IPAC2012 - List of Keywords (acceleration)

Paper	Title	Other Keywords	Page
MOOAB01	A Proton-driven Plasma Wakefield Accelerator Experiment with CERN SPS Bunches	plasma, proton, wakefield, electron	40
	P. Muggli MPI, Muenchen, Germany
	Funding: Presented for the PDPWFA collaboration. Existing relativistic proton (p⁺) bunches carry large amounts of energy (kJ) and are therefore attractive as drivers for plasma-based particle accelerators, such as the plasma wakefield accelerator or PWFA. However, short (~ps) p⁺ bunches capable of driving large amplitude (~GV/m) wakefields are not available today. It was recently proposed to use long (~300ps) p⁺ bunches self-modulated at the plasma wavelength by a transverse two-stream instability in a high-density (~10¹⁴-10¹⁵/cc) plasma to resonantly drive wakefields. Based on this idea and on the long term prospect for short p⁺ bunches a p⁺-driven PWFA experimental program was proposed to study the acceleration of electrons to the TeV energy range. Initial experiments will use the 450GeV, 1-3·10¹¹ p⁺ bunches from the CERN SPS and plasmas 5-10m in length. The wakefields will be sampled by an externally injected, low energy (10-20MeV) electron bunch that will gain energy in the GeV range. The experimental plan, as well as the expected results will be presented. N. Kumar et al., Phys. Rev. Lett. 104, 255003 (2010).
	Slides MOOAB01 [19.595 MB]

MOOAB02	First Results from the Electron Hose Instability Studies in FACET	plasma, electron, wakefield, status	43
	E. Adli University of Oslo, Oslo, Norway W. An, C.E. Clayton, C. Joshi, K.A. Marsh, W.B. Mori, N. Vafaei-Najafabadi UCLA, Los Angeles, California, USA S. Corde, R.J. England, J.T. Frederico, S.J. Gessner, M.J. Hogan, S.Z. Li, M.D. Litos, Z. Wu SLAC, Menlo Park, California, USA W. Lu TUB, Beijing, People's Republic of China P. Muggli MPI, Muenchen, Germany
	Funding: This work is supported by the Research Council of Norway and U.S. Department of Energy under contract number DE-AC02-76SF00515. We present the first results from experimental studies of the electron hose instability in the plasma-wakefield acceleration experiments at FACET. Theory and PIC simulations of an electron beam as it travels through a plasma indicate that hosing may lead to a significant distortion of the transverse phase space. The FACET dump line is equipped with a Cherenkov light based spectrometer which can resolve transverse motion as a function of beam energy. We compare the predictions from simulations and theory to the experimental results obtained.
	Slides MOOAB02 [4.654 MB]

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

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

MOPPC025	RHIC Polarized Proton Operation in Run 12	polarization, luminosity, proton, emittance	184
	V. Schoefer, L. A. Ahrens, A. Anders, E.C. Aschenauer, G. Atoian, M. Bai, J. Beebe-Wang, M. Blaskiewicz, J.M. Brennan, K.A. Brown, D. Bruno, R. Connolly, T. D'Ottavio, A. Dion, K.A. Drees, W. Fischer, C.J. Gardner, J.W. Glenn, X. Gu, M. Harvey, T. Hayes, L.T. Hoff, H. Huang, R.L. Hulsart, A. Kirleis, J.S. Laster, C. Liu, Y. Luo, Y. Makdisi, G.J. Marr, A. Marusic, F. Méot, K. Mernick, R.J. Michnoff, M.G. Minty, C. Montag, J. Morris, S. Nemesure, A. Poblaguev, V. Ptitsyn, V.H. Ranjbar, G. Robert-Demolaize, T. Roser, W.B. Schmidke, F. Severino, D. Smirnov, K.S. Smith, D. Steski, S. Tepikian, D. Trbojevic, N. Tsoupas, J.E. Tuozzolo, G. Wang, M. Wilinski, K. Yip, A. Zaltsman, A. Zelenski, K. Zeno, S.Y. Zhang BNL, Upton, Long Island, New York, USA
	Successful RHIC operation with polarized protons requires meeting demanding and sometimes competing goals for maximizing both luminosity and beam polarization. In Run 12 we sought to fully integrate into operation the many systems that were newly commissioned in Run 11 as well as to enhance collider performance with incremental improvements throughout the acceleration cycle. For luminosity maximization special attention was paid to several possible source of emittance dilution along the injector chain, in particular to optical matching during transfer between accelerators. Possible sources of depolarization in the AGS and RHIC were also investigated including the effects of local coupling and low frequency (10 Hz) oscillations in the vertical equilibrium orbit during the RHIC ramp. The results of a fine storage energy scan made in an effort to improve store polarization lifetime are also reported in this note.

MOPPC049	Status of the Non-scaling Fixed Field Alternating Gradient Ring Design for the International Design Study of the Neutrino Factory	factory, septum, lattice, electron	241
	J.S. Berg, H. Witte BNL, Upton, Long Island, New York, USA M. Aslaninejad, J. Pasternak Imperial College of Science and Technology, Department of Physics, London, United Kingdom N. Bliss, A.J. Moss STFC/DL, Daresbury, Warrington, Cheshire, United Kingdom D.J. Kelliher, S. Machida STFC/RAL/ASTeC, Chilton, Didcot, Oxon, United Kingdom S.M. Pattalwar STFC/DL/ASTeC, Daresbury, Warrington, Cheshire, United Kingdom
	Funding: This manuscript has been authored by employees of Brookhaven Science Associates, LLC under Contract No. DE-AC02-98CH10886 with the U.S. Department of Energy. The International Design Study of the Neutrino Factory is working towards delivering the optimized design of the neutrino factory facility to be presented in the Reference Design Report (RDR) in 2013. In the current baseline design a linear non-scaling fixed field alternating gradient accelerator (FFAG) was chosen as an efficient solution for the final muon acceleration. We describe updates to the design since our previous report. We report on beam dynamics studies on the lattice. We describe recent work on the engineering for the lattice, and the results of a recent first pass at a cost estimate for the machine. Finally, we describe how an FFAG may be applicable to a lower energy neutrino factory in light of recent experimental results regarding the value of the theta(13) neutrino mixing angle. J. S. Berg et al., in Proceedings of IPAC2011, San Sebastian, Spain, 832. ** F. P. An et al., Phys. Rev. Lett. 10⁸, 171803 (2012); J. K. Ahn et al., arXiv:1204.0626v2 [hep-ex] (2012).

MOPPC050	The International Design Study for the Neutrino Factory	factory, lattice, target, proton	244
	K.R. Long, J.K. Pozimski Imperial College of Science and Technology, Department of Physics, London, United Kingdom J.S. Berg BNL, Upton, Long Island, New York, USA
	A neutrino factory is a facility for producing a large neutrino flux from the decay of high energy muons. The International Design Study for the Neutrino Factory (IDS-NF) aims to produce a reference design report for such a facility. The report will contain the physics motivation for the facility, describe the accelerator and detector, and estimate the cost for the facility. We will briefly discuss the physics capabilities for a neutrino factory, including how recent neutrino physics results affect our understanding of a neutrino factory's performance and advantages. We will give an overview of our baseline design for the accelerator facility. We will then outline the most significant areas of progress in our studies of the accelerator subsystems. Paper submitted on behalf of the International Design Study for the Neutrino Factory collaboration.

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

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

MOPPC069	Quantitative Simulation of NIRS-930 Cyclotron	cyclotron, extraction, simulation, electromagnetic-fields	292
	V.L. Smirnov, S.B. Vorozhtsov JINR/DLNP, Dubna, Moscow region, Russia A. Goto, S. Hojo, T. Honma, K. Katagiri NIRS, Chiba-shi, Japan
	The results of the computer modelling of the structural elements of the NIRS-930 cyclotron operational at the National Institute of Radiological Sciences (Chiba, Japan) are presented. The integrated approach to modelling of the cyclotron, including calculation of electromagnetic fields of the structural elements and beam dynamics simulations is described. A computer model of the cyclotron was constructed. Electric and magnetic field distributions and mechanical structures were converted to the beam dynamics code for simulations, in which particle losses on the surfaces of the system elements were estimated. The existing data on the axial injection, magnetic, acceleration and extraction systems of the cyclotron and beam parameter measurements are used for calibration of the simulations. New acceleration regimes could be formulated with the help of the constructed computer model of the machine.

MOPPC080	Modeling Space Charge in an FFAG with Zgoubi	space-charge, lattice, emittance, synchrotron	322
	S.C. Tygier, R. Appleby, H.L. Owen UMAN, Manchester, United Kingdom R.J. Barlow University of Huddersfield, Huddersfield, United Kingdom
	The Zgoubi particle tracker uses a ray tracing algorithm that can accurately track particles with large offset from any reference momentum and trajectory, making it suitable for FFAGs. In high current FFAGs, for example an ADSR driver, space charge has a significant effect on the beam. A transverse space charge model was added to Zgoubi using the interface pyZgoubi. The magnets are sliced and a space charge kick is applied between each slice. Results are presented for an ADSR driver lattice.

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

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

MOPPD018	A FFAG Design Study for an Accelerator-driven System	proton, synchrotron, resonance, focusing	403
	T.-Y. Lee, H.-S. Kang, H.-S. Lee PAL, Pohang, Kyungbuk, Republic of Korea
	Design of a 1 GeV FFAG accelerator is studied for the accelerator-driven sub-critical nuclear reactor system. Scaling and non-scaling lattices are studied and compared with each other. Corresponding magnet design and RF system are considered.

MOPPD021	An Experimental Investigation of Slow Integer Tune Crossing in the EMMA Non-scaling FFAG	resonance, simulation, closed-orbit, proton	412
	J.M. Garland, H.L. Owen UMAN, Manchester, United Kingdom D.J. Kelliher, S. Machida STFC/RAL/ASTeC, Chilton, Didcot, Oxon, United Kingdom B.D. Muratori STFC/DL/ASTeC, Daresbury, Warrington, Cheshire, United Kingdom
	Funding: Student STFC grant number: ST/G004277/1. Results are presented from a slow integer tune crossing experiment performed in the EMMA accelerator. Under nominal conditions EMMA accelerates an electron beam from 10–20 MeV rapidly in 5–10 turns in a novel “serpentine” channel causing several transverse integer tunes to be crossed. During this rapid acceleration it has been shown that the betatron amplitude of the beam does not grow. If the potential of non-scaling FFAGs were to be realized in such fields as high-current proton acceleration then tune space would be crossed slower with acceleration in an RF bucket. The crossing speed in a non-scaling FFAG is in a previously unstudied intermediate region and hence conventional crossing theory may not apply. It was proposed to observe the effects on betatron amplitude when a beam crosses integer tunes by the variation of tune with momentum over a range of crossing speeds derived from different acceleration rates. This method can be realized by synchrotron acceleration inside a stable RF bucket. Betatron amplitude growth and beam loss as a function of turn are explored when crossing an integer tune and a relationship between crossing speed and these quantities is established.

MOPPP012	Experimental Observation of Energy Modulation in Electron Beams Passing through Terahertz Dielectric Wakefield Structures	wakefield, bunching, radiation, FEL	595
	S.P. Antipov, C.-J. Jing, A. Kanareykin, P. Schoessow Euclid TechLabs, LLC, Solon, Ohio, USA M.G. Fedurin, K. Kusche, V. Yakimenko BNL, Upton, Long Island, New York, USA W. Gai, A. Zholents ANL, Argonne, USA B.C. Jiang SINAP, Shanghai, People's Republic of China
	Funding: DOE SBIR. We report observation of a strong wakefield induced energy modulation in an energy-chirped electron bunch passing through a terahertz dielectric-lined waveguide. This modulation can be effectively converted into a spatial modulation by means of a chicane, forming micro-bunches (density modulation) with a periodicity of 0.5 - 1 picosecond, hence capable of driving coherent THz radiation. The experimental results agree well with theoretical predictions.

MOPPP022	ALICE: Status, Developments and Scientific Programme	FEL, gun, radiation, cryomodule	613
	Y.M. Saveliev STFC/DL/ASTeC, Daresbury, Warrington, Cheshire, United Kingdom
	ALICE (Accelerators and Lasers In Combined Experiments) is a multifunctional ERL based R&D facility that operates in various regimes, both energy recovery and non energy recovery, depending on the project undertaken (beam energy 10-28MeV, bunch charge 20-100pC, train length from a single bunch to 100us). In early 2012, the DC HV photoinjector gun is expected to begin operation at nominal 350kV and a new cryomodule, a result of a wide international collaboration, will be installed and commissioned on ALICE. The improvements in beam dynamics and the overall beam quality will be discussed in this paper. The overview of the ALICE scientific programme including IR-FEL lasing and its application for scanning near field optical microscopy, generation and applications of coherent broadband THz radiation for life sciences and solid state physics, studies of the first non-scaling FFAG EMMA for which ALICE serves as an injector and accelerator physics research will also be presented.

MOPPR009	Dynamic Closed Orbit Correction During the Fast Energy Ramp of ELSA	closed-orbit, polarization, electron, controls	789
	J.-P. Thiry, A. Balling, A. Dieckmann, F. Frommberger, W. Hillert ELSA, Bonn, Germany
	ELSA is a fast ramping stretcher ring supplying polarized electrons to hadron physics experiments. To preserve the degreee of polarization, it is necessary to continuously correct the vertical orbit when accelerating the beam from 1.2 GeV to 2.4 GeV. Acceleration is performed within 300 ms, thus with a ramping speed of 4 GeV/s. During the acceleration, beam positions are measured at a rate of 1 kHz using 32 beam position monitors, which are mounted close to the quadrupole magnets. The demanding task is to achieve a vertical rms deviation not exceeding 50 μm all along the fast energy ramp. Therefore, dynamic orbit corrections are applied by means of offline feed-forward techniques, driving 32 vertical steerer magnets which can change currents in less than 10 ms. In our contribution, we show the used concepts and the implementation of the precise closed orbit correction system at ELSA.

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

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

TUYB02	Manufacture and Testing of Optical-scale Accelerator Structures from Silicon and Silica	laser, electron, coupling, vacuum	1050
	R.J. England, E.R. Colby, R. Laouar, C. McGuinness, B. Montazeri, R.J. Noble, K. Soong, J.E. Spencer, D.R. Walz, Z. Wu SLAC, Menlo Park, California, USA R.L. Byer, C.M. Chang, K.J. Leedle, E.A. Peralta Stanford University, Stanford, California, USA B.M. Cowan Tech-X, Boulder, Colorado, USA M. Qi Purdue University, West Lafayette, Indiana, USA
	We report on recent progress in the design, manufacture and testing of optical-scale accelerator structures made from silicon and silica. The potential of these structures for the development of extremely compact, efficient, and low cost accelerators producing attosecond electron pulses will be discussed, together with various possible applications.
	Slides TUYB02 [17.226 MB]

TUYB03	FFAG Experience and Future Prospects	proton, focusing, betatron, lattice	1054
	Y. Mori Kyoto University, Research Reactor Institute, Osaka, Japan
	This talk should outline the various FFAG accelerators that have been constructed, and discuss the operational experience with different machines. Common issues should be identified, and contrasting experiences highlighted. A frank assessment of the capability of FFAGs to meet the requirements for applications such as ion therapy, accelerator-driven subcritical reactors, and muon colliders should be followed by a description of the main objectives and challenges for future R&D.
	Slides TUYB03 [14.162 MB]

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

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

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

TUPPC040	Model Calibration and Optics Correction Using Orbit Response Matrix in the Fermilab Booster	booster, optics, dipole, coupling	1251
	M.J. McAteer, S.E. Kopp The University of Texas at Austin, Austin, Texas, USA V.A. Lebedev, E. Prebys Fermilab, Batavia, USA A.V. Petrenko BINP SB RAS, Novosibirsk, Russia
	A beam-based method of optical model calibration using the measured orbit response matrix, known as the LOCO method, was successfully applied to Fermilab's rapid-cycling Booster synchrotron. Orbit responses were measured by individually changing the strength of each dipole corrector throughout the acceleration cycle, and dispersion was measured by changing the beam's radial offset. The model calibration procedure revealed large calibration errors for all elements in the Booster's recently-installed multipole corrector packages and beam position monitors. The resulting model was used to correct coupling and beta beating.

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

TUPPC054	Beam Acceleration by a Multicell RF Cavity Structure Proposed for Improved Yield in Hydroforming	cavity, electron, quadrupole, focusing	1293
	J.A. Holmes, Y.W. Kang ORNL, Oak Ridge, Tennessee, USA A.E. Fathy, K.R. Shin University of Tennessee, Knoxville, Tennessee, USA
	Funding: ORNL is managed by UT-Battelle, LLC, under contract DE-AC05-00OR22725 for the U.S. Department of Energy. We study the accelerating properties of a new multicell cavity structure with irises forming a rectangular aperture between the cavity cells. We are interested in this structure because, from a mechanical point of view, the rectangular iris may make possible a much improved structure quality using a hydroforming manufacturing process. RF analysis shows that the rectangular iris shape provides asymmetric transverse focusing per half RF period. If the horizontal and vertical rectangular irises are interleaved, the net transverse focusing can be increased. The present studies of the acceleration and transport properties of these cavities are conducted by tracking particles through time-dependent 3D cavity fields from CST MWS using the ORBIT Code.

TUPPD013	Bunch Coalescing in a Helical Channel	collider, emittance, simulation, factory	1434
	C. Y. Yoshikawa, C.M. Ankenbrandt Muons, Inc, Batavia, USA D.V. Neuffer, K. Yonehara Fermilab, Batavia, USA
	Funding: Supported in part by SBIR Grant 4725 · 09SC02739. A high-luminosity Muon Collider requires bunch recombination for optimal luminosity. In this paper, we take advantage of the large slip factor in a helical transport channel (HTC) to coalesce bunches of muons into a single one over a shorter distance than can be achieved over a straight channel. The coalescing subsystem that is designed to merge 9 bunches has a horizontal length of ~105m and is able to achieve efficiencies of 99.7%, 98.4%, and 94.2% for 9, 11, and 13 bunches, respectively, where each bunch has emittances expected at the end of an HCC. Simplified designs incorporating fill factors for RF cavities of ~25% and ~50% obtained efficiencies of 96%, 94-95%, and 90-91% for 9, 11, and 13 bunches, respectively. The efficiencies above do not include decay losses, which would be ~8% for muons with kinetic energy of 200 MeV.

TUPPD071	Development of Cesium Telluride Photocathodes for the AWA Accelerator Upgrade	wakefield, vacuum, electron, cathode	1569
	Z.M. Yusof, M.E. Conde, W. Gai ANL, Argonne, USA L.K. Spentzouris, E.E. Wisniewski Illinois Institute of Technology, Chicago, Illinois, USA
	Funding: U.S. Department of Energy Office of Science under Contract No. DE-AC02-06CH11357. Cesium telluride photocathodes have been fabricated for the Argonne Wakefield Accelerator (AWA) upgrade. The as-deposited photocathodes have consistently produced quantum efficiency values better than 10% with 254 nm light source and with variation of less than 5% over a circular area of 1.2 inches in diameter. We present various characterizations of the photocathode that have performed, including rejuvenation, lifetime, and performance in the L-band AWA photoinjector.

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

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

WEOAB01	New Results from the EMMA Experiment	injection, resonance, betatron, electron	2134
	B.D. Muratori, J.K. Jones STFC/DL/ASTeC, Daresbury, Warrington, Cheshire, United Kingdom C.S. Edmonds, K.M. Hock, M.G. Ibison, I.W. Kirkman The University of Liverpool, Liverpool, United Kingdom J.M. Garland, H.L. Owen UMAN, Manchester, United Kingdom D.J. Kelliher, S. Machida STFC/RAL/ASTeC, Chilton, Didcot, Oxon, United Kingdom J. Pasternak Imperial College of Science and Technology, Department of Physics, London, United Kingdom
	EMMA (Electron Model for Many Applications) is a prototype non-scaling electron FFAG hosted at Daresbury Laboratory. After demonstration of acceleration in the serpentine channel in April 2011, the beam study with EMMA continues to explore the large transverse and longitudinal acceptance and effects of integer tune crossing with slower rate on the betatron amplitude. Together with a comparison of detailed models based on measured field maps and the experimental mapping of the machine by relating the initial and final phase space coordinates. These recent results together with more practical improvements such as injection orbit matching with real-time monitoring of the coordinates in the transverse phase space will be reported in this paper.
	Slides WEOAB01 [2.120 MB]

WEIC06	Accelerator R&D: Research for Science - Science for Society	laser, hadron, proton, emittance	2161
	N.R. Holtkamp SLAC, Menlo Park, California, USA S. Biedron, S.V. Milton CSU, Fort Collins, Colorado, USA L. Boeh, J.E. Clayton, G. Zdasiuk VMS GTC, Palo Alto, California, USA S.A. Gourlay, M.S. Zisman LBNL, Berkeley, California, USA R.W. Hamm R&M Technical Enterprises, Pleasanton, California, USA S. Henderson Fermilab, Batavia, USA G.H. Hoffstaetter CLASSE, Ithaca, New York, USA L. Merminga TRIUMF, Canada's National Laboratory for Particle and Nuclear Physics, Vancouver, Canada S. Ozaki BNL, Upton, Long Island, New York, USA F.C. Pilat JLAB, Newport News, Virginia, USA M. White ANL, Argonne, USA
	In September 2011 the US Senate Appropriations Committee requested a ten-year strategic plan from the Department of Energy (DOE) that would describe how accelerator R&D today could advance applications directly relevant to society. Based on the 2009 workshop "Accelerators for America’s Future" an assessment was made on how accelerator technology developed by the nation’s laboratories and universities could directly translate into a competitive strength for industrial partners and a variety of government agencies in the research, defense and national security sectors. The Office of High Energy Physics, traditionally the steward for advanced accelerator R&D within DOE, commissioned a task force under its auspices to generate and compile ideas on how best to implement strategies that would help fulfill the needs of industry and other agencies, while maintaining focus on its core mission of fundamental science investigation.
	Slides WEIC06 [3.678 MB]

WEEPPB001	Progress Toward a High-Transformer-Ratio Dielectric Wakefield Experiment at FLASH	electron, wakefield, laser, simulation	2166
	F. Lemery, D. Mihalcea, P. Piot Northern Illinois University, DeKalb, Illinois, USA J. Osterhoff MPQ, Garching, Munich, Germany C.A.J. Palmer DESY, Hamburg, Germany P. Stoltz Tech-X, Boulder, Colorado, USA
	Funding: Work supported by the U.S. Department of Energy, Office of Science, Office of Basic Energy Sciences, under Contract No. DE-AC02-06CH11357 Dielectric wakefield accelerators offer many advantages over conventional RF accelerators such as higher acceleration gradients and cost effectiveness. In this paper we describe our experimental plans to demonstrate enhanced transformer ratios with drive and witness bunches. The experiment, will be performed at the Free-electron LASer in Hamburg (FLASH) and utilizes unique pulse shaping capabilities using the dual-frequency superconducting linac to produce high transformer ratios (>2). The beam-driven acceleration mechanism will be based on a cylindrical-symmetric dielectric-lined waveguide (DLW). The experimental setup is described, and start-to-end numerical simulations of the experiment will be presented.

WEEPPB002	Plasma Acceleration Experiment at SPARC_LAB with External Injection	plasma, electron, laser, injection	2169
	L. Serafini, A. Bacci Istituto Nazionale di Fisica Nucleare, Milano, Italy M. Bellaveglia, M. Castellano, E. Chiadroni, G. Di Pirro, M. Ferrario, A. Gallo, G. Gatti, A.R. Rossi, C. Vaccarezza INFN/LNF, Frascati (Roma), Italy A. Cianchi Università di Roma II Tor Vergata, Roma, Italy C. Maroli, V. Petrillo Universita' degli Studi di Milano, Milano, Italy A. Mostacci URLS, Rome, Italy P. Tomassini Università degli Studi di Milano, Milano, Italy
	At the SPARC-LAB facility of INFN-LNF we are installing two transport lines for ultra-short electron bunches and an ultra-intense laser pulses, generated by the SPARC photo-injector and by the FLAME laser in a synchronized fashion at the tens of fs level, to co-propagate inside a hydrogen filled glass capillary, in order to perform acceleration of the electron bunch by a plasma wave driven by the laser pulse. The main aim of this experiment is to demonstrate that a high brightness electron beam can be accelerated by a plasma wave without any significant degradation of its quality. A 10 pC electron bunch, 10 fs long is produced by SPARC and transported to injection into the capillary, which is 100 micron wide, at a gas density around 5*10¹⁷ ne/cm³ . The laser pulse, 25 fs long, focused down to 30 microns into the capillary is injected ahead of the bunch, drives a weakly non-linear plasma wave with wavelength of about 120 microns. A proper phasing of the two pulses allows acceleration of electrons from the injection energy of 150 MeV up to about 1 GeV for a 10 cm long capillary. Installation of the beam lines is foreseen by the end of 2012 and first tests starting in mid 2013.

WEEPPB003	Modeling of 10 GeV-1 TeV Laser-Plasma Accelerators Using Lorentz Boosted Simulations	laser, plasma, simulation, controls	2172
	J.-L. Vay, E. Esarey, C.G.R. Geddes, W. Leemans, C.B. Schroeder LBNL, Berkeley, California, USA E. Cormier-Michel Tech-X, Boulder, Colorado, USA D.P. Grote LLNL, Livermore, California, USA
	Funding: Supported by US-DOE Contracts DE-AC02-05CH11231 and DE-AC52-07NA27344, US-LHC program LARP, and US-DOE SciDAC program ComPASS. Modeling of laser-plasma wakefield accelerators in an optimal frame of reference [J.-L. Vay, Phys. Rev. Lett. 98 130405 (2007)] allows direct and efficient full-scale modeling of deeply depleted and beam loaded laser-plasma stages of 10 GeV-1 TeV (parameters not computationally accessible otherwise). This verifies the scaling of plasma accelerators to very high energies and accurately models the laser evolution and the accelerated electron beam transverse dynamics and energy spread. Over 4, 5 and 6 orders of magnitude speedup is achieved for the modeling of 10 GeV, 100 GeV and 1 TeV class stages, respectively. Agreement at the percentage level is demonstrated between simulations using different frames of reference for a 0.1 GeV class stage. Obtaining these speedups and levels of accuracy was permitted by solutions for handling data input (in particular particle and laser beams injection) and output in a relativistically boosted frame of reference, as well as mitigation of a high-frequency instability that otherwise limits effectiveness. Used resources of NERSC, supported by US-DOE Contract DE-AC02-05CH11231.

WEPPC027	A Quarter Wave Design for Crab Crossing in the LHC	cavity, HOM, high-voltage, higher-order-mode	2260
	R. Calaga CERN, Geneva, Switzerland S.A. Belomestnykh, I. Ben-Zvi, Q. Wu BNL, Upton, Long Island, New York, USA
	Funding: This work partially supported by the US Department of Energy through the US LHC Accelerator Research Program (LARP). The aperture constraints of the LHC interaction region and the alternating crossing schemes at two collision points calls for a superconducting deflecting cavity with very compact dimensions at low frequencies for the purpose of crab crossing. A new concept of using a superconducting 1/4-wave design, ideally suited to address the LHC constraints at 400 MHz, is proposed. The optimized RF cavity design and associated advantages of using a 1/4 wave resonator are presented. Aspects related to higher order mode damping, multipacting and frequency tuning are also addressed.

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

WEPPC047	Effects of the RF Field Asymmetry in SC Cavities of the Project X	linac, cavity, multipole, focusing	2318
	I.V. Gonin, M.H. Awida, P. Berrutti, A. Saini, B.G. Shteynas, N. Solyak, V.P. Yakovlev Fermilab, Batavia, USA P.N. Ostroumov ANL, Argonne, USA
	The low-energy SCRF section of CW SC linac of Project X starts from Half Wave Resonators (HWR) having operating frequency f=162.5 MHz, optimal β= 0.11 and will accelerate the beam from 2 MeV up to 11 MeV. The preliminary analysis of beam dynamics shows that multipole effects caused by asymmetry of RF fields in HWR cavities aren’t negligible. In this paper we present the analysis of influence of multipole effects on beam dynamics and discuss the possible solutions how to compensate these effects.

WEPPD016	Development of Glassy Carbon Blade for LHC Fast Vacuum Valve	vacuum, kicker, synchrotron, synchrotron-radiation	2528
	C. Garion, P. Coly CERN, Geneva, Switzerland
	An unexpected gas inrush in a vacuum chamber leads to the development of a fast pressure wave. It carries small particles that can compromise the functioning of sensitive machine systems such as the RF cavities or kickers. In the LHC machine, it has been proposed to protect these equipments by the installation of fast vacuum valves. The main requirements for the fast valves and in particular for the blade are: fast closure in the 20 ms range, high transparency and melting temperature in case of closure with beam in, dust free material to not contaminate sensitive adjacent elements and last but not least vacuum compatibility and adequate leak tightness across the blade. In this paper, a design based on a vitreous carbon blade is proposed. The main reasons for this material choice are given. The mechanical study of the blade behaviour under dynamic forces is shown. Fabrication considerations are addressed as well. Tests on prototypes have been carried out on pendulum type fast valves developed for LEP. Results on glassy carbon blades are presented as well as the motion parameter measurements. Qualification of the material for UHV applications has been carried out.

WEPPD045	An Application of Multi-stage Adjustable Shock Absorbers for the Girders of Storage Ring in Taiwan Photon Source	damping, controls, storage-ring, photon	2615
	C.-S. Lin, J.-R. Chen, M.L. Chen, H.C. Ho, K.H. Hsu, D.-G. Huang, C.K. Kuan, W.Y. Lai, C.J. Lin, H.M. Luo, S.Y. Perng, P.L. Sung, Y.L. Tsai, T.C. Tseng, H.S. Wang, M.H. Wu NSRRC, Hsinchu, Taiwan D.-Y. Chiang NCKU, Tainan city, Taiwan
	Beam stability is a major concern for the operation of the Taiwan Photon Source (TPS). One of the many factors to instability of electron beam is mechanical vibration of the accelerator components. The TPS uses steel girders to support the magnets and vacuum chambers in the storage ring. Three pedestal and six mover assemblies support the girders. Multi-stage adjustable shock absorbers are designed for passive vibration damping, and presently installed between the girders and the pedestals. Through adjusting the amount of hydraulic fluid which bypasses the damping passage between two hydraulic chambers, the desired damping coefficient of the damping absorbers can be achieved. Experimental results of modal testing presented in this paper show that the multi-stage adjustable damping absorbers under the assembly of the girders reduced the level of girder vibration.

WEPPD050	Upgrade of the RF Reference Distribution System for 400 MeV LINAC at J-PARC	linac, controls, klystron, injection	2630
	K. Futatsukawa, Z. Fang, Y. Fukui, T. Kobayashi, S. Michizono KEK, Ibaraki, Japan F. Sato, S. Shinozaki JAEA/J-PARC, Tokai-mura, Japan
	In J-PARC, the accelerator systems are controlled using the 12 MHz master clock in center control building. In the present J-PARC Linac, the negative hydrogen is accelerated by 181 MeV using the RFQ, DTLs, and SDTLs which have the resonance frequency of 324 MHz. The low-level radio frequency (LLRF) system is based on the reference signal of 312 MHz (LO) synchronized with the master clock. We are planning to upgrade Linac by the accelerated energy to 400 MeV by the installation of ACS cavities with the resonance frequency of 972 MHz. Then, not only 312 MHz but also 960 MHz reference signals are necessary. Therefore, a new RF reference signal oscillator was installed at J-PARC LINAC. The phase noise of the output signal in this module was measured by the signal source analyzer. The jitter of the output signal, which was estimated from the integration of phase noise from 10 Hz to 1 MHz, becomes about 40 fs and was two order smaller than that of the old system (about 1700 fs) by the installation of new oscillator and the optimization of the path of the master clock. It can be expected to improve the operating ratio in J-PARC LINAC.

WEPPD053	The LLNL/UCLA High Gradient Inverse Free Electron Laser Accelerator	electron, laser, undulator, simulation	2639
	J.T. Moody, P. Musumeci UCLA, Los Angeles, California, USA G.G. Anderson, S.G. Anderson, M. Betts, S.E. Fisher, D.J. Gibson, A.M. Tremaine, S.S.Q. Wu LLNL, Livermore, California, USA
	Funding: This work performed under the auspices of the U.S. Department of Energy by Lawrence Livermore National Laboratory under Contract DE-AC52-07NA27344. We describe the Inverse Free Electron Accelerator currently under construction at Lawrence Livermore National Lab. Upon completion of this accelerator, high brightness electrons generated in the photoinjector blowout regime and accelerated to 50 MeV by S-band accelerating sections will interact with > 4 TW peak power Ti:Sapphire laser in a highly tapered 50 cm undulator and experience an acceleration gradient of >200 MeV/m. We present the final design of the accelerator as well as the results of start to end simulations investigating preservation of beam quality and tolerances involved with this accelerator.

WEPPD059	Proton Acceleration by a Relativistic Laser Frequency-Chirp Driven Plasma Snowplow	laser, plasma, proton, electron	2654
	A. A. Sahai, T.C. Katsouleas Duke ECE, Durham, North Carolina, USA R. Bingham STFC/RAL/ASTeC, Chilton, Didcot, Oxon, United Kingdom W.B. Mori, A. Tableman, F.S. Tsung, M. Tzoufras UCLA, Los Angeles, California, USA
	Funding: NSF-PHY-0936278, NSF-PHY-0904039 and NSFPHY-0936266, US DOE DE-FC02-07ER41500 and DE-FG02-92ER40727, DOE Fusion Science Center through a University of Rochester Subcontract No. 415025-G. We analyze the use of a relativistic laser pulse with a controlled frequency chirp incident on a rising plasma density gradient to drive an acceleration structure for proton and light ion acceleration. The Chirp Induced Transparency Acceleration (ChITA) scheme is described with an analytical model of the velocity of the snowplow at critical density on a pre-formed rising plasma density gradient that is driven by positive chirp in the frequency of a relativistic laser pulse. The velocity of the ChITA-snowplow is shown to depend upon rate of rise of the frequency of the relativistic laser pulse, the normalized magnetic vector potential of the laser pulse and the plasma density gradient scale-length. We observe using 1-D OSIRIS simulations the formation and forward propagation of ChITA-snowplow, being continuously pushed by the chirping laser at a velocity in accordance with the analytical results. The trace protons reflect off of this propagating snowplow structure and accelerate monoenergetically. The control over ChITA-snowplow velocity allows the tuning of accelerated proton energies.

WEPPP003	Focusing of Accelerated Particles by Wakefields of a Drive Bunch in a Plasma-dielectric Waveguide	plasma, wakefield, electron, focusing	2723
	G.V. Sotnikov, R.R. Kniaziev NSC/KIPT, Kharkov, Ukraine
	Funding: The research is supported in part by the Science and Technology Center in Ukraine (STCU), project No. P522. One of wakefield acceleration methods as a slowing medium uses the plasma of a capillary discharge. The capillary tube is a slowing medium, therefore at propagation in it of a laser pulse or relativistic electron bunches (REB) along with plasma wakefields will be excited an eigen waves of dielectric structure. So far influence of electrodynamic properties of capillary tube material on plasma wakefields is not investigated. On an example of a cylindrical waveguide of gigahertz operation frequency range, we investigate excitation of wakefields by REB in a dielectric waveguide (DW) with the accelerating channel filled with isotropic plasma. The excited field consists of Langmuir wave fields (LW) and fields of eigen waves of DW. At certain plasma density a longitudinal electric field of LW it is significantly less than the similar of DW waves , and transverse components of the LW field are significantly higher than transverse component of DW waves. The periods of these two types of waves generally do not coincide. The range of plasma densities which provides a simultaneous acceleration and focusing of test bunch by LW is found. Steinhauer L.C., Kimura W.D. Phys. Rev. STAB. V.9, 081301 (2006).

WEPPP004	A Reciprocity Principle for Wakefields in a Two-Channel Coaxial Dielectric Structure	wakefield, vacuum, simulation, dipole	2726
	G.V. Sotnikov NSC/KIPT, Kharkov, Ukraine J.L. Hirshfield, T.C. Marshall, G.V. Sotnikov Omega-P, Inc., New Haven, USA S.V. Shchelkunov Yale University, Beam Physics Laboratory, New Haven, Connecticut, USA
	Funding: Research is supported by U.S. Department of Energy, Office of High Energy Physics. The reciprocity principle* is often used in applications of classical electromagnetism. We have employed this principle for testing wakefields set up by an electron bunch in a two-channel coaxial dielectric structure (CDWA)*. For numerical studies we take a ~1-THz fused silica structure which we plan to test at FACET/SLAC; it has dimensions: outer shell, OD=800 μm, ID=500 μm; inner shell OD=181 μm, ID=50 μm. The structure is energized by a 23-GeV, 3-nC bunch having axial RMS size=25 μm. FACET has no drive bunch of annular shape as required for a CDWA; nevertheless, our analytical studies and simulations prove that for the axial wakefield, an annular drive bunch can be replaced by a pencil-like bunch of the same charge traveling in the annular vacuum channel. The longitudinal electric field along the accelerator channel axis (as recorded by a witness bunch) set up by this pencil-like bunch is the same as in the conventional structure of the CDWA. Moreover, if we interchange the drive bunch and the witness bunch, the witness bunch will register the same axial wakefield. However, the stability of the annular bunch is far superior to that of the pencil bunch. L. D. Landau and E. M. Lifshitz, Electrodynamics of Continuous Media (Addison-Wesley: Reading, MA, 1960). **G. Sotnikov et al., PRST-AB, 061302 (2009).

WEPPP006	Using Simulations to Understand Particle Dynamics and Resonance in the Micro-accelerator Platform	laser, resonance, electron, coupling	2732
	J.C. McNeur, G. Travish UCLA, Los Angeles, USA H. Hairong UESTC, Chengdu, Sichuan, People's Republic of China R.B. Yoder Manhattanville College, Purchase, New York, USA
	Funding: Work funded in part by grant HDTRA1-09-1-0043 from the US Defense Threat Reduction Agency and under a grant from NNSA/NA-221 Office of Nonproliferation and Verification Research and Development. The Micro-Accelerator Platform (MAP) is a slab-symmetric micron-scale electron accelerator. Electrons gain energy via a standing wave electromagnetic resonance powered by a side coupled Ti:Sapphire laser. In this paper, we will discuss simulations of resonance and particle dynamics in this structure. Three-dimensional simulations showing evidence of stable 1 GeV/m acceleration are detailed along with simulations studying defocusing and wakefield effects in the MAP. Additionally, optimization of the structure and the coupling of laser power into the cavity will be explored.

WEPPP008	Vacuum Laser Acceleration Experiment Perspective at Brookhaven National Lab-Accelerator Test Facility	laser, electron, vacuum, simulation	2735
	X.P. Ding, D.B. Cline, L.S. Shao UCLA, Los Angeles, California, USA M.G. Fedurin, K. Kusche, I. Pogorelsky, V. Yakimenko BNL, Upton, Long Island, New York, USA Y.K. Ho, Q. Kong Fudan University, Shanghai, People's Republic of China J.J. Xu Shanghai Institute of Optics and Fine Mechanics, Shanghai, People's Republic of China
	Funding: Supported by the DOE under award number DE-FG02-92ER40695 (UCLA) This paper presents the pre-experiment plan and prediction of the first stage of Vacuum Laser Acceleration (VLA) collaborating by UCLA, Fudan University and ATF-BNL. This first stage experiment is a Proof-of-Principle to support our previously posted novel VLA theory. Simulations show that based on ATF’s current experimental conditions, the electron beam with initial energy of 15MeV can get net energy gain from intense CO2 laser beam. The difference of electron beam energy spread is observable by ATF beam line diagnostics system. Further this energy spread expansion effect increases along with the laser intensity increasing. The proposal has been approved by ATF committee and experiment will be the next project.

WEPPP009	Experimental Progress Towards a Resonant Slab-symmetric Dielectric Laser Accelerator	simulation, laser, electron, vacuum	2738
	G. Travish, K.S. Hazra, G. Liu, J.C. McNeur, E.B. Sozer, J. Zhou UCLA, Los Angeles, California, USA H. Hairong UESTC, Chengdu, Sichuan, People's Republic of China R.B. Yoder Manhattanville College, Purchase, New York, USA
	Funding: Work funded in part by grant HDTRA1-09-1-0043 from the US Defense Threat Reduction Agency and under a grant from NNSA/NA-221 Office of Nonproliferation and Verification Research and Development. TheμAccelerator Platform (MAP), a resonant dielectric structure for laser acceleration of electrons, has been in development for a number of years. It consists of a a vacuum gap between two slab-shaped reflecting boundaries, with a transmissive grating diffractive optic on one boundary that allows laser power to propagate into the gap and enforces an accelerating mode. We report on the progress of bench and beam tests carried out within the last year, and the challenges faced in diagnosing <pC beams from optical-scale structures. We also describe refinements to our fabrication techniques and lessons learned during the development of the fabrication process.

WEPPP010	FACET: SLAC's New User Facility	electron, positron, wakefield, linac	2741
	C.I. Clarke, F.-J. Decker, R.J. England, R.A. Erickson, C. Hast, M.J. Hogan, S.Z. Li, M.D. Litos, Y. Nosochkov, J.T. Seeman, J. Sheppard, U. Wienands, M. Woodley, G. Yocky SLAC, Menlo Park, California, USA
	Funding: Work supported by the U.S. Department of Energy under contract number DE-AC02-76SF00515. FACET (Facility for Advanced Accelerator Experimental Tests) is a new User Facility at SLAC National Accelerator Laboratory. The first User Run started in spring 2012 with 20 GeV, 3 nC electron beams. The facility is designed to provide short (20 um) bunches and small (20 um wide) spot sizes, producing uniquely high power beams. FACET supports studies from many fields but in particular those of Plasma Wakefield Acceleration and Dielectric Wakefield Acceleration. The creation of drive and witness bunches and shaped bunch profiles is possible with "Notch" Collimation. FACET is also a source of THz radiation for material studies. Positrons will be available at FACET in future user runs. We present the User Facility and the available tools and opportunities for future experiments.

WEPPP011	Multi-Cavity Proton Cyclotron Accelerator: An Electron Counterpart	cavity, proton, electron, cyclotron	2744
	M.A. LaPointe, S.V. Shchelkunov Yale University, Beam Physics Laboratory, New Haven, Connecticut, USA J.L. Hirshfield Omega-P, Inc., New Haven, USA V.P. Yakovlev Fermilab, Batavia, USA
	Funding: Supported by the Department of Energy, Office of Nuclear Physics. A multi-cavity multi-frequency proton cyclotron accelerator has been proposed. It would utilize cyclotron resonance in each of eight cavities of uniformly diminishing frequency in a uniform magnetic field to comprise a compact (25 m) 1 GeV proton accelerator, according to simulation results. A four cavity electron counterpart is under construction to test the mechanism of the multi-cavity setup, including phase acceptance, energy gain, and growth of energy spread and emittance for parameters equivalent to the proton case. The four electron counterpart cavities are driven by kW-level phase coherent RF sources at 1.5, 1.8, 2.1 and 2.4 GHz. Each cavity operates in the rotating TE111 mode and includes two feeds in quadrature to drive the rotating mode and two RF pickoffs for diagnostics. The electron beam source is a low-current gun with a BaO cathode which operates at -1200V and <50 microamps. After traversing the cavities, the beam is collected on either a Faraday cup or is imaged with a phosphor screen. Details of the setup and initial results from experiments with the four cavity electron counterpart will be presented. M.A. LaPointe, V.P. Yakovlev, S.Yu. Kazakov, and J.L. Hirshfield, Proc. of PAC 2009, May 4-8,Vancouver, BC, Canada, pp.3045-3047 (2011).

WEPPP012	High-Gradient THz-Scale Two-Channel Coaxial Dielectric-Lined Wakefield Accelerator	wakefield, radiation, vacuum, focusing	2747
	S.V. Shchelkunov, M.A. LaPointe Yale University, Beam Physics Laboratory, New Haven, Connecticut, USA J.L. Hirshfield, T.C. Marshall Omega-P, Inc., New Haven, USA G.V. Sotnikov NSC/KIPT, Kharkov, Ukraine
	Funding: Research is supported by U.S. Department of Energy, Office of High Energy Physics. A mm-scale THz Coaxial Dielectric Wakefield Accelerator structure is currently under study by Yale University Beam Physics Lab and collaborators for its performance with annular drive bunches. With our recent successful experiments with the cm-scale GHz rectangular module at AWA/Argonne (USA) and planned activity there with yet another cm-scale GHz coaxial structure, the program of new research has two objectives. The first is to design a structure to produce acceleration gradients approaching 0.35 GeV/m per each nC of drive charge when excited by an annular-like bunch; has an attractive feature that the drive and accelerated bunches both have good focusing and stability properties; and also exhibits a large transformer ratio. The second goal is to build and test the structure at FACET/SLAC (USA). At FACET the structure can be excited only with the available pencil-like drive bunch, but the reciprocity principle allows one to observe some of the properties that would be seen if the excitation were to be by an annular drive bunch. This presentation shows our latest findings, discusses related issues, and discusses our plans for experiments.

WEPPP014	Modeling of Quasi-phase Matching in an Aperiodic Corrugated Plasma Waveguide for High-efficiency Direct Laser Electron Acceleration	electron, plasma, laser, simulation	2750
	M.W. Lin The Pennsylvania State University, University Park, Pennsylvania, USA I. Jovanovic Penn State University, University Park, Pennsylvania, USA
	Funding: This work is supported by the Defense Threat Reduction Agency through contract HDTRA1-10^-1-0034. Direct laser acceleration (DLA) of charged particles using the axial electric field of a radially polarized intense laser pulse has the potential to realize a compact accelerator required in security and medical applications. The implementation of guided propagation of laser pulses over long distances and the phase matching between electrons and laser pulses may limit the performance of DLA in reality. A corrugated plasma waveguide could be applied to extend the laser beam propagation distance and for quasi-phase matching between laser and electron pulses for net acceleration. To accelerate electrons from a low initial energy (for example, ~5 MeV from a photoinjector gun) up to hundreds of MeV, an aperiodic corrugated plasma waveguide with successive increase of on-axis density modulation period is needed. We conducted particle-in-cell simulations to design the appropriate aperiodic plasma structure for DLA. For each section of the corrugated waveguide, the dependence of density modulation period on the initial electron energy and laser pulse intensity is investigated. The simulation results are guiding the design of proof-of-principle experiments for compact, tabletop DLA. P. Serafim, et al., IEEE Trans. Plasma Sci. 28, 1155 (2000). ** J. P. Palastro, et al., Phys. Rev. E. 77, 036405 (2008).

WEPPP018	A New Beam Injection Scheme for a Compact Low-energy Storage Ring	injection, kicker, damping, storage-ring	2761
	Y. Honda KEK, Ibaraki, Japan
	A very compact storage ring at low energy has an unique application such as Compton X-ray source. Scheme for efficient injection is an issue for such a compact storage ring. Utilizing a phase-shift in the non-relativistic energy region, a new idea for accumulating the incoming bunch on an already circulating bunch without any kicker or orbit bump has been presented. Its applicable parameter range will be presented.

WEPPP019	Designing of Photonic Crystal Accelerator for Radiation Biology	laser, electron, vacuum, injection	2763
	K. Koyama, Y. Matsumura University of Tokyo, Tokyo, Japan A. Aimidula, M. Uesaka The University of Tokyo, Nuclear Professional School, Ibaraki-ken, Japan T. Natsui, M. Yoshida KEK, Ibaraki, Japan
	Funding: This work was performed as part of the Global COE Program (Nuclear Education and Research Initiative, MEXT, Japan. A photonic crystal accelerator with a combination of a fiber laser is under development in order to apply it to the radiation biology. In order to investigate fundamental biological processes in a cell, a DNA is precisely shot by an electron bunch with an in situ observation of a radiation interaction using a microscope. Required beam diameter, bunch length, and beam energy are nanometer, attosecond, and 100 keV to 1 MeV, respectively. A photonic crystal or dielectric laser accelerator energized by a fiber laser is suitable for producing such a fine beam with a palm top device. A preliminary estimation shows that 200 keV electron bunch is available from a 0.8-mm-long accelerator and a few cm electron gun, which is driven by a few μJ, 5-ps laser pulse. We are developing a fiber laser in order to drive the photonic crystal accelerator. The Yb-fiber oscillator delivers mode-locked pulse train of ≈5 nJ/pulse at the repetition frequency of 62.5 MHz. The output pulse will be increased to several μJ by adopting a fiber amplifier

WEPPP020	Rebunching Low Energy Neutrons by Magnetic Acceleration and Deceleration	neutron, dipole, controls, focusing	2766
	Y. Iwashita Kyoto ICR, Uji, Kyoto, Japan Y. Arimoto, H.M. Shimizu KEK, Ibaraki, Japan P.W. Geltenbort ILL, Grenoble, France S. Imajo Kyoto University, Kyoto, Japan M. Kitaguchi Kyoto University, Research Reactor Institute, Osaka, Japan Y. Seki RIKEN Nishina Center, Wako, Japan T. Yoshioka Kyushu University, Fukuoka, Japan
	Funding: Supported by the Grant-in-Aid for Creative Scientific Research of MEXT under the Program 19GS0210, the Quantum Beam Fundamentals Development Program of the MEXT, and KEK Neutron Program 2009S03. Ultra cold neutrons (UCN) - neutrons with energies less than 300 neV - can be accelerated or decelerated by means of static magnetic and RF fields. The method and experimental setup will be described in detail and the results of a recent first test experiment will be presented. The detail cannot be disclosed until the paper is published.

WEPPP022	Analysis of a Rectangular Dielectric-lined Accelerating Structure with an Anisotropic Loading	wakefield, radiation, electron, impedance	2769
	I.L. Sheynman, S. Baturin LETI, Saint-Petersburg, Russia A. Kanareykin Euclid TechLabs, LLC, Solon, Ohio, USA
	Funding: Russian Fund of Basic Research Federal target program "Scientific and scientific and pedagogical personnel of innovative Russia" of the Ministry of Education and Science of Russia. Analysis of Cherenkov radiation generated by high current relativistic electron bunch passing through a rectangular waveguide with anisotropic dielectric loading has been carried out. Some of the materials used for the waveguide loading of accelerating structures (sapphire) possess significant anisotropic properties. In turn, it can influence excitation parameters of the wakefields generated by an electron beam. Using orthogonal eigenmodes decomposition for the rectangular dielectric waveguide, the analytical expressions for the wakefields have been obtained. Numerical modeling of the longitudinal and transverse (deflecting) wakefields has been carried out as well. It is shown that the dielectric anisotropy causes frequency shift in comparison to the dielectric-lined waveguide with the isotropic dielectric loading.

WEPPP023	Radiation of a Bunch Intersecting a Boundary between Vacuum and Dielectric in a Circular Waveguide	vacuum, wakefield, radiation, plasma	2772
	T.Yu. Alekhina, A.V. Tyukhtin Saint-Petersburg State University, Saint-Petersburg, Russia
	Funding: Saint Petersburg State University Analysis of a field of a particle bunch in a waveguide loaded with a dielectric is important for the wakefield acceleration technique and for other problems in accelerator physics. We investigate the field of the bunch crossing a boundary between two dielectrics in a circular waveguide. We take into account the finite length of the bunch and analyze both the field structure and the energy loss. Special attention is paid to two cases: the bunch flies from vacuum into dielectric and from dielectric into vacuum. In the first case, investigation of formation of stationary wakefield is of interest (this is important for the wakefield acceleration technique). In the second case, quasi monochromatic wave is generated in the vacuum region. This effect can be used for elaboration of a quasi-monochromatic radiation generator of new type. In both cases we also study dynamics of the energy loss of the bunch. * T.Yu. Alekhina, A.V. Tyukhtin. Proc. of IPAC2011, San Sebastian, Spain, WEPZ012, p. 2793 (2011).

WEPPP024	Cherenkov Radiation from a Small Bunch Moving in a Cold Magnetized Plasma	plasma, radiation, wakefield, electromagnetic-fields	2775
	S.N. Galyamin, D.Y. Kapshtan, A.V. Tyukhtin Saint-Petersburg State University, Saint-Petersburg, Russia
	Funding: Saint Petersburg State University. Investigation of the bunch radiation in plasma is important for the plasma wakefield acceleration (PWFA) technique and other applications in accelerator physics. We study the electromagnetic field of small relativistic bunch moving in a magnetized cold plasma along the magnetic field. The energy loss of the bunch was investigated earlier, however the structure of electromagnetic field was not analyzed. We perform analytical and numerical investigation of total field. Different equivalent representations for the field components are obtained. One of them allows separating quasistatic field and radiation one. Method of computation is developed as well. Some interesting physical effects are described. One of them is strong increase of some components of radiation field near the charge motion line (in the case of point charge). The case of a charged disc is considered as well. Prospects of use of obtained results for PWFA are discussed.

WEPPP025	A Test-bed for Future Linear Collider Technology: Argonne Wakefield Accelerator Facility (AWA)	wakefield, gun, electron, linac	2778
	M.E. Conde, D.S. Doran, W. Gai, R. Konecny, W. Liu, J.G. Power, Z.M. Yusof ANL, Argonne, USA S.P. Antipov, C.-J. Jing Euclid TechLabs, LLC, Solon, Ohio, USA E.E. Wisniewski Illinois Institute of Technology, Chicago, Illinois, USA
	Funding: Work supported by the U.S. Department of Energy under contract No. DE-AC02-06CH11357. Research at the AWA Facility has been focused on the development of electron beam driven wakefield structures. Accelerating gradients of up to 100 MV/m have been excited in dielectric loaded cylindrical structures operating in the microwave range of frequencies. Several upgrades, presently underway, will enable the facility to explore higher accelerating gradients, and also be able to generate longer RF pulses of higher intensity. The upgraded 75 MeV drive beam will consist of bunch trains of up to 32 bunches spaced by 0.77 ns with up to 100 nC per bunch. The RF pulses generated by the drive bunches are expected to reach GW power levels, establishing accelerating gradients of hundreds of MV/m.

WEPPP027	PBG-slab Embedded Traveling Wave Structure for Planar Beam Accelerator Application	electron, HOM, photon, lattice	2784
	Y.-M. Shin Fermilab, Batavia, USA
	The oversized traveling wave (TE10-mode) channel integrated with the photonic-band-gap (PBG) slab arrays have been investigated for planar beam accelerator application. Simulation analysis showed that the slab arrays allow only the PBG-modes (5-6 GHz) to propagate with ~ 2 dB of insertion loss, corresponding to ~ 1.14 dB/cm attenuation, which thereby effectively suppresses trapped non-PBG modes down to ~ -14.3 dB/cm. It will enable monochromatic propagation of fundamental acceleration modes along the heavily over-moded planar waveguide without anomalous excitation of unstable trapped HOMs. The saturated maximum field gradients of the accelerating structure have been analyzed with respect to operational frequency bands corresponding to structural sizes. The field gradient of the guided PBG-mode has been investigated with finite-integral-method (FIM) simulations at W-band. This mode-filter could be utilized for HOM dampers in high aspect ratio (HAR) planar beam accelerators. An experimental test is currently under consideration.

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

WEPPP032	Inverse Free Electron Laser Acceleration Using Ultra-fast Solid State Laser Technology	laser, undulator, simulation, electron	2795
	S.G. Anderson, G.G. Anderson, S.M. Betts, S.E. Fisher, D.J. Gibson, A.M. Tremaine, S.S.Q. Wu LLNL, Livermore, California, USA J.T. Moody, P. Musumeci UCLA, Los Angeles, California, USA
	Funding: This work performed under the auspices of the U.S. Department of Energy by Lawrence Livermore National Laboratory under Contract DE-AC52-07NA27344. We present a theoretical and computational study of the application of Ti:Sapphire laser technology to Inverse Free Electron Laser (IFEL) accelerators. Specifically, the regime in which the number of undulator periods is comparable to the number of cycles in the laser pulse is investigated and modifications to the IFEL accelerator equations and laser requirements are given. 1-D and 3-D simulations are used to study the IFEL interaction in this regime. In addition, the effects of non-Gaussian laser pulses, and astigmatic aberrations in the laser focus are analyzed. Finally, the tools developed for this study are applied to the LLNL/UCLA IFEL experiment, and potential future IFEL designs.

WEPPP036	Undulator Commissioning for a High-Energy-Gain Inverse Free Electron Laser Experiment	undulator, laser, electron, simulation	2804
	J.P. Duris, R.K. Li, P. Musumeci, E.W. Threlkeld UCLA, Los Angeles, California, USA
	Funding: This work was supported by DOE grant DE-FG02-92ER40693 and Defense of Threat Reduction Agency award HDTRA1-10^-1-0073. We present the construction and measurement details of a strongly tapered helical undulator for the Rubicon Inverse Free Electron Laser (IFEL) experiment. Results of the magnetic field measurements are presented, and these are used to produce simulations of the expected performance of the experiment. Finally, a study of the tolerances on the input parameters of the experiment is presented.

WEPPP040	Progress Report on Development of Novel Ultrafast Mid-IR Laser System	laser, FEL, wakefield, background	2810
	R. Tikhoplav, A.Y. Murokh RadiaBeam, Santa Monica, USA I. Jovanovic Penn State University, University Park, Pennsylvania, USA
	Finding alternate acceleration mechanisms that can provide very high gradients is of particular interest to the accelerator community. Those mechanisms are often based on either dielectric laser acceleration or laser wakefield acceleration techniques, which would greatly benefit from mid-IR ultrafast high peak power laser systems. The approach of this proposed work is to design a novel ultrafast mid-IR laser system based on optical parametric chirped-pulse amplification (OPCPA). OPCPA is a technique ideally suited for production of ultrashort laser pulses at the center wavelength of 2μm-5μm. Some of the key features of OPCPA are the wavelength agility, broad spectral bandwidth and negligible thermal load. This paper reports on the progress of the development of the ultrafast mid-IR laser system.

WEPPP042	Experimental Demonstration of Wakefield Effects in a 250 GHz Planar Diamond Accelerating Structure	wakefield, dipole, radiation, electron	2816
	S.P. Antipov, J.E. Butler, C.-J. Jing, A. Kanareykin, P. Schoessow, S.S. Zuo Euclid TechLabs, LLC, Solon, Ohio, USA M.G. Fedurin, K. Kusche, V. Yakimenko BNL, Upton, Long Island, New York, USA W. Gai ANL, Argonne, USA
	Funding: DOE SBIR We have directly measured the mm-wave wake fields induced by subpicosecond, intense relativistic electron bunches in a diamond loaded accelerating structure via the dielectric wake-field acceleration mechanism. Fields produced by a first, drive, beam were used to accelerate a second, witness, electron bunch which followed the driving bunch at an adjustable distance. The energy gain of the witness bunch as a function of its separation from the drive bunch is a direct measurement of the wake potential. We also present wakefield mapping results for THz quartz structures. In this case decelerating wake inside the bunch is inferred from the drive beam energy modulation.

WEPPP044	Advances in CVD Diamond for Accelerator Applications	wakefield, plasma, laser, electron	2819
	A. Kanareykin, S.P. Antipov, J.E. Butler, C.-J. Jing, S.S. Zuo Euclid TechLabs, LLC, Solon, Ohio, USA
	Funding: Work supported by the SBIR program of the US Department of Energy. Diamond is being evaluated as a dielectric material for dielectric loaded accelerating structures. It has a very low microwave loss tangent, high thermal conductivity, and supports high RF breakdown fields. We report on progress in fabricating chemical vapor deposited (CVD) diamond materials for cylindrical dielectric structures for use in wakefield particle accelerators. Tubes with inner diameters of 3 and 5 mm have been grown from polycrystalline CVD diamond on mandrels using microwave plasma assisted CVD. The material has been laser trimmed to the desired thicknesses and lengths. In addition, structures with smaller inner diameters (ca. 0.3 mm) have been laser machined from blocks of single crystal diamond grown by CVD. Rectangular (planar) dielectric structures have been constructed from plates of polished CVD diamond. Wakefields in these structures have been studied at the Brookhaven ATF.

WEPPP046	Nonlinear Dielectric Wakefield Experiment for FACET	wakefield, simulation, controls, factory	2825
	P. Schoessow, S.P. Antipov, C.-J. Jing, A. Kanareykin Euclid TechLabs, LLC, Solon, Ohio, USA S. Baturin LETI, Saint-Petersburg, Russia
	Funding: Work supported by the SBIR Program, US Dept. of Energy. Recent advances in ferroelectric ceramics have resulted in new possibilities for nonlinear devices for particle accelerator and rf applications. The new FACET (Facility for Advanced Accelerator Experimental Tests) at SLAC provides an opportunity to use the GV/m fields from its intense short pulse electron beams to perform experiments using the nonlinear properties of ferroelectrics. Simulations of Cherenkov radiation in the THz planar and cylindrical nonlinear structures to be used in FACET experiments will be presented. Signatures of nonlinearity are clearly present in the simulations: superlinear scaling of field strength with beam intensity, frequency upshift, and development of higher frequency spectral components.

WEPPR006	Serpentine Acceleration in Scaling FFAG	proton, closed-orbit, injection, betatron	2946
	E. Yamakawa, Y. Ishi, Y. Kuriyama, J.-B. Lagrange, Y. Mori, T. Uesugi Kyoto University, Research Reactor Institute, Osaka, Japan K. Okabe, I. Sakai University of Fukui, Faculty of Engineering, Fukui, Japan
	A serpentine acceleration in scaling FFAG accelerator is examined. In this scheme, high-energy and high-current beam can be obtained in non-relativistic energy region. Longitudinal hamiltonian is derived analytically. Experiment to demonstrate a serpentine acceleration in scaling FFAG is done.

WEPPR007	Simulation Calculation of Longitudinal Beam Distribution in J-PARC MR	injection, beam-loading, simulation, extraction	2949
	K. Hara, T. Koseki, C. Ohmori KEK, Tokai, Ibaraki, Japan Y. Sato J-PARC, KEK & JAEA, Ibaraki-ken, Japan
	The J-PARC accelerator complex consists of 3 accelerators, a linear accelerator, a rapid cycle synchrotron (RCS) and a Main Ring (MR) synchrotron. Simulation calculation of longitudinal beam distribution in J-PARC Main Ring has been performed. The effect that RF voltage pattern, space charge, and beam loading gave was examined.

WEPPR035	Optimization of Drive-bunch Current Profile for Enhanced Transformer Ratio in Beam-driven Acceleration Techniques	electron, simulation, vacuum, plasma	3012
	F. Lemery, D. Mihalcea, P. Piot, C.R. Prokop Northern Illinois University, DeKalb, Illinois, USA
	Funding: Work supported by the U.S. Department of Energy, Office of Science, Office of Basic Energy Sciences, under Contract No. DE-AC02-06CH11357. In recent years, wakefield acceleration has gained attention due to its high acceleration gradients and cost effectiveness. In beam-driven wakefield acceleration, a critical parameter to optimize is the transformer ratio. It has been shown that current shaping of electron beams allows for enhanced (>2) transformer ratios. In this paper we present the optimization of the pulse shape of the drive bunch for dielectric-wakefield acceleration. We also explore practical techniques capable of tailoring current profiles into these optimal shapes.

WEPPR090	A 4.2 GS/s Synchronized Vertical Excitation System for SPS Studies - Steps Toward Wideband Feedback	controls, feedback, kicker, injection	3144
	J.D. Fox, J.J. Olsen, C.H. Rivetta, I.I. Rivetta, O. Turgut, S. Uemura SLAC, Menlo Park, California, USA W. Höfle, U. Wehrle CERN, Geneva, Switzerland
	Funding: Work supported by the U.S. Department of Energy under contract DE-AC02-76SF00515 and the US LHC Accelerator Research Program (LARP). A 4.2 GS/s beam excitation system with accelerator synchronization and power stages is described. The system is capable of playing unique samples (32 samples/bunch) for 15,000 turns on selected bunch(es) in the SPS in synchronism with the injection and acceleration cycle. The purpose of the system is to excite internal modes of single-bunch vertical motion, and study the bunch dynamics in the presence of developing Electron cloud or TMCI effects. The system includes a synchronized master oscillator, SPS timing functions, an FPGA based arbitrary waveform generator, 4.2 GS/sec. D/A system and four 80W 20 -1000 MHz amplifiers driving a tapered stripline pickup/kicker. A software GUI allows specification of various modulation signals and selection of bunches and turns to excite, while a remote control interface allows simple control/monitoring of the RF power stages located in the tunnel. Excitation signals developed to excite head-tail and other modes of vertical motion are illustrated. The successful use of this system for SPS MD measurements in August and November 2011 is a vital proof-of-principle for wideband feedback using similar functions to correct the beam motion.

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

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

THPPC005	Design of Magnetic Alloy Resonant System (MARS) Cavity for J-PARC MR	cavity, impedance, beam-loading, status	3278
	C. Ohmori, K. Hara, K. Hasegawa, M. Toda, M. Yoshii KEK, Ibaraki, Japan M. Nomura, A. Schnase, T. Shimada, F. Tamura, M. Yamamoto JAEA/J-PARC, Tokai-mura, Japan
	The Magnetic Alloy Resonant System (MARS) cavity is a new type of Magnetic Alloy (MA) cavity using an external energy storage system. It is proposed as a back-up system of the present J-PARC high-Q MA cavity using cut cores. MARS consists of un-cut core loaded wideband MA cavities combined with an energy storage system using high-impedance, FT3L, cut cores. The main cavities are water-cooled and already established at J-PARC RCS. The energy storage system will be relatively high-Q (>100) to be stable under heavy beam loading. It also has a higher impedance than the main cavity and is air-cooled. The design of this cavity system will be presented.

THPPC009	Investigation of the Approaches to Measure the RF Cable Attenuation	controls, insertion, linac, radio-frequency	3290
	K. Futatsukawa, Z. Fang, Y. Fukui, T. Kobayashi, S. Michizono KEK, Ibaraki, Japan F. Sato, S. Shinozaki JAEA/J-PARC, Tokai-mura, Japan
	In the accelerator facilities, many RF cables are used for the various purposes such as the transmission system and the cavity monitor. The knowledge of the power attenuation in those cables is important role to control RF. In general, the cable attenuation is measured from S parameters to use a network analyzer. However, the control system is located far from the place of the cavities, and it difficult to measure by a network analyzer. Then we investigated other methods to measure the RF cable attenuation.

THPPC010	Beam Start-up of J-PARC Linac after the Tohoku Earthquake	linac, DTL, quadrupole, radiation	3293
	M. Ikegami, Z. Fang, K. Futatsukawa, T. Miyao KEK, Ibaraki, Japan T. Maruta, A. Miura, H. Sako, J. Tamura, G.H. Wei JAEA/J-PARC, Tokai-mura, Japan
	The beam operation of J-PARC linac was interrupted by the Tohoku earthquake in March 2011. After significant recovering effort including the realignment of most linac components, we have resumed the beam operation of J-PARC linac in December 2011. In this paper, we present the experience in the beam start-up tuning after the earthquake and the status of the linac operation thereafter.

THPPC017	Study of Physical Processes of Acceleration of Electron Bunches with Extremal Density by Means of Stored Energy in Disk Loaded Waveguide Sections	electron, linac, radiation, electromagnetic-fields	3314
	S. Proskin, A. Kulago MEPhI, Moscow, Russia
	This presentation should consider a new theoretical method of SHF power increasing in DWLG sections. Within the presentation physical processes of the acceleration of extremely charge densities in the sections of a DWLG by the stored energy are described. As a result optimum travelling wave DWLG is taken and a simulation of acceleration processes of 20 ns electron beams is conducted.

THPPC025	Improvements to ISIS RF Cavity Tuning	cavity, controls, synchrotron, proton	3332
	R.J. Mathieson, D. Bayley, N.E. Farthing, I.S.K. Gardner, A. Seville STFC/RAL/ISIS, Chilton, Didcot, Oxon, United Kingdom
	The ISIS facility at the Rutherford Appleton Laboratory in the UK routinely accelerates proton beam currents in excess of 230 uA to run two neutron spallation target stations. The accelerator consists of a 70 MeV H⁻ linac and an 800 MeV, 50 Hz, proton synchrotron. The synchrotron beam is accelerated using six fundamental (h=2), and four second harmonic (h=4) ferrite loaded RF cavities each having its own drive amplifier and bias system. Each RF cavity is driven as a high Q tuned RF circuit; the resonant frequency being controlled by biasing the ferrite using a current from the bias regulator system. The cavity is kept at the correct resonant frequency by an analogue feedback loop comparing the phase of the cavity voltage to the phase of the demand voltage at the amplifier, and a 50Hz digital correction function calculated from the estimated frequency response of the system. This paper describes work improving the performance of the tuning system by introducing better system identification of the tuning loop and a time varying transfer function.

THPPC032	Conditioning and Future Plans for a Multi-purpose 805 MHz Pillbox Cavity for Muon Acceleration	cavity, vacuum, solenoid, linac	3353
	G.M. Kazakevich, A. Dudas, G. Flanagan, R.P. Johnson, F. Marhauser, M.L. Neubauer, R. Sah Muons, Inc, Batavia, USA S.S. Kurennoy LANL, Los Alamos, New Mexico, USA A. Moretti, M. Popovic, G.V. Romanov, K. Yonehara Fermilab, Batavia, USA Y. Torun IIT, Chicago, Illinois, USA
	Funding: Supported in part by grant 4735 · 10 LANL and Dept. of Energy STTR grant DE-FG02-08ER86352. An 805 MHz RF pillbox cavity has been designed and constructed to investigate potential muon beam acceleration and cooling techniques for a Muon Collider or Neutrino Factory. The cavity can operate in vacuum or under pressure to 100 atmospheres, at room temperature or in a liquid nitrogen bath at 77 K. The cavity has been designed for easy assembly and disassembly with bolted construction using aluminum seals. To perform vacuum and high pressure breakdown studies of materials and geometries most suitable for the collider or factory, the surfaces of the end walls of the cavity can be replaced with different materials such as copper, aluminum, beryllium, or molybdenum, and with different geometries such as shaped windows or grid structures. The cavity has been designed to fit inside the 5-Tesla solenoid in the MuCool Test Area at Fermilab. In this paper we present the vacuum conditioning results and discuss plans for testing in a 5-Tesla magnetic field. Additionally, we discuss the testing plan for beryllium (a material research has shown to be ideal for the collider or factory) end walls.

THPPC045	Rapidly Tunable RF Cavity for Accelerators	cavity, synchrotron, vacuum, simulation	3386
	D.J. Newsham, N. Barov Far-Tech, Inc., San Diego, California, USA
	Funding: Work supported by the DOE-SBIR program, High Energy Physics Department. The performance and range efficient use of rapidly cycling accelerators would be improved with the fast frequency tuning and associated variable phase change provided by a tunable rf cavity. The progress in developing a cavity that can be tuned by as much as 10 percent in frequency in less than 100 nanoseconds is presented.

THPPD020	Test of a 1.8 Tesla, 400 Hz Dipole for a Muon Synchrotron	dipole, power-supply, simulation, synchrotron	3542
	D.J. Summers, L.M. Cremaldi, T.L. Hart, L.P. Perera, M. Reep UMiss, University, Mississippi, USA S.U. Hansen, M.L. Lopes Fermilab, Batavia, USA J. Reidy Oxford High School, Mississippi, USA H. Witte BNL, Upton, Long Island, New York, USA
	Funding: Supported by DE-FG05-91ER40622. A 1.8 Tesla dipole magnet using 0.011" AK Steel TRAN-COR H-1 grain oriented silicon steel laminations has been constructed as a prototype for a muon synchrotron ramping at 400 Hz. Following the practice in large 3 phase transformers and our own OPERA-2D simulations, joints are mitered to take advantage of the magnetic properties of the steel which are most effective in the direction in which the steel was rolled. Measurements with a Hysteresigraph 5500 and Epstein Frame show a high magnetic permeability which minimizes stored energy in the yoke so the magnet can ramp quickly with modest voltage. A power supply with a fast IGBT switch and a polypropylene capacitor was constructed. Coils are wound with 12 gauge copper wire which will eventually be cooled with with water flowing in stainless steel tubes. The magnetic field was measured with an F. W. Bell 5180 peak sensing Hall Probe connected to a Tektronics TDS3054B oscilloscope.

THPPD071	A Compact Switching Power Supply utilizing SiC-JFET for the Digital Accelerator	power-supply, induction, simulation, synchrotron	3677
	K. Okamura, T. Iwashita, K. Takayama, M. Wake KEK, Ibaraki, Japan K. Takaki, M. Toshiya Iwate university, Morioka, Iwate, Japan
	New induction synchrotron system using an induction cell has been developed and constructed at KEK. We refer to the accelerator using the induction acceleration system combined with digitally controlled PWM power supply as Digital Accelerator. In that system, the switching power supply is one of the key devices which realize digital acceleration. The requirements of the switching power supply are high voltage (2 kV) and high repetition frequency (1 MHz). In the present system, we used series connected MOSFETs as the switching device. However, series connection gives large complexity and less reliability. Among the various switching devices, a SiC-JFET is the promising candidates because it has ultrafast switching speed and voltage blocking capability. Therefore, we have developed a new device to substitute existing silicon MOSFET and succeeded to operate with 1 MHz – 1 kV – 27 A condition*. Then we designed and constructed a ultra compact full bridge switching power supply utilizing those devices as a next step. Design and test results will be presented in the conference. T. Iwashita et al., KEK Digital Accelerator, Phys. Rev. ST-AB 14, 071302 (2011) K. Takayama et al., in Proc. of IPAC’11, pp 1920-1922 * K. Okamura et al., in Proc. of IPAC’11, pp 3400-3402

THPPP011	Studies on a Wideband, Solid-state Driven RF System for the CERN PS Booster	impedance, feedback, cavity, booster	3749
	M.M. Paoluzzi, L. Arnaudon, N. Chritin, M. Haase, K. Hanke, B. Mikulec, T. Tardy CERN, Geneva, Switzerland
	In the framework of the LHC Injectors Upgrade project (LIU) the PS Booster (PSB) RF systems will undergo in depth consolidation and upgrade programs. The aim is increasing the extraction energy to 2 GeV and allowing reliable operations during next 25 years. Substantial improvements could come from the replacement of the existing narrowband, tuned systems covering the h=1 and h=2 frequency ranges (0.6 / 1.8 MHz and 1.2 / 3.6 MHz respectively) with wideband (0.5 / 4 MHz) Finemet® loaded cavities. The new system would be modular, allow multi-harmonic operation, use solid-state power stages and include fast RF feedback to compensate beam loading effects to some extent. A prove of principle system providing ≈3.0 kV accelerating voltage has been designed, constructed and installed in one of the PSB rings. This paper provides details on the design and measurements as well as information on the project status.

THPPP026	Experimental Effects of Orbit on Polarization Loss in RHIC	resonance, polarization, injection, proton	3788
	V.H. Ranjbar Tech-X, Boulder, Colorado, USA M. Bai, H. Huang, A. Marusic, M.G. Minty, V. Ptitsyn BNL, Upton, Long Island, New York, USA
	Funding: Work supported by Brookhaven Science Associates, LLC under Contract No. DE-AC02-98CH10886 with the U.S. Department of Energy. We are performing several experiments during the RHIC ramp to better understand the impact of orbit errors on the polarization at our current working point. These will be conducted by exciting specified orbit harmonics during the final two large intrinsic resonance crossing in RHIC during the 250 GeV polarized proton ramp. The resultant polarization response will then be measured.

THPPP030	Near Integer Tune for Polarization Preservation in the AGS	optics, polarization, injection, resonance	3797
	N. Tsoupas, L. A. Ahrens, M. Bai, K.A. Brown, J.W. Glenn, H. Huang, W.W. MacKay, T. Roser, V. Schoefer, K. Zeno BNL, Upton, Long Island, New York, USA
	Funding: Work supported by the US Department of Energy. The high energy (T=250 GeV) polarized proton beam experiments performed in RHIC, require high polarization of the beam. In order to preserve the polarization of the proton beam, during the acceleration in the AGS, which is the pre-injector to RHIC, two partial helical magnets have been installed in AGS. In order to minimize the loss of the beam polarization due to the various intrinsic spin resonances occurring during the proton acceleration, we constrain the value of the vertical tune to be higher than 8.97. With the AGS running at near integer tune the perturbations caused by the partial helical magnets is large resulting in large beta and dispersion waves. To mitigate the adverse effect of the partial helices on the optics of the AGS, we have introduced compensation quads** in AGS. In this paper we present the beam optics of the AGS which ameliorates this effect of the partial helices. * H. Huang, et al., Proc. EPAC06, p. 273, (2006). ** N. Tsoupas et al., Proc. PAC07, p. 3723 (2007).

THPPP084	Charge Stripping of Uranium-238 Ion Beam with Helium Gas Stripper	target, cyclotron, ion, radiation	3930
	H. Imao RIKEN Nishina Center for Accelerator-Based Science, Wako, Saitama, Japan N. Fukunishi, H. Hasebe, O. Kamigaito, M. Kase, H. Kuboki, H. Okuno, T. Watanabe, Y. Watanabe, Y. Yano, S. Yokouchi RIKEN Nishina Center, Wako, Japan
	Development of the reliable and efficient electric charge stripping method is one of the key issues in next-generation high-intensity heavy ion accelerators. Although conventional carbon-foil charge strippers provide a good charge stripping efficiency, two serious problems are emerging; the short usable time and thickness non-uniformity. A charge stripper using low-Z gas is an important candidate applicable for high-intensity 238U beams to replace carbon foil strippers. In the present work, the first actual charge stripping system using helium gas for 238U beams injected at 10.75 MeV/u has been developed and tested.

THPPP087	Beta Beams for Precision Measurements of Neutrino Oscillation Parameters	target, ion, proton, linac	3939
	E.H.M. Wildner, E. Benedetto, T. De Melo Mendonca, C. Hansen, T. Stora CERN, Geneva, Switzerland D. Berkovits Soreq NRC, Yavne, Israel A. Brondi, A. Di Nitto, G. La Rana, R. Moro, E. Vardaci Naples University Federico II, Napoli, Italy G. Burt Cockcroft Institute, Lancaster University, Lancaster, United Kingdom A. Chancé, J. Payet CEA/DSM/IRFU, France M. Cinausero, G. De Angelis, F. Gramegna, V. Kravtchouk, T. Marchi, G.P. Prete INFN/LNL, Legnaro (PD), Italy G. Collazuol Univ. degli Studi di Padova, Padova, Italy G. De Rosa, V.C. Palladino INFN-Napoli, Napoli, Italy F. Debray, C. Trophime GHMFL, Grenoble, France T. Delbar, T. Keutgen, M. Loiselet, S. Mitrofanov UCL, Louvain-la-Neuve, Belgium M. Hass, T. Hirsch Weizmann Institute of Science, Physics, Rehovot, Israel I. Izotov, V. Sidorov, V. Skalyga, V. Zorin IAP/RAS, Nizhny Novgorod, Russia T. Lamy, L. Latrasse, M. Marie-Jeanne, P. Sortais, T. Thuillier LPSC, Grenoble, France M. Mezzetto INFN- Sez. di Padova, Padova, Italy A. Stahl RWTH, Aachen, Germany
	Funding: CERN and European Community under the European Commission Framework Programme 7 Design Study: EUROnu, Project Number 212372 Neutrino oscillations have implications for the Standard Model of particle physics. The “CERN Beta Beam” has outstanding capabilities to contribute to precision measurements of the parameters governing neutrino oscillations. The FP7 collaboration “EUROnu” (2008-2012) is a design study that will review three facilities (Super-Beams, Beta Beams and Neutrino Factories) and perform a cost assessment that, coupled with the physics performance, will give means to the European research authorities to make decisions on future European neutrino oscillation facilities. "Beta Beams" produce collimated pure electron (anti)neutrino beams by accelerating beta active ions to high energies and having them decay in a storage ring. Using existing machines and infrastructure is an advantage for the cost evaluation; however, this choice is also constraining the Beta Beams. Recent work to make the Beta Beam facility a solid option will be described: production of Beta Beam isotopes, the 60 GHz pulsed ECR source development, integration into the LHC-upgrades, ensure the high intensity ion beam stability, and optimizations to get high neutrino fluxes. The costing approach will also be described.

THPPP088	Beam Loss Studies of the ISIS Synchrotron Using ORBIT	simulation, injection, synchrotron, emittance	3942
	D.J. Adams STFC/RAL/ASTeC, Chilton, Didcot, Oxon, United Kingdom I.S.K. Gardner, B. Jones, B.G. Pine, A. Seville, H. V. Smith, C.M. Warsop, R.E. Williamson STFC/RAL/ISIS, Chilton, Didcot, Oxon, United Kingdom
	The ISIS synchrotron forms part of the accelerator chain for the Spallation Neutron Source at RAL, UK. The synchrotron is an 800 MeV, 50Hz , RCS accelerating ~2.8·10¹³ protons per cycle. Beam loss is localized in two super periods of the ring using a system of collimators. The injection and acceleration processes, vacuum vessels and collimation systems have been modeled using the particle tracking code ORBIT. This paper presents simulation results in comparison to measurements of longitudinal profiles and beam loss.

THPPR026	Automated Phase Optimization for the HDSM at MAMI	synchrotron, linac, injection, microtron	4020
	M. Dehn IKP, Mainz, Germany
	Funding: This work has been supported by CRC 443 of the Deutsche Forschungsgemeinschaft. The Harmonic Double Sided Microtron (HDSM) at Mainz University is a very reliable stage of the 1.6 GeV CW microtron cascade MAMI. Nevertheless setting up and operating the machine depends largely upon an appropriate adjustment of the RF systems. To assist the MAMI operators, a new approach basing on the analysis of the synchrotron oscillation has been developed and enables the optimization of the RF phases of the linacs for the given RF amplitudes.

THPPR053	A CW FFAG for Proton Computed Tomography	cyclotron, proton, extraction, lattice	4094
	C. Johnstone, D.V. Neuffer Fermilab, Batavia, USA H.L. Owen STFC/DL/ASTeC, Daresbury, Warrington, Cheshire, United Kingdom P. Snopok IIT, Chicago, Illinois, USA
	Funding: Work supported by Fermi Research Alliance, LLC, under contract No. DE-AC02-07CH11359 with the U.S. Department of Energy An advantage of the cyclotron in proton therapy is the continuous (CW) beam output which reduces complexity and response time in the dosimetry requirements and beam controls. A CW accelerator requires isochronous particle orbits at all energies through the acceleration cycle and present compact isochronous cyclotrons for proton therapy reach only 250 MeV (kinetic energy) which is required for patient treatment, but low for full Proton Computed Tomography (PCT) capability. PCT specifications need 300-330 MeV in order for protons to transit the human body. Recent innovations in nonscaling FFAG design have achieved isochronous performance in a compact (~3 m radius) design at these higher energies. Preliminary isochronous designs are presented here. Lower energy beams can be efficiently extracted for patient treatment without changes to the acceleration cycle and magnet currents.

THPPR066	Racetrack Microtron for Nondestructive Nuclear Material Detection System	linac, electron, gun, microtron	4127
	T. Hori, T. Kii, R. Kinjo, H. Ohgaki, M. Omer, H. Zen Kyoto University, Institute for Advanced Energy, Kyoto, Japan I. Daito, R. Hajima, T. Hayakawa, M. Kando, H. Kotaki JAEA, Kyoto, Japan
	A nuclear material detection system using the quasi-monochromatic gamma-ray beam from a laser Compton Backscattering source has been proposed for the container inspection, where nuclear resonance fluorescence method would be employed for the specific isotope identification such as U-235. In the system an electron beam of good quality at about 220 MeV for the laser Compton backscattering is required. One candidate for such the practical use is a racetrack microtron which design is based on the existing 150 MeV microtron at JAEA.

FRXAA02	Advanced Solid State Lasers are Merging with Accelerators	laser, cavity, higher-order-mode, alignment	4157
	A. Tünnermann, J. Limpert Friedrich Schiller Universität, Jena, Germany T. Schreiber Fraunhofer-Institute for Applied Optics and Precision Engineering, Jena, Germany
	In recent years, lasers have been developed to an essential tool in accelerator science, for acceleration and diagnostics. Novel applications require for high average power lasers in continuous and pulsed operation with diffraction limited beam quality. Lasers are known as sophisticated systems with a notorious poor efficiency. Most recently, rare-earth-doped fibers have established themselves as an attractive and power scalable solid-state laser concept. Using advanced large mode area fibers, in continuous-wave operation output powers in the 10 kW-regime with diffraction-limited beam quality at electrical to optical efficiencies of 30 percent have been demonstrated. In the pulsed regime average powers of the order of 1 kW even for femtosecond fiber laser systems have been reported. Coherent beam combination of these lasers allows for the generation of high peak power pulses at high repetition rates and output powers. In this contribution the state of the art in solid state laser technology operating at high average powers with inherent high efficiencies is reviewed. The prospects for future developments that will meet the demands set by the accelerator community will be discussed.
	Slides FRXAA02 [11.729 MB]

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MOOAB01

A Proton-driven Plasma Wakefield Accelerator Experiment with CERN SPS Bunches

plasma, proton, wakefield, electron

40

P. Muggli
MPI, Muenchen, Germany

Funding: Presented for the PDPWFA collaboration.
Existing relativistic proton (p⁺) bunches carry large amounts of energy (kJ) and are therefore attractive as drivers for plasma-based particle accelerators, such as the plasma wakefield accelerator or PWFA. However, short (~ps) p⁺ bunches capable of driving large amplitude (~GV/m) wakefields are not available today. It was recently proposed to use long (~300ps) p⁺ bunches self-modulated at the plasma wavelength by a transverse two-stream instability in a high-density (~10¹⁴-10¹⁵/cc) plasma to resonantly drive wakefields*. Based on this idea and on the long term prospect for short p⁺ bunches a p⁺-driven PWFA experimental program was proposed to study the acceleration of electrons to the TeV energy range. Initial experiments will use the 450GeV, 1-3·10¹¹ p⁺ bunches from the CERN SPS and plasmas 5-10m in length. The wakefields will be sampled by an externally injected, low energy (10-20MeV) electron bunch that will gain energy in the GeV range. The experimental plan, as well as the expected results will be presented.
*N. Kumar et al., Phys. Rev. Lett. 104, 255003 (2010).

Slides MOOAB01 [19.595 MB]

MOOAB02

First Results from the Electron Hose Instability Studies in FACET

plasma, electron, wakefield, status

43

E. Adli
University of Oslo, Oslo, Norway
W. An, C.E. Clayton, C. Joshi, K.A. Marsh, W.B. Mori, N. Vafaei-Najafabadi
UCLA, Los Angeles, California, USA
S. Corde, R.J. England, J.T. Frederico, S.J. Gessner, M.J. Hogan, S.Z. Li, M.D. Litos, Z. Wu
SLAC, Menlo Park, California, USA
W. Lu
TUB, Beijing, People's Republic of China
P. Muggli
MPI, Muenchen, Germany

Funding: This work is supported by the Research Council of Norway and U.S. Department of Energy under contract number DE-AC02-76SF00515.
We present the first results from experimental studies of the electron hose instability in the plasma-wakefield acceleration experiments at FACET. Theory and PIC simulations of an electron beam as it travels through a plasma indicate that hosing may lead to a significant distortion of the transverse phase space. The FACET dump line is equipped with a Cherenkov light based spectrometer which can resolve transverse motion as a function of beam energy. We compare the predictions from simulations and theory to the experimental results obtained.

Slides MOOAB02 [4.654 MB]

MOEPPB001

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

linac, extraction, linear-collider, collider

73

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

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

MOEPPB006

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

ion, booster, proton, collider

88

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

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

MOPPC025

RHIC Polarized Proton Operation in Run 12

polarization, luminosity, proton, emittance

184

V. Schoefer, L. A. Ahrens, A. Anders, E.C. Aschenauer, G. Atoian, M. Bai, J. Beebe-Wang, M. Blaskiewicz, J.M. Brennan, K.A. Brown, D. Bruno, R. Connolly, T. D'Ottavio, A. Dion, K.A. Drees, W. Fischer, C.J. Gardner, J.W. Glenn, X. Gu, M. Harvey, T. Hayes, L.T. Hoff, H. Huang, R.L. Hulsart, A. Kirleis, J.S. Laster, C. Liu, Y. Luo, Y. Makdisi, G.J. Marr, A. Marusic, F. Méot, K. Mernick, R.J. Michnoff, M.G. Minty, C. Montag, J. Morris, S. Nemesure, A. Poblaguev, V. Ptitsyn, V.H. Ranjbar, G. Robert-Demolaize, T. Roser, W.B. Schmidke, F. Severino, D. Smirnov, K.S. Smith, D. Steski, S. Tepikian, D. Trbojevic, N. Tsoupas, J.E. Tuozzolo, G. Wang, M. Wilinski, K. Yip, A. Zaltsman, A. Zelenski, K. Zeno, S.Y. Zhang
BNL, Upton, Long Island, New York, USA

Successful RHIC operation with polarized protons requires meeting demanding and sometimes competing goals for maximizing both luminosity and beam polarization. In Run 12 we sought to fully integrate into operation the many systems that were newly commissioned in Run 11 as well as to enhance collider performance with incremental improvements throughout the acceleration cycle. For luminosity maximization special attention was paid to several possible source of emittance dilution along the injector chain, in particular to optical matching during transfer between accelerators. Possible sources of depolarization in the AGS and RHIC were also investigated including the effects of local coupling and low frequency (10 Hz) oscillations in the vertical equilibrium orbit during the RHIC ramp. The results of a fine storage energy scan made in an effort to improve store polarization lifetime are also reported in this note.

MOPPC049

Status of the Non-scaling Fixed Field Alternating Gradient Ring Design for the International Design Study of the Neutrino Factory

factory, septum, lattice, electron

241

J.S. Berg, H. Witte
BNL, Upton, Long Island, New York, USA
M. Aslaninejad, J. Pasternak
Imperial College of Science and Technology, Department of Physics, London, United Kingdom
N. Bliss, A.J. Moss
STFC/DL, Daresbury, Warrington, Cheshire, United Kingdom
D.J. Kelliher, S. Machida
STFC/RAL/ASTeC, Chilton, Didcot, Oxon, United Kingdom
S.M. Pattalwar
STFC/DL/ASTeC, Daresbury, Warrington, Cheshire, United Kingdom

Funding: This manuscript has been authored by employees of Brookhaven Science Associates, LLC under Contract No. DE-AC02-98CH10886 with the U.S. Department of Energy.
The International Design Study of the Neutrino Factory is working towards delivering the optimized design of the neutrino factory facility to be presented in the Reference Design Report (RDR) in 2013. In the current baseline design a linear non-scaling fixed field alternating gradient accelerator (FFAG) was chosen as an efficient solution for the final muon acceleration. We describe updates to the design since our previous report*. We report on beam dynamics studies on the lattice. We describe recent work on the engineering for the lattice, and the results of a recent first pass at a cost estimate for the machine. Finally, we describe how an FFAG may be applicable to a lower energy neutrino factory in light of recent experimental results regarding the value of the theta(13) neutrino mixing angle**.
* J. S. Berg et al., in Proceedings of IPAC2011, San Sebastian, Spain, 832.
** F. P. An et al., Phys. Rev. Lett. 10⁸, 171803 (2012); J. K. Ahn et al., arXiv:1204.0626v2 [hep-ex] (2012).

MOPPC050

The International Design Study for the Neutrino Factory

factory, lattice, target, proton

244

K.R. Long, J.K. Pozimski
Imperial College of Science and Technology, Department of Physics, London, United Kingdom
J.S. Berg
BNL, Upton, Long Island, New York, USA

A neutrino factory is a facility for producing a large neutrino flux from the decay of high energy muons. The International Design Study for the Neutrino Factory (IDS-NF) aims to produce a reference design report for such a facility. The report will contain the physics motivation for the facility, describe the accelerator and detector, and estimate the cost for the facility. We will briefly discuss the physics capabilities for a neutrino factory, including how recent neutrino physics results affect our understanding of a neutrino factory's performance and advantages. We will give an overview of our baseline design for the accelerator facility. We will then outline the most significant areas of progress in our studies of the accelerator subsystems.
Paper submitted on behalf of the International Design Study for the Neutrino Factory collaboration.

MOPPC058

Eigenmode Computation for Ferrite-loaded Cavity Resonators

cavity, resonance, heavy-ion, ion

265

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

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

MOPPC061

An Antiproton Recycler for Atom-Antiproton Collision Experiments

antiproton, injection, ion, target

274

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

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

MOPPC069

Quantitative Simulation of NIRS-930 Cyclotron

cyclotron, extraction, simulation, electromagnetic-fields

292

V.L. Smirnov, S.B. Vorozhtsov
JINR/DLNP, Dubna, Moscow region, Russia
A. Goto, S. Hojo, T. Honma, K. Katagiri
NIRS, Chiba-shi, Japan

The results of the computer modelling of the structural elements of the NIRS-930 cyclotron operational at the National Institute of Radiological Sciences (Chiba, Japan) are presented. The integrated approach to modelling of the cyclotron, including calculation of electromagnetic fields of the structural elements and beam dynamics simulations is described. A computer model of the cyclotron was constructed. Electric and magnetic field distributions and mechanical structures were converted to the beam dynamics code for simulations, in which particle losses on the surfaces of the system elements were estimated. The existing data on the axial injection, magnetic, acceleration and extraction systems of the cyclotron and beam parameter measurements are used for calibration of the simulations. New acceleration regimes could be formulated with the help of the constructed computer model of the machine.

MOPPC080

Modeling Space Charge in an FFAG with Zgoubi

space-charge, lattice, emittance, synchrotron

322

S.C. Tygier, R. Appleby, H.L. Owen
UMAN, Manchester, United Kingdom
R.J. Barlow
University of Huddersfield, Huddersfield, United Kingdom

The Zgoubi particle tracker uses a ray tracing algorithm that can accurately track particles with large offset from any reference momentum and trajectory, making it suitable for FFAGs. In high current FFAGs, for example an ADSR driver, space charge has a significant effect on the beam. A transverse space charge model was added to Zgoubi using the interface pyZgoubi. The magnets are sliced and a space charge kick is applied between each slice. Results are presented for an ADSR driver lattice.

MOPPC082

Beam Dynamics Simulations inProject X RFQ with CST Studio Suite

rfq, simulation, linac, quadrupole

328

G.V. Romanov
Fermilab, Batavia, USA

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

MOPPC089

CUDA Kernel Design for GPU-based Beam Dynamics Simulations

simulation, space-charge, impedance, linac

343

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

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

MOPPD018

A FFAG Design Study for an Accelerator-driven System

proton, synchrotron, resonance, focusing

403

T.-Y. Lee, H.-S. Kang, H.-S. Lee
PAL, Pohang, Kyungbuk, Republic of Korea

Design of a 1 GeV FFAG accelerator is studied for the accelerator-driven sub-critical nuclear reactor system. Scaling and non-scaling lattices are studied and compared with each other. Corresponding magnet design and RF system are considered.

MOPPD021

An Experimental Investigation of Slow Integer Tune Crossing in the EMMA Non-scaling FFAG

resonance, simulation, closed-orbit, proton

412

J.M. Garland, H.L. Owen
UMAN, Manchester, United Kingdom
D.J. Kelliher, S. Machida
STFC/RAL/ASTeC, Chilton, Didcot, Oxon, United Kingdom
B.D. Muratori
STFC/DL/ASTeC, Daresbury, Warrington, Cheshire, United Kingdom

Funding: Student STFC grant number: ST/G004277/1.
Results are presented from a slow integer tune crossing experiment performed in the EMMA accelerator. Under nominal conditions EMMA accelerates an electron beam from 10–20 MeV rapidly in 5–10 turns in a novel “serpentine” channel causing several transverse integer tunes to be crossed. During this rapid acceleration it has been shown that the betatron amplitude of the beam does not grow. If the potential of non-scaling FFAGs were to be realized in such fields as high-current proton acceleration then tune space would be crossed slower with acceleration in an RF bucket. The crossing speed in a non-scaling FFAG is in a previously unstudied intermediate region and hence conventional crossing theory may not apply. It was proposed to observe the effects on betatron amplitude when a beam crosses integer tunes by the variation of tune with momentum over a range of crossing speeds derived from different acceleration rates. This method can be realized by synchrotron acceleration inside a stable RF bucket. Betatron amplitude growth and beam loss as a function of turn are explored when crossing an integer tune and a relationship between crossing speed and these quantities is established.

MOPPP012

Experimental Observation of Energy Modulation in Electron Beams Passing through Terahertz Dielectric Wakefield Structures

wakefield, bunching, radiation, FEL

595

S.P. Antipov, C.-J. Jing, A. Kanareykin, P. Schoessow
Euclid TechLabs, LLC, Solon, Ohio, USA
M.G. Fedurin, K. Kusche, V. Yakimenko
BNL, Upton, Long Island, New York, USA
W. Gai, A. Zholents
ANL, Argonne, USA
B.C. Jiang
SINAP, Shanghai, People's Republic of China

Funding: DOE SBIR.
We report observation of a strong wakefield induced energy modulation in an energy-chirped electron bunch passing through a terahertz dielectric-lined waveguide. This modulation can be effectively converted into a spatial modulation by means of a chicane, forming micro-bunches (density modulation) with a periodicity of 0.5 - 1 picosecond, hence capable of driving coherent THz radiation. The experimental results agree well with theoretical predictions.

MOPPP022

ALICE: Status, Developments and Scientific Programme

FEL, gun, radiation, cryomodule

613

Y.M. Saveliev
STFC/DL/ASTeC, Daresbury, Warrington, Cheshire, United Kingdom

ALICE (Accelerators and Lasers In Combined Experiments) is a multifunctional ERL based R&D facility that operates in various regimes, both energy recovery and non energy recovery, depending on the project undertaken (beam energy 10-28MeV, bunch charge 20-100pC, train length from a single bunch to 100us). In early 2012, the DC HV photoinjector gun is expected to begin operation at nominal 350kV and a new cryomodule, a result of a wide international collaboration, will be installed and commissioned on ALICE. The improvements in beam dynamics and the overall beam quality will be discussed in this paper. The overview of the ALICE scientific programme including IR-FEL lasing and its application for scanning near field optical microscopy, generation and applications of coherent broadband THz radiation for life sciences and solid state physics, studies of the first non-scaling FFAG EMMA for which ALICE serves as an injector and accelerator physics research will also be presented.

MOPPR009

Dynamic Closed Orbit Correction During the Fast Energy Ramp of ELSA

closed-orbit, polarization, electron, controls

789

J.-P. Thiry, A. Balling, A. Dieckmann, F. Frommberger, W. Hillert
ELSA, Bonn, Germany

ELSA is a fast ramping stretcher ring supplying polarized electrons to hadron physics experiments. To preserve the degreee of polarization, it is necessary to continuously correct the vertical orbit when accelerating the beam from 1.2 GeV to 2.4 GeV. Acceleration is performed within 300 ms, thus with a ramping speed of 4 GeV/s. During the acceleration, beam positions are measured at a rate of 1 kHz using 32 beam position monitors, which are mounted close to the quadrupole magnets. The demanding task is to achieve a vertical rms deviation not exceeding 50 μm all along the fast energy ramp. Therefore, dynamic orbit corrections are applied by means of offline feed-forward techniques, driving 32 vertical steerer magnets which can change currents in less than 10 ms. In our contribution, we show the used concepts and the implementation of the precise closed orbit correction system at ELSA.

MOPPR055

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

ion, diagnostics, ion-source, vacuum

909

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

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

MOPPR056

Experimental and Theoretical Studies of a Low Energy H⁻ beam

rfq, ion-source, solenoid, ion

912

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

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

TUYB02

Manufacture and Testing of Optical-scale Accelerator Structures from Silicon and Silica

laser, electron, coupling, vacuum

1050

R.J. England, E.R. Colby, R. Laouar, C. McGuinness, B. Montazeri, R.J. Noble, K. Soong, J.E. Spencer, D.R. Walz, Z. Wu
SLAC, Menlo Park, California, USA
R.L. Byer, C.M. Chang, K.J. Leedle, E.A. Peralta
Stanford University, Stanford, California, USA
B.M. Cowan
Tech-X, Boulder, Colorado, USA
M. Qi
Purdue University, West Lafayette, Indiana, USA

We report on recent progress in the design, manufacture and testing of optical-scale accelerator structures made from silicon and silica. The potential of these structures for the development of extremely compact, efficient, and low cost accelerators producing attosecond electron pulses will be discussed, together with various possible applications.

Slides TUYB02 [17.226 MB]

TUYB03

FFAG Experience and Future Prospects

proton, focusing, betatron, lattice

1054

Y. Mori
Kyoto University, Research Reactor Institute, Osaka, Japan

This talk should outline the various FFAG accelerators that have been constructed, and discuss the operational experience with different machines. Common issues should be identified, and contrasting experiences highlighted. A frank assessment of the capability of FFAGs to meet the requirements for applications such as ion therapy, accelerator-driven subcritical reactors, and muon colliders should be followed by a description of the main objectives and challenges for future R&D.

Slides TUYB03 [14.162 MB]

TUOBC01

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

linac, target, emittance, gun

1101

R. Corsini
CERN, Geneva, Switzerland

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

Slides TUOBC01 [9.921 MB]

TUPPC019

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

alignment, simulation, injection, linac

1200

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

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

TUPPC021

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

emittance, linac, simulation, wakefield

1206

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

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

TUPPC040

Model Calibration and Optics Correction Using Orbit Response Matrix in the Fermilab Booster

booster, optics, dipole, coupling

1251

M.J. McAteer, S.E. Kopp
The University of Texas at Austin, Austin, Texas, USA
V.A. Lebedev, E. Prebys
Fermilab, Batavia, USA
A.V. Petrenko
BINP SB RAS, Novosibirsk, Russia

A beam-based method of optical model calibration using the measured orbit response matrix, known as the LOCO method, was successfully applied to Fermilab's rapid-cycling Booster synchrotron. Orbit responses were measured by individually changing the strength of each dipole corrector throughout the acceleration cycle, and dispersion was measured by changing the beam's radial offset. The model calibration procedure revealed large calibration errors for all elements in the Booster's recently-installed multipole corrector packages and beam position monitors. The resulting model was used to correct coupling and beta beating.

TUPPC053

Longitudinal Tuning of the SNS Superconducting Linac

cavity, linac, optics, controls

1290

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

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

TUPPC054

Beam Acceleration by a Multicell RF Cavity Structure Proposed for Improved Yield in Hydroforming

cavity, electron, quadrupole, focusing

1293

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

Funding: ORNL is managed by UT-Battelle, LLC, under contract DE-AC05-00OR22725 for the U.S. Department of Energy.
We study the accelerating properties of a new multicell cavity structure with irises forming a rectangular aperture between the cavity cells. We are interested in this structure because, from a mechanical point of view, the rectangular iris may make possible a much improved structure quality using a hydroforming manufacturing process. RF analysis shows that the rectangular iris shape provides asymmetric transverse focusing per half RF period. If the horizontal and vertical rectangular irises are interleaved, the net transverse focusing can be increased. The present studies of the acceleration and transport properties of these cavities are conducted by tracking particles through time-dependent 3D cavity fields from CST MWS using the ORBIT Code.

TUPPD013

Bunch Coalescing in a Helical Channel

collider, emittance, simulation, factory

1434

C. Y. Yoshikawa, C.M. Ankenbrandt
Muons, Inc, Batavia, USA
D.V. Neuffer, K. Yonehara
Fermilab, Batavia, USA

Funding: Supported in part by SBIR Grant 4725 · 09SC02739.
A high-luminosity Muon Collider requires bunch recombination for optimal luminosity. In this paper, we take advantage of the large slip factor in a helical transport channel (HTC) to coalesce bunches of muons into a single one over a shorter distance than can be achieved over a straight channel. The coalescing subsystem that is designed to merge 9 bunches has a horizontal length of ~105m and is able to achieve efficiencies of 99.7%, 98.4%, and 94.2% for 9, 11, and 13 bunches, respectively, where each bunch has emittances expected at the end of an HCC. Simplified designs incorporating fill factors for RF cavities of ~25% and ~50% obtained efficiencies of 96%, 94-95%, and 90-91% for 9, 11, and 13 bunches, respectively. The efficiencies above do not include decay losses, which would be ~8% for muons with kinetic energy of 200 MeV.

TUPPD071

Development of Cesium Telluride Photocathodes for the AWA Accelerator Upgrade

wakefield, vacuum, electron, cathode

1569

Z.M. Yusof, M.E. Conde, W. Gai
ANL, Argonne, USA
L.K. Spentzouris, E.E. Wisniewski
Illinois Institute of Technology, Chicago, Illinois, USA

Funding: U.S. Department of Energy Office of Science under Contract No. DE-AC02-06CH11357.
Cesium telluride photocathodes have been fabricated for the Argonne Wakefield Accelerator (AWA) upgrade. The as-deposited photocathodes have consistently produced quantum efficiency values better than 10% with 254 nm light source and with variation of less than 5% over a circular area of 1.2 inches in diameter. We present various characterizations of the photocathode that have performed, including rejuvenation, lifetime, and performance in the L-band AWA photoinjector.

TUPPR024

CLIC Recombination Scheme for the Low Energy Operation Mode

factory, luminosity, collider, linac

1864

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

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

WEXA02

Development of Electron Coolers in Novosibirsk

electron, ion, gun, proton

2068

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

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

Slides WEXA02 [7.872 MB]

WEOAB01

New Results from the EMMA Experiment

injection, resonance, betatron, electron

2134

B.D. Muratori, J.K. Jones
STFC/DL/ASTeC, Daresbury, Warrington, Cheshire, United Kingdom
C.S. Edmonds, K.M. Hock, M.G. Ibison, I.W. Kirkman
The University of Liverpool, Liverpool, United Kingdom
J.M. Garland, H.L. Owen
UMAN, Manchester, United Kingdom
D.J. Kelliher, S. Machida
STFC/RAL/ASTeC, Chilton, Didcot, Oxon, United Kingdom
J. Pasternak
Imperial College of Science and Technology, Department of Physics, London, United Kingdom

EMMA (Electron Model for Many Applications) is a prototype non-scaling electron FFAG hosted at Daresbury Laboratory. After demonstration of acceleration in the serpentine channel in April 2011, the beam study with EMMA continues to explore the large transverse and longitudinal acceptance and effects of integer tune crossing with slower rate on the betatron amplitude. Together with a comparison of detailed models based on measured field maps and the experimental mapping of the machine by relating the initial and final phase space coordinates. These recent results together with more practical improvements such as injection orbit matching with real-time monitoring of the coordinates in the transverse phase space will be reported in this paper.

Slides WEOAB01 [2.120 MB]

WEIC06

Accelerator R&D: Research for Science - Science for Society

laser, hadron, proton, emittance

2161

N.R. Holtkamp
SLAC, Menlo Park, California, USA
S. Biedron, S.V. Milton
CSU, Fort Collins, Colorado, USA
L. Boeh, J.E. Clayton, G. Zdasiuk
VMS GTC, Palo Alto, California, USA
S.A. Gourlay, M.S. Zisman
LBNL, Berkeley, California, USA
R.W. Hamm
R&M Technical Enterprises, Pleasanton, California, USA
S. Henderson
Fermilab, Batavia, USA
G.H. Hoffstaetter
CLASSE, Ithaca, New York, USA
L. Merminga
TRIUMF, Canada's National Laboratory for Particle and Nuclear Physics, Vancouver, Canada
S. Ozaki
BNL, Upton, Long Island, New York, USA
F.C. Pilat
JLAB, Newport News, Virginia, USA
M. White
ANL, Argonne, USA

In September 2011 the US Senate Appropriations Committee requested a ten-year strategic plan from the Department of Energy (DOE) that would describe how accelerator R&D today could advance applications directly relevant to society. Based on the 2009 workshop "Accelerators for America’s Future" an assessment was made on how accelerator technology developed by the nation’s laboratories and universities could directly translate into a competitive strength for industrial partners and a variety of government agencies in the research, defense and national security sectors. The Office of High Energy Physics, traditionally the steward for advanced accelerator R&D within DOE, commissioned a task force under its auspices to generate and compile ideas on how best to implement strategies that would help fulfill the needs of industry and other agencies, while maintaining focus on its core mission of fundamental science investigation.

Slides WEIC06 [3.678 MB]

WEEPPB001

Progress Toward a High-Transformer-Ratio Dielectric Wakefield Experiment at FLASH

electron, wakefield, laser, simulation

2166

F. Lemery, D. Mihalcea, P. Piot
Northern Illinois University, DeKalb, Illinois, USA
J. Osterhoff
MPQ, Garching, Munich, Germany
C.A.J. Palmer
DESY, Hamburg, Germany
P. Stoltz
Tech-X, Boulder, Colorado, USA

Funding: Work supported by the U.S. Department of Energy, Office of Science, Office of Basic Energy Sciences, under Contract No. DE-AC02-06CH11357
Dielectric wakefield accelerators offer many advantages over conventional RF accelerators such as higher acceleration gradients and cost effectiveness. In this paper we describe our experimental plans to demonstrate enhanced transformer ratios with drive and witness bunches. The experiment, will be performed at the Free-electron LASer in Hamburg (FLASH) and utilizes unique pulse shaping capabilities using the dual-frequency superconducting linac to produce high transformer ratios (>2). The beam-driven acceleration mechanism will be based on a cylindrical-symmetric dielectric-lined waveguide (DLW). The experimental setup is described, and start-to-end numerical simulations of the experiment will be presented.

WEEPPB002

Plasma Acceleration Experiment at SPARC_LAB with External Injection

plasma, electron, laser, injection

2169

L. Serafini, A. Bacci
Istituto Nazionale di Fisica Nucleare, Milano, Italy
M. Bellaveglia, M. Castellano, E. Chiadroni, G. Di Pirro, M. Ferrario, A. Gallo, G. Gatti, A.R. Rossi, C. Vaccarezza
INFN/LNF, Frascati (Roma), Italy
A. Cianchi
Università di Roma II Tor Vergata, Roma, Italy
C. Maroli, V. Petrillo
Universita' degli Studi di Milano, Milano, Italy
A. Mostacci
URLS, Rome, Italy
P. Tomassini
Università degli Studi di Milano, Milano, Italy

At the SPARC-LAB facility of INFN-LNF we are installing two transport lines for ultra-short electron bunches and an ultra-intense laser pulses, generated by the SPARC photo-injector and by the FLAME laser in a synchronized fashion at the tens of fs level, to co-propagate inside a hydrogen filled glass capillary, in order to perform acceleration of the electron bunch by a plasma wave driven by the laser pulse. The main aim of this experiment is to demonstrate that a high brightness electron beam can be accelerated by a plasma wave without any significant degradation of its quality. A 10 pC electron bunch, 10 fs long is produced by SPARC and transported to injection into the capillary, which is 100 micron wide, at a gas density around 5*10¹⁷ ne/cm³ . The laser pulse, 25 fs long, focused down to 30 microns into the capillary is injected ahead of the bunch, drives a weakly non-linear plasma wave with wavelength of about 120 microns. A proper phasing of the two pulses allows acceleration of electrons from the injection energy of 150 MeV up to about 1 GeV for a 10 cm long capillary. Installation of the beam lines is foreseen by the end of 2012 and first tests starting in mid 2013.

WEEPPB003

Modeling of 10 GeV-1 TeV Laser-Plasma Accelerators Using Lorentz Boosted Simulations

laser, plasma, simulation, controls

2172

J.-L. Vay, E. Esarey, C.G.R. Geddes, W. Leemans, C.B. Schroeder
LBNL, Berkeley, California, USA
E. Cormier-Michel
Tech-X, Boulder, Colorado, USA
D.P. Grote
LLNL, Livermore, California, USA

Funding: Supported by US-DOE Contracts DE-AC02-05CH11231 and DE-AC52-07NA27344, US-LHC program LARP, and US-DOE SciDAC program ComPASS.
Modeling of laser-plasma wakefield accelerators in an optimal frame of reference [J.-L. Vay, Phys. Rev. Lett. 98 130405 (2007)] allows direct and efficient full-scale modeling of deeply depleted and beam loaded laser-plasma stages of 10 GeV-1 TeV (parameters not computationally accessible otherwise). This verifies the scaling of plasma accelerators to very high energies and accurately models the laser evolution and the accelerated electron beam transverse dynamics and energy spread. Over 4, 5 and 6 orders of magnitude speedup is achieved for the modeling of 10 GeV, 100 GeV and 1 TeV class stages, respectively. Agreement at the percentage level is demonstrated between simulations using different frames of reference for a 0.1 GeV class stage. Obtaining these speedups and levels of accuracy was permitted by solutions for handling data input (in particular particle and laser beams injection) and output in a relativistically boosted frame of reference, as well as mitigation of a high-frequency instability that otherwise limits effectiveness.
Used resources of NERSC, supported by US-DOE Contract DE-AC02-05CH11231.

WEPPC027

A Quarter Wave Design for Crab Crossing in the LHC

cavity, HOM, high-voltage, higher-order-mode

2260

R. Calaga
CERN, Geneva, Switzerland
S.A. Belomestnykh, I. Ben-Zvi, Q. Wu
BNL, Upton, Long Island, New York, USA

Funding: This work partially supported by the US Department of Energy through the US LHC Accelerator Research Program (LARP).
The aperture constraints of the LHC interaction region and the alternating crossing schemes at two collision points calls for a superconducting deflecting cavity with very compact dimensions at low frequencies for the purpose of crab crossing. A new concept of using a superconducting 1/4-wave design, ideally suited to address the LHC constraints at 400 MHz, is proposed. The optimized RF cavity design and associated advantages of using a 1/4 wave resonator are presented. Aspects related to higher order mode damping, multipacting and frequency tuning are also addressed.

WEPPC034

LA³NET - An International Network on Laser Applications at Accelerators

laser, ion, diagnostics, electron

2281

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

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

WEPPC047

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

linac, cavity, multipole, focusing

2318

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

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

WEPPD016

Development of Glassy Carbon Blade for LHC Fast Vacuum Valve

vacuum, kicker, synchrotron, synchrotron-radiation

2528

C. Garion, P. Coly
CERN, Geneva, Switzerland

An unexpected gas inrush in a vacuum chamber leads to the development of a fast pressure wave. It carries small particles that can compromise the functioning of sensitive machine systems such as the RF cavities or kickers. In the LHC machine, it has been proposed to protect these equipments by the installation of fast vacuum valves. The main requirements for the fast valves and in particular for the blade are: fast closure in the 20 ms range, high transparency and melting temperature in case of closure with beam in, dust free material to not contaminate sensitive adjacent elements and last but not least vacuum compatibility and adequate leak tightness across the blade. In this paper, a design based on a vitreous carbon blade is proposed. The main reasons for this material choice are given. The mechanical study of the blade behaviour under dynamic forces is shown. Fabrication considerations are addressed as well. Tests on prototypes have been carried out on pendulum type fast valves developed for LEP. Results on glassy carbon blades are presented as well as the motion parameter measurements. Qualification of the material for UHV applications has been carried out.

WEPPD045

An Application of Multi-stage Adjustable Shock Absorbers for the Girders of Storage Ring in Taiwan Photon Source

damping, controls, storage-ring, photon

2615

C.-S. Lin, J.-R. Chen, M.L. Chen, H.C. Ho, K.H. Hsu, D.-G. Huang, C.K. Kuan, W.Y. Lai, C.J. Lin, H.M. Luo, S.Y. Perng, P.L. Sung, Y.L. Tsai, T.C. Tseng, H.S. Wang, M.H. Wu
NSRRC, Hsinchu, Taiwan
D.-Y. Chiang
NCKU, Tainan city, Taiwan

Beam stability is a major concern for the operation of the Taiwan Photon Source (TPS). One of the many factors to instability of electron beam is mechanical vibration of the accelerator components. The TPS uses steel girders to support the magnets and vacuum chambers in the storage ring. Three pedestal and six mover assemblies support the girders. Multi-stage adjustable shock absorbers are designed for passive vibration damping, and presently installed between the girders and the pedestals. Through adjusting the amount of hydraulic fluid which bypasses the damping passage between two hydraulic chambers, the desired damping coefficient of the damping absorbers can be achieved. Experimental results of modal testing presented in this paper show that the multi-stage adjustable damping absorbers under the assembly of the girders reduced the level of girder vibration.

WEPPD050

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

linac, controls, klystron, injection

2630

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

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

WEPPD053

The LLNL/UCLA High Gradient Inverse Free Electron Laser Accelerator

electron, laser, undulator, simulation

2639

J.T. Moody, P. Musumeci
UCLA, Los Angeles, California, USA
G.G. Anderson, S.G. Anderson, M. Betts, S.E. Fisher, D.J. Gibson, A.M. Tremaine, S.S.Q. Wu
LLNL, Livermore, California, USA

Funding: This work performed under the auspices of the U.S. Department of Energy by Lawrence Livermore National Laboratory under Contract DE-AC52-07NA27344.
We describe the Inverse Free Electron Accelerator currently under construction at Lawrence Livermore National Lab. Upon completion of this accelerator, high brightness electrons generated in the photoinjector blowout regime and accelerated to 50 MeV by S-band accelerating sections will interact with > 4 TW peak power Ti:Sapphire laser in a highly tapered 50 cm undulator and experience an acceleration gradient of >200 MeV/m. We present the final design of the accelerator as well as the results of start to end simulations investigating preservation of beam quality and tolerances involved with this accelerator.

WEPPD059

Proton Acceleration by a Relativistic Laser Frequency-Chirp Driven Plasma Snowplow

laser, plasma, proton, electron

2654

A. A. Sahai, T.C. Katsouleas
Duke ECE, Durham, North Carolina, USA
R. Bingham
STFC/RAL/ASTeC, Chilton, Didcot, Oxon, United Kingdom
W.B. Mori, A. Tableman, F.S. Tsung, M. Tzoufras
UCLA, Los Angeles, California, USA

Funding: NSF-PHY-0936278, NSF-PHY-0904039 and NSFPHY-0936266, US DOE DE-FC02-07ER41500 and DE-FG02-92ER40727, DOE Fusion Science Center through a University of Rochester Subcontract No. 415025-G.
We analyze the use of a relativistic laser pulse with a controlled frequency chirp incident on a rising plasma density gradient to drive an acceleration structure for proton and light ion acceleration. The Chirp Induced Transparency Acceleration (ChITA) scheme is described with an analytical model of the velocity of the snowplow at critical density on a pre-formed rising plasma density gradient that is driven by positive chirp in the frequency of a relativistic laser pulse. The velocity of the ChITA-snowplow is shown to depend upon rate of rise of the frequency of the relativistic laser pulse, the normalized magnetic vector potential of the laser pulse and the plasma density gradient scale-length. We observe using 1-D OSIRIS simulations the formation and forward propagation of ChITA-snowplow, being continuously pushed by the chirping laser at a velocity in accordance with the analytical results. The trace protons reflect off of this propagating snowplow structure and accelerate monoenergetically. The control over ChITA-snowplow velocity allows the tuning of accelerated proton energies.

WEPPP003

Focusing of Accelerated Particles by Wakefields of a Drive Bunch in a Plasma-dielectric Waveguide

plasma, wakefield, electron, focusing

2723

G.V. Sotnikov, R.R. Kniaziev
NSC/KIPT, Kharkov, Ukraine

Funding: The research is supported in part by the Science and Technology Center in Ukraine (STCU), project No. P522.
One of wakefield acceleration methods as a slowing medium uses the plasma of a capillary discharge*. The capillary tube is a slowing medium, therefore at propagation in it of a laser pulse or relativistic electron bunches (REB) along with plasma wakefields will be excited an eigen waves of dielectric structure. So far influence of electrodynamic properties of capillary tube material on plasma wakefields is not investigated. On an example of a cylindrical waveguide of gigahertz operation frequency range, we investigate excitation of wakefields by REB in a dielectric waveguide (DW) with the accelerating channel filled with isotropic plasma. The excited field consists of Langmuir wave fields (LW) and fields of eigen waves of DW. At certain plasma density a longitudinal electric field of LW it is significantly less than the similar of DW waves , and transverse components of the LW field are significantly higher than transverse component of DW waves. The periods of these two types of waves generally do not coincide. The range of plasma densities which provides a simultaneous acceleration and focusing of test bunch by LW is found.
* Steinhauer L.C., Kimura W.D. Phys. Rev. STAB. V.9, 081301 (2006).

WEPPP004

A Reciprocity Principle for Wakefields in a Two-Channel Coaxial Dielectric Structure

wakefield, vacuum, simulation, dipole

2726

G.V. Sotnikov
NSC/KIPT, Kharkov, Ukraine
J.L. Hirshfield, T.C. Marshall, G.V. Sotnikov
Omega-P, Inc., New Haven, USA
S.V. Shchelkunov
Yale University, Beam Physics Laboratory, New Haven, Connecticut, USA

Funding: Research is supported by U.S. Department of Energy, Office of High Energy Physics.
The reciprocity principle* is often used in applications of classical electromagnetism. We have employed this principle for testing wakefields set up by an electron bunch in a two-channel coaxial dielectric structure (CDWA)**. For numerical studies we take a ~1-THz fused silica structure which we plan to test at FACET/SLAC; it has dimensions: outer shell, OD=800 μm, ID=500 μm; inner shell OD=181 μm, ID=50 μm. The structure is energized by a 23-GeV, 3-nC bunch having axial RMS size=25 μm. FACET has no drive bunch of annular shape as required for a CDWA; nevertheless, our analytical studies and simulations prove that for the axial wakefield, an annular drive bunch can be replaced by a pencil-like bunch of the same charge traveling in the annular vacuum channel. The longitudinal electric field along the accelerator channel axis (as recorded by a witness bunch) set up by this pencil-like bunch is the same as in the conventional structure of the CDWA. Moreover, if we interchange the drive bunch and the witness bunch, the witness bunch will register the same axial wakefield. However, the stability of the annular bunch is far superior to that of the pencil bunch.
*L. D. Landau and E. M. Lifshitz, Electrodynamics of Continuous Media (Addison-Wesley: Reading, MA, 1960).
**G. Sotnikov et al., PRST-AB, 061302 (2009).

WEPPP006

Using Simulations to Understand Particle Dynamics and Resonance in the Micro-accelerator Platform

laser, resonance, electron, coupling

2732

J.C. McNeur, G. Travish
UCLA, Los Angeles, USA
H. Hairong
UESTC, Chengdu, Sichuan, People's Republic of China
R.B. Yoder
Manhattanville College, Purchase, New York, USA

Funding: Work funded in part by grant HDTRA1-09-1-0043 from the US Defense Threat Reduction Agency and under a grant from NNSA/NA-221 Office of Nonproliferation and Verification Research and Development.
The Micro-Accelerator Platform (MAP) is a slab-symmetric micron-scale electron accelerator. Electrons gain energy via a standing wave electromagnetic resonance powered by a side coupled Ti:Sapphire laser. In this paper, we will discuss simulations of resonance and particle dynamics in this structure. Three-dimensional simulations showing evidence of stable 1 GeV/m acceleration are detailed along with simulations studying defocusing and wakefield effects in the MAP. Additionally, optimization of the structure and the coupling of laser power into the cavity will be explored.

WEPPP008

Vacuum Laser Acceleration Experiment Perspective at Brookhaven National Lab-Accelerator Test Facility

laser, electron, vacuum, simulation

2735

X.P. Ding, D.B. Cline, L.S. Shao
UCLA, Los Angeles, California, USA
M.G. Fedurin, K. Kusche, I. Pogorelsky, V. Yakimenko
BNL, Upton, Long Island, New York, USA
Y.K. Ho, Q. Kong
Fudan University, Shanghai, People's Republic of China
J.J. Xu
Shanghai Institute of Optics and Fine Mechanics, Shanghai, People's Republic of China

Funding: Supported by the DOE under award number DE-FG02-92ER40695 (UCLA)
This paper presents the pre-experiment plan and prediction of the first stage of Vacuum Laser Acceleration (VLA) collaborating by UCLA, Fudan University and ATF-BNL. This first stage experiment is a Proof-of-Principle to support our previously posted novel VLA theory. Simulations show that based on ATF’s current experimental conditions, the electron beam with initial energy of 15MeV can get net energy gain from intense CO2 laser beam. The difference of electron beam energy spread is observable by ATF beam line diagnostics system. Further this energy spread expansion effect increases along with the laser intensity increasing. The proposal has been approved by ATF committee and experiment will be the next project.

WEPPP009

Experimental Progress Towards a Resonant Slab-symmetric Dielectric Laser Accelerator

simulation, laser, electron, vacuum

2738

G. Travish, K.S. Hazra, G. Liu, J.C. McNeur, E.B. Sozer, J. Zhou
UCLA, Los Angeles, California, USA
H. Hairong
UESTC, Chengdu, Sichuan, People's Republic of China
R.B. Yoder
Manhattanville College, Purchase, New York, USA

Funding: Work funded in part by grant HDTRA1-09-1-0043 from the US Defense Threat Reduction Agency and under a grant from NNSA/NA-221 Office of Nonproliferation and Verification Research and Development.
TheμAccelerator Platform (MAP), a resonant dielectric structure for laser acceleration of electrons, has been in development for a number of years. It consists of a a vacuum gap between two slab-shaped reflecting boundaries, with a transmissive grating diffractive optic on one boundary that allows laser power to propagate into the gap and enforces an accelerating mode. We report on the progress of bench and beam tests carried out within the last year, and the challenges faced in diagnosing <pC beams from optical-scale structures. We also describe refinements to our fabrication techniques and lessons learned during the development of the fabrication process.

WEPPP010

FACET: SLAC's New User Facility

electron, positron, wakefield, linac

2741

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

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

WEPPP011

Multi-Cavity Proton Cyclotron Accelerator: An Electron Counterpart

cavity, proton, electron, cyclotron

2744

M.A. LaPointe, S.V. Shchelkunov
Yale University, Beam Physics Laboratory, New Haven, Connecticut, USA
J.L. Hirshfield
Omega-P, Inc., New Haven, USA
V.P. Yakovlev
Fermilab, Batavia, USA

Funding: Supported by the Department of Energy, Office of Nuclear Physics.
A multi-cavity multi-frequency proton cyclotron accelerator has been proposed. It would utilize cyclotron resonance in each of eight cavities of uniformly diminishing frequency in a uniform magnetic field to comprise a compact (25 m) 1 GeV proton accelerator, according to simulation results*. A four cavity electron counterpart is under construction to test the mechanism of the multi-cavity setup, including phase acceptance, energy gain, and growth of energy spread and emittance for parameters equivalent to the proton case. The four electron counterpart cavities are driven by kW-level phase coherent RF sources at 1.5, 1.8, 2.1 and 2.4 GHz. Each cavity operates in the rotating TE111 mode and includes two feeds in quadrature to drive the rotating mode and two RF pickoffs for diagnostics. The electron beam source is a low-current gun with a BaO cathode which operates at -1200V and <50 microamps. After traversing the cavities, the beam is collected on either a Faraday cup or is imaged with a phosphor screen. Details of the setup and initial results from experiments with the four cavity electron counterpart will be presented.
* M.A. LaPointe, V.P. Yakovlev, S.Yu. Kazakov, and J.L. Hirshfield, Proc. of PAC 2009, May 4-8,Vancouver, BC, Canada, pp.3045-3047 (2011).

WEPPP012

High-Gradient THz-Scale Two-Channel Coaxial Dielectric-Lined Wakefield Accelerator

wakefield, radiation, vacuum, focusing

2747

S.V. Shchelkunov, M.A. LaPointe
Yale University, Beam Physics Laboratory, New Haven, Connecticut, USA
J.L. Hirshfield, T.C. Marshall
Omega-P, Inc., New Haven, USA
G.V. Sotnikov
NSC/KIPT, Kharkov, Ukraine

Funding: Research is supported by U.S. Department of Energy, Office of High Energy Physics.
A mm-scale THz Coaxial Dielectric Wakefield Accelerator structure is currently under study by Yale University Beam Physics Lab and collaborators for its performance with annular drive bunches. With our recent successful experiments with the cm-scale GHz rectangular module at AWA/Argonne (USA) and planned activity there with yet another cm-scale GHz coaxial structure, the program of new research has two objectives. The first is to design a structure to produce acceleration gradients approaching 0.35 GeV/m per each nC of drive charge when excited by an annular-like bunch; has an attractive feature that the drive and accelerated bunches both have good focusing and stability properties; and also exhibits a large transformer ratio. The second goal is to build and test the structure at FACET/SLAC (USA). At FACET the structure can be excited only with the available pencil-like drive bunch, but the reciprocity principle allows one to observe some of the properties that would be seen if the excitation were to be by an annular drive bunch. This presentation shows our latest findings, discusses related issues, and discusses our plans for experiments.

WEPPP014

Modeling of Quasi-phase Matching in an Aperiodic Corrugated Plasma Waveguide for High-efficiency Direct Laser Electron Acceleration

electron, plasma, laser, simulation

2750

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

Funding: This work is supported by the Defense Threat Reduction Agency through contract HDTRA1-10^-1-0034.
Direct laser acceleration (DLA) of charged particles using the axial electric field of a radially polarized intense laser pulse has the potential to realize a compact accelerator required in security and medical applications. The implementation of guided propagation of laser pulses over long distances and the phase matching between electrons and laser pulses may limit the performance of DLA in reality*. A corrugated plasma waveguide could be applied to extend the laser beam propagation distance and for quasi-phase matching between laser and electron pulses for net acceleration. To accelerate electrons from a low initial energy (for example, ~5 MeV from a photoinjector gun) up to hundreds of MeV, an aperiodic corrugated plasma waveguide with successive increase of on-axis density modulation period is needed**. We conducted particle-in-cell simulations to design the appropriate aperiodic plasma structure for DLA. For each section of the corrugated waveguide, the dependence of density modulation period on the initial electron energy and laser pulse intensity is investigated. The simulation results are guiding the design of proof-of-principle experiments for compact, tabletop DLA.
* P. Serafim, et al., IEEE Trans. Plasma Sci. 28, 1155 (2000).
** J. P. Palastro, et al., Phys. Rev. E. 77, 036405 (2008).

WEPPP018

A New Beam Injection Scheme for a Compact Low-energy Storage Ring

injection, kicker, damping, storage-ring

2761

Y. Honda
KEK, Ibaraki, Japan

A very compact storage ring at low energy has an unique application such as Compton X-ray source. Scheme for efficient injection is an issue for such a compact storage ring. Utilizing a phase-shift in the non-relativistic energy region, a new idea for accumulating the incoming bunch on an already circulating bunch without any kicker or orbit bump has been presented. Its applicable parameter range will be presented.

WEPPP019

Designing of Photonic Crystal Accelerator for Radiation Biology

laser, electron, vacuum, injection

2763

K. Koyama, Y. Matsumura
University of Tokyo, Tokyo, Japan
A. Aimidula, M. Uesaka
The University of Tokyo, Nuclear Professional School, Ibaraki-ken, Japan
T. Natsui, M. Yoshida
KEK, Ibaraki, Japan

Funding: This work was performed as part of the Global COE Program (Nuclear Education and Research Initiative, MEXT, Japan.
A photonic crystal accelerator with a combination of a fiber laser is under development in order to apply it to the radiation biology. In order to investigate fundamental biological processes in a cell, a DNA is precisely shot by an electron bunch with an in situ observation of a radiation interaction using a microscope. Required beam diameter, bunch length, and beam energy are nanometer, attosecond, and 100 keV to 1 MeV, respectively. A photonic crystal or dielectric laser accelerator energized by a fiber laser is suitable for producing such a fine beam with a palm top device. A preliminary estimation shows that 200 keV electron bunch is available from a 0.8-mm-long accelerator and a few cm electron gun, which is driven by a few μJ, 5-ps laser pulse. We are developing a fiber laser in order to drive the photonic crystal accelerator. The Yb-fiber oscillator delivers mode-locked pulse train of ≈5 nJ/pulse at the repetition frequency of 62.5 MHz. The output pulse will be increased to several μJ by adopting a fiber amplifier

WEPPP020

Rebunching Low Energy Neutrons by Magnetic Acceleration and Deceleration

neutron, dipole, controls, focusing

2766

Y. Iwashita
Kyoto ICR, Uji, Kyoto, Japan
Y. Arimoto, H.M. Shimizu
KEK, Ibaraki, Japan
P.W. Geltenbort
ILL, Grenoble, France
S. Imajo
Kyoto University, Kyoto, Japan
M. Kitaguchi
Kyoto University, Research Reactor Institute, Osaka, Japan
Y. Seki
RIKEN Nishina Center, Wako, Japan
T. Yoshioka
Kyushu University, Fukuoka, Japan

Funding: Supported by the Grant-in-Aid for Creative Scientific Research of MEXT under the Program 19GS0210, the Quantum Beam Fundamentals Development Program of the MEXT, and KEK Neutron Program 2009S03.
Ultra cold neutrons (UCN) - neutrons with energies less than 300 neV - can be accelerated or decelerated by means of static magnetic and RF fields. The method and experimental setup will be described in detail and the results of a recent first test experiment will be presented. The detail cannot be disclosed until the paper is published.

WEPPP022

Analysis of a Rectangular Dielectric-lined Accelerating Structure with an Anisotropic Loading

wakefield, radiation, electron, impedance

2769

I.L. Sheynman, S. Baturin
LETI, Saint-Petersburg, Russia
A. Kanareykin
Euclid TechLabs, LLC, Solon, Ohio, USA

Funding: Russian Fund of Basic Research Federal target program "Scientific and scientific and pedagogical personnel of innovative Russia" of the Ministry of Education and Science of Russia.
Analysis of Cherenkov radiation generated by high current relativistic electron bunch passing through a rectangular waveguide with anisotropic dielectric loading has been carried out. Some of the materials used for the waveguide loading of accelerating structures (sapphire) possess significant anisotropic properties. In turn, it can influence excitation parameters of the wakefields generated by an electron beam. Using orthogonal eigenmodes decomposition for the rectangular dielectric waveguide, the analytical expressions for the wakefields have been obtained. Numerical modeling of the longitudinal and transverse (deflecting) wakefields has been carried out as well. It is shown that the dielectric anisotropy causes frequency shift in comparison to the dielectric-lined waveguide with the isotropic dielectric loading.

WEPPP023

Radiation of a Bunch Intersecting a Boundary between Vacuum and Dielectric in a Circular Waveguide

vacuum, wakefield, radiation, plasma

2772

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

Funding: Saint Petersburg State University
Analysis of a field of a particle bunch in a waveguide loaded with a dielectric is important for the wakefield acceleration technique and for other problems in accelerator physics. We investigate the field of the bunch crossing a boundary between two dielectrics in a circular waveguide. We take into account the finite length of the bunch and analyze both the field structure and the energy loss. Special attention is paid to two cases: the bunch flies from vacuum into dielectric and from dielectric into vacuum. In the first case, investigation of formation of stationary wakefield is of interest (this is important for the wakefield acceleration technique). In the second case, quasi monochromatic wave is generated in the vacuum region. This effect can be used for elaboration of a quasi-monochromatic radiation generator of new type. In both cases we also study dynamics of the energy loss of the bunch.
* T.Yu. Alekhina, A.V. Tyukhtin. Proc. of IPAC2011, San Sebastian, Spain, WEPZ012, p. 2793 (2011).

WEPPP024

Cherenkov Radiation from a Small Bunch Moving in a Cold Magnetized Plasma

plasma, radiation, wakefield, electromagnetic-fields

2775

S.N. Galyamin, D.Y. Kapshtan, A.V. Tyukhtin
Saint-Petersburg State University, Saint-Petersburg, Russia

Funding: Saint Petersburg State University.
Investigation of the bunch radiation in plasma is important for the plasma wakefield acceleration (PWFA) technique and other applications in accelerator physics. We study the electromagnetic field of small relativistic bunch moving in a magnetized cold plasma along the magnetic field. The energy loss of the bunch was investigated earlier, however the structure of electromagnetic field was not analyzed. We perform analytical and numerical investigation of total field. Different equivalent representations for the field components are obtained. One of them allows separating quasistatic field and radiation one. Method of computation is developed as well. Some interesting physical effects are described. One of them is strong increase of some components of radiation field near the charge motion line (in the case of point charge). The case of a charged disc is considered as well. Prospects of use of obtained results for PWFA are discussed.

WEPPP025

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

wakefield, gun, electron, linac

2778

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

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

WEPPP027

PBG-slab Embedded Traveling Wave Structure for Planar Beam Accelerator Application

electron, HOM, photon, lattice

2784

Y.-M. Shin
Fermilab, Batavia, USA

The oversized traveling wave (TE10-mode) channel integrated with the photonic-band-gap (PBG) slab arrays have been investigated for planar beam accelerator application. Simulation analysis showed that the slab arrays allow only the PBG-modes (5-6 GHz) to propagate with ~ 2 dB of insertion loss, corresponding to ~ 1.14 dB/cm attenuation, which thereby effectively suppresses trapped non-PBG modes down to ~ -14.3 dB/cm. It will enable monochromatic propagation of fundamental acceleration modes along the heavily over-moded planar waveguide without anomalous excitation of unstable trapped HOMs. The saturated maximum field gradients of the accelerating structure have been analyzed with respect to operational frequency bands corresponding to structural sizes. The field gradient of the guided PBG-mode has been investigated with finite-integral-method (FIM) simulations at W-band. This mode-filter could be utilized for HOM dampers in high aspect ratio (HAR) planar beam accelerators. An experimental test is currently under consideration.

WEPPP029

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

ion, laser, target, light-ion

2787

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

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

WEPPP032

Inverse Free Electron Laser Acceleration Using Ultra-fast Solid State Laser Technology

laser, undulator, simulation, electron

2795

S.G. Anderson, G.G. Anderson, S.M. Betts, S.E. Fisher, D.J. Gibson, A.M. Tremaine, S.S.Q. Wu
LLNL, Livermore, California, USA
J.T. Moody, P. Musumeci
UCLA, Los Angeles, California, USA

Funding: This work performed under the auspices of the U.S. Department of Energy by Lawrence Livermore National Laboratory under Contract DE-AC52-07NA27344.
We present a theoretical and computational study of the application of Ti:Sapphire laser technology to Inverse Free Electron Laser (IFEL) accelerators. Specifically, the regime in which the number of undulator periods is comparable to the number of cycles in the laser pulse is investigated and modifications to the IFEL accelerator equations and laser requirements are given. 1-D and 3-D simulations are used to study the IFEL interaction in this regime. In addition, the effects of non-Gaussian laser pulses, and astigmatic aberrations in the laser focus are analyzed. Finally, the tools developed for this study are applied to the LLNL/UCLA IFEL experiment, and potential future IFEL designs.

WEPPP036

Undulator Commissioning for a High-Energy-Gain Inverse Free Electron Laser Experiment

undulator, laser, electron, simulation

2804

J.P. Duris, R.K. Li, P. Musumeci, E.W. Threlkeld
UCLA, Los Angeles, California, USA

Funding: This work was supported by DOE grant DE-FG02-92ER40693 and Defense of Threat Reduction Agency award HDTRA1-10^-1-0073.
We present the construction and measurement details of a strongly tapered helical undulator for the Rubicon Inverse Free Electron Laser (IFEL) experiment. Results of the magnetic field measurements are presented, and these are used to produce simulations of the expected performance of the experiment. Finally, a study of the tolerances on the input parameters of the experiment is presented.

WEPPP040

Progress Report on Development of Novel Ultrafast Mid-IR Laser System

laser, FEL, wakefield, background

2810

R. Tikhoplav, A.Y. Murokh
RadiaBeam, Santa Monica, USA
I. Jovanovic
Penn State University, University Park, Pennsylvania, USA

Finding alternate acceleration mechanisms that can provide very high gradients is of particular interest to the accelerator community. Those mechanisms are often based on either dielectric laser acceleration or laser wakefield acceleration techniques, which would greatly benefit from mid-IR ultrafast high peak power laser systems. The approach of this proposed work is to design a novel ultrafast mid-IR laser system based on optical parametric chirped-pulse amplification (OPCPA). OPCPA is a technique ideally suited for production of ultrashort laser pulses at the center wavelength of 2μm-5μm. Some of the key features of OPCPA are the wavelength agility, broad spectral bandwidth and negligible thermal load. This paper reports on the progress of the development of the ultrafast mid-IR laser system.

WEPPP042

Experimental Demonstration of Wakefield Effects in a 250 GHz Planar Diamond Accelerating Structure

wakefield, dipole, radiation, electron

2816

S.P. Antipov, J.E. Butler, C.-J. Jing, A. Kanareykin, P. Schoessow, S.S. Zuo
Euclid TechLabs, LLC, Solon, Ohio, USA
M.G. Fedurin, K. Kusche, V. Yakimenko
BNL, Upton, Long Island, New York, USA
W. Gai
ANL, Argonne, USA

Funding: DOE SBIR
We have directly measured the mm-wave wake fields induced by subpicosecond, intense relativistic electron bunches in a diamond loaded accelerating structure via the dielectric wake-field acceleration mechanism. Fields produced by a first, drive, beam were used to accelerate a second, witness, electron bunch which followed the driving bunch at an adjustable distance. The energy gain of the witness bunch as a function of its separation from the drive bunch is a direct measurement of the wake potential. We also present wakefield mapping results for THz quartz structures. In this case decelerating wake inside the bunch is inferred from the drive beam energy modulation.

WEPPP044

Advances in CVD Diamond for Accelerator Applications

wakefield, plasma, laser, electron

2819

A. Kanareykin, S.P. Antipov, J.E. Butler, C.-J. Jing, S.S. Zuo
Euclid TechLabs, LLC, Solon, Ohio, USA

Funding: Work supported by the SBIR program of the US Department of Energy.
Diamond is being evaluated as a dielectric material for dielectric loaded accelerating structures. It has a very low microwave loss tangent, high thermal conductivity, and supports high RF breakdown fields. We report on progress in fabricating chemical vapor deposited (CVD) diamond materials for cylindrical dielectric structures for use in wakefield particle accelerators. Tubes with inner diameters of 3 and 5 mm have been grown from polycrystalline CVD diamond on mandrels using microwave plasma assisted CVD. The material has been laser trimmed to the desired thicknesses and lengths. In addition, structures with smaller inner diameters (ca. 0.3 mm) have been laser machined from blocks of single crystal diamond grown by CVD. Rectangular (planar) dielectric structures have been constructed from plates of polished CVD diamond. Wakefields in these structures have been studied at the Brookhaven ATF.

WEPPP046

Nonlinear Dielectric Wakefield Experiment for FACET

wakefield, simulation, controls, factory

2825

P. Schoessow, S.P. Antipov, C.-J. Jing, A. Kanareykin
Euclid TechLabs, LLC, Solon, Ohio, USA
S. Baturin
LETI, Saint-Petersburg, Russia

Funding: Work supported by the SBIR Program, US Dept. of Energy.
Recent advances in ferroelectric ceramics have resulted in new possibilities for nonlinear devices for particle accelerator and rf applications. The new FACET (Facility for Advanced Accelerator Experimental Tests) at SLAC provides an opportunity to use the GV/m fields from its intense short pulse electron beams to perform experiments using the nonlinear properties of ferroelectrics. Simulations of Cherenkov radiation in the THz planar and cylindrical nonlinear structures to be used in FACET experiments will be presented. Signatures of nonlinearity are clearly present in the simulations: superlinear scaling of field strength with beam intensity, frequency upshift, and development of higher frequency spectral components.

WEPPR006

Serpentine Acceleration in Scaling FFAG

proton, closed-orbit, injection, betatron

2946

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

A serpentine acceleration in scaling FFAG accelerator is examined. In this scheme, high-energy and high-current beam can be obtained in non-relativistic energy region. Longitudinal hamiltonian is derived analytically. Experiment to demonstrate a serpentine acceleration in scaling FFAG is done.

WEPPR007

Simulation Calculation of Longitudinal Beam Distribution in J-PARC MR

injection, beam-loading, simulation, extraction

2949

K. Hara, T. Koseki, C. Ohmori
KEK, Tokai, Ibaraki, Japan
Y. Sato
J-PARC, KEK & JAEA, Ibaraki-ken, Japan

The J-PARC accelerator complex consists of 3 accelerators, a linear accelerator, a rapid cycle synchrotron (RCS) and a Main Ring (MR) synchrotron. Simulation calculation of longitudinal beam distribution in J-PARC Main Ring has been performed. The effect that RF voltage pattern, space charge, and beam loading gave was examined.

WEPPR035

Optimization of Drive-bunch Current Profile for Enhanced Transformer Ratio in Beam-driven Acceleration Techniques

electron, simulation, vacuum, plasma

3012

F. Lemery, D. Mihalcea, P. Piot, C.R. Prokop
Northern Illinois University, DeKalb, Illinois, USA

Funding: Work supported by the U.S. Department of Energy, Office of Science, Office of Basic Energy Sciences, under Contract No. DE-AC02-06CH11357.
In recent years, wakefield acceleration has gained attention due to its high acceleration gradients and cost effectiveness. In beam-driven wakefield acceleration, a critical parameter to optimize is the transformer ratio. It has been shown that current shaping of electron beams allows for enhanced (>2) transformer ratios. In this paper we present the optimization of the pulse shape of the drive bunch for dielectric-wakefield acceleration. We also explore practical techniques capable of tailoring current profiles into these optimal shapes.

WEPPR090

A 4.2 GS/s Synchronized Vertical Excitation System for SPS Studies - Steps Toward Wideband Feedback

controls, feedback, kicker, injection

3144

J.D. Fox, J.J. Olsen, C.H. Rivetta, I.I. Rivetta, O. Turgut, S. Uemura
SLAC, Menlo Park, California, USA
W. Höfle, U. Wehrle
CERN, Geneva, Switzerland

Funding: Work supported by the U.S. Department of Energy under contract DE-AC02-76SF00515 and the US LHC Accelerator Research Program (LARP).
A 4.2 GS/s beam excitation system with accelerator synchronization and power stages is described. The system is capable of playing unique samples (32 samples/bunch) for 15,000 turns on selected bunch(es) in the SPS in synchronism with the injection and acceleration cycle. The purpose of the system is to excite internal modes of single-bunch vertical motion, and study the bunch dynamics in the presence of developing Electron cloud or TMCI effects. The system includes a synchronized master oscillator, SPS timing functions, an FPGA based arbitrary waveform generator, 4.2 GS/sec. D/A system and four 80W 20 -1000 MHz amplifiers driving a tapered stripline pickup/kicker. A software GUI allows specification of various modulation signals and selection of bunches and turns to excite, while a remote control interface allows simple control/monitoring of the RF power stages located in the tunnel. Excitation signals developed to excite head-tail and other modes of vertical motion are illustrated. The successful use of this system for SPS MD measurements in August and November 2011 is a vital proof-of-principle for wideband feedback using similar functions to correct the beam motion.

THXA02

Operation and Patient Treatments at CNAO Facility

proton, ion, synchrotron, extraction

3180

E. Bressi
CNAO Foundation, Milan, Italy

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

Slides THXA02 [14.843 MB]

THYB02

Influence of Electron Beam Parameters on Coherent Electron Cooling

electron, FEL, ion, radiation

3213

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

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

Slides THYB02 [0.878 MB]

THPPC005

Design of Magnetic Alloy Resonant System (MARS) Cavity for J-PARC MR

cavity, impedance, beam-loading, status

3278

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

The Magnetic Alloy Resonant System (MARS) cavity is a new type of Magnetic Alloy (MA) cavity using an external energy storage system. It is proposed as a back-up system of the present J-PARC high-Q MA cavity using cut cores. MARS consists of un-cut core loaded wideband MA cavities combined with an energy storage system using high-impedance, FT3L, cut cores. The main cavities are water-cooled and already established at J-PARC RCS. The energy storage system will be relatively high-Q (>100) to be stable under heavy beam loading. It also has a higher impedance than the main cavity and is air-cooled. The design of this cavity system will be presented.

THPPC009

Investigation of the Approaches to Measure the RF Cable Attenuation

controls, insertion, linac, radio-frequency

3290

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

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

THPPC010

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

linac, DTL, quadrupole, radiation

3293

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

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

THPPC017

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

electron, linac, radiation, electromagnetic-fields

3314

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

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

THPPC025

Improvements to ISIS RF Cavity Tuning

cavity, controls, synchrotron, proton

3332

R.J. Mathieson, D. Bayley, N.E. Farthing, I.S.K. Gardner, A. Seville
STFC/RAL/ISIS, Chilton, Didcot, Oxon, United Kingdom

The ISIS facility at the Rutherford Appleton Laboratory in the UK routinely accelerates proton beam currents in excess of 230 uA to run two neutron spallation target stations. The accelerator consists of a 70 MeV H⁻ linac and an 800 MeV, 50 Hz, proton synchrotron. The synchrotron beam is accelerated using six fundamental (h=2), and four second harmonic (h=4) ferrite loaded RF cavities each having its own drive amplifier and bias system. Each RF cavity is driven as a high Q tuned RF circuit; the resonant frequency being controlled by biasing the ferrite using a current from the bias regulator system. The cavity is kept at the correct resonant frequency by an analogue feedback loop comparing the phase of the cavity voltage to the phase of the demand voltage at the amplifier, and a 50Hz digital correction function calculated from the estimated frequency response of the system. This paper describes work improving the performance of the tuning system by introducing better system identification of the tuning loop and a time varying transfer function.

THPPC032

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

cavity, vacuum, solenoid, linac

3353

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

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

THPPC045

Rapidly Tunable RF Cavity for Accelerators

cavity, synchrotron, vacuum, simulation

3386

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

Funding: Work supported by the DOE-SBIR program, High Energy Physics Department.
The performance and range efficient use of rapidly cycling accelerators would be improved with the fast frequency tuning and associated variable phase change provided by a tunable rf cavity. The progress in developing a cavity that can be tuned by as much as 10 percent in frequency in less than 100 nanoseconds is presented.

THPPD020

Test of a 1.8 Tesla, 400 Hz Dipole for a Muon Synchrotron

dipole, power-supply, simulation, synchrotron

3542

D.J. Summers, L.M. Cremaldi, T.L. Hart, L.P. Perera, M. Reep
UMiss, University, Mississippi, USA
S.U. Hansen, M.L. Lopes
Fermilab, Batavia, USA
J. Reidy
Oxford High School, Mississippi, USA
H. Witte
BNL, Upton, Long Island, New York, USA

Funding: Supported by DE-FG05-91ER40622.
A 1.8 Tesla dipole magnet using 0.011" AK Steel TRAN-COR H-1 grain oriented silicon steel laminations has been constructed as a prototype for a muon synchrotron ramping at 400 Hz. Following the practice in large 3 phase transformers and our own OPERA-2D simulations, joints are mitered to take advantage of the magnetic properties of the steel which are most effective in the direction in which the steel was rolled. Measurements with a Hysteresigraph 5500 and Epstein Frame show a high magnetic permeability which minimizes stored energy in the yoke so the magnet can ramp quickly with modest voltage. A power supply with a fast IGBT switch and a polypropylene capacitor was constructed. Coils are wound with 12 gauge copper wire which will eventually be cooled with with water flowing in stainless steel tubes. The magnetic field was measured with an F. W. Bell 5180 peak sensing Hall Probe connected to a Tektronics TDS3054B oscilloscope.

THPPD071

A Compact Switching Power Supply utilizing SiC-JFET for the Digital Accelerator

power-supply, induction, simulation, synchrotron

3677

K. Okamura, T. Iwashita, K. Takayama, M. Wake
KEK, Ibaraki, Japan
K. Takaki, M. Toshiya
Iwate university, Morioka, Iwate, Japan

New induction synchrotron system using an induction cell has been developed and constructed at KEK*. We refer to the accelerator using the induction acceleration system combined with digitally controlled PWM power supply as Digital Accelerator**. In that system, the switching power supply is one of the key devices which realize digital acceleration. The requirements of the switching power supply are high voltage (2 kV) and high repetition frequency (1 MHz). In the present system, we used series connected MOSFETs as the switching device. However, series connection gives large complexity and less reliability. Among the various switching devices, a SiC-JFET is the promising candidates because it has ultrafast switching speed and voltage blocking capability. Therefore, we have developed a new device to substitute existing silicon MOSFET and succeeded to operate with 1 MHz – 1 kV – 27 A condition***. Then we designed and constructed a ultra compact full bridge switching power supply utilizing those devices as a next step. Design and test results will be presented in the conference.
* T. Iwashita et al., KEK Digital Accelerator, Phys. Rev. ST-AB 14, 071302 (2011)
** K. Takayama et al., in Proc. of IPAC’11, pp 1920-1922
*** K. Okamura et al., in Proc. of IPAC’11, pp 3400-3402

THPPP011

Studies on a Wideband, Solid-state Driven RF System for the CERN PS Booster

impedance, feedback, cavity, booster

3749

M.M. Paoluzzi, L. Arnaudon, N. Chritin, M. Haase, K. Hanke, B. Mikulec, T. Tardy
CERN, Geneva, Switzerland

In the framework of the LHC Injectors Upgrade project (LIU) the PS Booster (PSB) RF systems will undergo in depth consolidation and upgrade programs. The aim is increasing the extraction energy to 2 GeV and allowing reliable operations during next 25 years. Substantial improvements could come from the replacement of the existing narrowband, tuned systems covering the h=1 and h=2 frequency ranges (0.6 / 1.8 MHz and 1.2 / 3.6 MHz respectively) with wideband (0.5 / 4 MHz) Finemet® loaded cavities. The new system would be modular, allow multi-harmonic operation, use solid-state power stages and include fast RF feedback to compensate beam loading effects to some extent. A prove of principle system providing ≈3.0 kV accelerating voltage has been designed, constructed and installed in one of the PSB rings. This paper provides details on the design and measurements as well as information on the project status.

THPPP026

Experimental Effects of Orbit on Polarization Loss in RHIC

resonance, polarization, injection, proton

3788

V.H. Ranjbar
Tech-X, Boulder, Colorado, USA
M. Bai, H. Huang, A. Marusic, M.G. Minty, V. Ptitsyn
BNL, Upton, Long Island, New York, USA

Funding: Work supported by Brookhaven Science Associates, LLC under Contract No. DE-AC02-98CH10886 with the U.S. Department of Energy.
We are performing several experiments during the RHIC ramp to better understand the impact of orbit errors on the polarization at our current working point. These will be conducted by exciting specified orbit harmonics during the final two large intrinsic resonance crossing in RHIC during the 250 GeV polarized proton ramp. The resultant polarization response will then be measured.

THPPP030

Near Integer Tune for Polarization Preservation in the AGS

optics, polarization, injection, resonance

3797

N. Tsoupas, L. A. Ahrens, M. Bai, K.A. Brown, J.W. Glenn, H. Huang, W.W. MacKay, T. Roser, V. Schoefer, K. Zeno
BNL, Upton, Long Island, New York, USA

Funding: *Work supported by the US Department of Energy.
The high energy (T=250 GeV) polarized proton beam experiments performed in RHIC, require high polarization of the beam. In order to preserve the polarization of the proton beam, during the acceleration in the AGS, which is the pre-injector to RHIC, two partial helical magnets* have been installed in AGS. In order to minimize the loss of the beam polarization due to the various intrinsic spin resonances occurring during the proton acceleration, we constrain the value of the vertical tune to be higher than 8.97. With the AGS running at near integer tune the perturbations caused by the partial helical magnets is large resulting in large beta and dispersion waves. To mitigate the adverse effect of the partial helices on the optics of the AGS, we have introduced compensation quads** in AGS. In this paper we present the beam optics of the AGS which ameliorates this effect of the partial helices.
* H. Huang, et al., Proc. EPAC06, p. 273, (2006).
** N. Tsoupas et al., Proc. PAC07, p. 3723 (2007).

THPPP084

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

target, cyclotron, ion, radiation

3930

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

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

THPPP087

Beta Beams for Precision Measurements of Neutrino Oscillation Parameters

target, ion, proton, linac

3939

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

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

THPPP088

Beam Loss Studies of the ISIS Synchrotron Using ORBIT

simulation, injection, synchrotron, emittance

3942

D.J. Adams
STFC/RAL/ASTeC, Chilton, Didcot, Oxon, United Kingdom
I.S.K. Gardner, B. Jones, B.G. Pine, A. Seville, H. V. Smith, C.M. Warsop, R.E. Williamson
STFC/RAL/ISIS, Chilton, Didcot, Oxon, United Kingdom

The ISIS synchrotron forms part of the accelerator chain for the Spallation Neutron Source at RAL, UK. The synchrotron is an 800 MeV, 50Hz , RCS accelerating ~2.8·10¹³ protons per cycle. Beam loss is localized in two super periods of the ring using a system of collimators. The injection and acceleration processes, vacuum vessels and collimation systems have been modeled using the particle tracking code ORBIT. This paper presents simulation results in comparison to measurements of longitudinal profiles and beam loss.

THPPR026

Automated Phase Optimization for the HDSM at MAMI

synchrotron, linac, injection, microtron

4020

M. Dehn
IKP, Mainz, Germany

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

THPPR053

A CW FFAG for Proton Computed Tomography

cyclotron, proton, extraction, lattice

4094

C. Johnstone, D.V. Neuffer
Fermilab, Batavia, USA
H.L. Owen
STFC/DL/ASTeC, Daresbury, Warrington, Cheshire, United Kingdom
P. Snopok
IIT, Chicago, Illinois, USA

Funding: Work supported by Fermi Research Alliance, LLC, under contract No. DE-AC02-07CH11359 with the U.S. Department of Energy
An advantage of the cyclotron in proton therapy is the continuous (CW) beam output which reduces complexity and response time in the dosimetry requirements and beam controls. A CW accelerator requires isochronous particle orbits at all energies through the acceleration cycle and present compact isochronous cyclotrons for proton therapy reach only 250 MeV (kinetic energy) which is required for patient treatment, but low for full Proton Computed Tomography (PCT) capability. PCT specifications need 300-330 MeV in order for protons to transit the human body. Recent innovations in nonscaling FFAG design have achieved isochronous performance in a compact (~3 m radius) design at these higher energies. Preliminary isochronous designs are presented here. Lower energy beams can be efficiently extracted for patient treatment without changes to the acceleration cycle and magnet currents.

THPPR066

Racetrack Microtron for Nondestructive Nuclear Material Detection System

linac, electron, gun, microtron

4127

T. Hori, T. Kii, R. Kinjo, H. Ohgaki, M. Omer, H. Zen
Kyoto University, Institute for Advanced Energy, Kyoto, Japan
I. Daito, R. Hajima, T. Hayakawa, M. Kando, H. Kotaki
JAEA, Kyoto, Japan

A nuclear material detection system using the quasi-monochromatic gamma-ray beam from a laser Compton Backscattering source has been proposed for the container inspection, where nuclear resonance fluorescence method would be employed for the specific isotope identification such as U-235. In the system an electron beam of good quality at about 220 MeV for the laser Compton backscattering is required. One candidate for such the practical use is a racetrack microtron which design is based on the existing 150 MeV microtron at JAEA.

FRXAA02

Advanced Solid State Lasers are Merging with Accelerators

laser, cavity, higher-order-mode, alignment

4157

A. Tünnermann, J. Limpert
Friedrich Schiller Universität, Jena, Germany
T. Schreiber
Fraunhofer-Institute for Applied Optics and Precision Engineering, Jena, Germany

In recent years, lasers have been developed to an essential tool in accelerator science, for acceleration and diagnostics. Novel applications require for high average power lasers in continuous and pulsed operation with diffraction limited beam quality. Lasers are known as sophisticated systems with a notorious poor efficiency. Most recently, rare-earth-doped fibers have established themselves as an attractive and power scalable solid-state laser concept. Using advanced large mode area fibers, in continuous-wave operation output powers in the 10 kW-regime with diffraction-limited beam quality at electrical to optical efficiencies of 30 percent have been demonstrated. In the pulsed regime average powers of the order of 1 kW even for femtosecond fiber laser systems have been reported. Coherent beam combination of these lasers allows for the generation of high peak power pulses at high repetition rates and output powers. In this contribution the state of the art in solid state laser technology operating at high average powers with inherent high efficiencies is reviewed. The prospects for future developments that will meet the demands set by the accelerator community will be discussed.

Slides FRXAA02 [11.729 MB]