IPAC2011 - List of Keywords (acceleration)

Paper	Title	Other Keywords	Page
MOYCA01	Status Report on the Commissioning of the Japanese XFEL at SPring-8	laser, undulator, electron, FEL	21
	H. Tanaka RIKEN SPring-8 Center, Sayo-cho, Sayo-gun, Hyogo, Japan
	The Japanese XFEL at SPring-8, which was named SACLA (Spring-8 Angstrom Compact free electron LAser), was completed in FY2010. After RF full-power aging for about four months the beam commissioning of SACLA has been started since 21 February 2011. About one month later, in 23 March a design beam energy of 8 GeV was achieved and a spontaneous undulator radiation of 0.8 Angstrom was observed at the beam-line optical hutch by closing XFEL undulator gaps down to 5 mm in full-width. The beam commissioning has proceeded smoothly and since the middle of April we have entered to a tuning phase towards SASE lasing, which is at least one month ahead of schedule. This talk will report the beam commissioning overview of SACLA including SASE XFEL performance, key tuning-processes and critical issues for achieving the lasing.
	Slides MOYCA01 [37.840 MB]

MOOCA02	Two Beam Test Stand Experiments in the CTF3 Facility	accelerating-gradient, linac, diagnostics, ion	29
	W. Farabolini, F. Peauger CEA/DSM/IRFU, France J. Barranco, S. Bettoni, B. Constance, R. Corsini, M. Csatari, S. Döbert, A. Dubrovskiy, C. Heßler, T. Persson, G. Riddone, P.K. Skowroński, F. Tecker CERN, Geneva, Switzerland D. Gudkov, A. Solodko JINR, Dubna, Moscow Region, Russia M. Jacewicz, T. Muranaka, A. Palaia, R.J.M.Y. Ruber, V.G. Ziemann Uppsala University, Uppsala, Sweden
	The CLEX building in the CTF3 facility is the place where essential experiments are performed to validate the Two-Beam Acceleration scheme upon which the CLIC project relies. The Drive Beam enters the CLEX after being recombined in the Delay loop and the Combiner Ring in intense beam trains of 24 A – 150 MeV lasting 140 ns and bunched at 12 GHz, although other beam parameters are also accessible. This beam is then decelerated in dedicated structures installed in the Test Beam Line (TBL) and in the Two-Beam Test Stand (TBTS) aimed at delivering bursts of 12 GHz RF power. In the TBTS this power is used to generate a high accelerating gradient of 100 MV/m in specially designed accelerating structures. To assess the performances of these structures a probe beam is used, produced by a small Linac. We reported here the various experiences conducted in the TBTS making use of the versatility the probe beam and of dedicated diagnostics.
	Slides MOOCA02 [3.003 MB]

MOPC009	Design of a Pi/2 Mode S-Band Low Energy TW Electron Linear Accelerator	electron, coupling, linac, simulation	80
	H. Shaker IPM, Tehran, Iran F. Ghasemi sbu, Tehran, Iran H. Shaker CERN, Geneva, Switzerland
	This design is related to a Pi/2 mode S-Band low energy TW electron linear accelerator which is in the construction stage. This project is supported by the school of particles and accelerators, institute for research in fundamental sciences (IPM), Tehran, Iran. This design consists of a buncher and an accelerating structure that are joined and two couplers for the input/output feedings. At each design stage, different methods (analytical or numerical) are used to confirm the results and also to have a better understanding.

MOPC018	Operation Status of C-band High Gradient Accelerator for XFEL/SPring-8 (SACLA)	electron, accelerating-gradient, klystron, target	104
	T. Inagaki, C. Kondo, T. Ohshima, Y. Otake, T. Sakurai, K. Shirasawa RIKEN SPring-8 Center, Sayo-cho, Sayo-gun, Hyogo, Japan T. Shintake RIKEN Spring-8 Harima, Hyogo, Japan
	XFEL project in SPring-8 have constructed a compact XFEL facility. In order to shorten an accelerator length, a C-band (5712 MHz) accelerator was employed due to a higher accelerating gradient than that of an S-band accelerator. Since a C-band accelerating structure generates a gradient of higher than 35 MV/m, the total length of an 8 GeV accelerator fits within 400 m, including 64 C-band RF units, 4 S-band RF units, an injector and three bunch compressors. The accelerator components were carefully installed by September 2010. Then we have performed high power RF conditioning. After 500 hours of the conditioning, the accelerating gradient of each C-band structure was reached up to 35 MV/m without any particular problem. The RF breakdown rate is low enough for an accelerator operation. Since February 2011, we started the beam commissioning for XFEL. The C-band accelerator has accelerated the electron beam up to 8 GeV, with an accelerating gradient of 33-35 MV/m in average. The energy and the trajectory of the electron beam was stable, thanks to the stabilization of a klystron voltage of 350 kV within 0.01% by a high precision high voltage charger. The facility was recently named SACLA (SPring-8 Angstrom Compact free electron LAser).

MOPC036	Design of RF Cavity for Compact 9 MeV Cyclotron	cavity, cyclotron, simulation, resonance	151
	H.S. Song, J.-S. Chai, H.W. Kim, B.N. Lee, J.H. Oh SKKU, Suwon, Republic of Korea
	The number of PET facility is rapidly increasing worldwide. To get PET image, circular accelerator such as cyclotron is needed. Compact 9 MeV H-cyclotron, which has a diameter of 1.25m is being designed at Sungkyunkwan University starting from July 2010 for getting F-18. It is expected to be constructed by next year. In this paper, RF system of 9 MeV cyclotron including design processes and detail analysis of result is reported. RF system mainly describes RF cavity design.

MOPC039	Optimization of IH-DTL Resonator for UNDULAC-RF	impedance, focusing, ion, undulator	160
	S.M. Polozov, A.S. Plastun, P.R. Safikanov MEPhI, Moscow, Russia
	The linear undulator accelerator (UNDULAC) was proposed early for ribbon ion beam acceleration. UNDULAC can be realized using two non-synchronous spatial harmonics. One of them must be RF field harmonic and the second can be RF (UNDULAC-RF) or electrostatic (UNDULAC-E). The acceleration mechanism in UNDULAC is similar as inverse free electron laser (IFEL). The beam dynamics in both types of UNDULAC was studied early and the design of UNDUAC-RF resonator was started in . Design of the 150 MHz IH-DTL for UNDULAC-RF will present. The optimization of the longitudinal field distributions will do. The most effective construction will show. Transverse electric field distributions within drift tube will optimize by blending support stems and drift tubes. E.S. Masunov, Sov. Phys. – Tech. Phys. 35(8), 962-965, 1990. ** S. M. Polozov, P. R. Safikanov, Proc. IPAC’10, Kyoto, Japan, p. 3762 (2010).

MOPC057	Loss of Landau Damping in the LHC	emittance, damping, injection, impedance	211
	E.N. Shaposhnikova, T. Argyropoulos, P. Baudrenghien, T. Bohl, A.C. Butterworth, J. Esteban Muller, T. Mastoridis, G. Papotti, J. Tückmantel, W. Venturini Delsolaro, U. Wehrle CERN, Geneva, Switzerland C.M. Bhat Fermilab, Batavia, USA
	Loss of Landau damping leading to a single bunch longitudinal quadrupole instability has been observed in the LHC during the ramp and on the 3.5 TeV flat top for small injected longitudinal emittances. The first measurements are in good agreement with the threshold calculated for the expected longitudinal reactive impedance budget of the LHC as well as with the threshold dependence on beam energy. The cure is a controlled longitudinal emittance blow-up during the ramp which for constant threshold through the cycle should provide an emittance proportional to the square root of energy.

MOPC058	Upgrade of the 200 MHz RF System in the CERN SPS	cavity, emittance, impedance, extraction	214
	E.N. Shaposhnikova, E. Ciapala, E. Montesinos CERN, Geneva, Switzerland
	The 200 MHz RF system, used in the SPS to accelerate all beams including those for the LHC, has four travelling wave structure cavities of different length. To stabilize the future higher intensity LHC beams in the SPS a larger (than now) controlled longitudinal emittance blow-up and therefore larger bucket and voltage amplitude will be necessary. However less voltage will be available in the existing system (which has a maximum peak RF power of 1 MW per cavity) due to the increased beam loading, in particular in the long cavities. This issue will be critical for beam acceleration but especially for beam transfer into the 400 MHz RF system of the LHC. The proposed solution is to shorten the two long cavities and use the freed sections together with spare sections to make two extra cavities and install two new power plants of 1.3 MW each. After this upgrade, which is a major part of the more general SPS upgrade for high luminosity LHC to be completed during 2017, the performance of the SPS RF system with high intensity beams will be significantly improved and at the same time the total impedance of the system will be reduced.

MOPC060	Bunching-frequency Multiplication for a THz Pulse-train Photoinjector	electron, bunching, linac, laser	220
	Y.-C. Huang, F.H. Chao, C.H. Chen, K.Y. Huang NTHU, Hsinchu, Taiwan
	Funding: This work is supported by National Science Council under Contract NSC 99-2112-M-007 -013 -MY3. A THz-pulse-train photoinjector* employs a THz-pulse-train laser as its driver laser to generate a beam with a bunching frequency in the THz range. However a laser frequency is on the order of a few hundred THz. It is not possible to generate a beam from the pulse-train photoinjector with a bunching frequency exceeding the laser’s carrier frequency. In view of the strong demand for a compact x-ray free-electron laser (FEL), it is highly desirable to multiply the bunching frequency of the beam from a pulse-train injector to the x-ray frequencies. We propose to chirp the energy of the THz electron pulse train in an accelerator and compress the whole beam in a magnet to increase the electron bunching frequency. Our study shows a compression ratio or a bunching-frequency multiplication factor of a few tens is achievable from a properly designed magnetic chicane compressor. The bunching factor, however, is unfortunately degraded due to the energy chirp, emittance growth, and wake-field generation. In the conference, we will show that a bunching factor of a few ppm in the bunch-frequency multiplied beam is sufficient to build up the FEL power from a 10-time length reduced undulator. * Y. C. Huang, “Laser-beat-wave bunched beam for compact superradiance sources,” International Journal of Modern Physics B, Vol. 21 Issue 3/4, p277-286 (2007).

MOPC062	EMMA RF Comissioning	cavity, LLRF, controls, beam-loading	226
	A.J. Moss, R.K. Buckley, P.A. McIntosh, A.E. Wheelhouse STFC/DL/ASTeC, Daresbury, Warrington, Cheshire, United Kingdom
	EMMA (Electron Model for Many Applications), the world’s first Non-Scaling Fixed Field Alternating Gradient (NS-FFAG) accelerator is presently in operation at Daresbury Laboratory. The LLRF system is required to synchronize with ALICE (Accelerators and Lasers in Combined Experiments) its injector, which operates at 1.3GHz, and to produce an offset frequency of (+1.5 MHz to -4 MHz) to probe the longitudinal beam dynamics and to also maintain the phase and amplitude of the 19 copper RF cavities of the EMMA machine. The design, commissioning and results of the EMMA RF system is presented.

MOPC078	Operation of Superconducting Cavities in a Fast Ramping Electron Storage Ring	cavity, HOM, impedance, storage-ring	253
	A. Roth, W. Hillert ELSA, Bonn, Germany
	Funding: Supported by German Research Foundation through SFB/TR 16. The achievable maximum energy of a medium-sized electron accelerator is mainly limited by the accelerating voltage. Using superconducting (sc) cavities, the energy limitation can be shifted considerably. However, the operation of sc multi-cell cavities in a fast ramping storage ring causes additional problems which were investigated at the 3.5 GeV Electron Stretcher Accelerator ELSA. We studied the use of two 500 MHz sc cavities providing the necessary resonator voltage of up to 14 MV and replacing the normal conducting cavities of PETRA type. A large cavity coupling factor is required, so that using the existing 250 kW klystron, an internal beam of 50 mA can be accelerated up to 5 GeV. In addition, a fast detuning of the resonance frequency of the cavities must be implemented during beam injection and the energy ramp of 4 GeV/s. An appropriate 500 MHz structure is given by a five-cell cavity constructed for the JAERI-FEL-LINAC. Based on this geometry, HOM have been calculated from a numerical simulation. Since all monopole and a larger number of dipole HOM are well above the multibunch instabilities threshold, further studies about beam instabilities damping are essential.

MOPC084	The Superconducting cw LINAC Demonstrator for GSI	linac, cavity, solenoid, ion	271
	F.D. Dziuba, M. Busch, H. Podlech, U. Ratzinger IAP, Frankfurt am Main, Germany M. Amberg, K. Aulenbacher HIM, Mainz, Germany W.A. Barth, S. Mickat GSI, Darmstadt, Germany
	Funding: BMBF Contr. No. 06FY9089I, Helmholtz Institut Mainz At GSI a new, superconducting (sc) continuous wave (cw) LINAC is under design in cooperation with the Institute for Applied Physics (IAP) of Frankfurt University and the Helmholtz Institut Mainz (HIM). This proposed LINAC is highly requested by a broad community of future users to fulfill the requirements of nuclear chemistry, nuclear physics, and especially in the research field of Super Heavy Elements (SHE). In this context the preliminary layout of the LINAC has been carried out by IAP. The main acceleration of up to 7.3 AMeV will be provided by nine sc Crossbar-H-mode (CH) cavities operated at 217 MHz. Currently, a prototype of the cw LINAC as a demonstrator is under development. The demonstrator comprises a sc CH-cavity embedded between two sc solenoids mounted in a horizontal cryomodule. A full performance test of the demonstrator in 2013/14 by injecting and accelerating a beam from the GSI High Charge Injector (HLI) is one important milestone of the project. The status of the demonstrator is presented.

MOPC134	Multifrequency High Power Microwave Electric-vacuum Devices	electron, klystron, vacuum, cavity	391
	K.G. Simonov, A.A. Borisov, A.V. Galdetsky, A.N. Korolev, A.V. Mamontov ISTOK, Moscow Region, Russia O.A. Morozov Research and Production Co. "MAGRATEP", Fryazino, Russia
	A new approach for the design of the multifrequency high power microwave vacuum devices is proposed. These devices provide simultaneously some output phased signals with operating frequencies ω, 2 ω, , nω while input frequency is ω. For example, it is possible obtain output power at frequencies ω and 2ω by using of double-gap output resonator tuned on two modes – sinphased mode at 2ω and antiphased mode at frequency ω. It is possible obtain power at four frequencies ω, 2ω, 3ω and 6ω by using of the two double-gap output resonators placed one inside the other. It is possible obtain power at multiple frequencies by using of the special coaxial resonator. A microwave vacuum device has been fabricated in which power was extracted at nine multiple frequencies simultaneously. The output signal has form of pulses with ultrashort duration and superhigh repetition frequency equal to the input signal frequency ω. Multifrequency high power microwave vacuum devices can be used for the development of compact accelerators of charged particles.

MOPC146	Development of Timing Distribution System with Femto-second Stability	feedback, linac, controls, laser	421
	T. Naito, K. Ebihara, S. Nozawa, N. Terunuma, J. Urakawa KEK, Ibaraki, Japan M. Amemiya AIST, Tsukuba, Japan
	A timing distribution system with femto-second stability has been developed for the RF synchronization of accelerator and the laser synchronization of the pump-probe experiments. The system uses a phase stabilized optical fiber(PSOF) and an active fiber length stabilization. The PSOF has 5 ps/km/degC of the temperature coefficient. The active fiber length stabilization uses the phase detection of the round-trip sinusoidal wave and the fiber stretcher for the compensation of the fiber length. In this paper, we present the test results on a 500 m long signal distribution. The preliminary results of the timing stability are 20 fs at several minutes and 100 fs at four days, respectively.

MOPC158	RF Capture of a Beam with Charge-exchanging Multi-turn Injection	injection, simulation, closed-orbit, linac	454
	T. Uesugi, Y. Ishi, Y. Kuriyama, J.-B. Lagrange, Y. Mori, R. Nakano, T. Planche, B. Qin, E. Yamakawa KURRI, Osaka, Japan Y. Niwa, K. Okabe, I. Sakai University of Fukui, Faculty of Engineering, Fukui, Japan
	Funding: This work was supported by MEXT of Japan in the framework of a task entitled ”Research and Development for an Accelerator-Driven Sub-critical System Using an FFAG Accelerator”. In the fixed field alternating gradient (FFAG) synchrotron in Kyoto university research reactor Institute (KURRI), charge exchange injection was adopted since 2011. The charge stripping foil is located on the closed orbit of the injection energy, and no bump orbit system is used. Instead, the injected beam escapes from the stripping foil according to the closed-orbit shift due to acceleration. In this scheme, it is important to minimize the number of foil hitting, which causes emittance growth and foil heating. In this paper, the rf capture is studied by means of simulation.

MOPO022	Precision Beam Instrumentation and Feedback-Based Beam Control at RHIC	feedback, coupling, controls, resonance	526
	M.G. Minty, W. Fischer, H. Huang, R.L. Hulsart, C. Liu, Y. Luo, G.J. Marr, A. Marusic, K. Mernick, R.J. Michnoff, V. Ptitsyn, G. Robert-Demolaize, T. Roser, V. Schoefer, S. Tepikian, M. Wilinski 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 report we present advances in beam instrumentation required for feedback-based beam control at the Relativistic Heavy Ion Collider (RHIC). Improved resolution has contributed to enabling now routine acceleration with multiple feedback loops. Better measurement and control of the beam’s properties have allowed acceleration at a new working point and have facilitated challenging experimental studies.

MOPS002	Mitigation of Space Charge and Nonlinear Resonance Induced Beam Loss in SIS100	beam-losses, resonance, space-charge, simulation	589
	G. Franchetti GSI, Darmstadt, Germany
	The control of beam loss in SIS100 is essential for avoiding vacuum instability and guarantee the delivery of the foreseen beam intensity. On the other hand simulations show that the simultaneous presence of space charge and lattice resonances creates during 1 second cycle a progressive beam loss exceeding the limit of 5%. Until now the mechanism of periodic resonance crossing were suspected to be, in conjunction with pure dynamic aperture effects, at the base of the beam loss. In this proceeding we present the state of the art in the beam loss prediction and we prove that the periodic resonance crossing is the deteriorating mechanism, and show that the compensation of a relevant resonance intercepting the space charge tune spread sensibly mitigate the beam loss. A short discussion on beam loss during acceleration is addressed as well.

MOPS021	Beam Dynamics of a Compact SC Isochronous Cyclotron - Preliminary Study of Central Region*	proton, cyclotron, ion, extraction	643
	J.X. Zhang, T.A. Antaya, R.E. Block MIT/PSFC, Cambridge, Massachusetts, USA
	Funding: Pennsylvania State University ARL S11-07 and N00024-02-D-6604 US Defense Threat Reduction Agency A compact high field superconducting isochronous cyclotron, Megatron (K250), is designed as a proof-of-principle for a single stage high power proton accelerator. This cyclotron is to accelerate proton to a final energy of 250 MeV with two 45° Dees with a radius ~40 cm. By employing a 20 mA external ECR proton source, the injected proton beam currents at high brightness are foreseen. Using phase selection in the center, a fully magnetized elliptical pole, low energy gain per turn, a precise relation between momentum and radius at large radius are expected. Two goals, a) to use this relationship to develop multi-turn extraction with passive elements only, to achieve a high external proton beam intensity (~1 mA); and b) to see if it is possible to achieve a high extraction efficiency (> 99%) without single turn extraction, with an energy spread \|DE/E\| ~0.1%. The RF acceleration is on the first harmonic with ωrf=ω0~64 MHz. Superconductor coils will provide a central field of B0 = 4.3 T and a peak hill field of 6.6 T. The general beam dynamics studies will be performed. Precise central field design including space charge effect will be shown in the presentation.

MOPS046	Impedances and Wakes in Round Three-layer Ceramic Waveguide	impedance, radiation, damping, accumulation	703
	M. Ivanyan, A.V. Tsakanian CANDLE, Yerevan, Armenia
	The round ceramic waveguide with inner and outer thin metal coating is considered. Using the exact methods the longitudinal impedances and potentials are calculated. Identification of the main patterns of changes in their properties by varying the electrodynamic and geometric parameters of the waveguide is performed as well. The possibility of optimizing the parameters of the waveguide for the effective implementation of two-beam acceleration is discussed.

MOPZ006	Main Magnets Design Studies for the Non-scaling Fixed Field Alternating Gradient Accelerator for a Final Acceleration Stage of the Neutrino Factory	dipole, quadrupole, factory, focusing	829
	J. Pasternak STFC/RAL, Chilton, Didcot, Oxon, United Kingdom M. Aslaninejad, C. Bonţoiu, J. Pasternak Imperial College of Science and Technology, Department of Physics, London, United Kingdom
	The International Design Study of the Neutrino Factory (IDS-NF) aims to design the next generation facility for the precision neutrino oscillation searches. The non scaling Fixed Field Alternating Gradient Accelerator was prosed for the final muon beam acceleration in order to reduce the cost of the final acceleration. The superconducting magnet design based on the independent multipole coils approach using the ROXIE code is presented. The feasibility of the magnet construction together with the quench limitations are discussed.

TUOAA01	The EUROnu Project: A High Intensity Neutrino Oscillation Facility in Europe	target, factory, proton, linac	894
	T.R. Edgecock STFC/RAL, Chilton, Didcot, Oxon, United Kingdom E.H.M. Wildner CERN, Geneva, Switzerland
	EUROnu is a European Commission funded FP7 Design Study investigating three possible options for a future high intensity neutrino oscillation facility in Europe. These options are a CERN to Frejus Super-Beam, a Neutrino Factory and a Beta Beam. The aims of the project are to undertake the crucial R&D on each of the accelerator facilities and determine their performance and relative cost, including the baseline detectors for each facility. A comparison will then be made and the results reported to the CERN Council as part of the CERN Strategy Review.
	Slides TUOAA01 [7.638 MB]

TUYB01	First Results from the EMMA Experiment	electron, cavity, injection, septum	951
	S. Machida STFC/RAL/ASTeC, Chilton, Didcot, Oxon, United Kingdom
	Report on first commissioning results and operational experience with EMMA, the world's first nonscaling FFAG. In particular review the effect of resonance crossing, and the efficiency of serpentine acceleration.
	Slides TUYB01 [9.201 MB]

TUPC021	The CLIC Feasibility Demonstration in CTF3	linac, cavity, electron, ion	1042
	P.K. Skowroński, J. Barranco, S. Bettoni, B. Constance, R. Corsini, A.E. Dabrowski, M. Divall Csatari, S. Döbert, A. Dubrovskiy, O. Kononenko, M. Olvegård, T. Persson, A. Rabiller, F. Tecker CERN, Geneva, Switzerland E. Adli University of Oslo, Oslo, Norway W. Farabolini CEA/DSM/IRFU, France R.L. Lillestol NTNU, Trondheim, Norway T. Muranaka, A. Palaia, R.J.M.Y. Ruber Uppsala University, Uppsala, Sweden
	The objective of the CLIC Test Facility CTF3 is to demonstrate the feasibility issues of the CLIC two-beam technology: the efficient generation of a very high current drive beam, used as the power source to accelerate the main beam to multi-TeV energies with gradient over 100MeV/m, stable drive beam deceleration over long distances. Results on successful beam acceleration with over 100 MeV/m energy gain are shown. Measurements of drive beam deceleration over a chain of Power Extraction Structures are presented. The achieved RF power levels, the stability of the power production and of the deceleration are discussed. Finally, we overview the remaining issues to be shown until the end of 2011.

TUPC036	S-band ps Pulse Photoinjector for THz Radiation Source	coupling, electromagnetic-fields, electron, gun	1078
	S.M. Polozov, T.V. Bondarenko MEPhI, Moscow, Russia
	S-band photoinjectors with ps pulse are becoming promising as e-guns for high-intensity sub-mm wavelength pulse source. Development of accelerating system for photoinjector with ps bunch is reported. The main aim is to develop a model of accelerating structure that provide top accelerating fields in respect to high electric strength and low RF power uses. The accelerating structures consisting of 1.6 cell of disk-loaded waveguide (DLW), 3 cells and 2 half-cells of DLW, 7 cels and 2 half-cells of DLW and accelerating structure based on running wave resonator with 7 cells and 2 half-cells of DLW are studying. The resonant models of these structures and the structures with power ports were designed. Electrodynamics characteristics, electric field distribution for all models were acquired. Accelerating structure consisting of 1.6 cells will operate in pi mode of standing wave, all other structures operate in pi/2 mode traveling wave. Accelerating structure based on running wave resonator with 7 cells and 2 half-cells of DLW has most suitable electrodynamics characteristics and field distribution for sub-mm pulse source according to simulation results.

TUPC082	Beam Current Measurements at the TSR Heidelberg	ion, pick-up, electron, storage-ring	1195
	M. Grieser, S.T. Artikova, K. Blaum, F. Laux, J. Ullrich MPI-K, Heidelberg, Germany
	To conduct experiments using low energy ion beams at the TSR heavy ion storage ring, the beam deceleration process must be well understood. During deceleration of the beam the revolution frequency decreases, resulting in low current, which is difficult to measure with a common DC transformer. The number of particles in a bunch is determined by measuring the voltage signal in the time domain using a capacitive pick-up. If the ratio of bunch length and RF period does not change during the deceleration or acceleration, measuring the pick-up signal spectrum, where the signal is directly proportional to the number of particles in a bunch, is a more sensitive method. An alternative method is using a beam profile monitor (BPM) for determining the number of particles in the storage ring via ionization rate measurements of the residual gas. A summary of these different methods to determine the number of particles is presented.

TUPC096	Solid-state Marx Generator Driven Einzel Lens Chopper	ion, ECRIS, high-voltage, extraction	1233
	K. Takayama, T. Arai KEK, Ibaraki, Japan T. Adachi, K.W. Leo Sokendai, Ibaraki, Japan A. Tokuchi Pulsed Power Japan Laboratory Ltd., Kusatsu-shi Shiga, Japan
	A new type of pulse chopper called an Einzel lens chopper* is described. The Einzel lens, placed immediately after an electron cyclotron resonance ion source, is driven by high-voltage pulses generated by a newly developed solid-state Marx generator. A rectangular negative barrier pulse-voltage is controlled in time. The barrier pulse is switched on only when a beam pulse is required. When the barrier pulse is off, the DC voltage across the Einzel lens reflects ions back upstream with almost zero velocity. The device has been actually used as a chopper for the KEK Digital Accelerator, which is a small-scale induction synchrotron employing no a large injector and capable of providing a wide variety of ions, has been constructed at KEK*. A He ion beam of 50 micro-ampere was chopped in 5 micro-sec with rise/fall time of 40 nsec. T.Adachi et al., “A Solid-State Marx Generator Driven Einzel Lens Chopper”, submitted to Appl. Phys. Lett. ** T. Iwashita et al., “KEK Digital Accelerator”, Phys. Rev. ST-AB, published in 2011.

TUPC137	UFOs in the LHC	beam-losses, injection, kicker, simulation	1347
	T. Baer, M.J. Barnes, B. Goddard, E.B. Holzer, J.M. Jimenez, A. Lechner, V. Mertens, E. Nebot Del Busto, A. Nordt, J.A. Uythoven, B. Velghe, J. Wenninger, F. Zimmermann CERN, Geneva, Switzerland
	One of the major known limitations for the performance of the Large Hadron Collider are so called UFOs (”Unidentified Falling Objects”). UFOs were first observed in July 2010 and have since caused numerous protection beam dumps. UFOs are thought to be micrometer sized dust particles which lead to fast beam losses with a duration of about 10 turns when they interact with the beam. In 2011, the diagnostics for such events was significantly improved which allows estimates of the properties, dynamics and production mechanisms of the dust particles. The state of knowledge and mitigation strategies are presented.

TUPO021	Dielectric Wakefield Accelerator to Drive the Future FEL Light Source	wakefield, FEL, linac, electron	1485
	C.-J. Jing, A. Kanareykin Euclid TechLabs, LLC, Solon, Ohio, USA J.G. Power, A. Zholents ANL, Argonne, USA
	X-ray free-electron lasers (FELs) are expensive instruments and a large part of the cost of the entire facility is driven by the accelerator. Using a high-energy gain dielectric wake-field accelerator (DWA) instead of the conventional accelerator may provide a significant cost saving and reduction of the facility size. In this article, we investigate using a collinear dielectric wakefield accelerator to provide a high repetition rate, high current, high energy beam to drive a future FEL x-ray light source. As an initial case study, a ~100 MV/m loaded gradient, 850 GHz quartz dielectric based 2-stage, wakefield accelerator is proposed to generate a main electron beam of 8 GeV, 50 pC/bunch, ~1.2 kA of peak current, 1MHz (10 beamlines) in just 100 meters with the fill factor and beam loading considered.

TUPS051	Design and Performance of the MICE Target*	target, controls, extraction, vacuum	1644
	C.N. Booth, P. Hodgson, E. Overton, M. Robinson, P.J. Smith Sheffield University, Sheffield, United Kingdom G.J. Barber, K.R. Long Imperial College of Science and Technology, Department of Physics, London, United Kingdom E.G. Capocci, J.S. Tarrant STFC/RAL, Chilton, Didcot, Oxon, United Kingdom B.J.A. Shepherd STFC/DL/ASTeC, Daresbury, Warrington, Cheshire, United Kingdom
	Funding: UK Science and Technology Facilities Council The MICE experiment uses a beam of low energy muons to study ionisation cooling. This beam is derived parasitically from the ISIS synchrotron at the Rutherford Appleton Laboratory. A mechanical drive has been developed which rapidly inserts a small titanium target into the beam after acceleration and before extraction, with minimal disturbance to the circulating protons. One mechanism has operated in ISIS for over half a million pulses, and its performance will be summarised. Upgrades to this design have been tested in parallel with MICE operation; the improvements in performance and reliability will be presented, together with a discussion of further future enhancements.

TUPS085	Mass Production Report of C-band Choke Mode Accelerating Structure and RF Pulse Compressor	resonance, coupling, cavity, electron	1737
	S. Miura, T. Hashirano, F. Inoue, K. Okihira MHI, Hiroshima, Japan T. Inagaki RIKEN/SPring-8, Hyogo, Japan H. Maesaka, T. Shintake RIKEN Spring-8 Harima, Hyogo, Japan
	RIKEN and JASRI already completed the construction of XFEL/SPring8. Recently the facility was named “SACLA” (SPring-8 Angstrom Compact Free Electron LAser). The commissioning team succeeded in acceleration of 8 GeV electron beam and observation of the undulator light of 0.8 angstrom wavelength in March 2011. Now the accelerator is stably operated for the XFEL commissioning. In this project, a C-band (5712 MHz) choke mode accelerating structures and C-band RF pulse compressors are employed to obtain a high acceleration gradient of more than 35 MeV/m. We completed the fabrication of 128 accelerating structures, 64 RF pulse compressors, and 64 units of waveguide components and conducted RF measurements on them until May 2010. We report the result of the mass-production of these 64 C-Band units.

TUPS088	Charge Stripping of Uranium-238 Ion Beam with Low-Z Gas Stripper	cyclotron, target, ion, vacuum	1746
	H. Imao RIKEN Nishina Center for Accelerator-Based Science, Wako, Saitama, Japan N. Fukunishi, A. Goto, H. Hasebe, O. Kamigaito, M. Kase, H. Kuboki, H. Okuno, T. Watanabe, Y. Yano, S. Yokouchi RIKEN Nishina Center, Wako, Japan
	One of the primary goals of the RIKEN RI beam factory is to generate unprecedented high-power uranium beams (up to tens kW), which yield an enormous breakthrough for exploring new domains of the nuclear chart. The development of reliable and efficient charge stripping scheme for such high-power beams is a key unsolved issue, affecting the overall performance of the heavy ion accelerations. A charge stripper using low-Z (low atomic number Z) gas is an important candidate. Because of the suppression of the electron capture process, the high equilibrium mean charge states for the low-Z gas stripper are expected in conjunction with the intrinsic robustness of the gas. There was, however, no direct experimental data of the charge evolution, because of the difficulty in making massive windowless low-Z gas targets. In the present work, the charge evolution of the 238U beams injected at 10.75 MeV/u were investigated using thick hydrogen and helium gas strippers with huge differential pumping system newly developed. In the energy region of interest, near 10 MeV/u, achievable mean charge states around 65+ with the low-Z gas strippers are far superior to those of the medium-Z ones around 55+.

TUPZ010	Longitudinal Emittance Blow-up in the LHC	emittance, synchrotron, damping, feedback	1819
	P. Baudrenghien, A.C. Butterworth, M. Jaussi, T. Mastoridis, G. Papotti, E.N. Shaposhnikova, J. Tückmantel CERN, Geneva, Switzerland
	The LHC relies on Landau damping for longitudinal stability. To avoid decreasing the stability margin at high energy, the longitudinal emittance must be continuously increased during the acceleration ramp. Longitudinal blow-up provides the required emittance growth. The method was implemented through the summer of 2010. We inject band-limited RF phase-noise in the main accelerating cavities during the whole ramp of about 11 minutes. Synchrotron frequencies change along the energy ramp, but the digitally created noise tracks the frequency change. The position of the noise-band, relative to the nominal synchrotron frequency, and the bandwidth of the spectrum are set by pre-defined constants, making the diffusion stop at the edges of the demanded distribution. The noise amplitude is controlled by feedback using the measurement of the average bunch length. This algorithm reproducibly achieves the programmed bunch length of about 1.2 ns (4 σ) at flat top with low bunch-to-bunch scatter and provides a stable beam for physics coast.

TUPZ030	Simulation of Linear Beam Parameters to Minimize the Duration of the Squeeze at the LHC	optics, simulation, controls, collider	1873
	X. Buffat EPFL, Lausanne, Switzerland G.J. Müller, S. Redaelli, M. Strzelczyk CERN, Geneva, Switzerland
	The betatron squeeze allows to increase the luminosity of a collider by reducing the β function at the interaction points. This operation has shown to be very critical in previous colliders. In this state of mind, the squeezing was performed extremely safely during the first year of operation of the Large Hadron Collider, at the expense of the duration of the process. As the turnaround time is a relevant parameter for the integrated luminosity, a squeeze of shorter duration is proposed for 2011 and further. MadX simulation of linear beam parameters based on settings extracted from the LHC control system are used to justify the proposal. Further optimization of the squeeze setting generation is also discussed.

WEOBA02	KEK Digital Accelerator and its Beam Commissioning	injection, ion, induction, kicker	1920
	K. Takayama, T. Arai, Y. Arakida, M. Hasimoto, T. Iwashita, E. Kadokura, T. Kawakubo, T. Kubo, H. Nakanishi, K. Okamura, H. Someya, A. Takagi, M. Wake KEK, Ibaraki, Japan T. Adachi, K.W. Leo Sokendai, Ibaraki, Japan K. Okazaki Nippon Advanced Technology Co. Ltd., Ibaraki-prefecture, Japan
	The digital accelerator (DA), which is a small-scale induction synchrotron no requiring a high-energy injector accelerator and capable of providing a wide variety of ions, has been constructed at KEK. Since the last winter beam commissioning has been carried out. Preliminary results of the beam commissioning experiment as well as the accelerator itself will be presented at the conference. The KEK-DA consists of a 200 kV high voltage terminal, in which an ECRIS is embedded, 15 m long LEBT, electro-static injection kicker, and a 10 Hz rapid cycle synchrotron, which is the recycle use of the former 500 MeV Booster synchrotron. An ion pulse, which is chopped in 5 μs by the newly developed Marx generator driven chopper, is guided through the LEBT and injected by the electrostatic kicker, which is turned off before the injected ion pulse completes the first turn. Then the ion pulse is captured with a pair of barrier voltages and accelerated with the induction acceleration voltage through a full acceleration period. Beam commissioning has been started with a He¹⁺ ion beam of 50 micro-ampere. Beam commissioning of other ions such as C, N, O, Ne, and Ar will be expected. T. Iwashita et al., “KEK Digital Accelerator”, Phys. Rev. ST-AB, published in 2011. ** T.Adachi et al., “A Solid-State Marx Generator Driven Einzel Lens Chopper”, these proceedings.
	Slides WEOBA02 [4.268 MB]

WEOBA03	Non-scaling Fixed Field Alternating Gradient Permanent Magnet Cancer Therapy Accelerator	proton, cavity, lattice, permanent-magnet	1923
	D. Trbojevic BNL, Upton, Long Island, New York, USA V.S. Morozov JLAB, Newport News, Virginia, USA
	Funding: Work performed under U.S. DOE Contract Number DE-AC02-98CH10886. We present a design of the proton therapy accelerator from 31 MeV to 250 MeV by using racetrack lattice made of Non-Scaling Fixed Field Alternating Gradient (NS-FFAG) arcs and two parallel straight sections. The magnets in the arcs are separated function Halbach type magnets. The dipole bending field is 2.3 T, while the Neodymium Iron Boron magnetic residual induction is Br=1.3 T. The radial orbit offsets in the NS-FFAG arcs, for the kinetic energy range between 31 MeV < Ek < 250 MeV or momentum offset range -50% < δp/p < 50%, are -11.6 mm < x max < 16.8 mm, correspondingly. The straight sections used for the cavities and single turn injection/extraction kickers and septa are with zero orbit offsets. The permanent magnets accelerator should reduce overall and operating cost. It could fit into 8 x 12 m space.
	Slides WEOBA03 [2.789 MB]

WEXB01	Advanced Acceleration Schemes	electron, laser, plasma, wakefield	1945
	P.A. Naik, P.D. Gupta, B.S. Rao RRCAT, Indore (M.P.), India
	Review the progress and prospects of advanced acceleration concepts, including plasma acceleration, laser acceleration, and dielectric accelerators. Report ongoing and near-future experiments, and longer-term prospects for applications (e.g. compact X-ray sources, linear colliders, hadrontherapy).
	Slides WEXB01 [8.636 MB]

WEPC009	Design of an Antiproton Injection and Matching Beam Line for the AD Recycler Ring	antiproton, injection, quadrupole, ion	2019
	O. Karamyshev, G.A. Karamysheva MPI-K, Heidelberg, Germany O. Karamyshev, A.I. Papash JINR, Dubna, Moscow Region, Russia M.R.F. Siggel-King, C.P. Welsch Cockcroft Institute, Warrington, Cheshire, United Kingdom
	Funding: Work supported by STFC, the Helmholtz Association and GSI under contract VH-NG.328. A small antiproton recycler ring (AD-Rec) for use in the MUSASHI beamline at the CERN AD has been designed by the QUASAR Group for operation at energies between 3 and 30 keV. A highly efficient beam line for capturing the beam after extraction from the trap, transporting and injecting it into the AD Rec is very important to minimize losses and full the ring up to its space charge limit. In this contribution, the beam optical and mechanical design of the injector is presented.

WEPC015	Tuning Methods for HIMAC Multiple-energy Operation	betatron, resonance, beam-losses, synchrotron	2037
	K. Katagiri, T. Furukawa, Y. Iwata, K. Noda, S. Sato, T. Shirai NIRS, Chiba-shi, Japan K. Mizushima Chiba University, Graduate School of Science and Technology, Chiba, Japan E. Takeshita Gunma University, Heavy-Ion Medical Research Center, Maebashi-Gunma, Japan
	Beam stability of multiple-energy operation at HIMAC synchrotron was improved for the fast raster-scanning irradiation. In order to improve the transverse stability, the working point of the betatron tune was investigated during one operation cycle. The signals were collected from the beam position monitor using a fast data-acquisition unit. The temporal evolution of the horizontal and vertical betatron tune was evaluated by using the short time Fourier transform. Analyzed results showed that variation of the betatron tune in the acceleration interval passed through the 3rd-order coupling resonance line, and it caused undesirable emittance growth. In order to keep the working point within the desirable operating region, the current pattern of the power supplies for the quadrupole magnets was corrected by using the variation of the betatron tune. The experimental results showed that the working point could be successfully stabilized, and the undesirable beam losses could be reduced during the acceleration interval.

WEPC128	Application of Dynamical Maps to the FFAG EMMA Commissioning*	lattice, simulation, closed-orbit, target	2304
	Y. Giboudot, R. Nilavalan Brunel University, Middlesex, United Kingdom A. Wolski The University of Liverpool, Liverpool, United Kingdom
	Funding: Work supported by the Engineering and Physical Sciences Research Council, UK. The lattice of the Non Scaling FFAG EMMA has four degrees of freedom (strengths and transverse positions of each of the two quadrupoles in each periodic cell). Dynamical maps computed from an analytical representation of the magnetic field may be used to predict the beam dynamics in any configuration of the lattice. An interpolation technique using a mixed variable generating function representation for the map provides an efficient way to generate the map for any required lattice configuration, while ensuring symplecticity of the map. The interpolation technique is used in an optimisation routine, to identify the lattice configuration most closely machine specified dynamical properties, including the variation of time of flight with beam energy (a key characteristic for acceleration in EMMA). yoel.giboudot@stfc.ac.uk

WEPO012	Calculation, Design and Manufacturing of a Resistive Quadrupole for the ESS-Bilbao Transfer Lines	quadrupole, linac, power-supply, DTL	2418
	I. Rodríguez, F.J. Bermejo, J.L. Munoz, D. de Cos ESS Bilbao, Bilbao, Spain
	The first stage of the ESS-Bilbao LINAC will accelerate H⁺ and H− high current beams up to 50 MeV for different applications. After the last acceleration step in the DTL, the beam will either be transported to the experimental laboratories by the means of several transfer lines, or continue to a further acceleration step in spoke cavities. The first design of one of the quadrupoles that focus the beam along the transfer lines is presented. The quadrupoles will have an aperture of 63 mm and 20 T/m maximum gradient, featuring a short iron yoke of 100 mm. All the quadrupoles of the transfer lines are expected to be similar in order to simplify the design and manufacturing processes. The iron yoke is small and highly saturated, and an optimization of the 3D harmonics in the load-line is developed to fulfil the field quality specifications. The required current density is high (about 8.2 A/mm2), therefore a water cooled hollow conductor is used to cool down the coils. The cooling and power supply requirements are calculated in this paper. The most important manufacturing indications are also presented.

WEPO017	Status of CLIC Magnets Studies	quadrupole, linac, permanent-magnet, solenoid	2433
	M. Modena CERN, Geneva, Switzerland A.S. Vorozhtsov JINR, Dubna, Moscow Region, Russia
	R&D Magnets activities for CLIC Project have now entered a new phase with the design & manufacturing of several prototypes investigating the most challenging aspects of the CLIC Project. As concerning the CLIC Magnet System, challenges can be related to pure technical aspects (e.g. the Final Focus QD0 quadrupole where a gradient of more than 550 T/m is requested) or to industrial production choices (e.g. the Main Beam Quadrupoles where compactness and high tolerances are requested for the mechanical assembly, or the Drive Beam Quadrupoles where a productions of more than 40000 units is needed). In this paper the key aspects of the magnets under studies such as the Drive Beam, Main Beam and the Final Focus quadrupoles will be presented and discussed. Results on prototypes under assembly and measured performances will also be addressed.

WEPS003	SIS18 – Intensity Record with Intermediate Charge State Heavy Ions	ion, heavy-ion, beam-losses, injection	2484
	P.J. Spiller GSI, Darmstadt, Germany L.H.J. Bozyk FIAS, Frankfurt am Main, Germany P. Puppel HIC for FAIR, Frankfurt am Main, Germany
	Funding: Project partly funded by the European Community DIRAC-PHASE-1 / Contract number: 515876 In order to reach the desired intensities of heavy ion beams for the experiments at FAIR, 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 upgrade program for SIS18 and a dedicated machine design for SIS100. The specific problems coming along with the intermediate charge state operation in terms of charge exchange processes at collisions with residual gas atoms, pressure bumps by ion induced desorption and corresponding beam loss appears far below the typical space charge limits. Thus, new design concepts and new technical equipment addressing these issues are developed and realized with highest priority. The upgrade program of SIS18 addressing the goal of minimum ionization beam loss and stable residual gas pressure conditions has been defined in 2005. A major part of this upgrade program has been successfully realized, with the result of a world record in accelerated number of intermediate charge state heavy ions.

WEPS010	Acceleration of High Intensity Proton Beams in the J-PARC Synchrotrons	cavity, impedance, injection, synchrotron	2502
	M. Yoshii KEK/JAEA, Ibaraki-Ken, Japan E. Ezura, K. Hara, K. Hasegawa, C. Ohmori, K. Takata, M. Toda KEK, Ibaraki, Japan T. Minamikawa University of Fukui, Fukui, Japan M. Nomura, A. Schnase, T. Shimada, F. Tamura, M. Yamamoto JAEA/J-PARC, Tokai-mura, Japan
	The J-PARC accelerator complex consists of the linac, the 3GeV rapid cycling synchrotron (RCS) and the 50GeV main synchrotron (MR). These synchrotrons are the first MW-class proton accelerators which employ the high electric field gradient magnetic alloy (MA) loaded RF cavities. The beam commissioning was started in October 2007 for RCS and in May 2008 for MR. High intensity beam operation studies and user runs have been performed, while carefully controlling and minimizing the beam loss. The cycle to cycle beam operation is reproducible and quite stable, because of the stable linac beam energy and the reproducible bending field in both synchrotrons. The MA loaded RF systems and the full digital LLRF also guarantee the stable longitudinal particle motion and precise beam transfer synchronization from RCS to the MLF user facility as well as to the MR. A high intensity proton beam of 2.5·10¹³ ppp is accelerated in RCS. And in MR, a beam intensity up to ~100 Tera ppp was obtained.　We summarize the RF systems and the longitudinal parameters in both rings.

WEPS013	Results of the Nuclotron Upgrade Program	ion, vacuum, power-supply, heavy-ion	2508
	A.V. Eliseev, N.N. Agapov, A.V. Alfeev, V. Andreev, V. Batin, D.E. Donets, E.D. Donets, E.E. Donets, E.V. Gorbachev, A. Govorov, V. Karpinsky, V.D. Kekelidze, H.G. Khodzhibagiyan, A. Kirichenko, A.D. Kovalenko, O.S. Kozlov, N.I. Lebedev, I.N. Meshkov, V.A. Mikhailov, V. Monchinsky, S. Romanov, T.V. Rukoyatkina, A.O. Sidorin, I. Slepnev, V. Slepnev, A.V. Smirnov, A. Sorin, G.V. Trubnikov, B. Vasilishin JINR, Dubna, Moscow Region, Russia O.I. Brovko, A.V. Butenko, N.V. Semin, V. Volkov JINR/VBLHEP, Moscow, Russia
	The Nuclotron upgrade – the Nuclotron-M project, which had been started in 2007, involved the modernization of almost all of the accelerator systems, using beam time during seven runs devoted to testing newly installed equipment. Following the project goals, in March 2010 Xe ions were accelerated to about 1.5 GeV/u. In December 2010, the stable and safe operation of the magnetic system was achieved with a main field of 2 T. The successful completion of the project paves the way for further development of the Nuclotron-based Ion Collider fAcility (NICA).

WEPS024	Beta Beams: An Accelerator-based Facility to Explore Neutrino Oscillation Physics	ion, target, linac, ECR	2535
	E.H.M. Wildner, E. Benedetto, T. De Melo Mendonca, C. Hansen, T. Stora CERN, Geneva, Switzerland D. Berkovits Soreq NRC, Yavne, Israel G. Burt, A.C. Dexter Cockcroft Institute, Lancaster University, Lancaster, United Kingdom A. Chancé, J. Payet CEA/DSM/IRFU, France M. Cinausero, G. De Angelis, F. Gramegna, T. Marchi, G.P. Prete INFN/LNL, Legnaro (PD), Italy G. Collazuol Univ. degli Studi di Padova, Padova, Italy F. Debray, C. Trophime GHMFL, Grenoble, France T. Delbar, T. Keutgen, M. Loiselet, S. Mitrofanov UCL, Louvain-la-Neuve, Belgium G. Di Rosa INFN-Napoli, Napoli, Italy M. Hass, T. Hirsch Weizmann Institute of Science, Physics, Rehovot, Israel I. Izotov, S. Razin, V. Skalyga, V. Zorin IAP/RAS, Nizhny Novgorod, Russia L.V. Kravchuk RAS/INR, Moscow, Russia T. Lamy, L. Latrasse, M. Marie-Jeanne, T. Thuillier LPSC, Grenoble, France M. Mezzetto INFN- Sez. di Padova, Padova, Italy A.V. Sidorov BINP SB RAS, Protvino, Moscow Region, Russia P. Sortais ISN, Grenoble, France A. Stahl RWTH, Aachen, Germany
	Funding: This contribution is a project funded by European Community under the European Commission Framework Programme 7 Design Study: EUROnu, Project Number 212372. The recent discovery of neutrino oscillations, has implications for the Standard Model of particle physics (SM). Knowing the contribution of neutrinos to the SM, needs precise measurements of the parameters governing the neutrino oscillations. The EUROν Design Study will review three facilities (the so-called 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 a decision on future European neutrino oscillation facility. "Beta Beams" produce collimated pure electron (anti-)neutrino by accelerating beta active ions to high energies and having them decay in a storage ring. EUROν Beta Beams are based on CERN’s infrastructure and existing machines. Using existing machines 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.

WEPS032	Conceptual Study for the New HE-Linac at GSI	cavity, linac, injection, DTL	2553
	G. Clemente, W.A. Barth, B. Schlitt GSI, Darmstadt, Germany
	The commissioning of the first three modules of the FAIR accelerator facility is planned to be completed in 2016. At that time the DTL section of the UNILAC will be more than 40 years old. Different proposals for a new high intensity, heavy ion linac which will replace the ALVAREZ DTL as synchrotron injector are under discussion. This new High Energy-UNILAC will be design accordingly to the advanced FAIR requirements and will allow for complete and reliable multi-ion-operation for at least the next 30 years. In a first step it is foreseen to replace the first two DTL cavity, up to 4.7 AMeV. 4 IH cavities will be used to accelerate U⁴⁺ to 3 AMeV and, after gas stripping, another cavity will provide the second step of acceleration for U³⁸⁺ to 4.77 AMeV. For the next upgrade different options concerning the injection energy are under investigation. The main target is to provide a higher charge state and a higher injection energy to increase the life time of the heavy ion beam inside the synchrotron. The paper presents the beam dynamics and RF investigation for the first upgrade together with a conceptual study design for the complete replacement of the GSI ALVAREZ DTL.

WEPS033	Matching a Laser Driven Proton Injector to a CH - Drift Tube Linacs	proton, laser, solenoid, electron	2556
	A. Almomani, M. Droba, U. Ratzinger IAP, Frankfurt am Main, Germany I. Hofmann HIJ, Jena, Germany
	Experimental results and theoretical predictions in laser acceleration of protons achieved energies of ten to several tens of MeV. The LIGHT project (Laser Ion Generation, Handling and Transport) is proposed to use the PHELIX laser accelerated protons and to provide transport, focusing and injection into a conventional accelerator. This study demonstrates transport and focusing of laser-accelerated 10 MeV protons by a pulsed 18 T magnetic solenoid. The effect of co-moving electrons on the beam dynamics is investigated. The unique features of the proton distribution like small emittances and high yield of the order of 10¹3 protons per shot open new research area. The possibility of creating laser based injectors for ion accelerators is addressed. With respect to transit energies, direct matching into DTL's seems adequate. The bunch injection into a proposed CH⁻ structure is under investigation at IAP Frankfurt. Options and simulation tools are presented.

WEPS038	Development of CH-Cavities for the 17 MeV MYRRHA-Injector	cavity, proton, DTL, rfq	2571
	D. Mäder, H. Klein, H. Podlech, U. Ratzinger, M. Vossberg, C. Zhang IAP, Frankfurt am Main, Germany
	Funding: European Union FP7 MAX Contract Number 269565 MYRRHA is conceived as an accelerator driven system (ADS) for transmutation of high level nuclear waste. The neutron source is created by coupling a proton accelerator of 600 MeV with a 4 mA proton beam, a spallation source and a sub-critical core. The IAP of Frankfurt University is responsible for the development of the 17 MeV injector operated at 176 MHz. The injector consists of a 1.5 MeV 4-Rod-RFQ and six CH-drifttube-structures. The first two CH-structures will be operated at room temperature and the other CH-structures are superconducting cavities assembled in one cryo-module. To achieve the extremely high reliability required by the ADS application, the design of the 17 MeV injector has been intensively studied, with respect to thermal issues, minimum peak fields and field distribution.

WEPS070	Commissioning Status of Kolkata Superconducting Cyclotron	cyclotron, extraction, ion, injection	2664
	C. Mallik, R.K. Bhandari DAE/VECC, Calcutta, India
	After completing the construction of the K~500 superconducting cyclotron at Kolkata, the internal beam acceleration was accomplished in August 2009 and several tests were conducted to confirm the acceleration. Earlier the superconducting magnet using Nb-Ti superconductor with 300 litre liquid helium cryostat and 80 tonne iron was commissioned and field mapped. The radiofrequency system spanning 9-27 MHz and with three independent resonators were integrated into the machine. Some difficulties were experienced with achieving the voltage related to ceramic failures. Finally, ~50 kV on the dees have been achieved with reasonable phase stability between the three dees. The cyclotron uses a 14 GHz external ECR ion source and the beam is injected through 28 metre long injection line. Till date several beams like neon, argon, nitrogen, oxygen etc. have been accelerated mostly in analogous mode and at around 14 MHz frequency and ~32 kG field. Valuable experience has been obtained with various systems. The paper would describe the experience with different subsystems and beam acceleration experience. Presently, beam extraction is being tried and will be achieved shortly.

WEPS075	Induction Sector Cyclotron for Cluster Ions	induction, ion, cyclotron, impedance	2679
	K. Takayama KEK, Ibaraki, Japan T. Adachi Sokendai, Ibaraki, Japan W. Jiang Nagaoka University of Technology, Nagaoka, Niigata, Japan H. Tsutsui SHI, Tokyo, Japan
	A novel scheme of a sector cyclotron to accelerate extremely heavy cluster ions, called Induction Sector Cyclotron (ISC), is described. Its key feature is fast induction acceleration. An ion bunch is accelerated and captured with pulse voltages generated by transformers. The acceleration and confinement in the longitudinal direction can be independently handled. Since the transformers are energized by the switching power supply, in which turning on/off of the switching gate is maneuvered by gate signals digitally manipulated from the circulating beam signal of an ion bunch, acceleration synchronizing with the revolution of ion beam is always guaranteed. A cluster ion beam such as C-60, which so far there has been no way to repeatedly accelerate, can be accelerated from extremely low energy to high energy. The fundamental concept of ISC is introduced and beam dynamical issues such as a life time of cluster ions under strong guide fields and repeatedly exerted pulse voltages in the existence of residual molecules are addressed. In addition, the present status of R&D works on a race track-shape induction accelerating cell will be presented. K.Takayama et al., submitted for publication (2011). ** K.Takayama and R.J.Briggs, Chapter 11 and 12 in Induction Accelerators (Springer, 2010).

WEPS079	Serpentine Acceleration in Scaling FFAG	injection, proton, electron, closed-orbit	2691
	E. Yamakawa, Y. Ishi, Y. Kuriyama, J.-B. Lagrange, Y. Mori, R. Nakano, T. Planche, B. Qin, T. Uesugi KURRI, Osaka, Japan K. Okabe, I. Sakai University of Fukui, Faculty of Engineering, Fukui, Japan
	A serpentine acceleration in scaling FFAG accelerator has been examined. In this scheme, high-energy and high-current beam can be obtained in non-relativistic energy region. Longitudinal hamiltonian is also derived analytically.

WEPS081	The Study of Helium Ion FFAG Accelerator*	ion, focusing, induction, lattice	2697
	H.L. Luo, H. Hao, X.Q. Wang, H.L. Wu, Y.C. Xu USTC/NSRL, Hefei, Anhui, People's Republic of China
	As helium ion source, the periodic focusing structure model of Helium ion (He+) FFAG (Fixed-Field Alternating Gradient) accelerator was designed, providing He⁺ beam with higher beam current at a lower cost, which could be used for the study of the impact of Helium embitterment on fusion reactor envelope material. A radial sector scaling FFAG accelerator type with eight super-periods and a conventional magnetic lattice structure, a triplet focusing lattice-DFD combination, is adopted for He⁺ FFAG accelerator. In this paper, magnetic lattice is optimizing by analytical and numerical techniques. A large-aperture magnet is designed by using a 3D magnetic field simulation code OPERA-3D. Runge-Kutta tracking code used specifically for FFAG accelerator based on MATLAB language was used to track the particle in the magnetic field generated by OPERA-3D, followed by linear and nonlinear beam dynamics study. Some results of magnet design, particle tracking and dynamics study are presented in the article.

WEPS083	DC280 Cyclotron Central Region with Independent Flat-Top System	cyclotron, ion, injection, heavy-ion	2703
	I.A. Ivanenko, B. Gikal, G.G. Gulbekyan, N.Yu. Kazarinov JINR, Dubna, Moscow Region, Russia
	At the present time, the activities on creation of the new isochronous cyclotron DC280 are carried out at the FLNR, JINR. The cyclotron DC280 is intended for accelerating the wide range of ion beams with A/Z= 4 - 7 to energy W= 4 - 8MeV/u and intensity up to 10pmcA. To achieve high-intensity ion beams the cyclotron is equipped with Flat-Top system. At the cyclotron DC280 the Flat-Top system is physically separated from main resonators. The investigation of the cyclotron centre region with independent Flat-Top is presented. The simulation of the beams acceleration is carried out by means of the computer code CENTR.

WEPS087	Dynamics of a Novel Isochronous Non-scaling FFAG	lattice, dynamic-aperture, closed-orbit, simulation	2712
	S.L. Sheehy STFC/RAL/ASTeC, Chilton, Didcot, Oxon, United Kingdom
	Many non-scaling FFAG accelerator designs involve magnetic fields that cannot be described in popular accelerator design codes, and complex beam dynamics that require extremely accurate simulations. A recent design of a 1 GeV isochronous non-scaling FFAG is used to compare the codes COSY Infinity and ZGOUBI, both of which are commonly used in FFAG design. Results are presented for the comparison of basic beam dynamics and calculated dynamic aperture.

WEPS088	Space Charge Studies of a 1 GeV Isochronous Non-scaling FFAG Proton Driver	space-charge, lattice, simulation, emittance	2715
	S.L. Sheehy STFC/RAL/ASTeC, Chilton, Didcot, Oxon, United Kingdom
	The production of very high power proton drivers in the 10 MW range is a considerable challenge to the accelerator community. Non-scaling FFAGs have gained interest in this field, as they may be able to provide smaller, cheaper accelerators than existing options. The recent development of an isochronous non-scaling FFAG is a promising advance, but must be shown to have stable beam dynamics in the presence of space charge. Simulations of this design including space charge are presented and the implications discussed.

WEPS097	Performance of Multi-harmonic RF Feedforward System for Beam Loading Compensation in the J-PARC RCS	cavity, impedance, beam-loading, beam-losses	2733
	F. Tamura, M. Nomura, A. Schnase, T. Shimada, M. Yamamoto JAEA/J-PARC, Tokai-Mura, Naka-Gun, Ibaraki-Ken, Japan K. Hara, C. Ohmori, M. Toda, M. Yoshii KEK/JAEA, Ibaraki-Ken, Japan K. Hasegawa KEK, Tokai, Ibaraki, Japan
	The beam loading compensation is a key part for acceleration of high intensity proton beams in the J-PARC RCS. In the wide-band MA-loaded RF cavity, the wake voltage consists of not only the accelerating harmonic component but also the higher harmonics. The higher harmonic components cause the RF bucket distortion. We employ the RF feedforward method to compensate the multi-harmonic beam loading. The full-digital feedforward system is developed, which compensates the first three harmonic components of the beam loading. We present the results of the beam test with a high intensity proton beam (2.5·10¹³ ppp). The impedance seen by the beam is greatly reduced, the impedance of the fundamental accelerating harmonic is reduced to less than 25 ohms in a full accelerating cycle, while the shunt resistance of the cavity is in the order of 800 ohms. The performance of the feedforward system is promising for achievement of the design beam power, 1 MW, in the future.

WEPS103	Design of a Rapid Cycling Synchrotron for the Final Stage of Acceleration in a Common Proton Driver for a Neutrino Factory and a Spallation Neutron Source Based on Megawatt Upgrades to ISIS	proton, booster, target, neutron	2751
	J. Pasternak STFC/RAL, Chilton, Didcot, Oxon, United Kingdom L.J. Jenner, J. Pasternak Imperial College of Science and Technology, Department of Physics, London, United Kingdom
	Potential upgrades to the ISIS accelerators at RAL in the UK to provide proton beams in the few GeV and few MW range could be envisaged as the starting point for a proton driver shared between a short pulse spallation neutron source and the Neutrino Factory. The accelerator chain for the spallation neutron source, consisting of an 800 MeV H⁻ linac and a 3.2 GeV rapid cycling synchrotron (RCS), is currently being designed and optimised. The design of the RCS for the final stage of acceleration, which would increase the final beam energy of the dedicated pulses to feed the Neutrino Factory pion production target is presented. The feasibility of the final bunch compression to the necessary nanosecond range is also discussed.

WEPZ006	Forming Attosecond Electron Pulses in Space-charge Dominated Regime	electron, radiation, laser, bunching	2775
	V.A. Papadichev LPI, Moscow, Russia
	Production of high-current attosecond electron pulses requires studying of the final bunching stage, which inevitably is space-charge dominated [, , *]. Two models are studied, both allow solving a one-dimensional equation of motion. The first is for a spherical bunch, which corresponds to a short emitted pulse from a one-spike cathode of diameter approximately equal to its length. The second model is suited for pulses emitted from a multi-spike or multi-blade cathode. The bunch in the latter case is a thin plate and its evolution can be studied by also solving one-dimensional equation of motion. It was shown that bunches of 10-attosecond (as) duration with peak current of dozens of amperes can be obtained when using a carbon dioxide laser and less than 0.1-as duration with currents up to 1 MA when employing a neodymium laser. Beam focusing in transverse directions is also studied using a model. Possible applications of such electron bunches are reviewed, including obtaining attosecond pulses of tunable coherent radiation in UV and X-ray regions. V.A.Papadichev, Proceedings of EPAC08, p.2815. V.A.Papadichev, Proceedings of IPAC'10, Kyoto, Japan, p. 4372. * V.A.Papadichev, Proc. RUPAC-2010, TUPSAO10, p. 56.

WEPZ008	Experimental Plans to Explore Dielectric Wakefield Acceleration in the THz Regime	wakefield, simulation, electron, dipole	2781
	F. Lemery, D. Mihalcea, P. Piot Northern Illinois University, DeKalb, Illinois, USA C. Behrens, E. Elsen, K. Flöttmann, C. Gerth, G. Kube, B. Schmidt DESY, Hamburg, Germany J. Osterhoff LBNL, Berkeley, California, USA P. Stoltz Tech-X, Boulder, Colorado, USA
	Funding: This work was supported by the Defense Threat Reduction Agency, Basic Research Award \# HDTRA1-10^-1-0051, to Northern Illinois University Dielectric wakefield accelerators have shown great promise toward high-gradient acceleration. We investigate tow experiments in preparation to explore the performance of cylindrically-symmetric and slab-shaped dielectric-loaded waveguides. The planned experiments at Fermilab and DESY will use unique pulse shaping capabilities offered at these facilities. The superconducting test accelerator at FNAL will ultimately provide flat beams with variable current profiles needed for enhancing the transformer ratio. The FLASH facility at DESY recently demonstrated the generation of a ramped round beam current profile that will enable us to explore the performance of cylindrically-symmetric structures. Finally both of these facilities incorporate superconducting linear accelerator that could generate bunch trains with closely spaced bunches thereby opening the exploration of dynamical effects in dielectric wakefield accelerators. We present the planned layout and simulated experimental performances.

WEPZ010	Modeling and Experimental Update on Direct Laser Acceleration	laser, electron, plasma, simulation	2787
	I. Jovanovic, M.W. Lin Penn State University, University Park, Pennsylvania, USA
	Funding: This work is supported by the Defense Threat Reduction Agency under contract HDTRA1-11-1-0009. Moderate-energy, high-repetition-rate electron beams are needed in a variety of applications such as those in security and medicine, while requiring that the acceleration be realized in a compact and relatively inexpensive package. Laser wakefield acceleration is an attractive technology which meets most of those requirements, but it requires the use of relatively high peak power lasers which do not scale readily to high repetition rates. We are developing the theoretical and experimental basis for advancing the science and technology of direct laser acceleration (DLA) of charged particles using the axial component of the electric field of a radially polarized intense laser pulse. DLA is an acceleration method which exhibits no threshold and is thus compatible with the use of lower peak power, but much higher repetition rate lasers. We are currently numerically investigating the conditions for quasi-phase-matched DLA of electrons in plasma waveguides and experimentally implementing the quasi-phase-matched waveguide structure in laser-produced plasmas.

WEPZ012	Influence of Transition Radiation on Formation of a Bunch Wakefield in a Circular Waveguide	vacuum, radiation, wakefield, plasma	2793
	T.Yu. Alekhina, A.V. Tyukhtin Saint-Petersburg State University, Saint-Petersburg, Russia
	Funding: The Education Agency of Russian Federation. Investigation of a field of a particle bunch in a waveguide loaded with a dielectric is important for the wakefield acceleration (WFA) technique and other problems in the accelerator physics. One of subjects of investigation in this area consists in analysis of transition radiation generated by the bunch flying into (out of) the dielectric structure. This radiation can be both destructive (for WFA) and useful (for diagnostics of bunch or material). We investigate the total field of small bunch crossing a boundary between two dielectrics in the waveguide. It includes a “forced” field and a “free” one. The “forced” field is the field of the charge in the unbounded waveguide (it can contain the wakefield). The “free” field is connected with influence of the boundary (it includes transition radiation). Two cases are analyzed in detail: the bunch flies from vacuum into dielectric and from dielectric into vacuum. The behavior of the field depending on distance and time is explored analytically and numerically. Some interesting physical effects are noted. As well, we make a comparison with the case of intersection between vacuum and cold plasma.

WEPZ014	Upgrade of the Argonne Wakefield Accelerator Facility (AWA): Commissioning of the RF Gun and Linac Structures for Drive Beam Generation	wakefield, gun, electron, linac	2799
	M.E. Conde, D.S. Doran, W. Gai, R. Konecny, W. Liu, J.G. Power, Z.M. Yusof ANL, Argonne, USA S.P. Antipov, C.-J. Jing Euclid TechLabs, LLC, Solon, Ohio, USA E.E. Wisniewski Illinois Institute of Technology, Chicago, Illinois, USA
	Funding: Work supported by the U.S. Department of Energy under contract No. DE-AC02-06CH11357. Research at the AWA Facility has been focused on the development of electron beam driven wakefield structures. Accelerating gradients of up to 100 MV/m have been excited in dielectric loaded cylindrical structures operating in the microwave range of frequencies. Several upgrades, presently underway, will enable the facility to explore higher accelerating gradients, and also be able to generate longer RF pulses of higher intensity. The major items included in the upgrade are: (a) a new RF gun with a higher quantum efficiency photocathode will replace the RF gun that has been used to generate the drive bunches; (b) the existing RF gun will be used to generate a witness beam to probe the wakefields; (c) three new L-band RF power stations, each providing 25 MW, will be added to the facility; (d) five linac structures will be added to the drive beamline, bringing the beam energy up from 15 MeV to 75 MeV. The upgraded drive beam will consist of bunch trains of up to 32 bunches spaced by 0.77 ns with up to 100 nC per bunch. The goal of future experiments is to reach accelerating gradients of several hundred MV/m and to extract RF pulses with GW power level.

WEPZ015	Staging in Two Beam Dielectric Wakefield Accelerators	cavity, wakefield, kicker, septum	2802
	J.G. Power, M.E. Conde, W. Gai, C.-J. Jing ANL, Argonne, USA
	Funding: The work is supported by the U.S. Department of Energy under Contract No. DE-AC02-06CH11357 with Argonne National Laboratory. A new experimental program to demonstrate staging in a two beam dielectric wakefield accelerator (DWA) is being planned at the Argonne Wakefield Accelerator facility. DWA uses a drive beam to generate acceleration fields to accelerate a main beam and is one of the most promising advanced acceleration methods being pursued for a future high-energy physics linear collider. Staging is the ability to use two accelerating modules back to back to accelerate a charged particle bunch and it is one of basic requirements of any acceleration method. In this paper, a new beamline design consisting of a fast kicker to pick pulses from the drive bunch train and deliver them to the individual acceleration modules will be presented.

WEPZ023	Results from Plasma Wakefield Acceleration Experiments at FACET	plasma, wakefield, electron, diagnostics	2814
	S.Z. Li, C.I. Clarke, R.J. England, J.T. Frederico, S.J. Gessner, M.J. Hogan, R.K. Jobe, M.D. Litos, D.R. Walz SLAC, Menlo Park, California, USA E. Adli University of Oslo, Oslo, Norway W. An, C.E. Clayton, C. Joshi, W. Lu, K.A. Marsh, W.B. Mori, S. Tochitsky UCLA, Los Angeles, California, USA P. Muggli USC, Los Angeles, California, USA
	Funding: Work supported by the U.S. Department of Energy under contract number DE- AC02-76SF00515. We report initial results of the Plasma Wakefield Acceleration (PWFA) Experiments performed at FACET - Facility for Advanced aCcelertor Experimental Tests at SLAC National Accelerator Laboratory. At FACET a 23 GeV electron beam with 1.8x10¹0 electrons is compressed to 20 microns longitudinally and focused down to 10 microns x 10 microns transverse spot size for user driven experiments. Construction of the FACET facility completed in May 2011 with a first run of user assisted commissioning throughout the summer. The first PWFA experiments will use single electron bunches combined with a high density lithium plasma to produce accelerating gradients >10GeV/m benchmarking the FACET beam and the newly installed experimental hardware. Future plans for further study of plasma wakefield acceleration will be reviewed.

WEPZ030	Study on a Gas-filled Capillary Waveguide for Laser Wakefield Acceleration	simulation, laser, electron, plasma	2829
	M.S. Kim, D. Jang, D. Jang, H. Suk APRI-GIST, Gwangju, Republic of Korea
	In gas-filled capillary waveguide for lase wakefield accelerators the gas flows through the two gas feed lines used to sustain constant pressure. Compared to the supersonic gas-jet system operated under high pressure, the gas at low pressure (<1atm) is injected inside capillary waveguide, so that this waveguide has experimental limit to the measurement of the neutral density. In order to investigate the gas pressure in capillary system we used computational fluid dynamics (CFD) simulation. In this paper, we presented the gas pressure changed by a variety of parameters, such as length and sizes of gas feed lines, and the method to decrease the turbulence effect at the ends of capillary.

WEPZ031	Accelerator Studies on a Possible Experiment on Proton-driven Plasma Wakefields at CERN	plasma, proton, electron, laser	2832
	R.W. Assmann, I. Efthymiopoulos, S.D. Fartoukh, G. Geschonke, B. Goddard, C. Heßler, S. Hillenbrand, M. Meddahi, S. Roesler, F. Zimmermann CERN, Geneva, Switzerland A. Caldwell, G.X. Xia MPI-P, München, Germany P. Muggli MPI, Muenchen, Germany
	There has been a proposal by Caldwell et al to use proton beams as drivers for high energy linear colliders. An experimental test with CERN's proton beams is being studied. Such a test requires a transfer line for transporting the beam to the experiment, a focusing section for beam delivery into the plasma, the plasma cell and a downstream beam section for measuring the effects from the plasma and safe disposal of the beam. The work done at CERN towards the conceptual layout and design of such a test area is presented. A possible development of such a test area into a CERN test facility for high-gradient acceleration experiments is discussed.

WEPZ032	Energy Spectrometer Studies for Proton-driven Plasma Acceleration	plasma, proton, electron, simulation	2835
	S. Hillenbrand, R.W. Assmann, F. Zimmermann CERN, Geneva, Switzerland S. Hillenbrand, A.-S. Müller KIT, Karlsruhe, Germany T. Tückmantel HHUD, Dusseldorf, Germany
	Plasma-based acceleration methods have seen important progress over the last years. Recently, it has been proposed to experimentally study plasma acceleration driven by proton beams, in addition to the established research directions of electron and laser driven plasmas. Here, we present the planned experiment with a focus on the energy spectrometer studies carried out.

THPC142	Burst Pulse Superimposed Electron Beam Acceleration in LEBRA FEL Linac	electron, FEL, linac, gun	3218
	T. Tanaka, K. Hayakawa, Y. Hayakawa, M. Inagaki, K. Nakao, K. Nogami, N. Sato LEBRA, Funabashi, Japan S. Aizawa, Y. Arisumi, K. Shinohara Nihon Koshuha Co. Ltd, Yokohama, Japan I. Sato Nihon University, Advanced Research Institute for the Sciences and Humanities, Funabashi, Japan
	The electron beam for free electron laser (FEL) at the Laboratory for Electron Beam Research and Application (LEBRA) in Nihon University had been extracted from a conventional DC triode electron gun system. In conjunction with the renewal of the gun high voltage terminal a Kentech high-speed grid pulser was installed in addition to the conventional grid pulser. The 89.25MHz sine wave frequency-divided from the 2856MHz accelerating RF has been applied to the high-speed grid pulser, generating 64 or 128 frequency-divided grid pulses synchronous with the round-trip time in the FEL optical resonator. The high-speed grid pulses have been applied to the EIMAC Y646B cathode simultaneously with the conventional macropulse through the pulse coupling strip-line circuit; the resultant beam has been the short pulse beam superimposed on the macropulse beam. By reducing the macropulse voltage, only the train of the burst beam with 0.6ns width has been extracted. The peak burst beam current roughly 6 times higher than the conventional macropulse beam has been obtained with the Farady cup at the end of the FEL beamline. The FEL lasing experiment with the burst beam is underway.

THPS013	Radiation Pressure Acceleration of Multi-ion Thin Foil	ion, laser, proton, target	3448
	T.-C. Liu, G. Dudnikova, M.Q. He, C.-S. Liu, R.Z. Sagdeev, X. Shao, J.-J. Su UMD, College Park, Maryland, USA
	Radiation pressure acceleration (RPA) is considered as an efficient way to produce quasi-monoenergetic ions, in which an ultra-thin foil is accelerated by high intensity circularly polarized laser. Our simulation study shows that an important factor limiting this acceleration process is the Rayleigh-Taylor instability, which results in the exponential growth of the foil density perturbation during the acceleration and hence the induced transparency of the foil and broadening of the particle energy spectrum. We will study RPA of multi-ion thin foil made of carbon and hydrogen and investigate the possibility of using abundant electrons supplied from carbon to delay the foil from becoming transparent, enhance the acceleration of protons and therefore improve the energy of quasi-monoenergetic proton beam. We will show the dependence of the energy of quasi-monoenergetic proton and carbon beam on the density and concentration ratio of carbon and hydrogen in the foil as well as foil thickness for RPA.

THPS014	Laser Thin Gas Target Acceleration for Quasi-monoenergetic Proton Generation	laser, ion, target, proton	3451
	M.Q. He, G. Dudnikova, C.-S. Liu, T.-C. Liu, R.Z. Sagdeev, X. Shao, J.-J. Su UMD, College Park, Maryland, USA Z.M. Sheng Shanghai Jiao Tong University, Shanghai, People's Republic of China
	We propose a scheme of laser thin gas target acceleration for quasi-monoenergetic proton generation. The scheme uses gas target of thickness about several laser wavelengths with gas density spatial distribution of Guassian or square of sine shape. We performed Particle-In-Cell simulation using circularly polarized laser of normalized maximum amplitude ~5 and hydrogen gas target of thickness ~5 laser wavelength with peak density three times of the critical density. The simulation demonstrates several key physical processes involved in the laser thin gas target acceleration and the observation of quasi-monoenergetic protons. During the early phase of the laser plasma interaction, electron and ion cavities are observed. A compressed plasma layer is formed. The reflected protons in front of the compressed layer are accelerated and thus a bunch of quasi-monoenergetic protons are obtained. The compressed layer is finally destroyed due to Rayleigh-Taylor instability. The acceleration of the quasi-monoenergetic proton then stops with maximum energy about 8 MeV. It is also found that gas target thickness plays an important role for efficient quasi-monoenergetic proton generation.

THPS016	Rare Ion Beam (RIB) Facility at VECC : Present and Future	cavity, ion, rfq, ion-source	3454
	R.K. Bhandari, A. Bandyopadhyay, A. Chakrabarti, V. Naik DAE/VECC, Calcutta, India
	Funding: This project if funded by Department of Atomic Energy, Government of India. An ISOL post accelerator type Rare Ion Beam (RIB) Facility is being developed at our centre. The RIBs will be produced by using light ion induced fusion evaporation and by using photo-fission reaction, using a 50 MeV 2mA SC electron linac that is being developed in collaboration with TRIUMF, Canada. The primary reaction products will be ionized using two-ion source charge breeder. The possibility of feeding the primary reaction products directly to an ECR ion source using multi-stage skimmer and gas jet transport technique is being explored at present. An extended rod type heavy ion RFQ, one buncher and three IH cavities have been successfully accelerated stable beams up to about 415 keV/u. Three more IH cavities will increase the energy to about 1.3 MeV/u and SC QWRs will augment the energy thereafter. In the next stage of development, an Advanced National Facility for Unstable & Rare Isotope Beams (ANURIB) has been envisaged. This green field project will deliver stable & RIBs from 1.5 keV/u to 100 MeV/u. This will have both ISOL type and PFS type facility. Neutron & positron beams based facilities will also be built around the e^- linac.

THPS020	Development of C⁶⁺ Laser Ion Source	ion, laser, target, ion-source	3460
	A. Yamaguchi Toshiba Corporation, Power And Industrial Systems Research and Development Center, Yokohama, Japan
	A C⁶⁺ laser ion source has been developed for a heavy ion accelerator, which supplies pulsed ion beam for single-turn injection system of a synchrotron by one laser shot. A graphite plate is irradiated with a Q-switched Nd:YAG laser (10⁶⁴ nm of wavelength, 1.4 J of maximum laser energy, 10 ns of pulse duration) to generate carbon ions. The characteristics of the ion beam were studied by using the time-of-flight mass spectroscopy and the magnetic momentum analyzer. Results of the experiments are presented.

THPS087	Engineering Prototype for a Compact Medical Dielectric Wall Accelerator	rfq, proton, kicker, laser	3636
	A. Zografos, T. Brown, A. Hening, V. Joshkin, K. Leung, Y.K. Parker, H.T. Pearce-Percy, D. Pearson, M. Rougieri, J. Weir CPAC, Livermore, CA, USA R. Becker SSS, Gelnhausen, Germany D.T. Blackfield, G.J. Caporaso, Y.-J. Chen, S. Falabella, G. Guethlein, S.A. Hawkins, S.D. Nelson, B. R. Poole, J.A. Watson LLNL, Livermore, California, USA R.W. Hamm R&M Technical Enterprises, Pleasanton, California, USA
	Funding: Prepared by LLNL under Contract DE-AC52-07NA27344. The Compact Particle Accelerator Corporation has developed an architecture to produce pulsed proton bunches that will be suitable for proton treatment of cancers. Subsystems include a RFQ injection system with a pulsed kicker to select the desired proton bunches and a linear accelerator incorporating a High Gradient Insulator with stacked Blumleins to produce the required voltage. The Blumleins are switched with solid state laser driven optical switches that are an integral part of the Blumlein assemblies. Other subsystems include a laser, a fiber optic distribution system, an electrical charging system and beam diagnostics. An engineering prototype has been constructed and it has been fully characterized. Results obtained from the engineering prototype support the development of an extremely compact 150 MeV system capable of modulating energy, beam current and spot size on a shot to shot basis within the next two years. The paper will detail the construction of the engineering prototype and discuss experimental results. In addition, future development milestones and commercialization plans will also be discussed.

FRYCA01	Towards a World Without Nuclear Weapons: How can Scientists Help?	target, controls, status	3794
	J. Duncan UK Mission for Multilateral Arms Control & Disarmament, Cointrin, Geneva, Switzerland
	The Nuclear Non-Proliferation Treaty could eventually result in a significant reduction - or even complete elimination - of nuclear weapons. Technologies from the accelerator field, such as transmutation of weapon-grade uranium and plutonium, alternative techniques for nuclear power generation, detection of fissile material and verification, will be very important for this effort. The present trend in modern diplomacy is to form unconventional alliances to make progress on challenging issues. Could an alliance between diplomats and scientists help to achieve the ultimate goal of reducing and eventually eliminating nuclear weapons?

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MOYCA01

Status Report on the Commissioning of the Japanese XFEL at SPring-8

laser, undulator, electron, FEL

21

H. Tanaka
RIKEN SPring-8 Center, Sayo-cho, Sayo-gun, Hyogo, Japan

The Japanese XFEL at SPring-8, which was named SACLA (Spring-8 Angstrom Compact free electron LAser), was completed in FY2010. After RF full-power aging for about four months the beam commissioning of SACLA has been started since 21 February 2011. About one month later, in 23 March a design beam energy of 8 GeV was achieved and a spontaneous undulator radiation of 0.8 Angstrom was observed at the beam-line optical hutch by closing XFEL undulator gaps down to 5 mm in full-width. The beam commissioning has proceeded smoothly and since the middle of April we have entered to a tuning phase towards SASE lasing, which is at least one month ahead of schedule. This talk will report the beam commissioning overview of SACLA including SASE XFEL performance, key tuning-processes and critical issues for achieving the lasing.

Slides MOYCA01 [37.840 MB]

MOOCA02

Two Beam Test Stand Experiments in the CTF3 Facility

accelerating-gradient, linac, diagnostics, ion

29

W. Farabolini, F. Peauger
CEA/DSM/IRFU, France
J. Barranco, S. Bettoni, B. Constance, R. Corsini, M. Csatari, S. Döbert, A. Dubrovskiy, C. Heßler, T. Persson, G. Riddone, P.K. Skowroński, F. Tecker
CERN, Geneva, Switzerland
D. Gudkov, A. Solodko
JINR, Dubna, Moscow Region, Russia
M. Jacewicz, T. Muranaka, A. Palaia, R.J.M.Y. Ruber, V.G. Ziemann
Uppsala University, Uppsala, Sweden

The CLEX building in the CTF3 facility is the place where essential experiments are performed to validate the Two-Beam Acceleration scheme upon which the CLIC project relies. The Drive Beam enters the CLEX after being recombined in the Delay loop and the Combiner Ring in intense beam trains of 24 A – 150 MeV lasting 140 ns and bunched at 12 GHz, although other beam parameters are also accessible. This beam is then decelerated in dedicated structures installed in the Test Beam Line (TBL) and in the Two-Beam Test Stand (TBTS) aimed at delivering bursts of 12 GHz RF power. In the TBTS this power is used to generate a high accelerating gradient of 100 MV/m in specially designed accelerating structures. To assess the performances of these structures a probe beam is used, produced by a small Linac. We reported here the various experiences conducted in the TBTS making use of the versatility the probe beam and of dedicated diagnostics.

Slides MOOCA02 [3.003 MB]

MOPC009

Design of a Pi/2 Mode S-Band Low Energy TW Electron Linear Accelerator

electron, coupling, linac, simulation

80

H. Shaker
IPM, Tehran, Iran
F. Ghasemi
sbu, Tehran, Iran
H. Shaker
CERN, Geneva, Switzerland

This design is related to a Pi/2 mode S-Band low energy TW electron linear accelerator which is in the construction stage. This project is supported by the school of particles and accelerators, institute for research in fundamental sciences (IPM), Tehran, Iran. This design consists of a buncher and an accelerating structure that are joined and two couplers for the input/output feedings. At each design stage, different methods (analytical or numerical) are used to confirm the results and also to have a better understanding.

MOPC018

Operation Status of C-band High Gradient Accelerator for XFEL/SPring-8 (SACLA)

electron, accelerating-gradient, klystron, target

104

T. Inagaki, C. Kondo, T. Ohshima, Y. Otake, T. Sakurai, K. Shirasawa
RIKEN SPring-8 Center, Sayo-cho, Sayo-gun, Hyogo, Japan
T. Shintake
RIKEN Spring-8 Harima, Hyogo, Japan

XFEL project in SPring-8 have constructed a compact XFEL facility*. In order to shorten an accelerator length, a C-band (5712 MHz) accelerator was employed due to a higher accelerating gradient than that of an S-band accelerator. Since a C-band accelerating structure generates a gradient of higher than 35 MV/m, the total length of an 8 GeV accelerator fits within 400 m, including 64 C-band RF units, 4 S-band RF units, an injector and three bunch compressors. The accelerator components were carefully installed by September 2010. Then we have performed high power RF conditioning. After 500 hours of the conditioning, the accelerating gradient of each C-band structure was reached up to 35 MV/m without any particular problem. The RF breakdown rate is low enough for an accelerator operation. Since February 2011, we started the beam commissioning for XFEL. The C-band accelerator has accelerated the electron beam up to 8 GeV, with an accelerating gradient of 33-35 MV/m in average. The energy and the trajectory of the electron beam was stable, thanks to the stabilization of a klystron voltage of 350 kV within 0.01% by a high precision high voltage charger.
*The facility was recently named SACLA (SPring-8 Angstrom Compact free electron LAser).

MOPC036

Design of RF Cavity for Compact 9 MeV Cyclotron

cavity, cyclotron, simulation, resonance

151

H.S. Song, J.-S. Chai, H.W. Kim, B.N. Lee, J.H. Oh
SKKU, Suwon, Republic of Korea

The number of PET facility is rapidly increasing worldwide. To get PET image, circular accelerator such as cyclotron is needed. Compact 9 MeV H-cyclotron, which has a diameter of 1.25m is being designed at Sungkyunkwan University starting from July 2010 for getting F-18. It is expected to be constructed by next year. In this paper, RF system of 9 MeV cyclotron including design processes and detail analysis of result is reported. RF system mainly describes RF cavity design.

MOPC039

Optimization of IH-DTL Resonator for UNDULAC-RF

impedance, focusing, ion, undulator

160

S.M. Polozov, A.S. Plastun, P.R. Safikanov
MEPhI, Moscow, Russia

The linear undulator accelerator (UNDULAC) was proposed early for ribbon ion beam acceleration*. UNDULAC can be realized using two non-synchronous spatial harmonics. One of them must be RF field harmonic and the second can be RF (UNDULAC-RF) or electrostatic (UNDULAC-E). The acceleration mechanism in UNDULAC is similar as inverse free electron laser (IFEL). The beam dynamics in both types of UNDULAC was studied early and the design of UNDUAC-RF resonator was started in **. Design of the 150 MHz IH-DTL for UNDULAC-RF will present. The optimization of the longitudinal field distributions will do. The most effective construction will show. Transverse electric field distributions within drift tube will optimize by blending support stems and drift tubes.
* E.S. Masunov, Sov. Phys. – Tech. Phys. 35(8), 962-965, 1990.
** S. M. Polozov, P. R. Safikanov, Proc. IPAC’10, Kyoto, Japan, p. 3762 (2010).

MOPC057

Loss of Landau Damping in the LHC

emittance, damping, injection, impedance

211

E.N. Shaposhnikova, T. Argyropoulos, P. Baudrenghien, T. Bohl, A.C. Butterworth, J. Esteban Muller, T. Mastoridis, G. Papotti, J. Tückmantel, W. Venturini Delsolaro, U. Wehrle
CERN, Geneva, Switzerland
C.M. Bhat
Fermilab, Batavia, USA

Loss of Landau damping leading to a single bunch longitudinal quadrupole instability has been observed in the LHC during the ramp and on the 3.5 TeV flat top for small injected longitudinal emittances. The first measurements are in good agreement with the threshold calculated for the expected longitudinal reactive impedance budget of the LHC as well as with the threshold dependence on beam energy. The cure is a controlled longitudinal emittance blow-up during the ramp which for constant threshold through the cycle should provide an emittance proportional to the square root of energy.

MOPC058

Upgrade of the 200 MHz RF System in the CERN SPS

cavity, emittance, impedance, extraction

214

E.N. Shaposhnikova, E. Ciapala, E. Montesinos
CERN, Geneva, Switzerland

The 200 MHz RF system, used in the SPS to accelerate all beams including those for the LHC, has four travelling wave structure cavities of different length. To stabilize the future higher intensity LHC beams in the SPS a larger (than now) controlled longitudinal emittance blow-up and therefore larger bucket and voltage amplitude will be necessary. However less voltage will be available in the existing system (which has a maximum peak RF power of 1 MW per cavity) due to the increased beam loading, in particular in the long cavities. This issue will be critical for beam acceleration but especially for beam transfer into the 400 MHz RF system of the LHC. The proposed solution is to shorten the two long cavities and use the freed sections together with spare sections to make two extra cavities and install two new power plants of 1.3 MW each. After this upgrade, which is a major part of the more general SPS upgrade for high luminosity LHC to be completed during 2017, the performance of the SPS RF system with high intensity beams will be significantly improved and at the same time the total impedance of the system will be reduced.

MOPC060

Bunching-frequency Multiplication for a THz Pulse-train Photoinjector

electron, bunching, linac, laser

220

Y.-C. Huang, F.H. Chao, C.H. Chen, K.Y. Huang
NTHU, Hsinchu, Taiwan

Funding: This work is supported by National Science Council under Contract NSC 99-2112-M-007 -013 -MY3.
A THz-pulse-train photoinjector* employs a THz-pulse-train laser as its driver laser to generate a beam with a bunching frequency in the THz range. However a laser frequency is on the order of a few hundred THz. It is not possible to generate a beam from the pulse-train photoinjector with a bunching frequency exceeding the laser’s carrier frequency. In view of the strong demand for a compact x-ray free-electron laser (FEL), it is highly desirable to multiply the bunching frequency of the beam from a pulse-train injector to the x-ray frequencies. We propose to chirp the energy of the THz electron pulse train in an accelerator and compress the whole beam in a magnet to increase the electron bunching frequency. Our study shows a compression ratio or a bunching-frequency multiplication factor of a few tens is achievable from a properly designed magnetic chicane compressor. The bunching factor, however, is unfortunately degraded due to the energy chirp, emittance growth, and wake-field generation. In the conference, we will show that a bunching factor of a few ppm in the bunch-frequency multiplied beam is sufficient to build up the FEL power from a 10-time length reduced undulator.
* Y. C. Huang, “Laser-beat-wave bunched beam for compact superradiance sources,” International Journal of Modern Physics B, Vol. 21 Issue 3/4, p277-286 (2007).

MOPC062

EMMA RF Comissioning

cavity, LLRF, controls, beam-loading

226

A.J. Moss, R.K. Buckley, P.A. McIntosh, A.E. Wheelhouse
STFC/DL/ASTeC, Daresbury, Warrington, Cheshire, United Kingdom

EMMA (Electron Model for Many Applications), the world’s first Non-Scaling Fixed Field Alternating Gradient (NS-FFAG) accelerator is presently in operation at Daresbury Laboratory. The LLRF system is required to synchronize with ALICE (Accelerators and Lasers in Combined Experiments) its injector, which operates at 1.3GHz, and to produce an offset frequency of (+1.5 MHz to -4 MHz) to probe the longitudinal beam dynamics and to also maintain the phase and amplitude of the 19 copper RF cavities of the EMMA machine. The design, commissioning and results of the EMMA RF system is presented.

MOPC078

Operation of Superconducting Cavities in a Fast Ramping Electron Storage Ring

cavity, HOM, impedance, storage-ring

253

A. Roth, W. Hillert
ELSA, Bonn, Germany

Funding: Supported by German Research Foundation through SFB/TR 16.
The achievable maximum energy of a medium-sized electron accelerator is mainly limited by the accelerating voltage. Using superconducting (sc) cavities, the energy limitation can be shifted considerably. However, the operation of sc multi-cell cavities in a fast ramping storage ring causes additional problems which were investigated at the 3.5 GeV Electron Stretcher Accelerator ELSA. We studied the use of two 500 MHz sc cavities providing the necessary resonator voltage of up to 14 MV and replacing the normal conducting cavities of PETRA type. A large cavity coupling factor is required, so that using the existing 250 kW klystron, an internal beam of 50 mA can be accelerated up to 5 GeV. In addition, a fast detuning of the resonance frequency of the cavities must be implemented during beam injection and the energy ramp of 4 GeV/s. An appropriate 500 MHz structure is given by a five-cell cavity constructed for the JAERI-FEL-LINAC. Based on this geometry, HOM have been calculated from a numerical simulation. Since all monopole and a larger number of dipole HOM are well above the multibunch instabilities threshold, further studies about beam instabilities damping are essential.

MOPC084

The Superconducting cw LINAC Demonstrator for GSI

linac, cavity, solenoid, ion

271

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

Funding: BMBF Contr. No. 06FY9089I, Helmholtz Institut Mainz
At GSI a new, superconducting (sc) continuous wave (cw) LINAC is under design in cooperation with the Institute for Applied Physics (IAP) of Frankfurt University and the Helmholtz Institut Mainz (HIM). This proposed LINAC is highly requested by a broad community of future users to fulfill the requirements of nuclear chemistry, nuclear physics, and especially in the research field of Super Heavy Elements (SHE). In this context the preliminary layout of the LINAC has been carried out by IAP. The main acceleration of up to 7.3 AMeV will be provided by nine sc Crossbar-H-mode (CH) cavities operated at 217 MHz. Currently, a prototype of the cw LINAC as a demonstrator is under development. The demonstrator comprises a sc CH-cavity embedded between two sc solenoids mounted in a horizontal cryomodule. A full performance test of the demonstrator in 2013/14 by injecting and accelerating a beam from the GSI High Charge Injector (HLI) is one important milestone of the project. The status of the demonstrator is presented.

MOPC134

Multifrequency High Power Microwave Electric-vacuum Devices

electron, klystron, vacuum, cavity

391

K.G. Simonov, A.A. Borisov, A.V. Galdetsky, A.N. Korolev, A.V. Mamontov
ISTOK, Moscow Region, Russia
O.A. Morozov
Research and Production Co. "MAGRATEP", Fryazino, Russia

A new approach for the design of the multifrequency high power microwave vacuum devices is proposed. These devices provide simultaneously some output phased signals with operating frequencies ω, 2 ω, , nω while input frequency is ω. For example, it is possible obtain output power at frequencies ω and 2ω by using of double-gap output resonator tuned on two modes – sinphased mode at 2ω and antiphased mode at frequency ω. It is possible obtain power at four frequencies ω, 2ω, 3ω and 6ω by using of the two double-gap output resonators placed one inside the other. It is possible obtain power at multiple frequencies by using of the special coaxial resonator. A microwave vacuum device has been fabricated in which power was extracted at nine multiple frequencies simultaneously. The output signal has form of pulses with ultrashort duration and superhigh repetition frequency equal to the input signal frequency ω. Multifrequency high power microwave vacuum devices can be used for the development of compact accelerators of charged particles.

MOPC146

Development of Timing Distribution System with Femto-second Stability

feedback, linac, controls, laser

421

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

A timing distribution system with femto-second stability has been developed for the RF synchronization of accelerator and the laser synchronization of the pump-probe experiments. The system uses a phase stabilized optical fiber(PSOF) and an active fiber length stabilization. The PSOF has 5 ps/km/degC of the temperature coefficient. The active fiber length stabilization uses the phase detection of the round-trip sinusoidal wave and the fiber stretcher for the compensation of the fiber length. In this paper, we present the test results on a 500 m long signal distribution. The preliminary results of the timing stability are 20 fs at several minutes and 100 fs at four days, respectively.

MOPC158

RF Capture of a Beam with Charge-exchanging Multi-turn Injection

injection, simulation, closed-orbit, linac

454

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

Funding: This work was supported by MEXT of Japan in the framework of a task entitled ”Research and Development for an Accelerator-Driven Sub-critical System Using an FFAG Accelerator”.
In the fixed field alternating gradient (FFAG) synchrotron in Kyoto university research reactor Institute (KURRI), charge exchange injection was adopted since 2011. The charge stripping foil is located on the closed orbit of the injection energy, and no bump orbit system is used. Instead, the injected beam escapes from the stripping foil according to the closed-orbit shift due to acceleration. In this scheme, it is important to minimize the number of foil hitting, which causes emittance growth and foil heating. In this paper, the rf capture is studied by means of simulation.

MOPO022

Precision Beam Instrumentation and Feedback-Based Beam Control at RHIC

feedback, coupling, controls, resonance

526

M.G. Minty, W. Fischer, H. Huang, R.L. Hulsart, C. Liu, Y. Luo, G.J. Marr, A. Marusic, K. Mernick, R.J. Michnoff, V. Ptitsyn, G. Robert-Demolaize, T. Roser, V. Schoefer, S. Tepikian, M. Wilinski
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 report we present advances in beam instrumentation required for feedback-based beam control at the Relativistic Heavy Ion Collider (RHIC). Improved resolution has contributed to enabling now routine acceleration with multiple feedback loops. Better measurement and control of the beam’s properties have allowed acceleration at a new working point and have facilitated challenging experimental studies.

MOPS002

Mitigation of Space Charge and Nonlinear Resonance Induced Beam Loss in SIS100

beam-losses, resonance, space-charge, simulation

589

G. Franchetti
GSI, Darmstadt, Germany

The control of beam loss in SIS100 is essential for avoiding vacuum instability and guarantee the delivery of the foreseen beam intensity. On the other hand simulations show that the simultaneous presence of space charge and lattice resonances creates during 1 second cycle a progressive beam loss exceeding the limit of 5%. Until now the mechanism of periodic resonance crossing were suspected to be, in conjunction with pure dynamic aperture effects, at the base of the beam loss. In this proceeding we present the state of the art in the beam loss prediction and we prove that the periodic resonance crossing is the deteriorating mechanism, and show that the compensation of a relevant resonance intercepting the space charge tune spread sensibly mitigate the beam loss. A short discussion on beam loss during acceleration is addressed as well.

MOPS021

Beam Dynamics of a Compact SC Isochronous Cyclotron - Preliminary Study of Central Region*

proton, cyclotron, ion, extraction

643

J.X. Zhang, T.A. Antaya, R.E. Block
MIT/PSFC, Cambridge, Massachusetts, USA

Funding: Pennsylvania State University ARL S11-07 and N00024-02-D-6604 US Defense Threat Reduction Agency
A compact high field superconducting isochronous cyclotron, Megatron (K250), is designed as a proof-of-principle for a single stage high power proton accelerator. This cyclotron is to accelerate proton to a final energy of 250 MeV with two 45° Dees with a radius ~40 cm. By employing a 20 mA external ECR proton source, the injected proton beam currents at high brightness are foreseen. Using phase selection in the center, a fully magnetized elliptical pole, low energy gain per turn, a precise relation between momentum and radius at large radius are expected. Two goals, a) to use this relationship to develop multi-turn extraction with passive elements only, to achieve a high external proton beam intensity (~1 mA); and b) to see if it is possible to achieve a high extraction efficiency (> 99%) without single turn extraction, with an energy spread |DE/E| ~0.1%. The RF acceleration is on the first harmonic with ωrf=ω0~64 MHz. Superconductor coils will provide a central field of B0 = 4.3 T and a peak hill field of 6.6 T. The general beam dynamics studies will be performed. Precise central field design including space charge effect will be shown in the presentation.

MOPS046

Impedances and Wakes in Round Three-layer Ceramic Waveguide

impedance, radiation, damping, accumulation

703

M. Ivanyan, A.V. Tsakanian
CANDLE, Yerevan, Armenia

The round ceramic waveguide with inner and outer thin metal coating is considered. Using the exact methods the longitudinal impedances and potentials are calculated. Identification of the main patterns of changes in their properties by varying the electrodynamic and geometric parameters of the waveguide is performed as well. The possibility of optimizing the parameters of the waveguide for the effective implementation of two-beam acceleration is discussed.

MOPZ006

Main Magnets Design Studies for the Non-scaling Fixed Field Alternating Gradient Accelerator for a Final Acceleration Stage of the Neutrino Factory

dipole, quadrupole, factory, focusing

829

J. Pasternak
STFC/RAL, Chilton, Didcot, Oxon, United Kingdom
M. Aslaninejad, C. Bonţoiu, J. Pasternak
Imperial College of Science and Technology, Department of Physics, London, United Kingdom

The International Design Study of the Neutrino Factory (IDS-NF) aims to design the next generation facility for the precision neutrino oscillation searches. The non scaling Fixed Field Alternating Gradient Accelerator was prosed for the final muon beam acceleration in order to reduce the cost of the final acceleration. The superconducting magnet design based on the independent multipole coils approach using the ROXIE code is presented. The feasibility of the magnet construction together with the quench limitations are discussed.

TUOAA01

The EUROnu Project: A High Intensity Neutrino Oscillation Facility in Europe

target, factory, proton, linac

894

T.R. Edgecock
STFC/RAL, Chilton, Didcot, Oxon, United Kingdom
E.H.M. Wildner
CERN, Geneva, Switzerland

EUROnu is a European Commission funded FP7 Design Study investigating three possible options for a future high intensity neutrino oscillation facility in Europe. These options are a CERN to Frejus Super-Beam, a Neutrino Factory and a Beta Beam. The aims of the project are to undertake the crucial R&D on each of the accelerator facilities and determine their performance and relative cost, including the baseline detectors for each facility. A comparison will then be made and the results reported to the CERN Council as part of the CERN Strategy Review.

Slides TUOAA01 [7.638 MB]

TUYB01

First Results from the EMMA Experiment

electron, cavity, injection, septum

951

S. Machida
STFC/RAL/ASTeC, Chilton, Didcot, Oxon, United Kingdom

Report on first commissioning results and operational experience with EMMA, the world's first nonscaling FFAG. In particular review the effect of resonance crossing, and the efficiency of serpentine acceleration.

Slides TUYB01 [9.201 MB]

TUPC021

The CLIC Feasibility Demonstration in CTF3

linac, cavity, electron, ion

1042

P.K. Skowroński, J. Barranco, S. Bettoni, B. Constance, R. Corsini, A.E. Dabrowski, M. Divall Csatari, S. Döbert, A. Dubrovskiy, O. Kononenko, M. Olvegård, T. Persson, A. Rabiller, F. Tecker
CERN, Geneva, Switzerland
E. Adli
University of Oslo, Oslo, Norway
W. Farabolini
CEA/DSM/IRFU, France
R.L. Lillestol
NTNU, Trondheim, Norway
T. Muranaka, A. Palaia, R.J.M.Y. Ruber
Uppsala University, Uppsala, Sweden

The objective of the CLIC Test Facility CTF3 is to demonstrate the feasibility issues of the CLIC two-beam technology: the efficient generation of a very high current drive beam, used as the power source to accelerate the main beam to multi-TeV energies with gradient over 100MeV/m, stable drive beam deceleration over long distances. Results on successful beam acceleration with over 100 MeV/m energy gain are shown. Measurements of drive beam deceleration over a chain of Power Extraction Structures are presented. The achieved RF power levels, the stability of the power production and of the deceleration are discussed. Finally, we overview the remaining issues to be shown until the end of 2011.

TUPC036

S-band ps Pulse Photoinjector for THz Radiation Source

coupling, electromagnetic-fields, electron, gun

1078

S.M. Polozov, T.V. Bondarenko
MEPhI, Moscow, Russia

S-band photoinjectors with ps pulse are becoming promising as e-guns for high-intensity sub-mm wavelength pulse source. Development of accelerating system for photoinjector with ps bunch is reported. The main aim is to develop a model of accelerating structure that provide top accelerating fields in respect to high electric strength and low RF power uses. The accelerating structures consisting of 1.6 cell of disk-loaded waveguide (DLW), 3 cells and 2 half-cells of DLW, 7 cels and 2 half-cells of DLW and accelerating structure based on running wave resonator with 7 cells and 2 half-cells of DLW are studying. The resonant models of these structures and the structures with power ports were designed. Electrodynamics characteristics, electric field distribution for all models were acquired. Accelerating structure consisting of 1.6 cells will operate in pi mode of standing wave, all other structures operate in pi/2 mode traveling wave. Accelerating structure based on running wave resonator with 7 cells and 2 half-cells of DLW has most suitable electrodynamics characteristics and field distribution for sub-mm pulse source according to simulation results.

TUPC082

Beam Current Measurements at the TSR Heidelberg

ion, pick-up, electron, storage-ring

1195

M. Grieser, S.T. Artikova, K. Blaum, F. Laux, J. Ullrich
MPI-K, Heidelberg, Germany

To conduct experiments using low energy ion beams at the TSR heavy ion storage ring, the beam deceleration process must be well understood. During deceleration of the beam the revolution frequency decreases, resulting in low current, which is difficult to measure with a common DC transformer. The number of particles in a bunch is determined by measuring the voltage signal in the time domain using a capacitive pick-up. If the ratio of bunch length and RF period does not change during the deceleration or acceleration, measuring the pick-up signal spectrum, where the signal is directly proportional to the number of particles in a bunch, is a more sensitive method. An alternative method is using a beam profile monitor (BPM) for determining the number of particles in the storage ring via ionization rate measurements of the residual gas. A summary of these different methods to determine the number of particles is presented.

TUPC096

Solid-state Marx Generator Driven Einzel Lens Chopper

ion, ECRIS, high-voltage, extraction

1233

K. Takayama, T. Arai
KEK, Ibaraki, Japan
T. Adachi, K.W. Leo
Sokendai, Ibaraki, Japan
A. Tokuchi
Pulsed Power Japan Laboratory Ltd., Kusatsu-shi Shiga, Japan

A new type of pulse chopper called an Einzel lens chopper* is described. The Einzel lens, placed immediately after an electron cyclotron resonance ion source, is driven by high-voltage pulses generated by a newly developed solid-state Marx generator. A rectangular negative barrier pulse-voltage is controlled in time. The barrier pulse is switched on only when a beam pulse is required. When the barrier pulse is off, the DC voltage across the Einzel lens reflects ions back upstream with almost zero velocity. The device has been actually used as a chopper for the KEK Digital Accelerator, which is a small-scale induction synchrotron employing no a large injector and capable of providing a wide variety of ions, has been constructed at KEK**. A He ion beam of 50 micro-ampere was chopped in 5 micro-sec with rise/fall time of 40 nsec.
* T.Adachi et al., “A Solid-State Marx Generator Driven Einzel Lens Chopper”, submitted to Appl. Phys. Lett.
** T. Iwashita et al., “KEK Digital Accelerator”, Phys. Rev. ST-AB, published in 2011.

TUPC137

UFOs in the LHC

beam-losses, injection, kicker, simulation

1347

T. Baer, M.J. Barnes, B. Goddard, E.B. Holzer, J.M. Jimenez, A. Lechner, V. Mertens, E. Nebot Del Busto, A. Nordt, J.A. Uythoven, B. Velghe, J. Wenninger, F. Zimmermann
CERN, Geneva, Switzerland

One of the major known limitations for the performance of the Large Hadron Collider are so called UFOs (”Unidentified Falling Objects”). UFOs were first observed in July 2010 and have since caused numerous protection beam dumps. UFOs are thought to be micrometer sized dust particles which lead to fast beam losses with a duration of about 10 turns when they interact with the beam. In 2011, the diagnostics for such events was significantly improved which allows estimates of the properties, dynamics and production mechanisms of the dust particles. The state of knowledge and mitigation strategies are presented.

TUPO021

Dielectric Wakefield Accelerator to Drive the Future FEL Light Source

wakefield, FEL, linac, electron

1485

C.-J. Jing, A. Kanareykin
Euclid TechLabs, LLC, Solon, Ohio, USA
J.G. Power, A. Zholents
ANL, Argonne, USA

X-ray free-electron lasers (FELs) are expensive instruments and a large part of the cost of the entire facility is driven by the accelerator. Using a high-energy gain dielectric wake-field accelerator (DWA) instead of the conventional accelerator may provide a significant cost saving and reduction of the facility size. In this article, we investigate using a collinear dielectric wakefield accelerator to provide a high repetition rate, high current, high energy beam to drive a future FEL x-ray light source. As an initial case study, a ~100 MV/m loaded gradient, 850 GHz quartz dielectric based 2-stage, wakefield accelerator is proposed to generate a main electron beam of 8 GeV, 50 pC/bunch, ~1.2 kA of peak current, 1MHz (10 beamlines) in just 100 meters with the fill factor and beam loading considered.

TUPS051

Design and Performance of the MICE Target*

target, controls, extraction, vacuum

1644

C.N. Booth, P. Hodgson, E. Overton, M. Robinson, P.J. Smith
Sheffield University, Sheffield, United Kingdom
G.J. Barber, K.R. Long
Imperial College of Science and Technology, Department of Physics, London, United Kingdom
E.G. Capocci, J.S. Tarrant
STFC/RAL, Chilton, Didcot, Oxon, United Kingdom
B.J.A. Shepherd
STFC/DL/ASTeC, Daresbury, Warrington, Cheshire, United Kingdom

Funding: UK Science and Technology Facilities Council
The MICE experiment uses a beam of low energy muons to study ionisation cooling. This beam is derived parasitically from the ISIS synchrotron at the Rutherford Appleton Laboratory. A mechanical drive has been developed which rapidly inserts a small titanium target into the beam after acceleration and before extraction, with minimal disturbance to the circulating protons. One mechanism has operated in ISIS for over half a million pulses, and its performance will be summarised. Upgrades to this design have been tested in parallel with MICE operation; the improvements in performance and reliability will be presented, together with a discussion of further future enhancements.

TUPS085

Mass Production Report of C-band Choke Mode Accelerating Structure and RF Pulse Compressor

resonance, coupling, cavity, electron

1737

S. Miura, T. Hashirano, F. Inoue, K. Okihira
MHI, Hiroshima, Japan
T. Inagaki
RIKEN/SPring-8, Hyogo, Japan
H. Maesaka, T. Shintake
RIKEN Spring-8 Harima, Hyogo, Japan

RIKEN and JASRI already completed the construction of XFEL/SPring8. Recently the facility was named “SACLA” (SPring-8 Angstrom Compact Free Electron LAser). The commissioning team succeeded in acceleration of 8 GeV electron beam and observation of the undulator light of 0.8 angstrom wavelength in March 2011. Now the accelerator is stably operated for the XFEL commissioning. In this project, a C-band (5712 MHz) choke mode accelerating structures and C-band RF pulse compressors are employed to obtain a high acceleration gradient of more than 35 MeV/m. We completed the fabrication of 128 accelerating structures, 64 RF pulse compressors, and 64 units of waveguide components and conducted RF measurements on them until May 2010. We report the result of the mass-production of these 64 C-Band units.

TUPS088

Charge Stripping of Uranium-238 Ion Beam with Low-Z Gas Stripper

cyclotron, target, ion, vacuum

1746

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

One of the primary goals of the RIKEN RI beam factory is to generate unprecedented high-power uranium beams (up to tens kW), which yield an enormous breakthrough for exploring new domains of the nuclear chart. The development of reliable and efficient charge stripping scheme for such high-power beams is a key unsolved issue, affecting the overall performance of the heavy ion accelerations. A charge stripper using low-Z (low atomic number Z) gas is an important candidate. Because of the suppression of the electron capture process, the high equilibrium mean charge states for the low-Z gas stripper are expected in conjunction with the intrinsic robustness of the gas. There was, however, no direct experimental data of the charge evolution, because of the difficulty in making massive windowless low-Z gas targets. In the present work, the charge evolution of the 238U beams injected at 10.75 MeV/u were investigated using thick hydrogen and helium gas strippers with huge differential pumping system newly developed. In the energy region of interest, near 10 MeV/u, achievable mean charge states around 65+ with the low-Z gas strippers are far superior to those of the medium-Z ones around 55+.

TUPZ010

Longitudinal Emittance Blow-up in the LHC

emittance, synchrotron, damping, feedback

1819

P. Baudrenghien, A.C. Butterworth, M. Jaussi, T. Mastoridis, G. Papotti, E.N. Shaposhnikova, J. Tückmantel
CERN, Geneva, Switzerland

The LHC relies on Landau damping for longitudinal stability. To avoid decreasing the stability margin at high energy, the longitudinal emittance must be continuously increased during the acceleration ramp. Longitudinal blow-up provides the required emittance growth. The method was implemented through the summer of 2010. We inject band-limited RF phase-noise in the main accelerating cavities during the whole ramp of about 11 minutes. Synchrotron frequencies change along the energy ramp, but the digitally created noise tracks the frequency change. The position of the noise-band, relative to the nominal synchrotron frequency, and the bandwidth of the spectrum are set by pre-defined constants, making the diffusion stop at the edges of the demanded distribution. The noise amplitude is controlled by feedback using the measurement of the average bunch length. This algorithm reproducibly achieves the programmed bunch length of about 1.2 ns (4 σ) at flat top with low bunch-to-bunch scatter and provides a stable beam for physics coast.

TUPZ030

Simulation of Linear Beam Parameters to Minimize the Duration of the Squeeze at the LHC

optics, simulation, controls, collider

1873

X. Buffat
EPFL, Lausanne, Switzerland
G.J. Müller, S. Redaelli, M. Strzelczyk
CERN, Geneva, Switzerland

The betatron squeeze allows to increase the luminosity of a collider by reducing the β function at the interaction points. This operation has shown to be very critical in previous colliders. In this state of mind, the squeezing was performed extremely safely during the first year of operation of the Large Hadron Collider, at the expense of the duration of the process. As the turnaround time is a relevant parameter for the integrated luminosity, a squeeze of shorter duration is proposed for 2011 and further. MadX simulation of linear beam parameters based on settings extracted from the LHC control system are used to justify the proposal. Further optimization of the squeeze setting generation is also discussed.

WEOBA02

KEK Digital Accelerator and its Beam Commissioning

injection, ion, induction, kicker

1920

K. Takayama, T. Arai, Y. Arakida, M. Hasimoto, T. Iwashita, E. Kadokura, T. Kawakubo, T. Kubo, H. Nakanishi, K. Okamura, H. Someya, A. Takagi, M. Wake
KEK, Ibaraki, Japan
T. Adachi, K.W. Leo
Sokendai, Ibaraki, Japan
K. Okazaki
Nippon Advanced Technology Co. Ltd., Ibaraki-prefecture, Japan

The digital accelerator (DA), which is a small-scale induction synchrotron no requiring a high-energy injector accelerator and capable of providing a wide variety of ions, has been constructed at KEK*. Since the last winter beam commissioning has been carried out. Preliminary results of the beam commissioning experiment as well as the accelerator itself will be presented at the conference. The KEK-DA consists of a 200 kV high voltage terminal, in which an ECRIS is embedded, 15 m long LEBT, electro-static injection kicker, and a 10 Hz rapid cycle synchrotron, which is the recycle use of the former 500 MeV Booster synchrotron. An ion pulse, which is chopped in 5 μs by the newly developed Marx generator driven chopper**, is guided through the LEBT and injected by the electrostatic kicker, which is turned off before the injected ion pulse completes the first turn. Then the ion pulse is captured with a pair of barrier voltages and accelerated with the induction acceleration voltage through a full acceleration period. Beam commissioning has been started with a He¹⁺ ion beam of 50 micro-ampere. Beam commissioning of other ions such as C, N, O, Ne, and Ar will be expected.
* T. Iwashita et al., “KEK Digital Accelerator”, Phys. Rev. ST-AB, published in 2011.
** T.Adachi et al., “A Solid-State Marx Generator Driven Einzel Lens Chopper”, these proceedings.

Slides WEOBA02 [4.268 MB]

WEOBA03

Non-scaling Fixed Field Alternating Gradient Permanent Magnet Cancer Therapy Accelerator

proton, cavity, lattice, permanent-magnet

1923

D. Trbojevic
BNL, Upton, Long Island, New York, USA
V.S. Morozov
JLAB, Newport News, Virginia, USA

Funding: Work performed under U.S. DOE Contract Number DE-AC02-98CH10886.
We present a design of the proton therapy accelerator from 31 MeV to 250 MeV by using racetrack lattice made of Non-Scaling Fixed Field Alternating Gradient (NS-FFAG) arcs and two parallel straight sections. The magnets in the arcs are separated function Halbach type magnets. The dipole bending field is 2.3 T, while the Neodymium Iron Boron magnetic residual induction is Br=1.3 T. The radial orbit offsets in the NS-FFAG arcs, for the kinetic energy range between 31 MeV < Ek < 250 MeV or momentum offset range -50% < δp/p < 50%, are -11.6 mm < x max < 16.8 mm, correspondingly. The straight sections used for the cavities and single turn injection/extraction kickers and septa are with zero orbit offsets. The permanent magnets accelerator should reduce overall and operating cost. It could fit into 8 x 12 m space.

Slides WEOBA03 [2.789 MB]

WEXB01

Advanced Acceleration Schemes

electron, laser, plasma, wakefield

1945

P.A. Naik, P.D. Gupta, B.S. Rao
RRCAT, Indore (M.P.), India

Review the progress and prospects of advanced acceleration concepts, including plasma acceleration, laser acceleration, and dielectric accelerators. Report ongoing and near-future experiments, and longer-term prospects for applications (e.g. compact X-ray sources, linear colliders, hadrontherapy).

Slides WEXB01 [8.636 MB]

WEPC009

Design of an Antiproton Injection and Matching Beam Line for the AD Recycler Ring

antiproton, injection, quadrupole, ion

2019

O. Karamyshev, G.A. Karamysheva
MPI-K, Heidelberg, Germany
O. Karamyshev, A.I. Papash
JINR, Dubna, Moscow Region, Russia
M.R.F. Siggel-King, C.P. Welsch
Cockcroft Institute, Warrington, Cheshire, United Kingdom

Funding: Work supported by STFC, the Helmholtz Association and GSI under contract VH-NG.328.
A small antiproton recycler ring (AD-Rec) for use in the MUSASHI beamline at the CERN AD has been designed by the QUASAR Group for operation at energies between 3 and 30 keV. A highly efficient beam line for capturing the beam after extraction from the trap, transporting and injecting it into the AD Rec is very important to minimize losses and full the ring up to its space charge limit. In this contribution, the beam optical and mechanical design of the injector is presented.

WEPC015

Tuning Methods for HIMAC Multiple-energy Operation

betatron, resonance, beam-losses, synchrotron

2037

K. Katagiri, T. Furukawa, Y. Iwata, K. Noda, S. Sato, T. Shirai
NIRS, Chiba-shi, Japan
K. Mizushima
Chiba University, Graduate School of Science and Technology, Chiba, Japan
E. Takeshita
Gunma University, Heavy-Ion Medical Research Center, Maebashi-Gunma, Japan

Beam stability of multiple-energy operation at HIMAC synchrotron was improved for the fast raster-scanning irradiation. In order to improve the transverse stability, the working point of the betatron tune was investigated during one operation cycle. The signals were collected from the beam position monitor using a fast data-acquisition unit. The temporal evolution of the horizontal and vertical betatron tune was evaluated by using the short time Fourier transform. Analyzed results showed that variation of the betatron tune in the acceleration interval passed through the 3rd-order coupling resonance line, and it caused undesirable emittance growth. In order to keep the working point within the desirable operating region, the current pattern of the power supplies for the quadrupole magnets was corrected by using the variation of the betatron tune. The experimental results showed that the working point could be successfully stabilized, and the undesirable beam losses could be reduced during the acceleration interval.

WEPC128

Application of Dynamical Maps to the FFAG EMMA Commissioning*

lattice, simulation, closed-orbit, target

2304

Y. Giboudot, R. Nilavalan
Brunel University, Middlesex, United Kingdom
A. Wolski
The University of Liverpool, Liverpool, United Kingdom

Funding: Work supported by the Engineering and Physical Sciences Research Council, UK.
The lattice of the Non Scaling FFAG EMMA has four degrees of freedom (strengths and transverse positions of each of the two quadrupoles in each periodic cell). Dynamical maps computed from an analytical representation of the magnetic field may be used to predict the beam dynamics in any configuration of the lattice. An interpolation technique using a mixed variable generating function representation for the map provides an efficient way to generate the map for any required lattice configuration, while ensuring symplecticity of the map. The interpolation technique is used in an optimisation routine, to identify the lattice configuration most closely machine specified dynamical properties, including the variation of time of flight with beam energy (a key characteristic for acceleration in EMMA).
yoel.giboudot@stfc.ac.uk

WEPO012

Calculation, Design and Manufacturing of a Resistive Quadrupole for the ESS-Bilbao Transfer Lines

quadrupole, linac, power-supply, DTL

2418

I. Rodríguez, F.J. Bermejo, J.L. Munoz, D. de Cos
ESS Bilbao, Bilbao, Spain

The first stage of the ESS-Bilbao LINAC will accelerate H⁺ and H− high current beams up to 50 MeV for different applications. After the last acceleration step in the DTL, the beam will either be transported to the experimental laboratories by the means of several transfer lines, or continue to a further acceleration step in spoke cavities. The first design of one of the quadrupoles that focus the beam along the transfer lines is presented. The quadrupoles will have an aperture of 63 mm and 20 T/m maximum gradient, featuring a short iron yoke of 100 mm. All the quadrupoles of the transfer lines are expected to be similar in order to simplify the design and manufacturing processes. The iron yoke is small and highly saturated, and an optimization of the 3D harmonics in the load-line is developed to fulfil the field quality specifications. The required current density is high (about 8.2 A/mm2), therefore a water cooled hollow conductor is used to cool down the coils. The cooling and power supply requirements are calculated in this paper. The most important manufacturing indications are also presented.

WEPO017

Status of CLIC Magnets Studies

quadrupole, linac, permanent-magnet, solenoid

2433

M. Modena
CERN, Geneva, Switzerland
A.S. Vorozhtsov
JINR, Dubna, Moscow Region, Russia

R&D Magnets activities for CLIC Project have now entered a new phase with the design & manufacturing of several prototypes investigating the most challenging aspects of the CLIC Project. As concerning the CLIC Magnet System, challenges can be related to pure technical aspects (e.g. the Final Focus QD0 quadrupole where a gradient of more than 550 T/m is requested) or to industrial production choices (e.g. the Main Beam Quadrupoles where compactness and high tolerances are requested for the mechanical assembly, or the Drive Beam Quadrupoles where a productions of more than 40000 units is needed). In this paper the key aspects of the magnets under studies such as the Drive Beam, Main Beam and the Final Focus quadrupoles will be presented and discussed. Results on prototypes under assembly and measured performances will also be addressed.

WEPS003

SIS18 – Intensity Record with Intermediate Charge State Heavy Ions

ion, heavy-ion, beam-losses, injection

2484

P.J. Spiller
GSI, Darmstadt, Germany
L.H.J. Bozyk
FIAS, Frankfurt am Main, Germany
P. Puppel
HIC for FAIR, Frankfurt am Main, Germany

Funding: Project partly funded by the European Community DIRAC-PHASE-1 / Contract number: 515876
In order to reach the desired intensities of heavy ion beams for the experiments at FAIR, 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 upgrade program for SIS18 and a dedicated machine design for SIS100. The specific problems coming along with the intermediate charge state operation in terms of charge exchange processes at collisions with residual gas atoms, pressure bumps by ion induced desorption and corresponding beam loss appears far below the typical space charge limits. Thus, new design concepts and new technical equipment addressing these issues are developed and realized with highest priority. The upgrade program of SIS18 addressing the goal of minimum ionization beam loss and stable residual gas pressure conditions has been defined in 2005. A major part of this upgrade program has been successfully realized, with the result of a world record in accelerated number of intermediate charge state heavy ions.

WEPS010

Acceleration of High Intensity Proton Beams in the J-PARC Synchrotrons

cavity, impedance, injection, synchrotron

2502

M. Yoshii
KEK/JAEA, Ibaraki-Ken, Japan
E. Ezura, K. Hara, K. Hasegawa, C. Ohmori, K. Takata, M. Toda
KEK, Ibaraki, Japan
T. Minamikawa
University of Fukui, Fukui, Japan
M. Nomura, A. Schnase, T. Shimada, F. Tamura, M. Yamamoto
JAEA/J-PARC, Tokai-mura, Japan

The J-PARC accelerator complex consists of the linac, the 3GeV rapid cycling synchrotron (RCS) and the 50GeV main synchrotron (MR). These synchrotrons are the first MW-class proton accelerators which employ the high electric field gradient magnetic alloy (MA) loaded RF cavities. The beam commissioning was started in October 2007 for RCS and in May 2008 for MR. High intensity beam operation studies and user runs have been performed, while carefully controlling and minimizing the beam loss. The cycle to cycle beam operation is reproducible and quite stable, because of the stable linac beam energy and the reproducible bending field in both synchrotrons. The MA loaded RF systems and the full digital LLRF also guarantee the stable longitudinal particle motion and precise beam transfer synchronization from RCS to the MLF user facility as well as to the MR. A high intensity proton beam of 2.5·10¹³ ppp is accelerated in RCS. And in MR, a beam intensity up to ~100 Tera ppp was obtained.　We summarize the RF systems and the longitudinal parameters in both rings.

WEPS013

Results of the Nuclotron Upgrade Program

ion, vacuum, power-supply, heavy-ion

2508

A.V. Eliseev, N.N. Agapov, A.V. Alfeev, V. Andreev, V. Batin, D.E. Donets, E.D. Donets, E.E. Donets, E.V. Gorbachev, A. Govorov, V. Karpinsky, V.D. Kekelidze, H.G. Khodzhibagiyan, A. Kirichenko, A.D. Kovalenko, O.S. Kozlov, N.I. Lebedev, I.N. Meshkov, V.A. Mikhailov, V. Monchinsky, S. Romanov, T.V. Rukoyatkina, A.O. Sidorin, I. Slepnev, V. Slepnev, A.V. Smirnov, A. Sorin, G.V. Trubnikov, B. Vasilishin
JINR, Dubna, Moscow Region, Russia
O.I. Brovko, A.V. Butenko, N.V. Semin, V. Volkov
JINR/VBLHEP, Moscow, Russia

The Nuclotron upgrade – the Nuclotron-M project, which had been started in 2007, involved the modernization of almost all of the accelerator systems, using beam time during seven runs devoted to testing newly installed equipment. Following the project goals, in March 2010 Xe ions were accelerated to about 1.5 GeV/u. In December 2010, the stable and safe operation of the magnetic system was achieved with a main field of 2 T. The successful completion of the project paves the way for further development of the Nuclotron-based Ion Collider fAcility (NICA).

WEPS024

Beta Beams: An Accelerator-based Facility to Explore Neutrino Oscillation Physics

ion, target, linac, ECR

2535

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

Funding: This contribution is a project funded by European Community under the European Commission Framework Programme 7 Design Study: EUROnu, Project Number 212372.
The recent discovery of neutrino oscillations, has implications for the Standard Model of particle physics (SM). Knowing the contribution of neutrinos to the SM, needs precise measurements of the parameters governing the neutrino oscillations. The EUROν Design Study will review three facilities (the so-called 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 a decision on future European neutrino oscillation facility. "Beta Beams" produce collimated pure electron (anti-)neutrino by accelerating beta active ions to high energies and having them decay in a storage ring. EUROν Beta Beams are based on CERN’s infrastructure and existing machines. Using existing machines 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.

WEPS032

Conceptual Study for the New HE-Linac at GSI

cavity, linac, injection, DTL

2553

G. Clemente, W.A. Barth, B. Schlitt
GSI, Darmstadt, Germany

The commissioning of the first three modules of the FAIR accelerator facility is planned to be completed in 2016. At that time the DTL section of the UNILAC will be more than 40 years old. Different proposals for a new high intensity, heavy ion linac which will replace the ALVAREZ DTL as synchrotron injector are under discussion. This new High Energy-UNILAC will be design accordingly to the advanced FAIR requirements and will allow for complete and reliable multi-ion-operation for at least the next 30 years. In a first step it is foreseen to replace the first two DTL cavity, up to 4.7 AMeV. 4 IH cavities will be used to accelerate U⁴⁺ to 3 AMeV and, after gas stripping, another cavity will provide the second step of acceleration for U³⁸⁺ to 4.77 AMeV. For the next upgrade different options concerning the injection energy are under investigation. The main target is to provide a higher charge state and a higher injection energy to increase the life time of the heavy ion beam inside the synchrotron. The paper presents the beam dynamics and RF investigation for the first upgrade together with a conceptual study design for the complete replacement of the GSI ALVAREZ DTL.

WEPS033

Matching a Laser Driven Proton Injector to a CH - Drift Tube Linacs

proton, laser, solenoid, electron

2556

A. Almomani, M. Droba, U. Ratzinger
IAP, Frankfurt am Main, Germany
I. Hofmann
HIJ, Jena, Germany

Experimental results and theoretical predictions in laser acceleration of protons achieved energies of ten to several tens of MeV. The LIGHT project (Laser Ion Generation, Handling and Transport) is proposed to use the PHELIX laser accelerated protons and to provide transport, focusing and injection into a conventional accelerator. This study demonstrates transport and focusing of laser-accelerated 10 MeV protons by a pulsed 18 T magnetic solenoid. The effect of co-moving electrons on the beam dynamics is investigated. The unique features of the proton distribution like small emittances and high yield of the order of 10¹3 protons per shot open new research area. The possibility of creating laser based injectors for ion accelerators is addressed. With respect to transit energies, direct matching into DTL's seems adequate. The bunch injection into a proposed CH⁻ structure is under investigation at IAP Frankfurt. Options and simulation tools are presented.

WEPS038

Development of CH-Cavities for the 17 MeV MYRRHA-Injector

cavity, proton, DTL, rfq

2571

D. Mäder, H. Klein, H. Podlech, U. Ratzinger, M. Vossberg, C. Zhang
IAP, Frankfurt am Main, Germany

Funding: European Union FP7 MAX Contract Number 269565
MYRRHA is conceived as an accelerator driven system (ADS) for transmutation of high level nuclear waste. The neutron source is created by coupling a proton accelerator of 600 MeV with a 4 mA proton beam, a spallation source and a sub-critical core. The IAP of Frankfurt University is responsible for the development of the 17 MeV injector operated at 176 MHz. The injector consists of a 1.5 MeV 4-Rod-RFQ and six CH-drifttube-structures. The first two CH-structures will be operated at room temperature and the other CH-structures are superconducting cavities assembled in one cryo-module. To achieve the extremely high reliability required by the ADS application, the design of the 17 MeV injector has been intensively studied, with respect to thermal issues, minimum peak fields and field distribution.

WEPS070

Commissioning Status of Kolkata Superconducting Cyclotron

cyclotron, extraction, ion, injection

2664

C. Mallik, R.K. Bhandari
DAE/VECC, Calcutta, India

After completing the construction of the K~500 superconducting cyclotron at Kolkata, the internal beam acceleration was accomplished in August 2009 and several tests were conducted to confirm the acceleration. Earlier the superconducting magnet using Nb-Ti superconductor with 300 litre liquid helium cryostat and 80 tonne iron was commissioned and field mapped. The radiofrequency system spanning 9-27 MHz and with three independent resonators were integrated into the machine. Some difficulties were experienced with achieving the voltage related to ceramic failures. Finally, ~50 kV on the dees have been achieved with reasonable phase stability between the three dees. The cyclotron uses a 14 GHz external ECR ion source and the beam is injected through 28 metre long injection line. Till date several beams like neon, argon, nitrogen, oxygen etc. have been accelerated mostly in analogous mode and at around 14 MHz frequency and ~32 kG field. Valuable experience has been obtained with various systems. The paper would describe the experience with different subsystems and beam acceleration experience. Presently, beam extraction is being tried and will be achieved shortly.

WEPS075

Induction Sector Cyclotron for Cluster Ions

induction, ion, cyclotron, impedance

2679

K. Takayama
KEK, Ibaraki, Japan
T. Adachi
Sokendai, Ibaraki, Japan
W. Jiang
Nagaoka University of Technology, Nagaoka, Niigata, Japan
H. Tsutsui
SHI, Tokyo, Japan

A novel scheme of a sector cyclotron to accelerate extremely heavy cluster ions, called Induction Sector Cyclotron (ISC)*, is described. Its key feature is fast induction acceleration. An ion bunch is accelerated and captured with pulse voltages generated by transformers**. The acceleration and confinement in the longitudinal direction can be independently handled. Since the transformers are energized by the switching power supply, in which turning on/off of the switching gate is maneuvered by gate signals digitally manipulated from the circulating beam signal of an ion bunch, acceleration synchronizing with the revolution of ion beam is always guaranteed. A cluster ion beam such as C-60, which so far there has been no way to repeatedly accelerate, can be accelerated from extremely low energy to high energy. The fundamental concept of ISC is introduced and beam dynamical issues such as a life time of cluster ions under strong guide fields and repeatedly exerted pulse voltages in the existence of residual molecules are addressed. In addition, the present status of R&D works on a race track-shape induction accelerating cell will be presented.
* K.Takayama et al., submitted for publication (2011).
** K.Takayama and R.J.Briggs, Chapter 11 and 12 in Induction Accelerators (Springer, 2010).

WEPS079

Serpentine Acceleration in Scaling FFAG

injection, proton, electron, closed-orbit

2691

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

A serpentine acceleration in scaling FFAG accelerator has been examined. In this scheme, high-energy and high-current beam can be obtained in non-relativistic energy region. Longitudinal hamiltonian is also derived analytically.

WEPS081

The Study of Helium Ion FFAG Accelerator*

ion, focusing, induction, lattice

2697

H.L. Luo, H. Hao, X.Q. Wang, H.L. Wu, Y.C. Xu
USTC/NSRL, Hefei, Anhui, People's Republic of China

As helium ion source, the periodic focusing structure model of Helium ion (He+) FFAG (Fixed-Field Alternating Gradient) accelerator was designed, providing He⁺ beam with higher beam current at a lower cost, which could be used for the study of the impact of Helium embitterment on fusion reactor envelope material. A radial sector scaling FFAG accelerator type with eight super-periods and a conventional magnetic lattice structure, a triplet focusing lattice-DFD combination, is adopted for He⁺ FFAG accelerator. In this paper, magnetic lattice is optimizing by analytical and numerical techniques. A large-aperture magnet is designed by using a 3D magnetic field simulation code OPERA-3D. Runge-Kutta tracking code used specifically for FFAG accelerator based on MATLAB language was used to track the particle in the magnetic field generated by OPERA-3D, followed by linear and nonlinear beam dynamics study. Some results of magnet design, particle tracking and dynamics study are presented in the article.

WEPS083

DC280 Cyclotron Central Region with Independent Flat-Top System

cyclotron, ion, injection, heavy-ion

2703

I.A. Ivanenko, B. Gikal, G.G. Gulbekyan, N.Yu. Kazarinov
JINR, Dubna, Moscow Region, Russia

At the present time, the activities on creation of the new isochronous cyclotron DC280 are carried out at the FLNR, JINR. The cyclotron DC280 is intended for accelerating the wide range of ion beams with A/Z= 4 - 7 to energy W= 4 - 8MeV/u and intensity up to 10pmcA. To achieve high-intensity ion beams the cyclotron is equipped with Flat-Top system. At the cyclotron DC280 the Flat-Top system is physically separated from main resonators. The investigation of the cyclotron centre region with independent Flat-Top is presented. The simulation of the beams acceleration is carried out by means of the computer code CENTR.

WEPS087

Dynamics of a Novel Isochronous Non-scaling FFAG

lattice, dynamic-aperture, closed-orbit, simulation

2712

S.L. Sheehy
STFC/RAL/ASTeC, Chilton, Didcot, Oxon, United Kingdom

Many non-scaling FFAG accelerator designs involve magnetic fields that cannot be described in popular accelerator design codes, and complex beam dynamics that require extremely accurate simulations. A recent design of a 1 GeV isochronous non-scaling FFAG is used to compare the codes COSY Infinity and ZGOUBI, both of which are commonly used in FFAG design. Results are presented for the comparison of basic beam dynamics and calculated dynamic aperture.

WEPS088

Space Charge Studies of a 1 GeV Isochronous Non-scaling FFAG Proton Driver

space-charge, lattice, simulation, emittance

2715

S.L. Sheehy
STFC/RAL/ASTeC, Chilton, Didcot, Oxon, United Kingdom

The production of very high power proton drivers in the 10 MW range is a considerable challenge to the accelerator community. Non-scaling FFAGs have gained interest in this field, as they may be able to provide smaller, cheaper accelerators than existing options. The recent development of an isochronous non-scaling FFAG is a promising advance, but must be shown to have stable beam dynamics in the presence of space charge. Simulations of this design including space charge are presented and the implications discussed.

WEPS097

Performance of Multi-harmonic RF Feedforward System for Beam Loading Compensation in the J-PARC RCS

cavity, impedance, beam-loading, beam-losses

2733

F. Tamura, M. Nomura, A. Schnase, T. Shimada, M. Yamamoto
JAEA/J-PARC, Tokai-Mura, Naka-Gun, Ibaraki-Ken, Japan
K. Hara, C. Ohmori, M. Toda, M. Yoshii
KEK/JAEA, Ibaraki-Ken, Japan
K. Hasegawa
KEK, Tokai, Ibaraki, Japan

The beam loading compensation is a key part for acceleration of high intensity proton beams in the J-PARC RCS. In the wide-band MA-loaded RF cavity, the wake voltage consists of not only the accelerating harmonic component but also the higher harmonics. The higher harmonic components cause the RF bucket distortion. We employ the RF feedforward method to compensate the multi-harmonic beam loading. The full-digital feedforward system is developed, which compensates the first three harmonic components of the beam loading. We present the results of the beam test with a high intensity proton beam (2.5·10¹³ ppp). The impedance seen by the beam is greatly reduced, the impedance of the fundamental accelerating harmonic is reduced to less than 25 ohms in a full accelerating cycle, while the shunt resistance of the cavity is in the order of 800 ohms. The performance of the feedforward system is promising for achievement of the design beam power, 1 MW, in the future.

WEPS103

Design of a Rapid Cycling Synchrotron for the Final Stage of Acceleration in a Common Proton Driver for a Neutrino Factory and a Spallation Neutron Source Based on Megawatt Upgrades to ISIS

proton, booster, target, neutron

2751

J. Pasternak
STFC/RAL, Chilton, Didcot, Oxon, United Kingdom
L.J. Jenner, J. Pasternak
Imperial College of Science and Technology, Department of Physics, London, United Kingdom

Potential upgrades to the ISIS accelerators at RAL in the UK to provide proton beams in the few GeV and few MW range could be envisaged as the starting point for a proton driver shared between a short pulse spallation neutron source and the Neutrino Factory. The accelerator chain for the spallation neutron source, consisting of an 800 MeV H⁻ linac and a 3.2 GeV rapid cycling synchrotron (RCS), is currently being designed and optimised. The design of the RCS for the final stage of acceleration, which would increase the final beam energy of the dedicated pulses to feed the Neutrino Factory pion production target is presented. The feasibility of the final bunch compression to the necessary nanosecond range is also discussed.

WEPZ006

Forming Attosecond Electron Pulses in Space-charge Dominated Regime

electron, radiation, laser, bunching

2775

V.A. Papadichev
LPI, Moscow, Russia

Production of high-current attosecond electron pulses requires studying of the final bunching stage, which inevitably is space-charge dominated [*, **, ***]. Two models are studied, both allow solving a one-dimensional equation of motion. The first is for a spherical bunch, which corresponds to a short emitted pulse from a one-spike cathode of diameter approximately equal to its length. The second model is suited for pulses emitted from a multi-spike or multi-blade cathode. The bunch in the latter case is a thin plate and its evolution can be studied by also solving one-dimensional equation of motion. It was shown that bunches of 10-attosecond (as) duration with peak current of dozens of amperes can be obtained when using a carbon dioxide laser and less than 0.1-as duration with currents up to 1 MA when employing a neodymium laser. Beam focusing in transverse directions is also studied using a model. Possible applications of such electron bunches are reviewed, including obtaining attosecond pulses of tunable coherent radiation in UV and X-ray regions.
* V.A.Papadichev, Proceedings of EPAC08, p.2815.
** V.A.Papadichev, Proceedings of IPAC'10, Kyoto, Japan, p. 4372.
*** V.A.Papadichev, Proc. RUPAC-2010, TUPSAO10, p. 56.

WEPZ008

Experimental Plans to Explore Dielectric Wakefield Acceleration in the THz Regime

wakefield, simulation, electron, dipole

2781

F. Lemery, D. Mihalcea, P. Piot
Northern Illinois University, DeKalb, Illinois, USA
C. Behrens, E. Elsen, K. Flöttmann, C. Gerth, G. Kube, B. Schmidt
DESY, Hamburg, Germany
J. Osterhoff
LBNL, Berkeley, California, USA
P. Stoltz
Tech-X, Boulder, Colorado, USA

Funding: This work was supported by the Defense Threat Reduction Agency, Basic Research Award \# HDTRA1-10^-1-0051, to Northern Illinois University
Dielectric wakefield accelerators have shown great promise toward high-gradient acceleration. We investigate tow experiments in preparation to explore the performance of cylindrically-symmetric and slab-shaped dielectric-loaded waveguides. The planned experiments at Fermilab and DESY will use unique pulse shaping capabilities offered at these facilities. The superconducting test accelerator at FNAL will ultimately provide flat beams with variable current profiles needed for enhancing the transformer ratio. The FLASH facility at DESY recently demonstrated the generation of a ramped round beam current profile that will enable us to explore the performance of cylindrically-symmetric structures. Finally both of these facilities incorporate superconducting linear accelerator that could generate bunch trains with closely spaced bunches thereby opening the exploration of dynamical effects in dielectric wakefield accelerators. We present the planned layout and simulated experimental performances.

WEPZ010

Modeling and Experimental Update on Direct Laser Acceleration

laser, electron, plasma, simulation

2787

I. Jovanovic, M.W. Lin
Penn State University, University Park, Pennsylvania, USA

Funding: This work is supported by the Defense Threat Reduction Agency under contract HDTRA1-11-1-0009.
Moderate-energy, high-repetition-rate electron beams are needed in a variety of applications such as those in security and medicine, while requiring that the acceleration be realized in a compact and relatively inexpensive package. Laser wakefield acceleration is an attractive technology which meets most of those requirements, but it requires the use of relatively high peak power lasers which do not scale readily to high repetition rates. We are developing the theoretical and experimental basis for advancing the science and technology of direct laser acceleration (DLA) of charged particles using the axial component of the electric field of a radially polarized intense laser pulse. DLA is an acceleration method which exhibits no threshold and is thus compatible with the use of lower peak power, but much higher repetition rate lasers. We are currently numerically investigating the conditions for quasi-phase-matched DLA of electrons in plasma waveguides and experimentally implementing the quasi-phase-matched waveguide structure in laser-produced plasmas.

WEPZ012

Influence of Transition Radiation on Formation of a Bunch Wakefield in a Circular Waveguide

vacuum, radiation, wakefield, plasma

2793

T.Yu. Alekhina, A.V. Tyukhtin
Saint-Petersburg State University, Saint-Petersburg, Russia

Funding: The Education Agency of Russian Federation.
Investigation of a field of a particle bunch in a waveguide loaded with a dielectric is important for the wakefield acceleration (WFA) technique and other problems in the accelerator physics. One of subjects of investigation in this area consists in analysis of transition radiation generated by the bunch flying into (out of) the dielectric structure. This radiation can be both destructive (for WFA) and useful (for diagnostics of bunch or material). We investigate the total field of small bunch crossing a boundary between two dielectrics in the waveguide. It includes a “forced” field and a “free” one. The “forced” field is the field of the charge in the unbounded waveguide (it can contain the wakefield). The “free” field is connected with influence of the boundary (it includes transition radiation). Two cases are analyzed in detail: the bunch flies from vacuum into dielectric and from dielectric into vacuum. The behavior of the field depending on distance and time is explored analytically and numerically. Some interesting physical effects are noted. As well, we make a comparison with the case of intersection between vacuum and cold plasma.

WEPZ014

Upgrade of the Argonne Wakefield Accelerator Facility (AWA): Commissioning of the RF Gun and Linac Structures for Drive Beam Generation

wakefield, gun, electron, linac

2799

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

Funding: Work supported by the U.S. Department of Energy under contract No. DE-AC02-06CH11357.
Research at the AWA Facility has been focused on the development of electron beam driven wakefield structures. Accelerating gradients of up to 100 MV/m have been excited in dielectric loaded cylindrical structures operating in the microwave range of frequencies. Several upgrades, presently underway, will enable the facility to explore higher accelerating gradients, and also be able to generate longer RF pulses of higher intensity. The major items included in the upgrade are: (a) a new RF gun with a higher quantum efficiency photocathode will replace the RF gun that has been used to generate the drive bunches; (b) the existing RF gun will be used to generate a witness beam to probe the wakefields; (c) three new L-band RF power stations, each providing 25 MW, will be added to the facility; (d) five linac structures will be added to the drive beamline, bringing the beam energy up from 15 MeV to 75 MeV. The upgraded drive beam will consist of bunch trains of up to 32 bunches spaced by 0.77 ns with up to 100 nC per bunch. The goal of future experiments is to reach accelerating gradients of several hundred MV/m and to extract RF pulses with GW power level.

WEPZ015

Staging in Two Beam Dielectric Wakefield Accelerators

cavity, wakefield, kicker, septum

2802

J.G. Power, M.E. Conde, W. Gai, C.-J. Jing
ANL, Argonne, USA

Funding: The work is supported by the U.S. Department of Energy under Contract No. DE-AC02-06CH11357 with Argonne National Laboratory.
A new experimental program to demonstrate staging in a two beam dielectric wakefield accelerator (DWA) is being planned at the Argonne Wakefield Accelerator facility. DWA uses a drive beam to generate acceleration fields to accelerate a main beam and is one of the most promising advanced acceleration methods being pursued for a future high-energy physics linear collider. Staging is the ability to use two accelerating modules back to back to accelerate a charged particle bunch and it is one of basic requirements of any acceleration method. In this paper, a new beamline design consisting of a fast kicker to pick pulses from the drive bunch train and deliver them to the individual acceleration modules will be presented.

WEPZ023

Results from Plasma Wakefield Acceleration Experiments at FACET

plasma, wakefield, electron, diagnostics

2814

S.Z. Li, C.I. Clarke, R.J. England, J.T. Frederico, S.J. Gessner, M.J. Hogan, R.K. Jobe, M.D. Litos, D.R. Walz
SLAC, Menlo Park, California, USA
E. Adli
University of Oslo, Oslo, Norway
W. An, C.E. Clayton, C. Joshi, W. Lu, K.A. Marsh, W.B. Mori, S. Tochitsky
UCLA, Los Angeles, California, USA
P. Muggli
USC, Los Angeles, California, USA

Funding: Work supported by the U.S. Department of Energy under contract number DE- AC02-76SF00515.
We report initial results of the Plasma Wakefield Acceleration (PWFA) Experiments performed at FACET - Facility for Advanced aCcelertor Experimental Tests at SLAC National Accelerator Laboratory. At FACET a 23 GeV electron beam with 1.8x10¹0 electrons is compressed to 20 microns longitudinally and focused down to 10 microns x 10 microns transverse spot size for user driven experiments. Construction of the FACET facility completed in May 2011 with a first run of user assisted commissioning throughout the summer. The first PWFA experiments will use single electron bunches combined with a high density lithium plasma to produce accelerating gradients >10GeV/m benchmarking the FACET beam and the newly installed experimental hardware. Future plans for further study of plasma wakefield acceleration will be reviewed.

WEPZ030

Study on a Gas-filled Capillary Waveguide for Laser Wakefield Acceleration

simulation, laser, electron, plasma

2829

M.S. Kim, D. Jang, D. Jang, H. Suk
APRI-GIST, Gwangju, Republic of Korea

In gas-filled capillary waveguide for lase wakefield accelerators the gas flows through the two gas feed lines used to sustain constant pressure. Compared to the supersonic gas-jet system operated under high pressure, the gas at low pressure (<1atm) is injected inside capillary waveguide, so that this waveguide has experimental limit to the measurement of the neutral density. In order to investigate the gas pressure in capillary system we used computational fluid dynamics (CFD) simulation. In this paper, we presented the gas pressure changed by a variety of parameters, such as length and sizes of gas feed lines, and the method to decrease the turbulence effect at the ends of capillary.

WEPZ031

Accelerator Studies on a Possible Experiment on Proton-driven Plasma Wakefields at CERN

plasma, proton, electron, laser

2832

R.W. Assmann, I. Efthymiopoulos, S.D. Fartoukh, G. Geschonke, B. Goddard, C. Heßler, S. Hillenbrand, M. Meddahi, S. Roesler, F. Zimmermann
CERN, Geneva, Switzerland
A. Caldwell, G.X. Xia
MPI-P, München, Germany
P. Muggli
MPI, Muenchen, Germany

There has been a proposal by Caldwell et al to use proton beams as drivers for high energy linear colliders. An experimental test with CERN's proton beams is being studied. Such a test requires a transfer line for transporting the beam to the experiment, a focusing section for beam delivery into the plasma, the plasma cell and a downstream beam section for measuring the effects from the plasma and safe disposal of the beam. The work done at CERN towards the conceptual layout and design of such a test area is presented. A possible development of such a test area into a CERN test facility for high-gradient acceleration experiments is discussed.

WEPZ032

Energy Spectrometer Studies for Proton-driven Plasma Acceleration

plasma, proton, electron, simulation

2835

S. Hillenbrand, R.W. Assmann, F. Zimmermann
CERN, Geneva, Switzerland
S. Hillenbrand, A.-S. Müller
KIT, Karlsruhe, Germany
T. Tückmantel
HHUD, Dusseldorf, Germany

Plasma-based acceleration methods have seen important progress over the last years. Recently, it has been proposed to experimentally study plasma acceleration driven by proton beams, in addition to the established research directions of electron and laser driven plasmas. Here, we present the planned experiment with a focus on the energy spectrometer studies carried out.

THPC142

Burst Pulse Superimposed Electron Beam Acceleration in LEBRA FEL Linac

electron, FEL, linac, gun

3218

T. Tanaka, K. Hayakawa, Y. Hayakawa, M. Inagaki, K. Nakao, K. Nogami, N. Sato
LEBRA, Funabashi, Japan
S. Aizawa, Y. Arisumi, K. Shinohara
Nihon Koshuha Co. Ltd, Yokohama, Japan
I. Sato
Nihon University, Advanced Research Institute for the Sciences and Humanities, Funabashi, Japan

The electron beam for free electron laser (FEL) at the Laboratory for Electron Beam Research and Application (LEBRA) in Nihon University had been extracted from a conventional DC triode electron gun system. In conjunction with the renewal of the gun high voltage terminal a Kentech high-speed grid pulser was installed in addition to the conventional grid pulser. The 89.25MHz sine wave frequency-divided from the 2856MHz accelerating RF has been applied to the high-speed grid pulser, generating 64 or 128 frequency-divided grid pulses synchronous with the round-trip time in the FEL optical resonator. The high-speed grid pulses have been applied to the EIMAC Y646B cathode simultaneously with the conventional macropulse through the pulse coupling strip-line circuit; the resultant beam has been the short pulse beam superimposed on the macropulse beam. By reducing the macropulse voltage, only the train of the burst beam with 0.6ns width has been extracted. The peak burst beam current roughly 6 times higher than the conventional macropulse beam has been obtained with the Farady cup at the end of the FEL beamline. The FEL lasing experiment with the burst beam is underway.

THPS013

Radiation Pressure Acceleration of Multi-ion Thin Foil

ion, laser, proton, target

3448

T.-C. Liu, G. Dudnikova, M.Q. He, C.-S. Liu, R.Z. Sagdeev, X. Shao, J.-J. Su
UMD, College Park, Maryland, USA

Radiation pressure acceleration (RPA) is considered as an efficient way to produce quasi-monoenergetic ions, in which an ultra-thin foil is accelerated by high intensity circularly polarized laser. Our simulation study shows that an important factor limiting this acceleration process is the Rayleigh-Taylor instability, which results in the exponential growth of the foil density perturbation during the acceleration and hence the induced transparency of the foil and broadening of the particle energy spectrum. We will study RPA of multi-ion thin foil made of carbon and hydrogen and investigate the possibility of using abundant electrons supplied from carbon to delay the foil from becoming transparent, enhance the acceleration of protons and therefore improve the energy of quasi-monoenergetic proton beam. We will show the dependence of the energy of quasi-monoenergetic proton and carbon beam on the density and concentration ratio of carbon and hydrogen in the foil as well as foil thickness for RPA.

THPS014

Laser Thin Gas Target Acceleration for Quasi-monoenergetic Proton Generation

laser, ion, target, proton

3451

M.Q. He, G. Dudnikova, C.-S. Liu, T.-C. Liu, R.Z. Sagdeev, X. Shao, J.-J. Su
UMD, College Park, Maryland, USA
Z.M. Sheng
Shanghai Jiao Tong University, Shanghai, People's Republic of China

We propose a scheme of laser thin gas target acceleration for quasi-monoenergetic proton generation. The scheme uses gas target of thickness about several laser wavelengths with gas density spatial distribution of Guassian or square of sine shape. We performed Particle-In-Cell simulation using circularly polarized laser of normalized maximum amplitude ~5 and hydrogen gas target of thickness ~5 laser wavelength with peak density three times of the critical density. The simulation demonstrates several key physical processes involved in the laser thin gas target acceleration and the observation of quasi-monoenergetic protons. During the early phase of the laser plasma interaction, electron and ion cavities are observed. A compressed plasma layer is formed. The reflected protons in front of the compressed layer are accelerated and thus a bunch of quasi-monoenergetic protons are obtained. The compressed layer is finally destroyed due to Rayleigh-Taylor instability. The acceleration of the quasi-monoenergetic proton then stops with maximum energy about 8 MeV. It is also found that gas target thickness plays an important role for efficient quasi-monoenergetic proton generation.

THPS016

Rare Ion Beam (RIB) Facility at VECC : Present and Future

cavity, ion, rfq, ion-source

3454

R.K. Bhandari, A. Bandyopadhyay, A. Chakrabarti, V. Naik
DAE/VECC, Calcutta, India

Funding: This project if funded by Department of Atomic Energy, Government of India.
An ISOL post accelerator type Rare Ion Beam (RIB) Facility is being developed at our centre. The RIBs will be produced by using light ion induced fusion evaporation and by using photo-fission reaction, using a 50 MeV 2mA SC electron linac that is being developed in collaboration with TRIUMF, Canada. The primary reaction products will be ionized using two-ion source charge breeder. The possibility of feeding the primary reaction products directly to an ECR ion source using multi-stage skimmer and gas jet transport technique is being explored at present. An extended rod type heavy ion RFQ, one buncher and three IH cavities have been successfully accelerated stable beams up to about 415 keV/u. Three more IH cavities will increase the energy to about 1.3 MeV/u and SC QWRs will augment the energy thereafter. In the next stage of development, an Advanced National Facility for Unstable & Rare Isotope Beams (ANURIB) has been envisaged. This green field project will deliver stable & RIBs from 1.5 keV/u to 100 MeV/u. This will have both ISOL type and PFS type facility. Neutron & positron beams based facilities will also be built around the e^- linac.

THPS020

Development of C⁶⁺ Laser Ion Source

ion, laser, target, ion-source

3460

A. Yamaguchi
Toshiba Corporation, Power And Industrial Systems Research and Development Center, Yokohama, Japan

A C⁶⁺ laser ion source has been developed for a heavy ion accelerator, which supplies pulsed ion beam for single-turn injection system of a synchrotron by one laser shot. A graphite plate is irradiated with a Q-switched Nd:YAG laser (10⁶⁴ nm of wavelength, 1.4 J of maximum laser energy, 10 ns of pulse duration) to generate carbon ions. The characteristics of the ion beam were studied by using the time-of-flight mass spectroscopy and the magnetic momentum analyzer. Results of the experiments are presented.

THPS087

Engineering Prototype for a Compact Medical Dielectric Wall Accelerator

rfq, proton, kicker, laser

3636

A. Zografos, T. Brown, A. Hening, V. Joshkin, K. Leung, Y.K. Parker, H.T. Pearce-Percy, D. Pearson, M. Rougieri, J. Weir
CPAC, Livermore, CA, USA
R. Becker
SSS, Gelnhausen, Germany
D.T. Blackfield, G.J. Caporaso, Y.-J. Chen, S. Falabella, G. Guethlein, S.A. Hawkins, S.D. Nelson, B. R. Poole, J.A. Watson
LLNL, Livermore, California, USA
R.W. Hamm
R&M Technical Enterprises, Pleasanton, California, USA

Funding: Prepared by LLNL under Contract DE-AC52-07NA27344.
The Compact Particle Accelerator Corporation has developed an architecture to produce pulsed proton bunches that will be suitable for proton treatment of cancers. Subsystems include a RFQ injection system with a pulsed kicker to select the desired proton bunches and a linear accelerator incorporating a High Gradient Insulator with stacked Blumleins to produce the required voltage. The Blumleins are switched with solid state laser driven optical switches that are an integral part of the Blumlein assemblies. Other subsystems include a laser, a fiber optic distribution system, an electrical charging system and beam diagnostics. An engineering prototype has been constructed and it has been fully characterized. Results obtained from the engineering prototype support the development of an extremely compact 150 MeV system capable of modulating energy, beam current and spot size on a shot to shot basis within the next two years. The paper will detail the construction of the engineering prototype and discuss experimental results. In addition, future development milestones and commercialization plans will also be discussed.

FRYCA01

Towards a World Without Nuclear Weapons: How can Scientists Help?

target, controls, status

3794

J. Duncan
UK Mission for Multilateral Arms Control & Disarmament, Cointrin, Geneva, Switzerland

The Nuclear Non-Proliferation Treaty could eventually result in a significant reduction - or even complete elimination - of nuclear weapons. Technologies from the accelerator field, such as transmutation of weapon-grade uranium and plutonium, alternative techniques for nuclear power generation, detection of fissile material and verification, will be very important for this effort. The present trend in modern diplomacy is to form unconventional alliances to make progress on challenging issues. Could an alliance between diplomats and scientists help to achieve the ultimate goal of reducing and eventually eliminating nuclear weapons?