current cyclotrons for accelerator-driven subcritical (ADS) fission. The design includes an ECR ion source, LEBT, RF quadrupole, and multi-stage chopper. A first cyclotron then accelerates the beams to 100 MeV for injection to the sector isochronous cyclotron. Provisions for control of emittance and bunch tails are described.

TUPPD048

Optical Emission Spectroscopy Studies of the Spallation Netron Source (SNS) H⁻ Ion Source

ion-source, plasma, neutron, background

1512

B. Han, S.N. Murray
ORNL RAD, Oak Ridge, Tennessee, USA
T.R. Pennisi, M. Santana, M.P. Stockli, R.F. Welton
ORNL, Oak Ridge, Tennessee, USA

A Cs enhanced, RF-driven H⁻ ion source feeds the SNS accelerator with a 65 keV H⁻ beam at 60 Hz with a pulse length of up to 1.0 ms. The ion source beam intensity and reliability are critical to the SNS operational power level and availability. The 1-MW level routine operation of the SNS requires ~38 mA beam in the linac. This requirement is normally met by the ion source in a persistent manner for a 4-5 weeks service-cycle of the ion source. But, in some occasions, the ion source either falls short of the beam current or fails to keep the beam current persistent. The key factor in achieving high current, persistent H⁻ beam is to have a proper coverage of Cs on the ion converter surface near the source outlet. To quantify the amount of Cs put into the system during cesiation(s) and to monitor the Cs migration during the source operation, an experimental study is under way with an optical spectrometer monitoring the emission lights from the ion source plasma. Another possible use of this emission spectroscopy study is to detect the indication of the ion source antenna deterioration before it develops into a total failure. The progress and some preliminary results are presented.

TUPPD052

A New Load Lock System for the Source of Polarized Electrons at ELSA

electron, vacuum, polarization, laser

1521

D. Heiliger, W. Hillert, B. Neff
ELSA, Bonn, Germany

Funding: supported by DFG (SFB/TR16)
Since 2000, an inverted source of polarized electrons at the electron stretcher accelerator ELSA routinely provides a pulsed beam with a current of 100 mA and a polarization degree of about 80%. One micro-second long pulses with 100 nC charge are produced by irradiating a GaAs strained-layer superlattice photocathode (8 mm in diameter) with laser light. Future accelerator operation requires a significantly higher beam intensity, which can be achieved by using photocathodes with sufficiently high quantum efficiency. Therefore, and in order to enhance the reliability and up time of the source, a new extreme high-vacuum (XHV) load lock system was installed and commissioned at the beginning of this year. It consists of three chambers: The activation chamber for heat cleaning of the photocathodes and activation with cesium and oxygen. The storage chamber in which up to five different types of photocathodes with various diameters of the emitting surface can be stored under XHV conditions. The loading chamber in which an atomic hydrogen source is used to remove any remaining surface oxidation. Additionally, tests of the photocathodes’ properties can be performed during operation.

TUPPR079

Ion Polarization in the MEIC Figure-8 Ion Collider Ring

polarization, proton, resonance, collider

2008

V.S. Morozov, Y.S. Derbenev, Y. Zhang
JLAB, Newport News, Virginia, USA
P. Chevtsov
Paul Scherrer Institut, Villigen, Switzerland
Y. Filatov
MIPT, Dolgoprudniy, Moscow Region, Russia
A.M. Kondratenko, M.A. Kondratenko
Science and Technique Laboratory Zaryad, Novosibirsk, Russia

Funding: Authored by Jefferson Science Associates, LLC under U.S. DOE Contract No. DE-AC05-06OR23177.
The nuclear physics program envisaged at the Medium-energy Electron-Ion Collider (MEIC) currently being developed at the Jefferson Lab calls for collisions of 3-11 GeV/c longitudinally polarized electrons and 20-100 GeV/c, in equivalent proton momentum, longitudinally or transversely polarized light ions. In this paper, we present a scheme based on figure-8 shaped booster and collider rings that provides the required ion polarization arrangement in the MEIC's ion collider ring.
The U.S. Government retains a non-exclusive, paid-up, irrevocable, world-wide license to publish or reproduce this manuscript for U.S. Government purposes.

TUPPR080

Integration of Detector into Interaction Region at MEIC

dipole, solenoid, optics, electron

2011

V.S. Morozov, R. Ent, P. Nadel-Turonski
JLAB, Newport News, Virginia, USA
C. Hyde
Old Dominion University, Norfolk, Virginia, USA

Funding: Notice: Authored by Jefferson Science Associates, LLC under U.S. DOE Contract No. DE-AC05-06OR23177.
The Jefferson Lab's Medium-energy Electron Ion Collider (MEIC) is proposed as a next-generation facility for the study of strong interaction (QCD). Accessing the relevant physics requires a full-acceptance detector with a dedicated small-angle high-resolution detection system capable of covering a wide range of momenta (and charge-to-mass ratios) with respect to the original ion beam. We present a design of such a detection system integrated into the collider's interaction region, in which full acceptance is attained by letting small-angle collision products pass through the nearest elements of the machine final-focusing system for further detection. The proposed design is consistent with the current collider optics and demonstrates an excellent performance in terms of detector acceptance and resolution.
The U.S. Government retains a non-exclusive, paid-up, irrevocable, world-wide license to publish or reproduce this manuscript for U.S. Government purposes.

TUPPR082

MEIC Design Progress

electron, collider, booster, polarization

2014

Y. Zhang, Y.S. Derbenev, D. Douglas, A. Hutton, G.A. Krafft, R. Li, F. Lin, V.S. Morozov, E.W. Nissen, F.C. Pilat, T. Satogata, C. Tennant, B. Terzić, B.C. Yunn
JLAB, Newport News, Virginia, USA
D.P. Barber
DESY, Hamburg, Germany
Y. Filatov
JINR, Dubna, Russia
C. Hyde
Old Dominion University, Norfolk, Virginia, USA
A.M. Kondratenko
Science and Technique Laboratory Zaryad, Novosibirsk, Russia
S.L. Manikonda, P.N. Ostroumov
ANL, Argonne, USA
M.K. Sullivan
SLAC, Menlo Park, California, USA

Funding: Supported by the U.S. Department of Energy, Office of Nuclear Physics, under Contract No. DE-AC05-06OR23177 and No. DE-AC02-06CH11357.
This paper will report the recent progress in the conceptual design of MEIC, a high luminosity medium energy polarized ring-ring electron-ion collider at Jefferson lab. The topics and achievements that will be covered are design of the ion large booster and the ERL-circulator-ring-based electron cooling facility, optimization of chromatic corrections and dynamic aperture studies, schemes and tracking simulations of lepton and ion polarization in the figure-8 collider ring, and the beam-beam and electron cooling simulations. A proposal of a test facility for the MEIC electron cooler will also be discussed.

TUPPR083

Kink Instability Suppression with Stochastic Cooling Pickup and Kicker

electron, feedback, pick-up, kicker

2017

Y. Hao, M. Blaskiewicz, V. Litvinenko, V. Ptitsyn
BNL, Upton, Long Island, New York, USA

Funding: Work supported by Brookhaven Science Associates, LLC under Contract No. DE-AC02-98CH10886 with the U.S. Department of Energy.
The kink instability is one of the major beam dynamics issues of the linac-ring based electron ion collider. This head-tail type instability arises from the oscillation of the electron beam inside the opposing ion beam. It must be suppressed to achieve the desired luminosity. There are various ways to suppress the instability, such as tuning the chromaticity in the ion ring or by a dedicated feedback system of the electron beam position at IP, etc. However, each method has its own limitation. In this paper, we will discuss an alternative opportunity of suppressing the kink instability of the proposed eRHIC at BNL using the existing pickup-kicker system of the stochastic cooling system in RHIC.

TUPPR087

Status of NSCL Cyclotron Gas Stopper

cyclotron, extraction, injection, emittance

2029

N.S. Joshi, G. Bollen, M. Brodeur, D.J. Morrissey, S. Schwarz
NSCL, East Lansing, Michigan, USA

A gas-filled reverse cyclotron for the thermalization of energetic beams is under construction at NSCL/MSU. Rare isotopes produced via projectile fragmentation after in-flight separation will be injected into the device and converted into low-energy beams through buffer gas interactions as they spiral towards the center of the device. The extracted thermal beams will be used for low energy experiments such as precision mass measurements with traps or laser spectroscopy, and further transport for reacceleration. Detailed calculations have been performed to optimize the magnetic field design as well as the transport and stopping of ions inside the gas. An RF-carpet will be used to transport the thermal ions to the axial extraction point. The calculations indicate that the cyclotron gas stopper will be much more efficient for the thermalization of light and medium mass ions compared to linear gas cells. In this contribution we will discuss simulations of the overall performance and acceptance of machine, the beam matching calculations to the fragment separator emittance, and the construction status.

WEXA02

Development of Electron Coolers in Novosibirsk

electron, gun, acceleration, proton

2068

V.V. Parkhomchuk
BINP SB RAS, Novosibirsk, Russia
S. Nagaitsev
Fermilab, Batavia, USA

An electron cooling method was proposed by G. Budker aproximately 50 years ago. Since the first demonstrations of strong cooling in 1972, the Novosibirsk Institute of Nuclear Physics has continued to develop this technique for various machines with increasingly higher energy beams. Recent application of the e-cooling method at LEIR appeared as a crucial application for a high luminosity achieved in lead-lead ion beam collisions at LHC. This talk should describe the fundamental mechanism of strong cooling, describe historical progress at the BINP and present recent results achieved at the LHC. New 2MeV cooler for COSY ring under commissioning just now at BINP.

Slides WEXA02 [7.872 MB]

WEOBA03

Beam Tests of a High Pressure Gas-Filled Cavity for a Muon Collider

cavity, electron, pick-up, collider

2131

T.A. Schwarz, M.A. Leonova, A. Moretti, M. Popovic, A.V. Tollestrup, K. Yonehara
Fermilab, Batavia, USA
M. Chung
Handong Global University, Pohang, Republic of Korea
B.T. Freemire, P.M. Hanlet, Y. Torun
IIT, Chicago, Illinois, USA
R.P. Johnson
Muons, Inc, Batavia, USA

Funding: US DOE under contract DE-AC02-07CH11359.
One of the greatest challenges in constructing a Muon Collider is cooling the hot muons into a focused beam after their production. Because the beam must be cooled quickly before the muons decay, compact cooling designs require high gradient cavities inside strong magnetic fields. Unfortunately, due to focused field emission, an external magnetic field degrades the performance of the cavity below what is required for a muon collider. High-pressure gas inside the cavity has been proposed to both mitigate this effect, as well as serve as an absorber for transversely cooling the muon beam. A prototype of a high pressure gas-filled cavity is currently being studied at the Muon Test Area at Fermilab. The experimental setup as well as several measurements of the physics and performance of the apparatus while operating in a 400-MeV proton beam will be discussed.

Slides WEOBA03 [6.912 MB]

WEPPC018

Design of a Spoke Cavity for RIKEN RI-beam Factory

cavity, vacuum, simulation, heavy-ion

2245

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

Designs of a CW superconducting rebuncher tri-spoke cavity for uranium beams with β = 0.303 has been studied. The estimated peak voltage is rather high as 3 mega-voltages (MV). The resonator frequency was chose as 219MHz which is 12 times of the foundational frequency. The buncher would be settled in a location between two booster cyclotrons (RRC: K = 540MeV, fRC: K = 570 MeV). In this cavity design, a flat E field distribution on beam axis was designed based on the Microwave Studio (MWS) simulations. The cavity parameters, detail designs and some simulated results will be reported in this paper.

WEPPC034

LA³NET - An International Network on Laser Applications at Accelerators

laser, acceleration, diagnostics, electron

2281

C.P. Welsch
Cockcroft Institute, Warrington, Cheshire, United Kingdom
C.P. Welsch
The University of Liverpool, Liverpool, United Kingdom

Funding: This project is funded by the European Union under contract PITN-GA-2011-289191.
Lasers have become increasingly important for the successful operation and continuous optimization of particle accelerators: Laser-based particle sources are well suited for delivering the highest quality ion and electron beams, laser acceleration has demonstrated unprecedented accelerating gradients and might be an alternative for conventional particle accelerators in the future, and without laser-based beam diagnostics it would not be possible to unravel the characteristics of many complex particle beams. The LA³NET project will bring together research centers, universities, and industry partners to jointly train 17 early stage researchers. In addition, the consortium will also organize a number of international training events, such as schools, topical workshops and conferences. This contribution gives examples from the network's broad research program and summarizes planned training events.

WEPPC037

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

quadrupole, impedance, cavity, linac

2289

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

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

WEPPC039

Development of a Half-Wave Resonator for Project X

cavity, linac, SRF, cryomodule

2295

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

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

WEPPC095

Evaluation of Silicon Diodes as In-situ Cryogenic Field Emission Detectors for SRF Cavity Development

cavity, radiation, SRF, cryogenics

2438

A.D. Palczewski, R.L. Geng
JLAB, Newport News, Virginia, USA

Funding: This work is authored by Jefferson Science Associates, LLC under U.S. DOE Contract No. DE-AC05-06OR23177.
We performed in-situ cryogenic testing of five silicon diodes as possible candidates for field emission monitor of SRF cavities in vertical testing dewars and in cryo-modules. We evaluated diodes from 2 companies - from Hamamatsu corporation model S5821-02 (used at KEK)* and S1223-02; and from OSI Optoelectronics models OSD35-LR-A, XUV-50C, and FIL-UV20. The measurements were done by placing the diodes in superfluid liquid helium near a field emitting 9-cell cavity during its vertical test. For each diode, we will discuss their viability as a 2K cryogenic detector for FE mapping of SRF cavities and their directionality in such environments. We will also present calibration curves between the diodes and JLab’s standard radiation detector placed above the dewar top plate and within radiation shielding.
* H. Sakai et al., Proc of IPAC10, WEPEC028 p. 2950 (2010).

WEPPC097

Development of Nb and Alternative Material Thin Films Tailored for SRF Applications

SRF, ECR, vacuum, plasma

2444

A-M. Valente-Feliciano, H.L. Phillips, C.E. Reece, J.K. Spradlin, X. Zhao
JLAB, Newport News, Virginia, USA
B. Xiao
The College of William and Mary, Williamsburg, USA

Funding: *Authored by Jefferson Science Associates LLC under U.S. DOE Contract No. DE-AC05-06OR23177.
Avenues for the production of thin films tailored for Superconducting RF (SRF) applications are showing promise with recent developments in vacuum deposition techniques using energetic ions. JLab is using energetic condensation via Electron Cyclotron Resonance and High Power Impulse Magnetron Sputtering (HiPIMS) for the development of Nb films and multilayer SIS (superconductor-insulator-superconductor) structures to reach bulk Nb performance and beyond. Nb films with RRR comparable to bulk values are readily produced. The influence of the deposition energy on the material and RF properties of the Nb thin film is investigated with the characterization of their surface, structure, superconducting properties and RF response. Nucleation studies are investigating the best conditions to create a favorable template for growing the final SRF surface. This paper presents results on surface impedance measurements correlated with surface and material characterization for Nb and multilayered SIS films produced on a variety of substrates.

WEPPC100

Design of Electron and Ion Crabbing Cavities for an Electron-Ion Collider

cavity, HOM, electron, damping

2447

A. Castilla, J.R. Delayen, G.A. Krafft
ODU, Norfolk, Virginia, USA
A. Castilla
JLAB, Newport News, Virginia, USA

Beyond the 12 GeV upgrade at the Jefferson Lab a Medium Energy Electron-Ion Collider (MEIC) has been considered. In order to achieve the desired high luminosities at the Interaction Points (IP), the use of crabbing cavities is under study. In this work, we will present to-date designs of superconducting cavities, considered for crabbing both ion and electron bunches. A discussion of properties such as peak surface fields and higher-order mode separation will be presented.

WEPPD008

Recondenser Performance: Impact on the Superconducting Undulator Magnet at Argonne National Laboratory

undulator, cryogenics, background, factory

2513

J.M. Pfotenhauer, D.M. Schick
UW-Madison/EP, Madison, Wisconsin, USA

Funding: This work is supported by Argonne National Laboratory, subcontract number 9F-31982.
The current sharing temperature of 6.5 K for the superconducting undulator magnet being developed at Argonne National Laboratory drives the thermal design of the magnet’s cooling system. In order to remain below the current sharing temperature, a thermo-siphon cooling loop is being developed to sweep the anticipated heat load away from the magnet windings and deposit it in the associated liquid helium reservoir located above the magnet. Performance of the magnet’s cooling system is crucially dependent on the ability of the re-condenser to maintain the reservoir’s saturation temperature near 4 K, despite thermal stratification and slowly varying thermal profiles within the vapor region above the liquid in the reservoir. Here we report the results of an experimental investigation of the impact of various geometric configurations for the re-condenser and the thermal resistance associated with the film layer at the re-condensing surface, on the time-varying saturation temperature within the helium reservoir. The resulting temporal thermal variations in the superconducting winding are highlighted as well as the impact they have on the magnet’s stability.

WEPPD011

Study of the Pressure Profile Inside the NEG Coated Chambers of the SIS 18

vacuum, dipole, simulation, quadrupole

2519

M.C. Bellachioma, H. Kollmus, A. Krämer, J. Kurdal, H. Reich-Sprenger, L. Urban, M. Wengenroth
GSI, Darmstadt, Germany

In the context of the technical developments for the construction of FAIR at GSI, an intensive programme for the vacuum upgrade of the existing SIS 18 was started in 2005, with the aim to improve the beam lifetime and intensity. To reach these purposes also the installation of NEG coated dipole and quadrupole chambers is foreseen. During the upgrade shutdowns performed between 2006 and 2009 the vacuum chambers of approximately 65% of the SIS18 circumference were replaced by NEG coated pipes. To evaluate in detail the pressure profile inside the coated chambers mounted into the accelerator a dedicated experimental set-up, which reproduces a vacuum environment similar to the one of the SIS 18, was built. Using three gauges, mounted in different positions of a coated chamber, it was possible to measure the pressure in the range of 10^-12 mbar inside the activated NEG pipe and 10^-11 mbar outside the pipe at the pumping posts. Additionally, a modelling of a SIS18 vacuum sector was realised and the pressure variation values obtained by a Monte-Carlo simulation were compared with those measured. In this paper the experimental results and the vacuum simulations are described and discussed.

WEPPD013

Status of the Vacuum System in J-PARC RCS

vacuum, proton, site, electron

2522

J. Kamiya, Y. Hikichi, M. Kinsho, M. Nishikawa, N. Ogiwara, T. Yanagibashi
JAEA/J-PARC, Tokai-Mura, Naka-Gun, Ibaraki-Ken, Japan

In the vacuum system of J-PARC Rapid cycling synchrotron (RCS), we use beam pipes and bellows whose materials are vacuum fired at 700~850 oC in order to eliminate atoms in their bulk who are origin of outgassing. Until now, beam power has been increased up to 300 kW. Pressure in synchrotron beam line increased when the high power beam was accelerated. However, increment of pressure has reduced during the continuous beam operation. It is because the molecules, which adsorb on surface of the wall of the vacuum chambers, desorb by an ion bombardment and a heat generation due to an eddy current. Because the atoms in the bulk is eliminated, desorption of the molecules, which adsorb on the surface, means the reduction of the outgassing from the wall. In this presentation, we will report the past situation of the vacuum system during the beam operation. In addition, we also show the status after the Great East Japan Earthquake.

WEPPD020

Vacuum System for TPS Booster

vacuum, booster, lattice, electron

2540

C.M. Cheng, C.K. Chan, C.L. Chen, J.-R. Chen, G.-Y. Hsiung, S-N. Hsu, H.P. Hsueh
NSRRC, Hsinchu, Taiwan

The TPS booster is designed for lower beam emittance and 3GeV full energy injection ramped up from 150MeV. It is a synchrotron accelerator of 496.8m in circumference and located concentric with the electron storage ring in the same tunnel. The vacuum system for the booster is divided into six super periods and each has nine bending magnet chambers. The beam duct is made of thin stainless steel tube extruded to the elliptical cross section with inner diameters of 35 mm×20 mm and thickness of 0.7 mm. All the chambers will be supported on the inner wall of the tunnel. The straightness of the extruded thin chambers is controlled within 2.5 mm in 4 m length. The bending chamber is made by mechanical bending from the straight tube. All the beam ducts will be chemical cleaned prior to welding, with flanges or BPM chambers, to form the long chambers in the clean room before installation. The arrangement of vacuum pumps are distributed to fulfill an average pressure of ＜1×10^-6 Pa. The detailed design and the construction status will be described in the paper.

WEPPD025

LHC Detector Vacuum System Consolidation for Long Shutdown 1 (LS1) in 2013-2014

vacuum, background, radiation, electron

2555

M.A. Gallilee, J. Chaure, P. Cruikshank, J.E. Gallagher, C. Garion, J.M. Jimenez, R. Kersevan, H. Kos, L. Leduc, P. Lepeule, N. Provot, H. Rambeau, R. Veness
CERN, Geneva, Switzerland

The LHC has ventured into unchartered territory for Particle Physics accelerators. A dedicated consolidation program is required between 2013 and 2014 to ensure optimal physics performance. The experiments, ALICE, ATLAS, CMS, and LHCb, will utilise this shutdown, along with the gained experience of three years of physics running, to make optimisations to the detectors. New vacuum technologies have been developed for the experimental areas, to be integrated during this first phase shutdown. These technologies include bellows, vacuum chambers and ion pumps in aluminium, new beryllium vacuum chambers, and composite mechanical supports. An overview of this first phase consolidation program for the LHC experiments is presented.

WEPPD027

Global and Local Loss Suppression in the UA9 Crystal Collimation Experiment

collimation, proton, simulation, collider

2561

W. Scandale
LAL, Orsay, France
S. Montesano
CERN, Geneva, Switzerland

UA9 was operated in the CERN-SPS for some years in view of investigating the feasibility of the halo collimation assisted by bent crystals. Two-millimeter-long silicon crystals, with bending angles of about 150 mirrored, are used as primary collimators. The crystal collimation process is obtained consistently through channeling with high efficiency. The loss profiles in the area of the crystal-collimator setup and in the downstream dispersion suppressor area show a steady reduction of slightly less than one order of magnitude at the onset of the channeling process. This result holds both for protons and for lead-ions. The corresponding loss map in the accelerator ring is accordingly reduced. These observations strongly support our expectation that the coherent deflection of the beam halo by a bent crystal should enhance the collimation efficiency in hadron colliders, such as LHC.
for the UA9 Collaboration

WEPPD028

Collimators and Materials for High Intensity Heavy Ion Synchrotrons

heavy-ion, simulation, proton, collimation

2564

J. Stadlmann, H. Kollmus, P.J. Spiller, I. Strašík, N.A. Tahir, M. Tomut, C. Trautmann
GSI, Darmstadt, Germany
L.H.J. Bozyk
TU Darmstadt, Darmstadt, Germany

Funding: Funded by EU FP7 WP8 ColMat and Federal Republic of Germany
The operation of high power high brightness accelerators requires huge efforts for beam cleaning and machine protection. Within the WP 8 (ColMat)of the EU research framework EuCARD we investigate new materials and methods for beam collimation and machine protection. TWe present an overview of these activities at the GSI Helmholtzzentrum für Schwerioneforschung in Darmstadt. Simulations of accidental beam losses in LHC and SIS100 have been performed. Scenarios for halo collimation of heavy ions and protons in SIS100 routine operation have been investigated. A prototype of a cryogenic collimator for charge exchange losses during intermediate charge state heavy ion operation in SIS100 has been build and tested with beam. Several candidates of advances composite materials for collimation system upgrades of present and construction of future high power accelerators have been irradiated and their properties are being characterized. Most deliverables and milestones of the R&D programm have already been reached before the end of the funding period. A summary of the obtained results will be presented.

WEPPD031

A Transverse Electron Target for Heavy Ion Storage Rings

electron, target, interaction-region, simulation

2573

S. Geyer, O. Meusel
IAP, Frankfurt am Main, Germany
O.K. Kester
GSI, Darmstadt, Germany

Funding: supported by HIC for FAIR
A transverse electron target is a well suited concept for storage rings to investigate electron-ion interactions processes relevant for heavy ion accelerators. In comparison with an internal gas target, it promises a better energy resolution but still has the advantage, in contrast to an electron cooler, of access to the interaction region for photon and electron spectroscopy under large solid angles. The new electron target is suited for the use under the UHV requirements of a storage ring and realizes an open geometry for spectroscopy. A simple design based on electrostatic fields was chosen. The sheet beam application provides a higher perveance limit and a smaller potential depression than a cylindrical gun arrangement. The adjustable electron energy ranges between several 10eV and a few keV. The setup will be installed applying the so-called animated beam technique. The electron target is dedicated to the NESR at the new FAIR facility. First measurements are planned at a test bench and subsequent tests at the Frankfurt Low Energy Storage Ring (FLSR) are envisaged. An overview of the progress in the development of the transverse electron target will be given.

WEPPD035

Design Considerations for an MEBT Chopper Absorber of 2.1MeV H⁻ at the Project X Injector Experiment at Fermilab

vacuum, cryomodule, radiation, neutron

2585

C.M. Baffes, M.H. Awida, A.Z. Chen, Y.I. Eidelman, V.A. Lebedev, L.R. Prost, A.V. Shemyakin, N. Solyak, V.P. Yakovlev
Fermilab, Batavia, USA

Funding: Operated by Fermi Research Alliance, LLC, under Contract No. DE-AC02-07CH11359 with the United States Department of Energy
The Project X Injector Experiment (PXIE) will be a prototype of the Project X front end that will be used to validate the design concept and decrease technical risks. One of the most challenging components of PXIE is the wide-band chopping system of the Medium Energy Beam Transport (MEBT) section, which will form an arbitrary bunch pattern from the initially CW 162.5 MHz 5mA beam. The present scenario assumes diverting 80% of the beam to an absorber to provide a beam with the average current of 1mA to SRF linac. This absorber must withstand a high level of energy deposition and high ion fluence, while being positioned in proximity of the superconductive cavities. This paper discusses design considerations for the absorber, including specific challenges as spreading of energy deposition, management of temperatures and temperature-induced mechanical stresses, radiation effects, surface effects (sputtering and blistering), and maintaining vacuum quality. Thermal and mechanical analyses of a conceptual design are presented, and future plans for the fabrication and testing of a prototype are described.

WEPPD044

Machine Protection System for the SPIRAL2 Facility

controls, beam-losses, diagnostics, target

2612

M.H. Moscatello, C. Berthe, C. Jamet, G. Normand
GANIL, Caen, France

The phase 1 of the SPIRAL2 facility, extension project of the GANIL laboratory, is under construction. The accelerator is based on a linear solution, mainly composed of a normal conducting RFQ and a superconducting linac. One of its specificities is to be designed to accelerate high power deuteron and heavy ion beams (40-200kW), and medium intensity heavy ion beams as well (a few kW). The associated Machine Protection System, has thus to be able to control and protect the accelerator for a very large range in terms of beam intensities and beam powers. This paper presents the technical solutions chosen for this system and the present status of its construction.

WEPPD058

The Project-X 3 GeV Beam Distribution System

cavity, cryogenics, kaon, linac

2651

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

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

WEPPD070

Automatic Tuner Unit Operation for the Microwave System of the ESS-Bilbao H⁺ Ion Source

impedance, plasma, ion-source, controls

2684

L. Muguira, I. Arredondo, D. Belver, M. Eguiraun, F.J. Fernandez Huerta, J. Feuchtwanger, N. Garmendia, O. González, P.J. González
ESS Bilbao, LEIOA, Spain
V. Etxebarria, J. Jugo, J. Portilla
University of the Basque Country, Faculty of Science and Technology, Bilbao, Spain
J. Verdu
EPFL, Lausanne, Switzerland

Funding: The present work is supported by the Basque Government and Spanish Ministry of Science and Innovation.
The operation of the waveguide automatic tuner unit (ATU) for optimizing the impedance matching and the RF power coupling in the ESS-Bilbao H⁺ Ion Source (ISHP) is presented. Since the plasma chamber can be considered as a time varying load impedance for the pulsed RF 2.7 GHz high power generator, several approaches have been studied for accurately measuring the load impedance. In the later case, a set of power detectors connected to electric field probes, IQ demodulators and gain/phase detectors connected to dual directional couplers have been integrated. An experimental comparison of these approaches is presented, showing their accuracy, limitations and error-correction methods. Finally, the control system developed for the automatic operation of the triple capacitive post tuner is described, as well as illustrative results.

WEPPD082

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

gun, site, vacuum, linac

2717

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

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

WEPPP029

Quasi-Monoenergetic Ion Bunch Generating by Two-Stage Laser Acceleration

laser, acceleration, target, light-ion

2787

G. Dudnikova
UMD, College Park, Maryland, USA
D. Gorpinchenko
ICM&MG SB RAS, Novosibirsk, Russia

Experiments carried out in recent years on the laser-plasma interaction show the possibility of ions acceleration to high energy. The energy spectrum of these ions is typically broad. Practical applications require that the beams of accelerated ions be monoenergetic. A scheme is proposed for producing a quasi-monoenergetic ion bunch by irradiating a foil with two subsequent laser pulses–a prepulse followed by a stronger main pulse. We have demonstrated a possible mechanism for generating a quasi-monoenergetic ion bunch from a homogeneous target consisting of atoms of the same species by the two-stage acceleration. Results are presented from 2D and 3D PIC simulation that illustrate the scheme and determine the space–time and energy characteristics of the accelerated ions. Investigation was made by varying such control parameters as the duration and amplitude of the main laser pulse and the prepulse, the time lag between the pulses, and the thickness and density of the foil.

WEPPP061

A Method to Obtain the Frequency of the Longitudinal Dipole Oscillation for Modeling and Control in Synchrotrons with Single or Double Harmonic RF Systems

synchrotron, controls, dipole, emittance

2846

J. Grieser, J. Adamy, D.E.M. Lens
TU Darmstadt, RTR, Darmstadt, Germany
H. Klingbeil
TEMF, TU Darmstadt, Darmstadt, Germany

Funding: This work was partly funded by GSI Helmholtzzentrum für Schwerionenforschung GmbH
In a heavy-ion synchrotron the bunched beam can perform longitudinal oscillations around the synchronous particle (single bunch dipole oscillation, SBDO). If disturbances/instabilities exciting the SBDO exceed the rate of Landau damping, the beam can become unstable. Furthermore, Landau damping is accompanied by an increase of the beam emittance which may be undesired. Thus, control efforts are taken to stabilize the beam and to keep the emittance small. It is known that for a single harmonic cavity and a small bunch the SBDO oscillates with the synchrotron frequency* if the oscillation amplitudes are small. For a larger bunch or a double harmonic RF systems that introduces nonlinearities**, this is no longer valid. This work shows how the frequency of the SBDO can be determined in general. As a result, the SBDO can again be modeled as a harmonic oscillator with an additional damping term to account for Landau damping. This model can be used for feedback designs which is shown by means of a simple example. As the frequency of the SBDO and the damping rate depend on the size of the bunch in phase space, it is shown how this information can be obtained from the measured beam current.
* F. Pedersen and F. Sacherer, IEEE Transactions on Nuclear Science, 24:1296–1398, 1977
** A. Hofmann and S. Myers, Proc. of the 11th International Conference on High Energy Acceleration, 1980

WEPPP084

Weighted SVD Algorithm for Close-Orbit Correction and 10 Hz Feedback in RHIC

feedback, electron, proton, closed-orbit

2906

C. Liu, R.L. Hulsart, A. Marusic, R.J. Michnoff, M.G. Minty, V. Ptitsyn
BNL, Upton, Long Island, New York, USA

Funding: Work supported by Brookhaven Science Associates, LLC under Contract No. DE-AC02-98CH10886 with the U.S. Department of Energy.
Measurements of the beam position along an accelerator are typically treated equally using standard SVD-based orbit correction algorithms so distributing the residual errors, modulo the local beta function, equally at the measurement locations. However, sometimes a more stable orbit at select locations is desirable. In this paper, we introduce an algorithm for weighting the beam position measurements to achieve a more stable local orbit. The results of its application to close-orbit correction and 10-Hz orbit feedback will be shown and analyzed.

WEPPR001

Experimental Observation of Space Charge Effects in Transverse Bunch Oscillations in the SIS18 Synchrotron

space-charge, synchrotron, simulation, damping

2931

V. Kornilov, O. Boine-Frankenheim
GSI, Darmstadt, Germany

Coherent signals from transverse bunch oscillations in the heavy-ion synchrotron SIS18 are used for direct measurements of the space charge effect. The bunch oscillations are excited by a transverse kick and the resulting decoherence is observed. The transverse coherent motion in the SIS18 experiments is strongly affected by space charge. The bunches are long, thus the nonlinear motion in the rf bucket plays an important role and must be taken into account. The signals from the measurements are analyzed and explained using analytical and numerical models.

WEPPR003

Longitudinal Dynamics of Intense Heavy-Ion Bunches in SIS-100

impedance, space-charge, heavy-ion, beam-loading

2937

M. Mehler, O. Boine-Frankenheim, O. Chorniy, O.K. Kester
GSI, Darmstadt, Germany

In the SIS-100 highest heavy-ion intensities have to be accelerated to deliver beam to the FAIR experiments. In the projected SIS-100 synchrotron the heavy ion bunches will be strongly affected by the longitudinal space charge force. Due to the limited RF bucket area all mechanisms which might cause longitudinal phase space dilution must be understood and controlled. Space charge effects, like the reduction in the RF voltage and the loss of Landau damping, have already been part of elaborate studies. It has been shown that cavity beam loading can deform the flattened bunch shape in the dual rf bucket. Among the different counter measures an inductive insert has been proposed in order to partially compensate the longitudinal space charge impedance. Optimized settings for the difference between the two rf phases in a dual rf bucket might be an option to reduce the effect of beam loading. In this contribution we will analyse the matched bunch distribution for SIS-100 parameters in single and dual rf buckets. Analytical and numerical studies of the interplay of longitudinal space charge, cavity beam loading and an inductive insert will be presented.

WEPPR016

Potential for Luminosity Improvement for Low-energy RHIC Operation

luminosity, space-charge, electron, emittance

2973

A.V. Fedotov
BNL, Upton, Long Island, New York, USA

Funding: Work supported by Brookhaven Science Associates, LLC under Contract No. DE-AC02-98CH10886 with the U.S. Department of Energy.
At the Brookhaven National Laboratory, a physics program, motivated by the search of the QCD phase transition critical point, requires operation of the Relativistic Heavy Ion Collider (RHIC) with heavy ions at very low beam energies corresponding to 2.5-20 GeV/n. Several physics runs were already successfully performed at these low energies. However, the luminosity is very low at lowest energies of interest (< 10 GeV/n) limited by the intra-beam scattering and space-charge, as well as by machine nonlinearities. At these low energies, electron cooling is very effective in counteracting luminosity degradation due to the IBS, while it is less effective against other limitations. Overall potential luminosity improvement for low-energy RHIC operation from cooling is summarized for various energies, taking into account all these limitations as well as beam lifetime measured during the low-energy RHIC runs. We also explore a possibility of further luminosity improvement under the space-charge limitation.

WEPPR049

The Impact of Fill Patterns on the Fast Ion Instability in the ILC Damping Ring

damping, emittance, feedback, electron

3036

G.X. Xia
MPI-P, München, Germany

The ions produced via collisional ionization of the residual gas molecules in vacuum pipe with the circulating electron beam have deleterious effect on the beam properties and may become a limiting factor in the machine’s performance. In this paper, the various beam fill patterns are investigated and their effects on the fast ion instability are discussed. The simulations show that an optimal fill pattern can reduce growth rate of the fast ion instability significantly.

WEPPR059

The Simulation of Ion Cloud Build-up in Electron Storage Ring

electron, simulation, space-charge, storage-ring

3060

X.L. Yu, W. Li, L. Wang
USTC/NSRL, Hefei, Anhui, People's Republic of China

In electron storage rings, positive ions are created by the ionization of the residual gas. Three main collision types including elastic collision, excitation collision and ionization collision are considered in this paper. In order to calculate the probability of the gas ionization using DSMC method, the total cross section, total inelastic cross section, elastic cross section, excitation cross section and ionization cross section are deduced separately. Once ions are created，PIC is adopted to trace the ion，s motion under the combined action due to externally applied field and self-field. The purpose of all study is to present how ion cloud gets to equilibrium little by little.

WEPPR092

Beam Ion Instability in ILC Damping Ring with Multi-gas Species

vacuum, damping, simulation, lattice

3150

L. Wang, M.T.F. Pivi
SLAC, Menlo Park, California, USA

Ion induced beam instability is one critical issue for the electron damping ring of the International Linear Collider (ILC) due to its ultra small emittance of 2 pm. The beam ion instability with various beam filling patterns for the latest lattice DTC02 is studied using code IONCLOUD. The code has been benchmarked with SPEAR3 experimental data and there is a good agreement between the simulation and observations. It uses the optics from MAD and can handle arbitrary beam filling pattern and vacuum. Different from previous studies, multi-gas species have been used simultaneously in the simulation. This feature makes it more accurate.

WEPPR093

Impedance Budget for Crab Cavity in MEIC Electron Ring

impedance, electron, cavity, collider

3153

S. Ahmed, G.A. Krafft, B.C. Yunn
JLAB, Newport News, Virginia, USA

Funding: Authored by Jefferson Science Associates, LLC under U.S. DOE Contract No. DE-AC05-06OR23177.
The Medium Energy Electron-Ion Collider (MEIC) at Jefferson Lab has been envisioned as a first stage high energy particle accelerator beyond the 12 GeV upgrade of CEBAF. The estimate of impedance budget is important from the view point of beam stability and matching with other accelerator components driving currents. The detailed study of impedance budget for electron ring has been performed by considering the current design parameters of the e-ring. A comprehensive picture of the calculations involved in this study has been illustrated in the paper.

THXA02

Operation and Patient Treatments at CNAO Facility

proton, synchrotron, extraction, acceleration

3180

E. Bressi
CNAO Foundation, Milan, Italy

The CNAO (National Centre for Oncological Hadrontherapy) has been realized in Pavia. It is a clinical facility created and financed by the Italian Ministry of Health and conceived to supply hadrontherapy treatments to patients recruited all over the Country. A qualified network of clinical and research Institutes, the CNAO Collaboration, has been created to build and to run the centre. Three treatment rooms (three horizontal and one vertical) are installed. Beams of protons with kinetic energies up to 250 MeV and beams of carbon ions with maximum kinetic energy of 400 MeV/u are transported and delivered by active scanning systems. CNAO commissioning concerning the high technology started in 2009. First patient was treated with Proton beam in September 2011, the 22nd. This presentation presents the features of the system, together with the results of the first treatments.

Slides THXA02 [14.843 MB]

THYA03

Critical Technologies and Future Directions in High Intensity ISOL RIB Production

target, ion-source, ISOL, proton

3195

P.G. Bricault, F. Ames, M. Dombsky, P. Kunz, J. Lassen, G. Minor, A. Mjøs, B. Moss, M. Nozar
TRIUMF, Canada's National Laboratory for Particle and Nuclear Physics, Vancouver, Canada

This presentation should review the technology challenges and future directions in the production of high intensity RIBs, including the operation of targets/ion sources in high radiation environment, high efficiency charge stripping, and high reliability.

Slides THYA03 [5.010 MB]

THYB02

Influence of Electron Beam Parameters on Coherent Electron Cooling

electron, FEL, acceleration, radiation

3213

G. Wang, Y. Hao
BNL, Upton, Long Island, New York, USA
V. Litvinenko
Stony Brook University, Stony Brook, USA
S.D. Webb
Tech-X, Boulder, Colorado, USA

Coherent electron cooling (CeC) is promising to revolutionize the cooling of high energy hadron beams. The intricate dynamics of the CeC depends both on the local density and energy distribution of the beam. This talk should present a rigorous analytical model of the 3D processes (including diffraction) in the modulator and the FEL and describe how the theory is applied to electron beams with inhomogeneous longitudinal density- and energy distributions in the process of CeC. The SPC would like you to describe the influence of electron beam energy and current variations along the bunch length.

Slides THYB02 [0.878 MB]

THEPPB002

High-Fidelity 3D Modulator Simulations of Coherent Electron Cooling Systems

electron, plasma, simulation, shielding

3231

G.I. Bell, D.L. Bruhwiler, I.V. Pogorelov, B.T. Schwartz
Tech-X, Boulder, Colorado, USA
Y. Hao, V. Litvinenko, G. Wang
BNL, Upton, Long Island, New York, USA

Funding: This work is supported by the US DOE Office of Science, Office of Nuclear Physics, grant numbers DE-SC0000835 and DE-FC02-07ER41499. Resources of NERSC were used under contract No. DE-AC02-05CH11231.
Next generation electron-hadron colliders will require effective cooling of high-energy, high-intensity hadron beams. Coherent electron cooling (CeC) can in principle cool relativistic hadron beams on orders-of-magnitude shorter time scales than other techniques*. The parallel VORPAL framework is used for 3D delta-f PIC simulations of anisotropic Debye shielding in a full longitudinal slice of the co-propagating electron beam, choosing parameters relevant to the proof-of-principle experiment under development at BNL. The transverse density conforms to an exponential Vlasov equilibrium for Gaussian velocities, with no longitudinal density variation. Comparison with 1D1V Vlasov/Poisson simulations shows good agreement in 1D. Parallel 3D simulations at NERSC show 3D effects for ions moving longitudinally and transversely. Simulation results are compared with the constant-density theory of Wang and Blaskiewicz**.
* V.N. Litvinenko and Y.S. Derbenev, Phys. Rev. Lett. 10², 114801 (2009).
** Wang and Blaskiewicz, Phys Rev E 78, 026413 (2008).

THEPPB004

Development of a Cryocatcher-System for SIS100

vacuum, heavy-ion, simulation, cryogenics

3237

L.H.J. Bozyk, H. Kollmus, P.J. Spiller
GSI, Darmstadt, Germany

Funding: Work supported by EU (FP7 workpackage COLMAT) and GP-HIR – Graduate Program for Hadron and Ion Research at GSI.
The main accelerator SIS100 of the FAIR-facility will provide heavy ion beams of highest intensities using intermediate charge state heavy ions. Ionization beam loss is the most important loss mechanism, therefore, a special synchrotron layout has been developed, which includes a dedicated cold ion catcher system which provides almost hundred percent catching efficiency. Dynamic vacuum effects are suppressed effectively by means of special low desorption yield surfaces. A prototype of the cryocatcher system has been developed, constructed and tested with heavy ion beam from SIS18. It is a work package of the EU-FP-7 project COLMAT. Results from these tests are presented as well as implications for the production of the 60 SIS100 cryocatchers.

THEPPB006

Improving the Synchrotron Performance of the Heidelberg Ionbeam Therapy Center

synchrotron, controls, extraction, dipole

3243

Th. Haberer
HIT, Heidelberg, Germany

The HIT linac-synchrotron-system routinely delivers pencil beams to the dose delivering rasterscanning devices at 3 treatment rooms, including the worldwide first scanning ion gantry, and 1 experimental cave. At HIT the quality-assured library of pencil beam parameters covers roughly 100.000 combinations of the ion, energy, intensity and beam size. Each patient-specific treatment plan defines a subset of these pencil beams being subsequently requested during the dose delivery. Aiming at shortened irradiation times an upgrade program making heavy use of feed-back mechanisms is under way. Driven by patient-specific data out of the scanning beam dose delivery process central synchrotron components are coupled to the therapy control system in order to tailor the beam characteristics in real-time to the clinical requirements. The paper will discuss the functional upgrades and report about the impact on the medical application at HIT.

THEPPB009

The CRISP Project – Building Synergies between Research Infrastructures

neutron, electron, laser, ion-source

3248

P. Antici
INFN/LNF, Frascati (Roma), Italy

Recently, the European Commission granted 12 M€ for a project aiming at the implementation of common solutions in infrastructures on the ESFRI* roadmap in the fields of physics, astronomy and analytical sciences. The objective of this initiative is to generate synergies in the development of components of interest for several infrastructures and thus promote efficiency and optimisation in the use of resources. The project, called "CRISP (Cluster of Research Infrastructures for Synergies in Physics) and started October 2011, gathers many major European large-scale infrastructures (CERN, XFEL, ESRF, ESS, FAIR, ILL, SKA, SLHC, SPIRAL-2, ELI, EuroFEL, ILC-Higrade etc). The generated synergies will be crucial to stimulate scientific and technological progress and to respond to the rapidly evolving user community. A brief overview of the different activities that are part of the project will be given, presenting the innovative approach of crossing boundaries between scientific disciplines and thus generating synergies.
*ESFRI stands for European Strategy Forum on Research Infrastructures

THEPPB011

Apparatus and Experimental Procedures to Test Crystal Collimation

collimation, alignment, instrumentation, proton

3254

S. Montesano
CERN, Geneva, Switzerland
W. Scandale
LAL, Orsay, France

UA9 is an experimental setup operated in the CERN-SPS in view of investigating the feasibility of halo collimation assisted by bent crystals. The UA9 collimation system is composed only of one crystal acting as primary halo deflector and one single absorber. Different crystals are tested in turn using two-arm goniometers with an angular reproducibility of better than 10 microrad. The performance of the system are assessed through the study of the secondary and tertiary halo in critical areas, by using standard machine instrumentation and few customized equipments. The alignment of the crystal is verified by measuring the loss rate close to the crystal position. The collimation efficiency is computed by intercepting the deflected halo with a massive collimator or with an imaging device installed into a Roman Pot. The leakage of the system is evaluated in the dispersion suppressor by means of movable aperture restrictions. In this contribution the setup and the experimental methods in use are revisited in a critical way and thoroughly discussed. Particular emphasis is given on feasibility, reproducibility and effectiveness of the operational procedures.
For the UA9 Collaboration

THEPPB013

Progress in Modeling Arcs

plasma, electron, cavity, simulation

3260

J. Norem, Z. Insepov
ANL, Argonne, USA
S. Mahalingam, S.A. Veitzer
Tech-X, Boulder, Colorado, USA
A. Moretti
Fermilab, Batavia, USA
I. Morozov, G.E. Norman
JIHT RAS, Moscow, Russia

Funding: DOE Office of High Energy Physics.
We are continuing to extend and simplify our understanding of vacuum arcs. We believe that all the breakdown phenomena we see (with and without B fields) can be explained by: 1) fracture due to electrostatic forces at surface crack junctions, 2) the development of a unipolar arc driven by the cavity electric field, and 3) cooling, and cracking of the surface after the event is finished. Recent progress includes the evaluation of non-Debye sheaths using Molecular Dynamics, studies of sheath driven instabilities, a model of degradation of gradient limits in strong B fields, analysis of the variety of arcs that can occur in cavities and their damage and further studies of breakdown triggers.

THPPC003

Development of a Broad-band Magnetic Alloy Cavity at GSI

cavity, impedance, coupling, storage-ring

3275

T.S. Mohite, U. Ratzinger
IAP, Frankfurt am Main, Germany
R. Balß, P. Hülsmann
GSI, Darmstadt, Germany

FINEMET, a Magnetic Alloy material, is often used to build a broad-band cavity for an accelerator or a storage ring. A research on the broad-band FINEMET cavity is of prime importance not only for the present accelerator facility but also for the future storage rings and synchrotron in upcoming FAIR facility alongside the GSI, Darmstadt. In several measurements, high intensity rare-isotope beams, with lower life time, are demanded at injection energy in Experimental Storage Ring (ESR) at GSI. A longitudinal beam stacking of such beams by means of using a special barrier-bucket RF cavity is found appropriate to serve this purpose*. Additionally, this cavity is supposed to provide the compressed bunches at lower energies for HITRAP, an ion-trap facility for experiments with highly charged ions, in FAIR. Several measurements are being performed, along with the theoretical analysis, to achieve the designed parameters for the planned barrier-bucket cavity. 60 FINEMET ring cores have been tested to confirm their designed electrical properties. Some of these ring cores are then loaded, in steps, in a test cavity, which will further be used as the barrier-bucket cavity for the ESR.
* C. Dimopoulou et al., JACoW Proceedings of COOL 2007, Bad Kreuznach, Germany

THPPC013

Progress on Coupled RFQ-SFRFQ Accelerator for Materials Irradiation Research

rfq, cavity, ion-source, ECR

3302

Z. Wang, J.E. Chen, S.L. Gao, Z.Y. Guo, Y.R. Lu, S.X. Peng, W.L. Xia, X.Q. Yan, J. Zhao, K. Zhu
PKU/IHIP, Beijing, People's Republic of China

Funding: Project supported by the National Natural Science Foundation of China (Grant No.10905003) and China Postdoctoral Science Foundation.
There is always high interest to study material irradiation damage effects based on accelerators. The bombardment of solids with high energy particles causes some changes in many important engineering properties. By implanting helium ions, it may be possible to simulate the damage process occurs in vessels and unravel the complexμstructural andμchemical evolutions that are expected in advanced nuclear energy systems. A materials irradiation facility based on coupled RFQ-SFRFQ accelerator will be built in Peking University, attribute to the commissioning of prototype SFRFQ accelerator, we have coupled the SFRFQ electrodes and the traditional RFQ electrodes in one cavity to form a more compact accelerator which can provide helium beam with energy of 0.8MeV for materials irradiation research.

THPPC014

Commissioning Status of the 3 MeV RFQ for the Compact Pulsed Hadron Source (CPHS) at Tsinghua University

rfq, proton, vacuum, status

3305

Q.Z. Xing, Y.J. Bai, D.T. Bin, J.C. Cai, C. Cheng, L. Du, Q. Du, C. Jiang, Q. Qiang, D. Wang, X.W. Wang, Z.F. Xiong, S.Y. Yang, H.Y. Zhang, S.X. Zheng
TUB, Beijing, People's Republic of China
J.H. Billen
TechSource, Santa Fe, New Mexico, USA
W.Q. Guan, Y. He, J. Li
NUCTECH, Beijing, People's Republic of China
X.L. Guan
Tsinghua University, Beijing, People's Republic of China
J. Stovall
CERN, Geneva, Switzerland
L.M. Young
AES, Medford, NY, USA

Funding: Work supported by the “985 Project” of the Ministry of Education of China.
We present, in this paper, the commissioning status of a Radio Frequency Quadrupole (RFQ) accelerator for the Compact Pulsed Hadron Source (CPHS) at Tsinghua University. In 2012 the 3-meter-long RFQ will deliver 3 MeV protons to the downstream High Energy Beam Transport (HEBT) with the peak current of 50 mA, pulse length of 0.5 ms and beam duty factor of 2.5%. Braze of the vanes was completed in September, 2011. The final field tuning of the whole cavity was completed in October, 2011. Initial commissioning will be underway at the beginning of 2012.

THPPC040

Improved RF Design for an 805 MHz Pillbox Cavity for the US MuCool Program

cavity, coupling, simulation, multipactoring

3371

Z. Li, C. Adolphsen, L. Ge
SLAC, Menlo Park, California, USA
D.L. Bowring, D. Li
LBNL, Berkeley, California, USA

Funding: Work supported by US DOE under contract number DE-AC02-05CH11231, and DE-AC02-76SF00515.
Normal conducting RF cavities are required to operate at high gradient in the presence of strong magnetic field in muon ionization cooling channels for a Muon Collider. Experimental studies using an 805 MHz pillbox cavity at MTA of Fermilab has shown significant degradation in gradient performance and damage in the regions that are correlated with high RF fields in magnetic field up to 4 Tesla. These effects are believed to be related to the dark current and/or multipacting activities in the presence of external magnetic field. To improve the performance of the cavity, a new RF cavity with significantly lower surface field enhancement was designed, and will be built and tested in the near future. Numerical analyses of multipacting and dark current were performed using the 3D parallel code Track3P for both the original and new improved cavity profiles in order to gain more insight in understanding of the gradient issues under strong external magnetic field. In this paper, we will present the improved RF design and the dark current and multipacting analyses for the 805 MHz cavity.

THPPD045

High Temperature Superconducting Magnets for Efficient Low Energy Beam Transport Systems

solenoid, rfq, emittance, vacuum

3614

J.H. Nipper, G. Flanagan, R.P. Johnson
Muons, Inc, Batavia, USA
M. Popovic
Fermilab, Batavia, USA

Modern ion accelerators and ion implantation systems need very short, highly versatile, Low Energy Beam Transport (LEBT) systems. The need for reliable and continuous operation requires LEBT designs to be simple and robust. The energy efficiency of available high temperature superconductors (HTS), with efficient and simple cryocooler refrigeration, is an additional attraction. Innovative, compact LEBT systems based on solenoids designed and built with high-temperature superconductor will be developed using computer models and prototyped. The parameters will be chosen to make this type of LEBT useful in a variety of ion accelerators, ion implantation systems, cancer therapy synchrotrons, and research accelerators, including the ORNL SNS. The benefits of solenoids made with HTS will be evaluated with analytical and numerical calculations for a two-solenoid configuration, as will be used in the SNS prototype LEBT that will replace the electrostatic one at SNS, and a single solenoid configuration, as was proposed for the Fermilab proton driver that will be most applicable to ion implantation applications.

THPPD049

Conceptual Design of a Superconducting Septum for FFAGs

septum, extraction, proton, simulation

3620

H. Witte
BNL, Upton, Long Island, New York, USA
M. Aslaninejad, J. Pasternak
Imperial College of Science and Technology, Department of Physics, London, United Kingdom
K.J. Peach, T. Yokoi
JAI, Oxford, United Kingdom

Funding: This work was supported by STFC grant ST/G008531/1 and EPSRC Grant EP/E032869/1.
The fixed magnetic field in FFAG (Fixed Field Alternating Gradient) accelerators means that particles can be accelerated very rapidly. This makes them attractive candidates for many applications, for example for accelerating muons for a neutrino factory or for charged particle therapy (CPT). To benefit fully from this the particles have to be extracted at the same rate. In combination with the high magnetic rigidity of the particles this represents a significant challenge, especially where variable energy extraction is required, which implies extraction at variable radius. This paper presents a conceptual design of a 4T superconducting septum for the PAMELA accelerator, which is an FFAG for a combined proton/carbon ion therapy facility. The field in the septum is varied as a function of the horizontal position, which allows variable energy extraction without the need for sweeping of the magnetic field.

THPPD074

Effect of a Metallized Chamber upon the Field Response of a Kicker Magnet: Simulation Results and Analytical Calculations

kicker, simulation, vacuum, booster

3686

M.J. Barnes, M.G. Atanasov, T. Fowler, T. Kramer, T. Stadlbauer
CERN, Geneva, Switzerland

Metallized racetrack vacuum chambers will be used in the pulsed magnets of the Austrian cancer therapy and research facility, MedAustron. It is important that the metallization does not unduly degrade field rise and fall times or the flattop of the field pulse in the pulsed magnets. This was of particular concern for a tune kicker magnet, which has a specified rise and fall time of 100 ns. The impact of the metallization, upon the transient field response, has been determined by finite element method (FEM) simulations: the dependency of the field response to the metallization thickness and resistivity are presented. Formulae for the field response, which permit the use of a ramped transient excitation current, are presented: thus the coating thickness and resistivity can be determined which result in a maximum permissible field attenuation and delay for a given current rise time. In addition, results of simulations of the effect of a magnetic brazing collar, located between the ceramic vacuum chamber and flange, are reported.

THPPP001

High Intensity Intermediate Charge State Heavy Ions in Synchrotrons

injection, septum, emittance, heavy-ion

3719

P.J. Spiller, U. Blell, L.H.J. Bozyk, H. Reich-Sprenger, J. Stadlmann
GSI, Darmstadt, Germany
Y. El-Hayek
FIAS, Frankfurt am Main, Germany

In order to reach the desired FAIR intensities for heavy ions, SIS18 and SIS100 have to be operated with intermediate charge states. Operation with intermediate charge state heavy ions at the intensity level of about 1011 ions per cycle has never been demonstrated elsewhere and requires a dedicated machine design. After partially completing the upgrade program of SIS18, the number of intermediate charge state heavy ions accelerated to the FAIR booster energy of 200 MeV/u, could be increased by a factor of 70. The specific challenge for the SIS18 and SIS100 booster operation is the high cross section for ionization of the intermediate charge state heavy ions, in combination with gas desorption processes and the dynamic vacuum pressure. The achieved progress in minimizing the ionization beam loss underlines that the chosen technical strategies described in this report are appropriate. The latest intensity records and results from the machine development programs are presented.

THPPP002

Operation of the HESR Storage Ring of the FAIR Project with Ions and Rare Isotopes

target, electron, antiproton, storage-ring

3722

M. Steck, C. Dimopoulou, A. Dolinskii, T. Katayama, Yu.A. Litvinov, T. Stöhlker
GSI, Darmstadt, Germany
R. Maier, D. Prasuhn, H. Stockhorst
FZJ, Jülich, Germany

The HESR storage ring of the FAIR project is designed for experiments with cooled antiprotons. The HESR receives pre-cooled antiprotons from the Collector Ring CR which is also designed for cooling of rare isotope beams. The magnetic rigidity of 13 Tm is the same for the pre-cooling of antiprotons and rare isotopes in the CR. Therefore the transfer of ions or rare isotopes from the CR to the HESR can be performed under similar condition, except the different polarity of the magnetic components. This is an option for the first stage of the FAIR project when no other storage ring is available for experiments with stored ions. In the HESR the ions can be decelerated or accelerated, like the antiprotons, to energies corresponding to the magnetic rigidity range from 5 to 50 Tm. The planned beam cooling systems of the HESR, stochastic and electron cooling, can be applied to improve the quality of the ion beams in the HESR and support experiments using an internal target or the accumulation of rare isotope beams in the HESR. Scenarios for operating the HESR with ions and rare isotopes as well as achievable performance, beam intensity and quality for internal experiments will be discussed.

THPPP012

Performance of the CERN Heavy Ion Production Complex

target, injection, proton, luminosity

3752

D. Manglunki, M. E. Angoletta, H. Bartosik, G. Bellodi, A. Blas, T. Bohl, C. Carli, E. Carlier, S. Cettour Cave, K. Cornelis, H. Damerau, I. Efthymiopoulos, A. Findlay, S.S. Gilardoni, S. Hancock, J.M. Jowett, D. Kuchler, S. Maury, M. O'Neil, Y. Papaphilippou, S. Pasinelli, R. Scrivens, G. Tranquille, B. Vandorpe, U. Wehrle, J. Wenninger
CERN, Geneva, Switzerland

The second LHC ion run took place at 1.38 A TeV/c per beam in autumn 2011; more than 100 inverse microbarns was accumulated by each of the experiments. In addition, the LHC injector chain delivered primary Pb and secondary Be ion beams to fixed target experiments in the North Area. This paper presents the current performance of the heavy ion production complex, and prospects to further improve it in the near future.

THPPP027

The Design of a Large Booster Ring for the Medium Energy Electron-Ion Collider at JLab

booster, collider, dipole, electron

3791

E.W. Nissen, T. Satogata, Y. Zhang
JLAB, Newport News, Virginia, USA

Funding: Notice: Authored by Jefferson Science Associates, LLC under U.S. DOE Contract No. DE-AC05-06OR23177.
In this paper, we present the current design of the large booster ring for the Medium Energy Electron-Ion Collder (MEIC) at JLab. The booster ring takes 3 GeV protons or ions of equivalent energy from a pre-booster ring, and accelerates them to 20 GeV for protons or equivalent energy for light to heavy ions before sending them to the ion collider ring. The present design calls for a figure-8 shape of the ring for superior preservation of ion polarization. The ring is made of warm magnets and shares a tunnel with the two collider rings. Acceleration is achieved by warm RF systems. A linear optics has been designed with the transition energy above the highest beam energy in the ring so crossing of transition energy will be avoided. Preliminary beam dynamics studies including chromaticity compensation, analyses of dynamic aperture, working point and high order effects are also presented in this paper.

THPPP032

Advanced Layout Studies for the GSI CW-Linac

linac, solenoid, cavity, heavy-ion

3803

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

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

THPPP033

New Developments for the Present and Future GSI Linacs

linac, cavity, emittance, proton

3806

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

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

THPPP040

Heavy-ion Beam Acceleration at RIKEN for the Super-Heavy Element Search

target, ion-source, ECR, cyclotron

3823

M. Kase, M. Fujimaki, Y. Higurashi, E. Ikezawa, O. Kamigaito, M. Komiyama, T. Nakagawa, K. Ozeki, N. Sakamoto, K. Suda
RIKEN Nishina Center, Wako, Japan
T. Aihara, T.O. Ohki, K. Oyamada, M. Tamura, A. Uchiyama, H. Yamauchi
SHI Accelerator Service Ltd., Tokyo, Japan

In RIKEN Nishina accelerator center, the experiment on the super-heavy element (Z=113) search has been being carried out since 2003. The RIKEN heavy-ion linac is supplying a heavy-ion beam of 70Zn with energies around 5MeV/nucleon. The beam intensities are required more than 1 particle maicro amper on the target. Very long-term and stable operations are intrinsic for this kind of experiments. So far two events for Z=113 have been found during a net irradiation time of 10345 hours (431 days) with a total dose 1.1 x 10²⁰ (12.8 mg). Heavy operation of the linac will be reported.

THPPP041

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

rfq, linac, resonance, focusing

3826

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

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

THPPP042

The First Step of RFQ Development in KBSI

rfq, quadrupole, emittance, dipole

3829

J.W. Ok, S. Choi, B.C. Kim, B.S. Lee, J.Y. Park, M. Won, J.H. Yoon
Korea Basic Science Institute, Busan, Republic of Korea

The RFQ for accelerating an ion beam is being developed in Korea Basic Science Institute (KBSI). The KBSI RFQ is designed to accelerate 1 mA lithium beam (Q/A=3/7) at 88 MHz. It is considered to be a 4-vane RFQ structure. The injection beam energy into RFQ is 12 keV/u, the output beam energy downstream from RFQ is 300 keV/u. The RFQ has to show stable operation, meet availability, and have the minimum losses so as to guarantee the best performance/cost ratio. At the first step, two dimensional geometry structure was studied using SUPERFISH code for the resonance frequency of quadrupole and dipole modes. Three dimensional field distributions were investigated by CST microwave studio. The beam dynamics in RFQ accelerator were studied using PARMTEQM code. Based on these results, the structural analysis should be studied and a cold model will be fabricated and investigated. The practical KBSI RFQ will be manufactured in next year.

THPPP045

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

linac, proton, ion-source, site

3838

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

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

THPPP048

Linac4 - Low Energy Beam Measurements

solenoid, emittance, rfq, linac

3847

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

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

THPPP050

HIE-ISOLDE SC Linac: Operational Aspects and Commissioning Preparation

linac, emittance, diagnostics, cryomodule

3853

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

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

THPPP051

Status of the RAL Front End Test Stand

ion-source, rfq, beam-transport, simulation

3856

A.P. Letchford, M.A. Clarke-Gayther, D.C. Faircloth, S.R. Lawrie
STFC/RAL/ISIS, Chilton, Didcot, Oxon, United Kingdom
S.M.H. Alsari, M. Aslaninejad, A. Kurup, P. Savage
Imperial College of Science and Technology, Department of Physics, London, United Kingdom
J.J. Back
University of Warwick, Coventry, United Kingdom
G.E. Boorman, A. Bosco
Royal Holloway, University of London, Surrey, United Kingdom
C. Gabor, D.C. Plostinar
STFC/RAL/ASTeC, Chilton, Didcot, Oxon, United Kingdom
A. Garbayo
AVS, Eibar, Gipuzkoa, Spain
S. Jolly
UCL, London, United Kingdom
J.K. Pozimski
STFC/RAL, Chilton, Didcot, Oxon, United Kingdom

The Front End Test Stand (FETS) under construction at RAL is a demonstrator for front end systems of a future high power proton linac. Possible applications include a linac upgrade for the ISIS spallation neutron source, new future neutron sources, accelerator driven sub-critical systems, a neutrino factory etc. Designed to deliver a 60mA H-minus beam at 3MeV with a 10% duty factor, FETS consists of a high brightness ion source, magnetic low energy beam transport (LEBT), 4-vane 324MHz radio frequency quadrupole, medium energy beam transport (MEBT) containing a high speed beam chopper plus comprehensive diagnostics. This paper describes the current status of the project and future plans.

THPPP058

PXIE: Project X Injector Experiment

rfq, cryomodule, solenoid, ion-source

3874

S. Nagaitsev, S.D. Holmes, R.D. Kephart, J.S. Kerby, V.A. Lebedev, C.S. Mishra, A.V. Shemyakin, N. Solyak, R.P. Stanek
Fermilab, Batavia, USA
D. Li
LBNL, Berkeley, California, USA
P.N. Ostroumov
ANL, Argonne, USA

A multi-MW proton facility, Project X has been proposed and is currently under development at Fermilab. As part of this development program, we are constructing a prototype of the front end of the Project X linac at Fermilab. The construction and successful operations of this facility will validate the concept for the Project X front end, thereby minimizing the primary technical risk element within the Project. The Project X Injector Experiment (PXIE) can be constructed over the period FY12-16 and will include an H⁻ ion source, a CW 2.1-MeV RFQ and two SC cryomodules providing up to 30 MeV energy gain at an average beam current of 1 mA. Successful operations of the facility will demonstrate the viability of novel front end technologies that will find applications beyond Project X in the longer term.

THPPP066

Beam Tuning Strategy of the FRIB Linac Driver

linac, cavity, solenoid, coupling

3889

Y. Zhang
FRIB, East Lansing, Michigan, USA

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

THPPP067

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

linac, electron, radiation, emittance

3892

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

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

THPPP084

Charge Stripping of Uranium-238 Ion Beam with Helium Gas Stripper

target, cyclotron, acceleration, radiation

3930

H. Imao
RIKEN Nishina Center for Accelerator-Based Science, Wako, Saitama, Japan
N. Fukunishi, H. Hasebe, O. Kamigaito, M. Kase, H. Kuboki, H. Okuno, T. Watanabe, Y. Watanabe, Y. Yano, S. Yokouchi
RIKEN Nishina Center, Wako, Japan

Development of the reliable and efficient electric charge stripping method is one of the key issues in next-generation high-intensity heavy ion accelerators. Although conventional carbon-foil charge strippers provide a good charge stripping efficiency, two serious problems are emerging; the short usable time and thickness non-uniformity. A charge stripper using low-Z gas is an important candidate applicable for high-intensity 238U beams to replace carbon foil strippers. In the present work, the first actual charge stripping system using helium gas for 238U beams injected at 10.75 MeV/u has been developed and tested.

THPPP087

Beta Beams for Precision Measurements of Neutrino Oscillation Parameters

target, proton, linac, acceleration

3939

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

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

THPPP092

Progress of the Front-End System Development for Project X at LBNL

rfq, ion-source, simulation, emittance

3951

D. Li, M.D. Hoff, Q. Ji, A.R. Lambert, T. Schenkel, J.W. Staples, S.P. Virostek
LBNL, Berkeley, California, USA
S. Nagaitsev, L.R. Prost, G.V. Romanov, A.V. Shemyakin
Fermilab, Batavia, USA
C. Zhang
IAP, Frankfurt am Main, Germany

Funding: This work is supported by the Office of Science, United States Department of Energy under DOE contract DE-AC02-05CH11231.
A multi-MW proton facility, Project X has been proposed and is currently under development at Fermilab. Project X is a key accelerator complex for intensity frontier of future high energy physics programs in the US. In collaboration with Fermilab, LBNL takes the responsibility in the development and design studies of the front-end system for Project X. The front-end system would consist of H⁻ ion source(s), low-energy beam transport (LEBT), 162.5 MHz normal conducting CW Radio-Frequency-Quadrupole (RFQ) accelerator, medium-energy beam transport (MEBT), and beam chopper(s). In this paper, we will review and present recent progress of the front-end system studies, which will include the RFQ beam dynamics design, RF structure design, thermal and mechanical analyses and fabrication plan, LEBT simulation studies and concept for LEBT chopper.

THPPP096

Recent Developments and Applications of the Beam Simulation Code Warp

plasma, simulation, diagnostics, heavy-ion

3957

J.-L. Vay, P.A. Seidl
LBNL, Berkeley, California, USA
A. Friedman, D.P. Grote
LLNL, Livermore, California, USA

Funding: Supported by US-DOE Contracts DE-AC02-05CH11231 and DE-AC52-07NA27344. Used resources of NERSC, supported by US-DOE Contract DE-AC02-05CH11231.
The Particle-In-Cell Framework Warp is being developed by the Heavy Ion Fusion US program to guide the development of accelerators for high energy density experiments and ultimately for inertial fusion energy. Accurate predictions of the beam phase space are important for understanding the limits to the pulse compression, in particular for NDCX-II now under construction at LBNL. We will present a new numerical method that correct for the effects of linear correlations, offering accurate mapping of energy spread and temperature. The interaction of the beam with the neutralizing plasma can affect non linearly the phase space of the beam. We will present fully kinetic simulation of the beam/plasma interaction aimed toward a better understanding of these effects and possibilities for mitigating or exploiting them. We will also present an application of the original warped coordinate algorithm to the modeling of charge separation in the transition of a 50 MeV singly charged Uranium beam to higher charge state upon passing through a stripping foil, with the goal of decreasing the cost of a Heavy Ion Fusion driver. We also describe studies of beams in plasmas and of injector optimization.
Used resources of NERSC.

THPPR003

Progresses on !CHAOS Development

controls, LabView, status, diagnostics

3969

L.G. Foggetta, C. Bisegni, S. Calabrò, P. Ciuffetti, G. Di Pirro, G. Mazzitelli, A. Stecchi
INFN/LNF, Frascati (Roma), Italy
L. Catani, D. Di Giovenale, F. Zani
INFN-Roma II, Roma, Italy

!CHAOS(Control System based on Highly Abstracted and Open Structure), the new control system architecture proposed by INFN is in development and some parts of it are now under test on the DAØNE and SPARC complexes. Although the main goal of the !CHAOS project remains the accelerator-based research facility proposed for the Cabibbo Lab and the SuperB accelerator, other applications are under study in order to adapt this new design to the needs coming from different fields, with a growing interest from many companies. Recent developments, tests results, potential applications and future project's plans are presented.

THPPR030

High Power Test of RF Separator For 12 GeV Upgrade of CEBAF at Jefferson Lab

cavity, vacuum, extraction, coupling

4032

S. Ahmed, C. Hovater, G.A. Krafft, J.D. Mammosser, M. Spata, M.J. Wissmann
JLAB, Newport News, Virginia, USA
J.R. Delayen
ODU, Norfolk, Virginia, USA

Funding: Authored by Jefferson Science Associates, LLC under U.S. DOE Contract No. DE-AC05-06OR23177.
CEBAF at JLab is in the process of an energy upgrade from 6 GeV to 12 GeV. The existing setup of the RF separator cavities in the 5th pass will not be adequate enough to extract the highest energy (11 GeV) beam to any two existing halls (A, B or C) while simultaneously delivering to the new hall D in the case of the proposed 12 GeV upgrade of the machine. To restore this capability, several options including the extension of existing normal conducting (NC) and a potential 499 MHz TEM-type superconducting (SC) cavity design have been investigated using computer simulations. Detailed numerical studies suggest that six 2-cell normal conducting structures meet the requirements; each 2-cell structure will require up to 4 kW RF input power in contrast with the current nominal operating power of 1.0 to 2.0 kW. A high power test to 4 kW is required to confirm the cavity’s operate-ability at these elevated gradient and power levels. We have assembled a 2-cell cavity, pumped down to 2.0·10^-9 torr using ion pump and confirmed the low level RF performance. A high power test is in progress and will be completed soon. The detailed numerical and experimental results will be discussed in the paper.

THPPR032

A Split-Electrode for Clearing Scattered Electrons in the RHIC E-Lens

electron, proton, scattering, solenoid

4038

X. Gu, W. Fischer, D.M. Gassner, K. Hamdi, J. Hock, Y. Luo, C. Montag, M. Okamura, A.I. Pikin, P. Thieberger
BNL, Upton, Long Island, New York, USA

Funding: Work supported by Brookhaven Science Associates, LLC under Contract No. DE-AC02-98CH10886 with the U.S. Department of Energy.
We are designing two electron lenses that will be installed at RHIC IR10 to compensate for the head-on beam-beam effect. To clear accumulated scattered electrons from 100 GeV proton-electron head-on collisions in the e-lens, a clearing split electrode may be constructed. The feasibility of this proposed electrode was demonstrated via the CST Particle Studio and Opera program simulations. By splitting one of the drift tubes in the e-lens and applying ~ 380 V across the two parts, the scattered electrons can be cleared out within several hundred micro-seconds. At the same time we can restrict the unwanted shift of the primary electron-beam that already passed the 2-m interaction region in e-lens, to less than 15um.

THPPR046

Status of the MedAustron Ion Beam Therapy Centre

controls, synchrotron, ion-source, diagnostics

4077

U. Dorda
CERN, Geneva, Switzerland
M. Benedikt, A. Fabich, F. Osmic
EBG MedAustron, Wr. Neustadt, Austria

MedAustron is a synchrotron based light-ion beam therapy centre for cancer treatment as well as for clinical and non-clinical research currently in its construction phase. The accelerator design is based on the CERN-PIMMS study and its technical implementation by CNAO. This paper presents a status overview over the whole project detailing the achieved progress of the building construction & technical infrastructure installation in Wiener Neustadt, Austria, as well as of the accelerator development, performed at CERN and partially at PSI. The design and procurement status and future planning of the various accelerator components is elaborated.

THPPR047

Design of Superconducting Rotating-gantry for Heavy-ion Therapy

superconducting-magnet, simulation, heavy-ion, optics

4080

Y. Iwata, T. Furukawa, A. I. Itano, K. Mizushima, S. Mori, K. Noda, T. Shirai
NIRS, Chiba-shi, Japan
N. Amemiya
Kyoto University, Kyoto, Japan
T. Fujimoto
AEC, Chiba, Japan
T.F. Fujita
National Institute of Radiological Sciences, Chiba, Japan
T. Obana
NIFS, Gifu, Japan
T. Ogitsu
KEK, Ibaraki, Japan
T. Orikasa, S.T. Takami, S. Takayama, I. Watanabe
Toshiba, Yokohama, Japan

We designed a superconducting rotating-gantry for heavy-ion therapy. This isocentric rotating-gantry can transport heavy ions having 430 MeV/u to the isocenter with irradiation angles between 0-360 degrees, and further has the capability of our fast raster-scanning irradiation, as employed in the existing fixed-irradiation-ports. For the magnets, combined-function superconducting-magnets will be employed. The use of these superconducting magnets allowed us to design the compact gantry, while keeping a sufficient scan size at the isocenter; the length and radius of the gantry would be approximately 13m and 5.5m, respectively, which are comparable to those of the existing proton gantries. Superconducting coils were designed by using the 3D field solver, so as to obtain uniform field distributions. The two superconducting magnets are being constructed. We will present the design of the superconducting gantry as well as details of the superconducting magnets.

THPPR054

Progress in the Design of a Curved Superconducting Dipole for a Therapy Gantry

dipole, proton, target, solenoid

4097

S. Caspi, D. Arbelaez, L.N. Brouwer, D.R. Dietderich, R.R. Hafalia, D. Robin, A. Sessler, C. Sun, W. Wan
LBNL, Berkeley, California, USA

A curved superconducting magnet for a carbon therapy gantry requires a large bore and a field around 5T. The design reduces the gantry’s size and weight and makes it more comparable with gantries used for proton therapy. In this paper we report on a combined function superconducting dipole magnet that is half the size needed for carbon gantry and is about the size of a proton gantry. The half scale, with a 130 mm bore diameter that is curved 90 degrees at a radius of 634 mm, superimposes two layers of oppositely wound and skewed solenoids that are energized in a way that nulls the solenoid field and doubles the dipole field. Furthermore, the combined architecture of the windings can create a selection of field terms that are off the near-pure dipole field. In this paper we report on the design of a two layers curved coil and the production of the winding mandrel. Some details on the magnet assembly are included.

THPPR062

Handling GEM*STER Volatile Radioactive Fission Products

neutron, proton, target, simulation

4115

M. Notani, C.M. Ankenbrandt, R.P. Johnson, T.J. Roberts
Muons, Inc, Batavia, USA
C. Bowman
ADNA, Los Alamos, New Mexico, USA

A next-generation advanced technology of nuclear power has been developed for many years. One of the promising future reactor designs with accelerator-produced neutrons is GEM*STAR (Green Energy Multiplier*Subcritical Technology for Alternative Reactors) developed by Accelerator Driven Neutron Application (ADNA), which is a subcritical thermal-spectrum reactor operating with molten salt fuel in a graphite matrix. GEM*STAR is able to use natural uranium as well as unreprocessed spent fuel from light-water reactors (LWR), generating as much electricity as the LWR had generated from the same fuel. Since the advanced design of GEM*STAR is quite different from LWR that uses solid nuclear fuel loaded in the Zircaloy, it requires emission control for volatiles emitted from the molten salt fuel, like as radioactive iodine and cesium. The volatiles caught in the helium gas circulating around the core reactor will be trapped in the cryogenic bottles. Numerical simulations to estimate the amount of fission products were performed for the design of confinement of the volatiles. The result of simulation with spent nuclear fuel from LWR is presented.

THPPR075

The UK MEIS Facility : A New Future

scattering, target, quadrupole, alignment

4151

R.J. Barlow
University of Huddersfield, Huddersfield, United Kingdom

The Medium Energy Ion Scattering facility at the Daresbury Laboratory, one of only ~10 such facilities in the world, has served the UK community since 1996. It provides a 50-400 keV ion beam and a very comprehensive experimental station where samples can be studied and the energies and angles of the recoil ions measured. It is now closing, but will be be relocated some 50 miles to the University of Huddersfield: it should be recommissioned and available to users in early 2012. We will report on progress, and on the facilities which will be available for users at the new site and under the new management.

FRXCB01

Review of Microwave Schottky Beam Diagnostics

pick-up, proton, antiproton, diagnostics

4175

R.J. Pasquinelli
Fermilab, Batavia, USA

Non-intercepting beam diagnostics for detection of the incoherent motion of the finite number of beam particles, i.e. Schottky beam monitors, have been proven as extremely useful to characterize tune, chromaticity, and momentum spread in circular accelerators and colliders. This beam instrument, based on advanced microwave techniques, operates successfully in Recycler and Tevatron, and was recently implemented in the Large Hadron Collider. This presentation should review the technology of Schottky beam diagnostics systems with an emphasis on initial deployment at the Tevatron, concluding with the latest measurement results from the LHC and an outlook of possible improvements and extensions of the diagnostics.

Slides FRXCB01 [22.518 MB]