WEPS —  Poster Session   (07-Sep-11   16:00—18:00)
Paper Title Page
WEPS001 A New Lattice for the Beta-beam Decay Ring to Reduce the Head Tail Effects 2478
 
  • A. Chancé, J. Payet
    CEA/DSM/IRFU, France
  • C. Hansen
    CERN, Geneva, Switzerland
 
  Funding: I acknowledge the financial support of the European Community under the European Commission Framework Programme 7 Design Study: EUROnu, Project Number 212372.
The beta-beam concept relies on the production, by beta decay of radioactive ions of a very high flux, of an electron neutrino and anti-neutrino beam towards a distant detector. In this aim, the radioactive isotopes are stored in a long racetrack-shaped ring, called the decay ring, where they orbit until they decay or are lost. The intensities to store in the decay ring to obtain the required neutrino fluxes are very high (several amperes in average). Therefore, collective effects occur. Among them, the head tail effect, caused by transversal resonance impedance, is one of the main issues: the beam was shown to be unstable with the previous decay ring lattice. The transition gamma was reduced to mitigate this problem. For this purpose the lattice was changed by removing the injection from the arc to put it in a chicane which is added in one of the long straight sections. After presenting the limitation due to head tail effects, we will present the modification in the lattice and their impact on the dynamic aperture in the decay ring. Then the improvement on the beta-beam performance with respect to the lower transition gamma will be shown.
 
 
WEPS002 Limitations in Mitigating Collective Effects in the Beta-Beam Decay Ring by the Use of Octupoles 2481
 
  • C. Hansen
    CERN, Geneva, Switzerland
  • E. Benedetto
    National Technical University of Athens, Zografou, Greece
  • A. Chancé, J. Payet
    CEA/DSM/IRFU, France
 
  Funding: I acknowledge the financial support of the European Community under the European Commission Framework Programme 7 Design Study: EUROnu, Project Number 212372.
The beta-beam concept relies on the production, by beta decay of radioactive ions of a very high flux, of an electron neutrino and anti-neutrino beam towards a distant detector. After production and acceleration in an accelerator complex consisting of a rapid cycling synchrotron, the CERN PS and the CERN SPS, the radioactive isotopes are injected into a long racetrack-shaped ring, called the decay ring, where they orbit until they decay or are lost. The required intensities to store in the decay ring to reach the aimed neutrino fluxes are very high. Among the collective effects, the head tail effect, caused by transversal resonance impedance, is one of the main issues: the beam was shown to be unstable with the previous decay ring lattice. The lattice was changed to handle this problem; e.g. octupoles were included to increase the stability limit with an amplitude detuning. We here report on the improvement on the beta-beam performance with respect to amplitude detuning in the decay ring and discuss other mitigation attempts.
 
 
WEPS003 SIS18 – Intensity Record with Intermediate Charge State Heavy Ions 2484
 
  • P.J. Spiller
    GSI, Darmstadt, Germany
  • L.H.J. Bozyk
    FIAS, Frankfurt am Main, Germany
  • P. Puppel
    HIC for FAIR, Frankfurt am Main, Germany
 
  Funding: Project partly funded by the European Community DIRAC-PHASE-1 / Contract number: 515876
In order to reach the desired intensities of heavy ion beams for the experiments at FAIR, SIS18 and SIS100 have to be operated with intermediate charge states. Operation with intermediate charge state heavy ions at the intensity level of about 1011 ions per cycle has never been demonstrated elsewhere and requires a dedicated upgrade program for SIS18 and a dedicated machine design for SIS100. The specific problems coming along with the intermediate charge state operation in terms of charge exchange processes at collisions with residual gas atoms, pressure bumps by ion induced desorption and corresponding beam loss appears far below the typical space charge limits. Thus, new design concepts and new technical equipment addressing these issues are developed and realized with highest priority. The upgrade program of SIS18 addressing the goal of minimum ionization beam loss and stable residual gas pressure conditions has been defined in 2005. A major part of this upgrade program has been successfully realized, with the result of a world record in accelerated number of intermediate charge state heavy ions.
 
 
WEPS004 Confinement, Accumulation and Diagnostic of Low Energy Ion Beams in Toroidal Fields 2487
 
  • M. Droba, A. Ates, O. Meusel, H. Niebuhr, U. Ratzinger, J.F. Wagner
    IAP, Frankfurt am Main, Germany
 
  An optimized design of a stellarator-type storage ring for low energy ion beams was numerically investigated. The magnetic field variation along the circumference and therefore magnetic heating is suppressed by using simple circular correction coils. Particle-in-Cell (PIC) simulations in a magnetic flux coordinate system show the ability of high current ion beam accumulation in such a configuration with unique features for clockwise and anticlockwise moving beams. Additionally scaled down experiments with two 30 degree room temperature toroidal segments were performed to demonstrate toroidal transport and to develop optical beam diagnostics. Properties of multi-component beams, redistribution of transversal momenta in the non-adiabatic part of the experimental configuration and investigation of strongly confined beam induced electron clouds will be addressed.  
 
WEPS005 Investigation of Intrabeam Scattering in the Heavy Ion Storage Ring TSR 2490
 
  • S.T. Artikova, M. Grieser, J. Ullrich
    MPI-K, Heidelberg, Germany
 
  Intrabeam scattering (IBS) is a multiple scattering effect between stored beam particles. It leads to diffusion in all three spatial dimensions and thus, causes an expansion of the whole beam. IBS plays an important role in the equilibrium diameter of a low-velocity, electron-cooled ion beam. IBS effects for coasting and bunched 12C6+ ion beams at an energy of 73.3 MeV were studied using the TSR heavy ion cooler storage ring. Experimental results of the IBS rates are presented.  
 
WEPS006 CNAO RF System: Hardware Description. 2493
 
  • L. Falbo, G. Burato
    CNAO Foundation, Milan, Italy
  • M.M. Paoluzzi, G. Primadei
    CERN, Geneva, Switzerland
 
  CNAO is the Italian National Center of Oncological Hadrontherapy in Pavia. Proton beams are accelerated in the synchrotron and extracted in the energy range 60 to 250 MeV/u and carbon ion beams in the energy range 120 to 400 MeV/u. Trapping at the injection energy of 7 MeV/u and acceleration up to the extraction energy are done by an RF cavity which covers the needed wide range of frequency (0.4 to 3 MHz) and voltage (25 V to 5 kV) thanks to the use of a Vitrovac amorphous alloy. RF Gymnastics, including phase jumps to increase the momentum spread and empty bucket channelling, is requested and has been performed. A description of the hardware characteristics of the CNAO RF system and of its performance in terms of dynamic and static behaviour are reported in this paper.  
 
WEPS007 CNAO Synchrotron Commissioning 2496
 
  • C. Priano, G. Balbinot, G. Bazzano, J. Bosser, E. Bressi, M. Caldara, H. Caracciolo, L. Falbo, A. Parravicini, M. Pullia, C. Viviani
    CNAO Foundation, Milan, Italy
  • C. Biscari, A. Ghigo
    INFN/LNF, Frascati (Roma), Italy
 
  The CNAO (National Center for Oncological Hadrontherapy), located in Pavia, is the first Italian center for deep hadrontherapy with proton and carbon ion beams. The CNAO synchrotron initial commissioning has been carried out using proton beams in the full range of energies: 60 to 250 MeV/u. The first foreseen treatments will need energies between 120 and 170 MeV/u. The nominal proton currents have been reached. The energy scaling of the synchrotron systems and parameters leads to an extracted energy that matches the measured particle range better than 0.1 mm, fitting the treatment requirements, with repeatable beam size and beam current in the treatment room at all investigated energies. A summary of the main results of the synchrotron commissioning is presented.  
 
WEPS008 Operation Status and Future Plan of J-PARC Main Ring 2499
 
  • T. Koseki
    KEK, Ibaraki, Japan
 
  The J-PARC Main Ring (MR) has started users operation since 2009. The MR has two beam extraction systems. One is a fast extraction (FX) system for beam delivery to the neutrino beam line of the Tokai-to-Kamioka (T2K) experiment, and the other is a slow extraction (SX) system for beam delivery to the hadron experimental hall. For the T2K experiment, the maximum beam power of 145 kW is delivered continuously. For users of the hadron experimental hall, the beam power of 3 kW is delivered with extraction efficiency of 99.5%. In this paper, status of the high power beam operation of the MR is presented. Future prospect for increasing beam intensity is also discussed.  
 
WEPS010 Acceleration of High Intensity Proton Beams in the J-PARC Synchrotrons 2502
 
  • M. Yoshii
    KEK/JAEA, Ibaraki-Ken, Japan
  • E. Ezura, K. Hara, K. Hasegawa, C. Ohmori, K. Takata, M. Toda
    KEK, Ibaraki, Japan
  • T. Minamikawa
    University of Fukui, Fukui, Japan
  • M. Nomura, A. Schnase, T. Shimada, F. Tamura, M. Yamamoto
    JAEA/J-PARC, Tokai-mura, Japan
 
  The J-PARC accelerator complex consists of the linac, the 3GeV rapid cycling synchrotron (RCS) and the 50GeV main synchrotron (MR). These synchrotrons are the first MW-class proton accelerators which employ the high electric field gradient magnetic alloy (MA) loaded RF cavities. The beam commissioning was started in October 2007 for RCS and in May 2008 for MR. High intensity beam operation studies and user runs have been performed, while carefully controlling and minimizing the beam loss. The cycle to cycle beam operation is reproducible and quite stable, because of the stable linac beam energy and the reproducible bending field in both synchrotrons. The MA loaded RF systems and the full digital LLRF also guarantee the stable longitudinal particle motion and precise beam transfer synchronization from RCS to the MLF user facility as well as to the MR. A high intensity proton beam of 2.5·1013 ppp is accelerated in RCS. And in MR, a beam intensity up to ~100 Tera ppp was obtained. We summarize the RF systems and the longitudinal parameters in both rings.  
 
WEPS011 Application of Orbit Response Matrix Method at CSNS/RCS 2505
 
  • Y.W. An, S. Wang
    IHEP Beijing, Beijing, People's Republic of China
 
  The China Spallation Neutron Source(CSNS) consists of a low energy linac and a high energy Rapid Cycling Synchrotron(RCS). RCS accumulates 80MeV beam and accelerates to 1.6GeV with 25Hz repetition rate and the average extraction beam power is 100kW. For controlling beam loss, the closed orbit should be adjusted as flexible as possible. The orbit response matrix(ORM) method is applied to correct the closed orbit distortion in RCS. The simulation study was made by using the code Linear Optics from Closed Orbit(LOCO) for CSNS/RCS, and the results of simulation study are presented.  
 
WEPS013 Results of the Nuclotron Upgrade Program 2508
 
  • A.V. Eliseev, N.N. Agapov, A.V. Alfeev, V. Andreev, V. Batin, D.E. Donets, E.D. Donets, E.E. Donets, E.V. Gorbachev, A. Govorov, V. Karpinsky, V.D. Kekelidze, H.G. Khodzhibagiyan, A. Kirichenko, A.D. Kovalenko, O.S. Kozlov, N.I. Lebedev, I.N. Meshkov, V.A. Mikhailov, V. Monchinsky, S. Romanov, T.V. Rukoyatkina, A.O. Sidorin, I. Slepnev, V. Slepnev, A.V. Smirnov, A. Sorin, G.V. Trubnikov, B. Vasilishin
    JINR, Dubna, Moscow Region, Russia
  • O.I. Brovko, A.V. Butenko, N.V. Semin, V. Volkov
    JINR/VBLHEP, Moscow, Russia
 
  The Nuclotron upgrade – the Nuclotron-M project, which had been started in 2007, involved the modernization of almost all of the accelerator systems, using beam time during seven runs devoted to testing newly installed equipment. Following the project goals, in March 2010 Xe ions were accelerated to about 1.5 GeV/u. In December 2010, the stable and safe operation of the magnetic system was achieved with a main field of 2 T. The successful completion of the project paves the way for further development of the Nuclotron-based Ion Collider fAcility (NICA).  
 
WEPS014 RF Systems and Bunch Formation at NICA 2511
 
  • A.V. Eliseev, I.N. Meshkov, A.O. Sidorin, G.V. Trubnikov
    JINR, Dubna, Moscow Region, Russia
  • O.I. Brovko
    JINR/VBLHEP, Moscow, Russia
  • G.Y. Kurkin, V.M. Petrov
    BINP SB RAS, Novosibirsk, Russia
 
  The NICA facility being constructed at JINR will consists of two synchrotrons (Booster and Nuclotron) and collider working at constant magnetic field. To reach required luminosity level the collider rings will be operated with short ion bunches. The bunch formation in the collider as well as longitudinal dynamics in all the rings is described. The parameters and preliminary design of RF systems are presented.  
 
WEPS016 Update on Comparison of the Particle Production using MARS Simulation Code 2514
 
  • G. Prior, S.S. Gilardoni
    CERN, Geneva, Switzerland
  • X.P. Ding
    UCLA, Los Angeles, California, USA
  • H.G. Kirk, N. Souchlas
    BNL, Upton, Long Island, New York, USA
 
  Funding: EU FP7 EUROnu WP3
In the International Design Study for the Neutrino Factory (IDS-NF), a 5-15 GeV (kinetic energy) proton beam impinges a Hg jet target in order to produce pions that will decay into muons. The muons are then captured and transformed into a beam that can be passed to the downstream acceleration system. The target sits in a solenoid field tapering from 20 T down to below 2 T over several meters permitting a optimized capture of the pions that will produce useful muons for the machine. The target and pion capture system have been simulated in MARS simulation code and this work presents an updated comparison of the particles production using the MARS code versions m1507 and m1510.
 
 
WEPS017 Plans for the Upgrade of the LHC Injectors 2517
 
  • R. Garoby, S.S. Gilardoni, B. Goddard, K. Hanke, M. Meddahi, M. Vretenar
    CERN, Geneva, Switzerland
 
  The LHC Injectors Upgrade (LIU) project has been launched at the end of 2010 to prepare the CERN accelerator complex for reliably providing beam with the challenging characteristics required by the high luminosity LHC until at least 2030. Based on the work already started on Linac4, PS Booster, PS and SPS, the LIU project coordinates studies and implementation, and interfaces with the High Luminosity LHC (HL-LHC) project which looks after the upgrade of the LHC itself, expected by the end of the present decade. The anticipated beam characteristics are described, as well as the status of the studies and the solutions envisaged for improving the injector performances.  
 
WEPS018 The Proposed CERN Proton-Synchrotron Upgrade Program 2520
 
  • S.S. Gilardoni, S. Bart Pedersen, W. Bartmann, S. Bartolome, O.E. Berrig, C. Bertone, A. Blas, D. Bodart, J. Borburgh, R.J. Brown, A.C. Butterworth, M.C.L. Buzio, C. Carli, P. Chiggiato, H. Damerau, T. Dobers, R. Folch, R. Garoby, B. Goddard, M. Gourber-Pace, S. Hancock, M. Hourican, P. Le Roux, L.A. Lopez Hernandez, A. Masi, G. Metral, Y. Muttoni, E. Métral, M. Nonis, J. Pierlot, S. Pittet, C. Rossi, I. Ruehl, G. Rumolo, L. Sermeus, R.R. Steerenberg, M. Widorski
    CERN, Geneva, Switzerland
 
  In the framework of the High-Luminosity LHC project, the CERN Proton Synchrotron would require a major upgrade to match the future beam parameters requested as pre-injector of the collider. The different beam dynamics issues, from space-charge limitations to longitudinal instabilities are discussed, as well as the proposed technical solutions to overcome them, covering the increase of the injection energy to RF related improvements.  
 
WEPS019 Study of a Rapid Cycling Synchrotron to Replace the CERN PS Booster 2523
 
  • K. Hanke, O. Aberle, M. E. Angoletta, B. Balhan, W. Bartmann, M. Benedikt, J. Borburgh, D. Bozzini, C. Carli, P. Dahlen, T. Dobers, M. Fitterer, R. Garoby, S.S. Gilardoni, B. Goddard, J. Hansen, T. Hermanns, M. Hourican, S. Jensen, A. Kosmicki, L.A. Lopez Hernandez, M. Meddahi, B. Mikulec, A. Newborough, M. Nonis, S. Olek, M.M. Paoluzzi, S. Pittet, B. Puccio, V. Raginel, I. Ruehl, H.O. Schönauer, L. Sermeus, R.R. Steerenberg, J. Tan, J. Tückmantel, M. Vretenar, M. Widorski
    CERN, Geneva, Switzerland
 
  CERN’s proton injector chain is undergoing a massive consolidation and upgrade program in order to deliver beams meeting the needs of the LHC Luminosity Upgrade. As an alternative to the upgrade of the existing Proton Synchrotron Booster (PSB), the construction of a Rapid Cycling Synchrotron (RCS) has been studied. This machine would replace the PSB and deliver beams to the LHC as well as to CERN’s rich fixed-target physics program. This paper summarizes the outcome of the feasibility study along with a tentative RCS design.  
 
WEPS020 Study of an Energy Upgrade of the CERN PS Booster 2526
 
  • K. Hanke, O. Aberle, M. E. Angoletta, W. Bartmann, S. Bartolome, C. Bertone, A. Blas, J. Borburgh, D. Bozzini, A.C. Butterworth, C. Carli, P. Dahlen, T. Dobers, A. Findlay, R. Folch, N. Gilbert, J. Hansen, T. Hermanns, S. Jensen, P. Le Roux, L.A. Lopez Hernandez, E. Mahner, A. Masi, B. Mikulec, Y. Muttoni, A. Newborough, D. Nisbet, M. Nonis, S. Olek, M.M. Paoluzzi, S. Pittet, B. Puccio, V. Raginel, I. Ruehl, J. Tan, B. Todd, W.J.M. Weterings, M. Widorski
    CERN, Geneva, Switzerland
 
  CERN’s LHC injector chain will have to deliver beams with ultimate brilliance as the LHC is heading for increased luminosity in the coming years. In order to overcome bottlenecks in the injector chain, an increase of the beam transfer energy from the CERN Proton Synchrotron Booster (PSB) to the Proton Synchrotron (PS) has been investigated as a possible upgrade scenario. This paper gives an overview of the technical solutions and summarizes the conclusions of the feasibility study.  
 
WEPS022 Ions for LHC: Performance of the Injector Chain 2529
 
  • D. Manglunki, M. E. Angoletta, P. Baudrenghien, G. Bellodi, A. Blas, T. Bohl, C. Carli, E. Carlier, S. Cettour Cave, M. Chanel, K. Cornelis, H. Damerau, A. Findlay, S.S. Gilardoni, S. Hancock, J.M. Jowett, D. Kuchler, S. Maury, E. Métral, S. Pasinelli, M. Schokker, G. Tranquille, B. Vandorpe, U. Wehrle, J. Wenninger
    CERN, Geneva, Switzerland
 
  The first LHC Pb ion run took place at 1.38 A TeV/c per beam in autumn 2010. After a short period of running-in, the injector chain was able to fill the collider with up to 137 bunches per ring, with an intensity of 108 Pb ions/bunch, about 50% higher than the design value. This yielded a luminosity of 3E25 Hz/cm2, allowing the experiments to accumulate just under 10 inverse microbarn each during the four week run. We review the performance of the individual links of the injector chain, and address the main issues limiting the LHC luminosity, in view of reaching 1026 Hz/cm2 in 2011, and substantially beyond when the LHC energy increases after the long shutdown in 2013-14.  
 
WEPS023 A Possible RF System for CERN RCS 2532
 
  • M.M. Paoluzzi
    CERN, Geneva, Switzerland
 
  As part of the LHC Injectors Upgrade (LIU) program at CERN the possibility of replacing the PSB with a new Rapid Cycling Synchrotron (RCS) is considered. The requirements in terms of accelerating voltage (60 kV), frequency range (1.7 MHz – 9.5 MHz) and available space (4 m) make the RF system development quite challenging. The improved loss characteristics of the new FINEMET® type (FT3L) combined with a filter-like topology, allows achieving all the requirements. This paper describes the design of such a RF system.  
 
WEPS024 Beta Beams: An Accelerator-based Facility to Explore Neutrino Oscillation Physics 2535
 
  • E.H.M. Wildner, E. Benedetto, T. De Melo Mendonca, C. Hansen, T. Stora
    CERN, Geneva, Switzerland
  • D. Berkovits
    Soreq NRC, Yavne, Israel
  • G. Burt, A.C. Dexter
    Cockcroft Institute, Lancaster University, Lancaster, United Kingdom
  • A. Chancé, J. Payet
    CEA/DSM/IRFU, France
  • M. Cinausero, G. De Angelis, F. Gramegna, T. Marchi, G.P. Prete
    INFN/LNL, Legnaro (PD), Italy
  • G. Collazuol
    Univ. degli Studi di Padova, Padova, Italy
  • F. Debray, C. Trophime
    GHMFL, Grenoble, France
  • T. Delbar, T. Keutgen, M. Loiselet, S. Mitrofanov
    UCL, Louvain-la-Neuve, Belgium
  • G. Di Rosa
    INFN-Napoli, Napoli, Italy
  • M. Hass, T. Hirsch
    Weizmann Institute of Science, Physics, Rehovot, Israel
  • I. Izotov, S. Razin, V. Skalyga, V. Zorin
    IAP/RAS, Nizhny Novgorod, Russia
  • L.V. Kravchuk
    RAS/INR, Moscow, Russia
  • T. Lamy, L. Latrasse, M. Marie-Jeanne, T. Thuillier
    LPSC, Grenoble, France
  • M. Mezzetto
    INFN- Sez. di Padova, Padova, Italy
  • A.V. Sidorov
    BINP SB RAS, Protvino, Moscow Region, Russia
  • P. Sortais
    ISN, Grenoble, France
  • A. Stahl
    RWTH, Aachen, Germany
 
  Funding: This contribution is a project funded by European Community under the European Commission Framework Programme 7 Design Study: EUROnu, Project Number 212372.
The recent discovery of neutrino oscillations, has implications for the Standard Model of particle physics (SM). Knowing the contribution of neutrinos to the SM, needs precise measurements of the parameters governing the neutrino oscillations. The EUROν Design Study will review three facilities (the so-called Super-Beams, Beta Beams and Neutrino Factories) and perform a cost assessment that, coupled with the physics performance, will give means to the European research authorities to make a decision on future European neutrino oscillation facility. "Beta Beams" produce collimated pure electron (anti-)neutrino by accelerating beta active ions to high energies and having them decay in a storage ring. EUROν Beta Beams are based on CERN’s infrastructure and existing machines. Using existing machines is an advantage for the cost evaluation, however, this choice is also constraining the Beta Beams. Recent work to make the Beta Beam facility a solid option will be described: production of Beta Beam isotopes, the 60 GHz pulsed ECR source development, integration into the LHC-upgrades, ensure the high intensity ion beam stability, and optimizations to get high neutrino fluxes.
 
 
WEPS025 First Beam Experiments at ISIS with a Low Output-impedance Second Harmonic Cavity 2538
 
  • Y. Irie, S. Fukumoto, K. Muto, H. Nakanishi, T. Oki, A. Takagi
    KEK, Ibaraki, Japan
  • D. Bayley, I.S.K. Gardner, R.J. Mathieson, A. Seville, J.W.G. Thomason
    STFC/RAL/ISIS, Chilton, Didcot, Oxon, United Kingdom
  • J.C. Dooling, D. Horan, R. Kustom
    ANL, Argonne, USA
  • M.E. Middendorf
    ORNL RAD, Oak Ridge, Tennessee, USA
 
  A Low Output-Impedance (LOI) rf drive, which may be suitable for future high intensity accelerator applications, has been developed jointly by ANL, ISIS and KEK for an ISIS synchrotron second harmonic cavity. The cavity is ferrite-loaded, and is driven by a high-power triode (240 kW plate dissipation) with a plate-to-grid feedback circuit. The impedance is designed to be 20~30 ohms over a 2-6 MHz frequency range. Beam induced voltage has been measured with the ISIS beam, and compared with that calculated from the designed output impedance.  
 
WEPS028 Lattice Design of a Rapid Cycling Medical Synchrotron for Carbon/Proton Therapy 2541
 
  • D. Trbojevic, J.G. Alessi, M. Blaskiewicz, C. Cullen, H. Hahn, D.I. Lowenstein, I. Marneris, W. Meng, J.-L. Mi, C. Pai, D. Raparia, A. Rusek, J. Sandberg, N. Tsoupas, J.E. Tuozzolo, A. Zaltsman, W. Zhang
    BNL, Upton, Long Island, New York, USA
  • N.M. Cook
    Stony Brook University, Stony Brook, USA
  • J.P. Lidestri
    HHMI, New York, USA
  • M. Okamura
    RBRC, Upton, Long Island, New York, USA
  • S. Peggs
    ESS, Lund, Sweden
 
  Funding: Work supported by Cooperative Research and Development Agreement (CRADA), No. BNL-C-10-03 between the Brookhaven National Laboratory and Best Medical International, Inc.
We present a design of the ion Rapid Cycling Medical Synchrotron (iRCMS) for carbon/proton cancer therapy facility. The facility design, produced at Brookhaven National Accelerator (BNL) at the Collider Accelerator Division (CAD) for the BEST Medical International, Inc., will be able to treat the cancer patients with carbon, lighter ions and protons. The low energy part accelerates ions and protons to the kinetic energy of 8 MeV. It consists of two ion sources (one of fully stripped carbon ions and one for protons), a Radio-Frequency Quadrupole (RFQ) and linac. The 8 GeV beam is injected into a fast cycling synchrotron (iRCMS). The lattice design is a racetrack, with zero dispersion two parallel straight sections. There are 24 combined function magnets in the two arcs with a radius of ~5.6 meters with maximum magnetic field of less than 1.3 T. The acceleration is performed in 30 Hz up to the required energy for the cancer tumor treatment assuming the spot scanning technique. The maximum energy for carbon ions is 400 MeV. Ions are extracted in a single turn and fed to different beam lines for patient treatment.
 
 
WEPS029 Innovative Superconducting Non Scaling Fixed Field Alternating Gradient Isocentric Gantry for Carbon Cancer Therapy* 2544
 
  • D. Trbojevic
    BNL, Upton, Long Island, New York, USA
  • V.S. Morozov
    JLAB, Newport News, Virginia, USA
 
  Funding: Work performed under a Contract Number DE-AC02-98CH10886 with the auspices of the US Department of Energy.
Numbers of proton/carbon cancer therapy facilities in recent years is rising fast due to a clear advantage with respect to the other radiation therapy treatments. Cost of the ion cancer therapy is dominated by the delivery systems. An update on a design of the carbon and proton isocentric gantries is presented, using the non-scaling alternating gradient fixed field magnets (NS-FFAG). Size and weight of these magnets much smaller than any other magnets used today in cancer therapy treatment. The weight of the transport elements of the carbon isocentric gantry is estimated to be 1.5 tons to be compared to the 130 tons weight of the top-notch Heidelberg facility gantry. For the transport elements of the proton, the permanent magnet isocentric gantry is 500 kg.
 
 
WEPS030 Ion Optics Alignment in the Electrostatic Double Storage Ring DESIREE 2547
 
  • P. Löfgren, M. Blom, F. Hellberg, L. Liljeby, A. Simonsson
    MSL, Stockholm, Sweden
  • P. Reinhed
    Stockholm University, Stockholm, Sweden
 
  DESIREE is a cryogenic electrostatic double storage ring under construction at Stockholm University. The two rings have similar circumference, 8.8 m and a common straight section for merged beam experiments. In each ring the ions are guided by two 160° cylindrical deflectors and four 10° deflectors and focused by four quadrupole doublets. In terms of ion optics alignment the quadrupoles are the most important factor for the ion beam acceptance and the goal is to align all quadrupoles with precision of 0.1 mm. DESIREE is constructed as a double walled cryostat with an inner and an outer vacuum chamber. All optical elements are mounted directly on the bottom of the inner chamber. For positioning of the ion optics, the bottom plate is prepared with a number of footprints where each footprint consists of four small machined surfaces that define the height and two alignment holes that define the lateral position. The optical elements were aligned on the bottom plate using a portable measuring device in combination with a level instrument. In this work we describe the alignment procedure in detail and report on the overall precision obtained and the consequence for the ion beam.  
 
WEPS031 Future Heavy Ion Linacs at GSI 2550
 
  • W.A. Barth, G. Clemente, L.A. Dahl, S. Mickat, B. Schlitt, W. Vinzenz
    GSI, Darmstadt, Germany
 
  The UNILAC-upgrade program for FAIR will be realized in the next three years; the required U28+-beam intensity of 15 emA (for SIS 18 injection). The replacement of the Alvarez-DTL by a new high energy linac is advised to provide a stable operation for the next decades. An additional linac-upgrade option sufficient to boost the beam energy up to 150 MeV/u may help to reach the desired heavy ion intensities in the SIS 100. The SHIP-upgrade program has also to be realized until 2011, such that an enhanced primary beam intensity at the target is available. It is planned to build a new cw-heavy ion-linac behind the present high charge state injector. This linac should feed the GSI flagship experiments SHIP and TASCA, as well as material research, biophysics and plasma physics experiments in the MeV/u-area. The whole injector family is housed by the existing constructions. Different layout scenarios of a multipurpose high intensity heavy ion facility will be presented.  
 
WEPS032 Conceptual Study for the New HE-Linac at GSI 2553
 
  • G. Clemente, W.A. Barth, B. Schlitt
    GSI, Darmstadt, Germany
 
  The commissioning of the first three modules of the FAIR accelerator facility is planned to be completed in 2016. At that time the DTL section of the UNILAC will be more than 40 years old. Different proposals for a new high intensity, heavy ion linac which will replace the ALVAREZ DTL as synchrotron injector are under discussion. This new High Energy-UNILAC will be design accordingly to the advanced FAIR requirements and will allow for complete and reliable multi-ion-operation for at least the next 30 years. In a first step it is foreseen to replace the first two DTL cavity, up to 4.7 AMeV. 4 IH cavities will be used to accelerate U4+ to 3 AMeV and, after gas stripping, another cavity will provide the second step of acceleration for U38+ to 4.77 AMeV. For the next upgrade different options concerning the injection energy are under investigation. The main target is to provide a higher charge state and a higher injection energy to increase the life time of the heavy ion beam inside the synchrotron. The paper presents the beam dynamics and RF investigation for the first upgrade together with a conceptual study design for the complete replacement of the GSI ALVAREZ DTL.  
 
WEPS033 Matching a Laser Driven Proton Injector to a CH - Drift Tube Linacs 2556
 
  • A. Almomani, M. Droba, U. Ratzinger
    IAP, Frankfurt am Main, Germany
  • I. Hofmann
    HIJ, Jena, Germany
 
  Experimental results and theoretical predictions in laser acceleration of protons achieved energies of ten to several tens of MeV. The LIGHT project (Laser Ion Generation, Handling and Transport) is proposed to use the PHELIX laser accelerated protons and to provide transport, focusing and injection into a conventional accelerator. This study demonstrates transport and focusing of laser-accelerated 10 MeV protons by a pulsed 18 T magnetic solenoid. The effect of co-moving electrons on the beam dynamics is investigated. The unique features of the proton distribution like small emittances and high yield of the order of 1013 protons per shot open new research area. The possibility of creating laser based injectors for ion accelerators is addressed. With respect to transit energies, direct matching into DTL's seems adequate. The bunch injection into a proposed CH structure is under investigation at IAP Frankfurt. Options and simulation tools are presented.  
 
WEPS034 A CW RFQ Prototype 2559
 
  • U. Bartz, A. Schempp
    IAP, Frankfurt am Main, Germany
 
  A short RFQ prototype was built for RF-tests of high power RFQ structures. We will study thermal effects and determine critical points of the design. HF-simulations with CST Microwave Studio and measurements were done. The cw-tests with 20 kW/m RF-power and simulations of thermal effects with ALGOR were finished successfully. The optimization of some details of the HF design is on focus now. First results and the status of the project will be presented.  
 
WEPS035 Beam Measurements with the New RFQ Beam Matching Section at the Frankfurt Funneling Experiment 2562
 
  • M. Baschke, A. Schempp, J.S. Schmidt
    IAP, Frankfurt am Main, Germany
  • H. Zimmermann
    Accelerator Services, Oberursel, Germany
 
  Funding: BMBF
Funneling is a method to increase low energy beam currents in multiple stages. The Frankfurt Funneling Experiment is a model of such a stage. The experiment is built up of two ion sources with electrostatic lens systems, a Two-Beam-RFQ accelerator, a funneling deflector and a beam diagnostic system. The two beams are bunched and accelerated in a Two-Beam RFQ. A funneling deflector combines the bunches to a common beam axis. A new beam transport system between RFQ accelerator and deflector has been constructed and mounted. With these extended RFQ-electrodes the drift between the Two-Beam-RFQ and the rf-deflector will be minimized and therefore unwanted emittance growth reduced. After first rf measurements current work are beam tests with the improved Two-Beam-RFQ. First results will be presented.
 
 
WEPS036 First Coupled CH Power Cavity for the FAIR Proton Injector 2565
 
  • R. M. Brodhage, C. Fix, H. Podlech, U. Ratzinger
    IAP, Frankfurt am Main, Germany
  • G. Clemente, L. Groening
    GSI, Darmstadt, Germany
 
  For the research program with cooled antiprotons at FAIR a dedicated 70 MeV, 70 mA proton injector is required. The main acceleration of this room temperature linac will be provided by six CH cavities operated at 325 MHz. Each cavity will be powered by a 2.5 MW Klystron. For the second acceleration unit from 11.5 MeV to 24.2 MeV a 1:2 scaled model has been built. Low level RF measurements have been performed to determine the main parameters and to prove the concept of coupled CH cavities. For this second tank technical and mechanical investigations have been performed in 2010 to develop a complete technical concept for the manufacturing. In Spring 2011, the construction of the first power prototype has started. The main components of this cavity will be ready for measurements in summer 2011. At that time, the cavity will be tested with a preliminary aluminum drift tube structure, which will allow precise frequency and field tuning. This paper will report on the recent technical development and achievements. It will outline the main fabrication steps towards that novel type of proton DTL. Also first low level RF measurements are expected.  
 
WEPS037 RF Design of a 325 MHz 4-ROD RFQ 2568
 
  • B. Koubek, A. Schempp, J.S. Schmidt
    IAP, Frankfurt am Main, Germany
  • L. Groening
    GSI, Darmstadt, Germany
 
  Usually 4-ROD Radio Frequency Quadrupoles (RFQ) are built for frequencies up to 216 MHz. For higher frequencies 4-VANE structures are more common. The advantages of 4-Rod structures, the greater flexibility for tuning and being more comfortable for maintenance, are motivating the development of a 4-Rod RFQ for higher frequencies than 216 MHz. In particular a 325 MHz RFQ with an output energy of 3 MeV is needed for the proton linac for the FAIR project of GSI. This paper reports about the design studies and the latest developments of this RFQ.  
 
WEPS038 Development of CH-Cavities for the 17 MeV MYRRHA-Injector 2571
 
  • D. Mäder, H. Klein, H. Podlech, U. Ratzinger, M. Vossberg, C. Zhang
    IAP, Frankfurt am Main, Germany
 
  Funding: European Union FP7 MAX Contract Number 269565
MYRRHA is conceived as an accelerator driven system (ADS) for transmutation of high level nuclear waste. The neutron source is created by coupling a proton accelerator of 600 MeV with a 4 mA proton beam, a spallation source and a sub-critical core. The IAP of Frankfurt University is responsible for the development of the 17 MeV injector operated at 176 MHz. The injector consists of a 1.5 MeV 4-Rod-RFQ and six CH-drifttube-structures. The first two CH-structures will be operated at room temperature and the other CH-structures are superconducting cavities assembled in one cryo-module. To achieve the extremely high reliability required by the ADS application, the design of the 17 MeV injector has been intensively studied, with respect to thermal issues, minimum peak fields and field distribution.
 
 
WEPS039 General Layout of the 17 MeV Injector for MYRRHA 2574
 
  • H. Podlech, M. Busch, F.D. Dziuba, H. Klein, D. Mäder, U. Ratzinger, A. Schempp, R. Tiede, C. Zhang
    IAP, Frankfurt am Main, Germany
  • M. Amberg
    HIM, Mainz, Germany
 
  Funding: European Union FP7 MAX Contract Number 269565
The MYRRHA Project (Multi Purpose Hybrid Reactor for High Tech Applications) at Mol/belgium will be a user facility with emphasis on research with neutron generated by a spallation source. One main aspect is the demonstration of nuclear waste technology using an accelerator driven system. A superconducting linac delivers a 4 mA, 600 MeV proton beam. The first accelerating section is covered by the 17 MeV injector. It consists of a proton source, an RFQ, two room temperature CH cavities and 4 superconducting CH-cavities. The initial design has used an RF frequency of 352 MHz. Recently the frequency of the injector has been set to 176 MHz. The main reason is the possible use of a 4-rod-RFQ with reduced power dissipation and energy, respectively. The status of the overall injector layout including cavity design is presented.
 
poster icon Poster WEPS039 [2.281 MB]  
 
WEPS040 The Driver Linac of the Neutron Source FRANZ 2577
 
  • U. Ratzinger, B. Basten, L.P. Chau, H. Dinter, M. Droba, M. Heilmann, M. Lotz, O. Meusel, I. Müller, D. Mäder, Y.C. Nie, D. Noll, H. Podlech, A. Schempp, W. Schweizer, K. Volk, C. Wiesner, C. Zhang
    IAP, Frankfurt am Main, Germany
 
  FRANZ is under construction at the Goethe University Frankfurt. A 2MeV ± 100 keV proton beam will produce 1 keV to 200 keV neutrons on a Li7 target. Experiments are planned in the field of nuclear astrophysics as well as in applied physics. A dc operated proton source with a maximum beam current of 200 mA was successfully beam tested end of 2010. FRANZ will have two experimental areas: One for activation experiments with cw proton beams of a few mA generating a usable neutron flux of some 10 billion per square cm per second, the other one for 250 kHz, 1 ns short neutron bunches generated by 1 ns proton pulses of a few Ampere beam current. A special 2 MeV, 175 MHz high current cavity is realized at present as a RFQ-DTL combination. Novel techniques have been invented to reach the needed pulsed target beam current by a bunch compressor system.
Work supported by HICforFAIR and GSI.
 
 
WEPS041 Tuning of the New 4-Rod RFQ for FNAL 2580
 
  • J.S. Schmidt, B. Koubek, A. Schempp
    IAP, Frankfurt am Main, Germany
 
  For the injector upgrade at FNAL a 4-rod Radio Frequency Quadrupole (RFQ) with a resonance frequency of 200 MHz has been build. With this short structure of only 1.3 m a very compact injector design has been realized. Simulations with CST Microwave Studio® were performed for the design. Their results leading to the RF characterizations of the RFQ and the final RF setup which has been accomplished at IAP of the Goethe-University Frankfurt are presented in this paper.  
 
WEPS043 From EUROTRANS to MAX: New Strategies and Approaches for the Injector Development 2583
 
  • C. Zhang, H. Klein, D. Mäder, H. Podlech, U. Ratzinger, A. Schempp, R. Tiede
    IAP, Frankfurt am Main, Germany
 
  Funding: The research leading to these results has received funding from the European Atomic Energy Community’s (Euratom) Seventh Framework Programme FP7/2007-2011 under grant agreement n° [269565].
As the successor of the EUROTRANS project, the MAX project is aiming to continue the R&D effects for a European Accelerator-Driven System and to bring the conceptual design to reality. The layout of the driver linac for MAX will follow the reference design made for the XT-ADS phase of the EUROTRANS project. For the injector part, new design strategies and approaches, e.g. half resonant frequency, half transition-energy between the RFQ and the CH-DTL, and using the 4-rod RFQ structure instead of the originally proposed 4-vane RFQ, have been conceived and studied to reach a more reliable CW operation at reduced costs. In this paper, the design and simulation results of the MAX injector are presented.
 
 
WEPS044 Status of the Ion Source and RFQ Test Bench at the Heidelberg Ion Beam Therapy Centre 2586
 
  • R. Cee, E. Feldmeier, M. Galonska, Th. Haberer, J.M. Mosthaf, B. Naas, A. Peters, S. Scheloske, J. Schreiner, T. Winkelmann
    HIT, Heidelberg, Germany
 
  The possibility of cancer treatment with proton and carbon beams provides HIT (Heidelberg Ion Beam Therapy Centre) with an exceptional feature and gives it a unique position in Europe. In the future, the variety of available ions will be extended towards helium and oxygen. To allow fast switching between three of these ion species an additional ion-source / spectrometer combination will be installed in the LEBT. For comprehensive tests of the new components a dedicated test bench including a beam emittance analyzer has been set up at the HIT facility. It opens up the opportunity to perform detailed investigations of the improved ECR ion source with its enhanced extraction system and the redesigned RFQ of the HIT injector. Parallel to the measurements, the beam optical model of the assembly could be refined to better reproduce the beam diagnostic results. Since August 2010 the test bench has been in operation in different configurations. Behind the RFQ a beamline comprising a phase-probe-based time-of-flight system and beam current measurement devices is set up. The aim is to determine the RFQ working point and to validate the optimizations in terms of particle transmission.  
 
WEPS045 Feasibility Study of a High-gradient Linac for Hadrontherapy 2589
 
  • S. Verdú-Andrés, U. Amaldi, A. Degiovanni
    TERA, Novara, Italy
  • A. Faus-Golfe, S. Verdú-Andrés
    IFIC, Valencia, Spain
  • P.A. Posocco
    CERN, Geneva, Switzerland
 
  Funding: The research leading to this results has been funded by the Seventh Framework Program [FP7/2007-2013] under grant agreement number 215840-2.
Compact, reliable and little consuming accelerators are needed for tumor treatment with hadrons. As solution, TERA proposes CABOTO (CArbon BOoster for Therapy in Oncology), a linac which boosts the energy of carbon ions and H2 molecules coming from a cyclotron. The linac, typically a Side-Coupled Linac (SCL), is divided into several modules. The beam energy can be varied in steps of about 15 MeV/u without using absorbers by acting on the power (amplitude and/or phase) that feeds the different modules of the linac. This work presents the structure design of a 5.7 GHz high repetition rate SCL for a cyclinac, that accelerates carbon ions from 150 up to 400 MeV/u in less than 25 meters. The beam dynamics for this linac and its particular energy selection system is also discussed for different beam energy outputs.
 
 
WEPS046 Longitudinal Beam Acceptance of J-PARC Drift Tube Linac 2592
 
  • T. Maruta
    KEK/JAEA, Ibaraki-Ken, Japan
  • M. Ikegami
    KEK, Ibaraki, Japan
  • A. Miura, G.H. Wei
    JAEA/J-PARC, Tokai-mura, Japan
  • H. Sako
    JAEA, Ibaraki-ken, Japan
 
  The longitudinal acceptance of the J-PARC Drift Tube Linac (DTL) was measured by synchronous phase scan method. The IMPACT simulation indicated DTL longitudinal acceptance is shrinked if the DTL tank level reduced, but beam energy finally acheved at the Linac is almost same as the case of nominal tank level. We measured the acceptance and confirmed the simulation is correct.  
 
WEPS047 Beamloss Study at J-PARC Linac by using Geant4 Simulation 2595
 
  • T. Maruta
    JAEA/J-PARC, Tokai-mura, Japan
 
  Beamloss is one of the key issue for intense hadron beam accelerators. Most of case, origin of beamloss is scattering process between beam particle and residual gas inside vacuum duct. In the case of J-PARC Linac, H ions emitted from an Ion source are accelerated up to 181 MeV, then the beam is transported to RCS. The H ion is the system comprised from a proton and two electrons. If the H ion is scattered with residual gas, these one or two electrons are escaped, then H becomes H0 or H+(proton). H0 or H+ is uncontrollable and finally it goes to beam duct. This process is based on physics process, and Geant4 is matched to this kind of simulation study. I programmed SDTL (50 MeV) to L3BT (181 MeV) section at J-PARC Linac by using Geant4 code. I also wrote H and H0 library which makes it possible for Geant4 to simulate them. I will show the simulation results.  
 
WEPS048 Dependence of Beam Loss on Vacuum Pressure Level in J-PARC Linac 2598
 
  • G.H. Wei
    KEK/JAEA, Ibaraki-Ken, Japan
  • K. Hirano, T. Maruta, A. Miura
    JAEA/J-PARC, Tokai-Mura, Naka-Gun, Ibaraki-Ken, Japan
  • K. Ikegami
    J-PARC, KEK & JAEA, Ibaraki-ken, Japan
 
  In J-PARC linac, a 181-MeV negative hydrogen beam is supported to a succeeding 3-GeV synchrotron with normal operation power at 100-300 kW. During operation, a beam loss in the straight section of the beam transport line immediately after the linac exit is found. The residual radiation level reaches 0.3 mSv/h on the surface of the vacuum chamber several hours after the beam shutdown with the linac beam power of 12 kW. We suppose that the residual gas scattering of negative hydrogen ions generates neutral hydrogen atoms and they give rise to the beam loss by hitting the vacuum chamber wall. To confirm this speculation, the vacuum pressure level in the linac had been changed in order to find the dependence of the beam loss on it. After data analysis, we found the relationship between beam loss amplitude, which was attained from beam loss signal, and vacuum pressure was linear. Corresponding deduction and simulation has been down according to the residual gas components in linac chamber. In this paper, we present the experimental result and some simulations in this study.  
 
WEPS049 Floor Deformation of J-PARC Linac after the Tohoku Earthquake in Japan 2601
 
  • T. Morishita, H. Asano
    JAEA/J-PARC, Tokai-Mura, Naka-Gun, Ibaraki-Ken, Japan
  • M. Ikegami
    KEK, Ibaraki, Japan
 
  J-PARC linac has finalized its precise alignment at the end of summer 2006, and the beam provision to the Rapid Cycling Synchrotron has been started at Sept. 2007. Since then, the deformation of the accelerator tunnel is small enough to keep the soundness of the alignment accuracy. Therefore, the linac has been operated without realignment of the accelerator components for these four years. However, the alignment has seriously been damaged due to the large earthquake at Mar. 11th, 2011 in eastern Japan. Now, work for restoration is being continued. In this paper, the deformation of the linac tunnel floor due to the earthquake is reported. Since then, aftershock happens frequently. We also report the stability of the tunnel floor.  
 
WEPS050 The MEBT Design for the China Accelerator Driven System 2604
 
  • H. Geng, H.F. Ouyang, J. Tang
    IHEP Beijing, Beijing, People's Republic of China
  • Z. Li, S. Pei, F. Yan
    IHEP Beijng, Beijing, People's Republic of China
 
  The Medium Eneryg Beam Transport (MEBT) line plays an important role in transporting and matching the beam from the RFQ exit to the entrance to the next type of acceleration structures while provides enough beam diagnostics for beam commissing and tuning. The beam dynamics design for the 1GeV China Accelerator Driven System (CADS) is making great progress. In this paper, we will describe the design–both element choosing and beam dynamics study of the 3MeV MEBT for the CADS project.  
 
WEPS051 Linac for the Compact Pulsed Hadron Source Project at Tsinghua University Beijing 2607
 
  • X. Guan
    TUB, Beijing, People's Republic of China
 
  Funding: Work supported by the “985 Project” of the Ministry of Education of China, & Tsinghua University Independent Science and research Plan 20091081263.
A project of the Compact Pulsed Hadron Source (CPHS) led by the Department of Engineering Physics of Tsinghua University in Beijing, China has been reported in this paper. CPHS consists of a proton linac, a neutron target station (a Be target, moderators and reflector), and a small-angle neutron scattering instrument, a neutron imaging/radiology station, and a proton irradiation station. The accelerator part is composed of an ECR ion source. LEBT section, a RFQ accelerator, a DTL linac and a HEBT. An ECR ion source will give us a up to 60mA at 50keV proton beam with proton ration larger than 85%, and 0. 2 πmm mrad normalized emittance. A short LEBT will be used to matching the beam from ion source to the RFQ entrance. A 3 meters long RFQ machine can accelerate the proton to 3MeV. The Drift Tube Linac with permanent magnets focusing lens will accept the proton beam direct from RFQ. A 4.3 meters length of DTL with 43 cells will accelerate the beam up to 13MeV. The initial phase of the CPHS construction is scheduled to complete in the end of 2012.
 
 
WEPS052 Progress of Linear Injector for SSC at HIRFL 2610
 
  • Y. He, X. Du, L.P. Sun, Z.J. Wang, C. Xiao, Y.Q. Yang, Y.J. Yuan, X.H. Zhang, Z.L. Zhang
    IMP, Lanzhou, People's Republic of China
  • J.E. Chen, S.L. Gao, G. Liu, Y.R. Lu, K. Zhu
    PKU/IHIP, Beijing, People's Republic of China
  • J. Wang
    Lanzhou University of Technology, People's Republic of China
 
  A heavy ion linear accelerator for Separate Sector Cyclotron (SSC) is constructing at Heavy Ion Research Facility at Lanzhou (HIRFL). It is a new injector for SSC to improve its output beam intensity of 2 times for Super Heavy Experiment (SHE) and 10 times for injection of Cooling Storage Ring (CSR) than old Cyclotron. It has a normal conducting linac at upstream of SSC and one superconducting cryomodule at downstream of SSC to shift beam energy. The designed current of the linac is 0.5 mA and output energy is 0.57 MeV/u and 1.02 MeV/u. Beam dynamic study and prototype fabrication are introduced in the paper.  
 
WEPS053 The Conceptual Design of One of Injector II of ADS in China 2613
 
  • Y. He, H. Jia, C. Li, Y. Liu, Z.J. Wang, C. Xiao, Y. Yang, B. Zhang, H.W. Zhao
    IMP, Lanzhou, People's Republic of China
 
  A 10mA / 50 MeV superconducting proton linac as the demo of an ADS driver is designing and constructing in China. One of 10 MeV segments and corresponding prototypes are designed and fabricating at Institute of Modern Physics of the Chinese Academy of Sciences. It consists of 2.5 MeV RFQ and superconducting structure from 2.5 to 10 MeV. The conceptual design and development of prototype are introduced in the paper.  
 
WEPS054 The Comparison of ADS Injector II with HWR Cavity and CH Cavity 2616
 
  • Z.J. Wang, Y. He
    IMP, Lanzhou, People's Republic of China
 
  High current superconducting proton linac is being studied for Accelerator-driven System (ADS) Project hold by the Chinese Academic of Sciences (CAS). The injector II, which will accelerate proton beam from 2.1 MeV to 10 MeV, will be operated with superconducting cavity. At low energy part, there are two alternative choose, one is HWR cavity, the other is CH cavity. In this paper, the comparison of design with the two type cavities will be presented in view of beam dynamics.  
 
WEPS055 Beam Commissioning Plan of PEFP 100-MeV linac 2619
 
  • J.-H. Jang, Y.-S. Cho, H.-J. Kwon
    KAERI, Daejon, Republic of Korea
 
  Funding: This work was supported by Ministry of Education, Science and Technology of the Korean Government.
Proton engineering frontier project (PEFP) is developing a 100-MeV proton linear accelerator. It is scheduled to install the linac at Kyeungju site from the end of 2011. The linear accelerator consists of a 50-keV injector, a 3-MeV radio-frequency quadrupole (RFQ), and a 100-MeV drift tube linac (DTL). An important characteristic of this accelerator is extracting 20-MeV proton beams just after four DTL tanks. In this region, a medium energy beam transport (MEBT) will be installed for matching the proton beam to the following accelerator and extracting proton beams. The 100-MeV proton beams will be supplied to the users through another beam line which is located after the linac. This work summarized the beam commissioning plan of the proton linear accelerator.
 
 
WEPS056 First Beam Test of 81.5 MHz RFQ for ITEP-TWAC 2622
 
  • V. Andreev, N.N. Alexeev, A. Kolomiets, B. Kondratyev, V.A. Koshelev, A.M. Kozodaev, V.G. Kuzmichev, Y. Orlov, V. Stolbunov, T. Tretyakova
    ITEP, Moscow, Russia
 
  The 4 vane RFQ resonator with magnetic coupling windows as initial part of high-current Heavy Ion Linac for ITEP TWAC Facility is presently under commissioning at ITEP. It was constructed for acceleration of ions with 1/3 charge-to-mass ratio to the energy of 1.57 MeV/u with beam current up to 100 mA. Additional beam dynamics simulations have been carried out for actual fields of the RFQ in order to determine both extreme output beam properties for different ion species with charge-to-mass ratio in the range of 1-0.25 and limitations for high-brightness of the high-current injector. The beam test of RFQ has been started with protons at relatively low electrode voltage for experimental studying the RFQ beam dynamics. First results of the beam test in comparison with beam dynamics simulations are presented.  
 
WEPS057 Beam Dynamics Simulation in DTL with RF Quadrupole Focusing 2625
 
  • S.M. Polozov, A.S. Plastun
    MEPhI, Moscow, Russia
 
  There are a number of ion linear accelerators using RF focusing. Radio Frequency Quadrupole (RFQ) is the most useful RF linac in low energy range. Using of RFQ for medium energies is impractical because of low energy gain rate. Therefore, proposed to combine Drift Tube Linac (DTL), keeping tolerable energy gain rate, and RFQ. Such linac consists of periodic sequence of a several number of drift tubes and RF quadrupole electrodes, located in the same IH resonator. Different variants of the structure will be considered. Beam dynamics simulation will be carried out through these variants. Main parameters of the linac will be determine. The RF model design, providing combination of DTL and RFQ, will be proposed.  
 
WEPS058 The Medium Energy Beam Transport Line (MEBT) of IFMIF/EVEDA LIPAc 2628
 
  • I. Podadera, J.C. Calvo, J.M. Carmona, A. Ibarra, D. Iglesias, A. Lara, C. Oliver, F. Toral
    CIEMAT, Madrid, Spain
 
  Funding: Work partially supported by Spanish Ministry of Science and Innovation under project AIC10-A-000441 and ENE2009-11230.
The IFMIF-EVEDA Linear IFMIF Prototype Accelerator (LIPAc)will be a 9 MeV, 125 mA CW deuteron accelerator which aims to validate the technology that will be used in the future IFMIF accelerator. The acceleration of the beam will be carried out in two stages. An RFQ will increase the energy up to 5 MeV before a Superconducting RF (SRF) linac made of a chain of eight Half Wave Resonators bring the particles to the final energy. Between both stages, a Medium Energy Beam Transport line (MEBT) is in charge of transporting and matching the beam between the RFQ and the SRF. The transverse focusing of the beam is controlled by five quadrupole magnets with integrated steerers, grouped in one triplet and one doublet. Two buncher cavities surrounding the doublet handle the longitudinal dynamics. Two movable collimators are also included to purify the beam optics coming out the RFQ and avoid losses in the SRF. From the inputs of the beam dynamics group, CIEMAT is in charge of designing, manufacturing and integrating all the components of the beamline. In this contribution, the MEBT subsystem will be described and the main objectives and issues for each component will be discussed.
 
 
WEPS059 Layout of the ESS Linac 2631
 
  • H. Danared, M. Eshraqi, W. Hees, A. Jansson, M. Lindroos, S. Peggs, A. Ponton
    ESS, Lund, Sweden
 
  The European Spallation Source will use a 2.5 GeV, 50 mA pulsed proton linac to produce an average 5 MW of power on the spallation target. It will consist of normal-conducting part accelerating particles to 50 MeV in an RFQ and a drift-tube linac and a superconducting part with spoke resonators and two families of elliptical cavities. A high-energy beam transport takes the particles through an upgrade section and at least one bend and demagnifies the beam on to the target. The paper will present the current layout of the linac and discuss parameters that define its length from source to target.  
 
WEPS060 Design and Optimization of ESS LINAC 2634
 
  • M. Eshraqi
    ESS, Lund, Sweden
 
  The {\sc linac} of the European Spallation Source will accelerate the proton beam to its final energy mainly by using superconducting structures. Therefore choosing the right transition energy between these superconducting structures as well as choosing the cavity length and number of cells which enhances the acceleration is of great importance. Two types of {\sc linac}s will be studied, a {\sc linac} with superconducting quadrupoles and a {\sc linac} with normal conducting, resistive, quadrupoles. The procedure to find the optimized {\sc linac} will be described here.  
 
WEPS061 ESS LINAC, Design and Beam Dynamics 2637
 
  • M. Eshraqi, H. Danared
    ESS, Lund, Sweden
 
  The European Spallation Source, {\sc ESS}, will use a linear accelerator delivering a high intensity proton beam with an average beam power of 5~MW to the target station at 2.5~GeV in long pulses of 2~msec. The ESS {\sc Linac} will use two types of superconducting cavities, spoke resonators at low energy and elliptical cavities at high energies. The possibilities to upgrade to a higher power {\sc Linac} at fixed energy are considered. This paper will present a review of the superconducting {\sc Linac} design and the beam dynamics studies.  
 
WEPS062 Design and Beam Dynamics Study of Hybrid ESS LINAC 2640
 
  • M. Eshraqi, H. Danared, W. Hees, A. Jansson
    ESS, Lund, Sweden
 
  The European Spallation Source, {\sc ESS}, will use a superconducting linear accelerator delivering high current long pulses with an average beam power of 5~MW to the target station at 2.5~GeV. A new cryomodule architecture is proposed which allows for a transition between cryomodules in the sub-100~K region, this region can work even at room temperature. This new hybrid design will generate a lower heat load with respect to a fully segmented design - while still providing easy access to individual cryomodules for maintenance and repair. This paper will present a review of the {\sc linac} design, beam dynamics studies and a preliminary cryogenic analysis of the transition region.  
 
WEPS063 Compersation of Effect of Malfunctioning Spoke Resonators on Ess Beam Quality 2643
 
  • M. Eshraqi
    ESS, Lund, Sweden
 
  The {\sc linac} of the European Spallation Source will accelerate the proton beam to 2.5~GeV, 98\% of this energy is gained using superconducting structures. The superconducting {\sc linac} is composed of two types of cavities, double spoke resonators and five-cell elliptical cavities. The {\sc linac}, which is five times more powerful than the most powerful existing {\sc linac}, and the spoke cavities that have never been used at such a scale make it necessary to study the effect of one or a few spoke resonators not functioning properly and to find a solution where the defect is compensated by retuning of the neighbouring cavities.  
 
WEPS064 Upgrade Strategies for High Power Proton Linacs 2646
 
  • M. Lindroos, H. Danared, M. Eshraqi, D.P. McGinnis, S. Molloy, S. Peggs, K. Rathsman
    ESS, Lund, Sweden
  • R.D. Duperrier
    CEA/DSM/IRFU, France
  • J. Galambos
    ORNL, Oak Ridge, Tennessee, USA
 
  High power proton linacs are used as drivers for spallation neutron sources, and are proposed as drivers for sub-critical accelerator driven thorium reactors. A linac optimized for a specific average pulse current can be difficult, or inefficient, to operate at higher currents, for example due to mis-matching between the RF coupler and the beam loaded cavity, and due to Higher Order Mode effects. Hardware is in general designed to meet specific engineering values, such as pulse length and repetition rate, that can be costly and difficult to change, for example due to pre-existing space constraints. We review the different upgrade strategies that are available to proton driver designers, both for linacs under design, such as the European Spallation Source (ESS) in Lund, and also for existing linacs, such as the Spallation Neutron Source (SNS) in Oak Ridge. Potential ESS upgrades towards a beam power higher than 5 MW preserve the original time structure, while the SNS upgrade is directed towards the addition of a second target station.  
 
WEPS065 Segmentation in the Project-X Low Energy CW Linac Front End 2649
 
  • J.-F. Ostiguy, B.G. Shteynas, N. Solyak
    Fermilab, Batavia, USA
 
  Funding: Fermi National Accelerator Laboratory (Fermilab) is operated by Fermi Research Alliance, LLC. for the U.S. Department of Energy under contract DE-AC02-07CH11359
The low-energy front-end of the Project-X 2.5 MeV - 3 GeV linac utilizes superconducting single-spoke resonators for acceleration and solenoids for transverse focusing. To take advantage of the available accelerating field in the cavities, it is necessary to minimize the period length. This leads to a compact arrangement of cavities and solenoids with very minimal open longitudinal space. While beam position monitors and correctors can be integrated to the solenoid assemblies inside a cryostat, some instrumentation such as beam profile monitors require dedicated warm longitudinal space. In this paper we discuss an arrangement where the front-end is segmented in crystats comprising about half a dozen lattice periods separated by a minimal amount of warm longitudinal space. We discuss the impact of introducting such openings and present an optical solution integrating them. The strategy and constraints leading to this solution are outlined.
 
 
WEPS066 Residual Focusing Asymmetry in Superconducting Spoke Cavities 2652
 
  • J.-F. Ostiguy, N. Solyak
    Fermilab, Batavia, USA
 
  Funding: Fermi National Accelerator Laboratory (Fermilab) is operated by Fermi Research Alliance, LLC. for the U.S. Department of Energy under contract DE-AC02-07CH11359.
Project-X is a proposed high intensity proton source at Fermilab. Protons (H) are first accelerated from 2.5 to 3 GeV in a superconducting linac operating in CW mode. While most of the particles are delivered to a variety of precision experiments, a fraction ( about 10%) is further accelerated to 8 GeV in a second superconducting linac operating in pulsed mode. In the low energy front-end of the first stage CW linac, single-spoke cavities are used for acceleration while solenoids and quadrupole doublets provide transverse focusing. The transverse rf defocusing arising from the spoke cavities has a small residual asymmetry whose effect can become noticeable in periods where the transverse phase advance is low. In this paper we discuss this effect, its practical consequences, as well as possible mitigation strategies.
 
 
WEPS067 An H-Mode Accelerator with PMQ Focusing as a LANSCE DTL Replacement 2655
 
  • S.S. Kurennoy, L. Rybarcyk, T.P. Wangler
    LANL, Los Alamos, New Mexico, USA
 
  High-efficiency normal-conducting RF accelerating structures based on H-mode cavities with a transverse beam focusing by permanent-magnet quadrupoles (PMQ) have been developed for beam velocities in the range of a few percent of the speed of light*. At these low beam velocities, an inter-digital H-mode (IH-PMQ) linac is an order of magnitude more efficient than a standard drift-tube linac (DTL). At the Los Alamos Neutron Science Center (LANSCE), upgrades of the proton linac front end are currently under consideration. In view of these plans, we explore a further option of replacing the aging LANSCE DTL by an efficient H-PMQ accelerator. Here we assume that a 201.25-MHz RFQ-based front end up to 750 keV (4% of the speed of light) is followed first by IH-PMQ structures and then by cross-bar H-mode cavities with PMQ focusing (CH-PMQ). Such an H-PMQ linac would bring proton and H beams to the energy of 100 MeV and transfer them into the existing side-coupled-cavity linac (CCL). Results of the combined electromagnetic and beam-dynamics modeling of the proposed H-PMQ accelerator will be presented.
* S.S. Kurennoy et al., “H-Mode Accelerating Structures with PMQ Beam Focusing,” PRST-AB, 2011 (submitted).
 
 
WEPS068 Progress towards an RFQ-based Front End for LANSCE 2658
 
  • R.W. Garnett, S.S. Kurennoy, J.F. O'Hara, L. Rybarcyk
    LANL, Los Alamos, New Mexico, USA
  • A. Schempp
    IAP, Frankfurt am Main, Germany
 
  Funding: This work is supported by the U. S. Department of Energy Contract DE-AC52-06NA25396.
The LANSCE linear accelerator at Los Alamos National Laboratory provides H and H+ beams to several user facilities that support Isotope Production, NNSA Stockpile Stewardship, and Basic Energy Science programs. These beams are initially accelerated to 750 keV using Cockcroft-Walton (CW) based injectors that have been in operation for over 37 years. They have failure modes which can result in prolonged operational downtime due to the unavailability of replacement parts. To reduce long-term operational risks and to realize future beam performance goals in support of the Materials Test Station (MTS) and the Matter-Radiation Interactions in Extremes (MaRIE) Facility, plans are underway to develop a Radio-Frequency Quadrupole (RFQ) based front end as a modern injector replacement for the existing CW injectors. Our progress to date will be discussed.
 
 
WEPS069 The C70 ARRONAX and Beam Lines Status 2661
 
  • F. Poirier, F. Haddad
    SUBATECH, Nantes, France
  • S. Auduc, S. Girault, C. Huet, E. Mace, F. Poirier
    Cyclotron ARRONAX, Saint-Herblain, France
  • J.L. Delvaux
    IBA, Louvain-la-Neuve, Belgium
 
  Funding: The cyclotron ARRONAX is supported by the Regional Council of Pays de la Loire, local authorities, the French government and the European Union.
The C70 Arronax project is a high intensity (up to 350 ·10-6 A) and high energy (70 MeV) multi-particle cyclotron aiming at R&D on material and radiolysis, and production of rare radioisotopes. The project began its hands-on phase in December 2010, and is now undergoing beam lines’ modification in experimental halls for both present and future experiments. Characterization of the beams at the end of the beam lines is of particular importance to determine the capacity of the cyclotron for the end-line experimental users. A program of beam characterization is being performed based on dedicated diagnostics, e.g. beam profilers, Faraday cups, alumina foils, and also on a series of Geant4 beam simulations. The results of the measurements, along with the simulations, are detailed in this report for proton and alpha particle beams, as well as the future prospects of the characterization program.
 
 
WEPS070 Commissioning Status of Kolkata Superconducting Cyclotron 2664
 
  • C. Mallik, R.K. Bhandari
    DAE/VECC, Calcutta, India
 
  After completing the construction of the K~500 superconducting cyclotron at Kolkata, the internal beam acceleration was accomplished in August 2009 and several tests were conducted to confirm the acceleration. Earlier the superconducting magnet using Nb-Ti superconductor with 300 litre liquid helium cryostat and 80 tonne iron was commissioned and field mapped. The radiofrequency system spanning 9-27 MHz and with three independent resonators were integrated into the machine. Some difficulties were experienced with achieving the voltage related to ceramic failures. Finally, ~50 kV on the dees have been achieved with reasonable phase stability between the three dees. The cyclotron uses a 14 GHz external ECR ion source and the beam is injected through 28 metre long injection line. Till date several beams like neon, argon, nitrogen, oxygen etc. have been accelerated mostly in analogous mode and at around 14 MHz frequency and ~32 kG field. Valuable experience has been obtained with various systems. The paper would describe the experience with different subsystems and beam acceleration experience. Presently, beam extraction is being tried and will be achieved shortly.  
 
WEPS071 High Power, High Energy Cyclotrons for Muon Antineutrino Production: the DAEdALUS Project 2667
 
  • J.R. Alonso, T. Smidt
    MIT, Cambridge, Massachusetts, USA
 
  Neutrino physics is very much at the forefront of today's research. Large detectors installed in deep underground locations study neutrino masses, CP violation, and oscillations using neutrino-sources including long- and short-baseline beams of neutrinos from muons decaying in flight. DAEdALUS* looks at neutrinos from stopped muons, “Decay At Rest (DAR)” neutrinos. The DAR neutrino spectrum has no electron antineutrinos (nu-e-bar) (pi-minus are absorbed), so a detector with much hydrogen (water-Cherenkov or liquid scintillator) is sensitive to appearance of nu-e-bar’s oscillating from nu-mu-bar via inverse-beta-decay. Oscillations are studied using shorter baselines, less than 20 km reaching the same range as the current and planned high-energy neutrino lines at Fermilab. As the neutrino flux is not variable, nor is the energy, the baseline is varied, plans call for 3 accelerator-based neutrino sources at 1.5, 8 and 20 km with staggered beam-on cycles. Key is cost-effectively generating megawatt beams of 800 MeV protons. A superconducting ring cyclotron is being designed by L. Calabretta and his group**. This revolutionary design could find application in many ADS-related fields.
* DAEdALUS Expression of Interest, arXiv:1006.0260
** Calabretta et al., "A Superconducting Ring Cyclotron to Search for CP Violation in the Neutrino Sector", this conference
 
 
WEPS072 A Superconducting Ring Cyclotron to Search for CP Violation in the Neutrino Sector 2670
 
  • L.A.C. Piazza, M.M. Maggiore
    INFN/LNL, Legnaro (PD), Italy
  • L. Calabretta, D. Campo, D. Rifuggiato
    INFN/LNS, Catania, Italy
  • A. Calanna
    CSFNSM, Catania, Italy
 
  Multi Megawatt accelerators are today requested for different use. In particular the experiment DAEdALUS*, recently proposed by MIT scientist to search for CP violation in the neutrino sector, needs three accelerator with energy of about 800 MeV, average power of some MW and duty cycle of 20%. To reduce the cost of the accelerators a cyclotron complex consisting of an injector** and of a booster ring cyclotron has been proposed***. The booster Superconducting Ring Cyclotron, able to accelerate a H2+ molecule beam up to 800 MeV/n and average power higher than 1.6 MW, will be described. Although the average power is 1.6 MW, due to the low duty cycle, the peak power will be 8 MW. The main advantages to accelerate H2+ are a reduction of space charge effects, a simple extraction process, extraction of two beams at the same time from each booster cyclotron to simplify the beam dump. The features of the magnetic sector, of the superconducting coils and the magnetic forces evaluated by the code TOSCA are presented. The isochronous magnetic field, the beam dynamics along the injection and extraction path and during the acceleration are presented, too.
*J.Alonso etal., Novel Search for CP Violation in the Neutrino Sector: DAEdALUS, June2010;e-Print arXiv:1006.0260.
**L.Calabretta, IPAC 2011,this conference.
***L.Calabretta, Cyclotrons 2010, Lanzhou.
 
 
WEPS073 A Low Energy Cyclotron Injector for DAEdALUS Experiment 2673
 
  • L.A.C. Piazza, M.M. Maggiore
    INFN/LNL, Legnaro (PD), Italy
  • L. Calabretta, D. Campo, D. Rifuggiato
    INFN/LNS, Catania, Italy
  • A. Calanna
    CSFNSM, Catania, Italy
 
  Multi Megawatt accelerators are today requested for different use. In particular the experiment DAEdALUS*, recently proposed by MIT scientist to search for CP violation in the neutrino sector, needs three accelerator with energy of about 800 MeV, average power of some MW and duty cycle of 20%. To reduce the cost of the accelerators a cyclotron complex consisting of an injector and of a booster ring cyclotron has been proposed**. The main characteristics of the new kind of a separated sector cyclotron injector able to accelerate a H2+ molecule beam up to 50 MeV/n will be presented. Due to the low duty cycle, the peak current to be accelerated is 5 mA. The problem related to the injection of a H2+ beam, delivered by a compact ion source, and to the space charge effects will be discussed. The main parameters of the magnetic sectors, RF cavities, the isochronous magnetic field and the beam dynamics along the injection and extraction path and during the acceleration will be presented, too.
* J. Alonso et al., “A Novel Search for CP Violation in the Neutrino Sector: DAEdALUS”, June 2010. e-Print: arXiv:1006.0260
** L. Calabretta et al., ICCA, Lanzhou 2010; http://www. JACoW.org.
 
 
WEPS074 H Injection Studies of FFAG Accelerator at KURRI 2676
 
  • K. Okabe, Y. Niwa, I. Sakai
    University of Fukui, Faculty of Engineering, Fukui, Japan
  • Y. Ishi, Y. Kuriyama, J.-B. Lagrange, Y. Mori, R. Nakano, B. Qin, T. Uesugi, E. Yamakawa
    KURRI, Osaka, Japan
 
  Aiming to demonstrate the basic feasibility of the accelerator driven sub-critical reactor (ADSR), proton Fixed Field Alternating Gradient (FFAG) accelerator complex as a neutron production driver has been constructed in Kyoto University Research Reactor Institute (KURRI). In order to upgrade beam power of the FFAG neutron source, a project about a new H linac injector for FFAG main ring instead of present injector has been started. A charge exchange multi-turn beam injection has been performed for the first time at FFAG main ring in KURRI. In this paper, the detail of injection system and beam study of low energy H injection at FFAG is described.  
 
WEPS075 Induction Sector Cyclotron for Cluster Ions 2679
 
  • K. Takayama
    KEK, Ibaraki, Japan
  • T. Adachi
    Sokendai, Ibaraki, Japan
  • W. Jiang
    Nagaoka University of Technology, Nagaoka, Niigata, Japan
  • H. Tsutsui
    SHI, Tokyo, Japan
 
  A novel scheme of a sector cyclotron to accelerate extremely heavy cluster ions, called Induction Sector Cyclotron (ISC)*, is described. Its key feature is fast induction acceleration. An ion bunch is accelerated and captured with pulse voltages generated by transformers**. The acceleration and confinement in the longitudinal direction can be independently handled. Since the transformers are energized by the switching power supply, in which turning on/off of the switching gate is maneuvered by gate signals digitally manipulated from the circulating beam signal of an ion bunch, acceleration synchronizing with the revolution of ion beam is always guaranteed. A cluster ion beam such as C-60, which so far there has been no way to repeatedly accelerate, can be accelerated from extremely low energy to high energy. The fundamental concept of ISC is introduced and beam dynamical issues such as a life time of cluster ions under strong guide fields and repeatedly exerted pulse voltages in the existence of residual molecules are addressed. In addition, the present status of R&D works on a race track-shape induction accelerating cell will be presented.
* K.Takayama et al., submitted for publication (2011).
** K.Takayama and R.J.Briggs, Chapter 11 and 12 in Induction Accelerators (Springer, 2010).
 
 
WEPS076 Straight Scaling FFAG 2682
 
  • J.-B. Lagrange, Y. Ishi, Y. Kuriyama, Y. Mori, T. Planche, B. Qin, T. Uesugi, E. Yamakawa
    KURRI, Osaka, Japan
  • K. Okabe
    University of Fukui, Faculty of Engineering, Fukui, Japan
  • A. Sardet, R. Wasef
    LPSC, Grenoble Cedex, France
 
  Recent developments in scaling fixed field alternating gradient (FFAG) accelerators have opened new ways for lattice design, with straight sections, and insertions like dispersion suppressors. An experiment to study straight sections and dispersion suppressors is under progress at KURRI.  
 
WEPS077 Present Status of FFAG Proton Accelerator at KURRI* 2685
 
  • Y. Mori, Y. Ishi, Y. Kuriyama, J.-B. Lagrange, R. Nakano, T. Planche, T. Uesugi, E. Yamakawa
    KURRI, Osaka, Japan
  • Y. Niwa, K. Okabe, I. Sakai
    University of Fukui, Faculty of Engineering, Fukui, Japan
 
  The 150MeV FFAG proton accelerator has been developed at Kyoto University Research Reactor Institute(KURRI) for the fundamental study of Accelerator Driven Sub-crittical Reactor (ADSR). Recently, a new H injector was constructed to improve the beam quality and intensity. The paper will describe the detail of the preset status of FFAG proton accelerator at KURRI.  
 
WEPS078 Compact FFAG Accelerators for Medium Energy Hadron Applications 2688
 
  • B. Qin, Y. Ishi, Y. Kuriyama, J.-B. Lagrange, Y. Mori, K. Okabe, T. Uesugi, E. Yamakawa
    KURRI, Osaka, Japan
 
  Funding: This work was supported by Japan Science and Technology Agency under Strategic Promotion of Innovative Research and Development Program.
Medium energy hadron beams are widely applied in accelerator driven subcritical systems (ADSR), high intensity neutron sources and carbon therapy. Compactness feature is important for this energy region, especially in the case of medical use purposes. This paper introduces a novel superferric scheme with scaling fixed-field alternating gradient (FFAG) accelerators, which can deliver 400MeV/u carbon ions or 1.2GeV protons. By using high permeability materials, 5T magnetic field with high field index can be achieved to reduce accelerator circumference significantly. The lattice configuration and design of superferric magnet are described in details.
 
 
WEPS079 Serpentine Acceleration in Scaling FFAG 2691
 
  • E. Yamakawa, Y. Ishi, Y. Kuriyama, J.-B. Lagrange, Y. Mori, R. Nakano, T. Planche, B. Qin, T. Uesugi
    KURRI, Osaka, Japan
  • K. Okabe, I. Sakai
    University of Fukui, Faculty of Engineering, Fukui, Japan
 
  A serpentine acceleration in scaling FFAG accelerator has been examined. In this scheme, high-energy and high-current beam can be obtained in non-relativistic energy region. Longitudinal hamiltonian is also derived analytically.  
 
WEPS080 Development of High-quality Intense Proton Beam at the RCNP Cyclotron Facility 2694
 
  • M. Fukuda, K. Hatanaka, M. Kibayashi, S. Morinobu, K. Nagayama, T. Saito, H. Tamura, H. Ueda, H. Yamamoto, T. Yorita
    RCNP, Osaka, Japan
 
  A 2.45 GHz ECR proton source, equipped with a set of three permanent magnets, was developed to increase the intensity of a high-quality proton beam. A 15 keV proton beam with intensity of 0.6 mA was produced with a proton ratio of more than 80 %. Emittance of the proton beam with intensity of 50 to 100 micro-A in the LEBT system was around 50 pi-mm-mrad. Beam transmission, defined by the ratio of the beam intensity between a Faraday cup placed in the axial injection beam line and an inflector electrode of the AVF cyclotron, was improved from 25 % for a 70 micro-A proton beam to more than 90 % for 30 micro-A obtained by defining the injection beam with a beam slit of iris type. The result indicated that the beam transmission was limited by the acceptance of the axial injection beam line. Emittance of the 65 MeV proton beam accelerated by the K140 AVF cyclotron was a few pi-mm-mrad for beam intensity of several-micro-A. In this paper, development of the intense proton beam and evaluation of the proton beam quality will be mainly reported.  
 
WEPS081 The Study of Helium Ion FFAG Accelerator* 2697
 
  • H.L. Luo, H. Hao, X.Q. Wang, H.L. Wu, Y.C. Xu
    USTC/NSRL, Hefei, Anhui, People's Republic of China
 
  As helium ion source, the periodic focusing structure model of Helium ion (He+) FFAG (Fixed-Field Alternating Gradient) accelerator was designed, providing He+ beam with higher beam current at a lower cost, which could be used for the study of the impact of Helium embitterment on fusion reactor envelope material. A radial sector scaling FFAG accelerator type with eight super-periods and a conventional magnetic lattice structure, a triplet focusing lattice-DFD combination, is adopted for He+ FFAG accelerator. In this paper, magnetic lattice is optimizing by analytical and numerical techniques. A large-aperture magnet is designed by using a 3D magnetic field simulation code OPERA-3D. Runge-Kutta tracking code used specifically for FFAG accelerator based on MATLAB language was used to track the particle in the magnetic field generated by OPERA-3D, followed by linear and nonlinear beam dynamics study. Some results of magnet design, particle tracking and dynamics study are presented in the article.  
 
WEPS082 Development of FLNR JINR Heavy Ion Accelerator Complex in the Next Seven Years: New DC-280 Cyclotron Project 2700
 
  • G.G. Gulbekyan, S.L. Bogomolov, O.N. Borisov, S.N. Dmitriev, J. Franko, B. Gikal, I.A. Ivanenko, I.V. Kalagin, V.I. Kazacha, N.Yu. Kazarinov, N.F. Osipov, A. Tikhomirov
    JINR, Dubna, Moscow Region, Russia
 
  At present time four isochronous cyclotrons: U-400, U-400M, U-200 and IC-100 are in operation at the JINR FLNR. Total operation time is about 10000 hours per year. The U400M is a primary beam generator and U400 is as postaccelerator in RIB (DRIBs) experiments to produce and accelerate exotic nuclides such as 6He, 8He etc. One of the basic scientific programs which are carried out in FLNR - synthesis of new elements which demands intensive beams of heavy ions. Now U-400 is capable to provide long term experiments on Ca 48 beams with intensity of 1 pμA.In order to improve efficiency of the experiments for the next 7 years it is necessary to obtain the accelerated ion beams with the following parameters. Ion energy 4/8 MeV/n Masses 10/238 Beam intensity (up to A=50) 10 pμA Beam emittance less 30 π mm·mrad These parameters have underlain the project of new cyclotron DC-280.  
 
WEPS083 DC280 Cyclotron Central Region with Independent Flat-Top System 2703
 
  • I.A. Ivanenko, B. Gikal, G.G. Gulbekyan, N.Yu. Kazarinov
    JINR, Dubna, Moscow Region, Russia
 
  At the present time, the activities on creation of the new isochronous cyclotron DC280 are carried out at the FLNR, JINR. The cyclotron DC280 is intended for accelerating the wide range of ion beams with A/Z= 4 - 7 to energy W= 4 - 8MeV/u and intensity up to 10pmcA. To achieve high-intensity ion beams the cyclotron is equipped with Flat-Top system. At the cyclotron DC280 the Flat-Top system is physically separated from main resonators. The investigation of the cyclotron centre region with independent Flat-Top is presented. The simulation of the beams acceleration is carried out by means of the computer code CENTR.  
 
WEPS085 Deveopment of the IBA-JINR Cyclotron C235-V3 for Dmitrovgrad Hospital Center of the Proton Therapy 2706
 
  • E. Syresin, G.A. Karamysheva, M.Y. Kazarinov, S.A. Kostromin, N.A. Morozov, A.G. Olshevsky, V.M. Romanov, E. Samsonov, N.G. Shakun, G. Shirkov, S.G. Shirkov
    JINR, Dubna, Moscow Region, Russia
  • M. Abs, A. Blondin, P. Cahay, Y. Jongen, W.J.G.M. Kleeven, S. Zaremba
    IBA, Louvain-la-Neuve, Belgium
 
  The approval of the Dmitrovgrad project - the first Russian hospital center of the proton therapy was announced in 2010. The JINR-IBA collaboration have developed and constructed the proton cyclotron C235-V3 for this center. We plan to assemble this cyclotron in JINR in 2011 and perform tests with the extracted proton beam in 2012. This cyclotron is an essentially modified version of IBA C235 cyclotron. Modification of the extraction system is aim of new C235-V3 cyclotron. The new extraction system was constructed and tested. The experimentally measured extraction efficiency was improved from 60% for the old system to 77% for the new one. The new field mapping system was developed for the C235-V3 cyclotron. It system consists of the axial field mapping system and an additional system applied for radial field Br measurements. One of the goals of the cyclotron improvement is the modification of the sector spiral angle for reducing of coherent beam losses at acceleration. The coherent beam displacement from the median plane is defined by the vertical betatron tune Qz. An increase of the vertical betatron tune permits to reduce the coherent losses at proton acceleration.  
 
WEPS086 Three-lens Lattices for Extending the Energy Range of Non-scaling FFAGs 2709
 
  • S.J. Brooks
    STFC/RAL/ASTeC, Chilton, Didcot, Oxon, United Kingdom
 
  In this paper it is found that a three-quadrupole focussing system can be morphed continuously through FFD, FDF and DFF variants and back again while maintaining stable optics and even keeping the two transverse tunes constant. This relates to non-scaling FFAGs, where the magnet gradients define both the focussing and the variation of the field with momentum as the closed orbit sweeps across it. A two-lens focussing system cannot change the sign of either gradient without becoming unstable, meaning non-scaling FFAGs built with such a lattice eventually encounter too large a magnetic field at low energies. However, a theoretical system of magnet field variations using three lenses, with a potentially unlimited energy range and fixed tunes is presented here.  
 
WEPS087 Dynamics of a Novel Isochronous Non-scaling FFAG 2712
 
  • S.L. Sheehy
    STFC/RAL/ASTeC, Chilton, Didcot, Oxon, United Kingdom
 
  Many non-scaling FFAG accelerator designs involve magnetic fields that cannot be described in popular accelerator design codes, and complex beam dynamics that require extremely accurate simulations. A recent design of a 1 GeV isochronous non-scaling FFAG is used to compare the codes COSY Infinity and ZGOUBI, both of which are commonly used in FFAG design. Results are presented for the comparison of basic beam dynamics and calculated dynamic aperture.  
 
WEPS088 Space Charge Studies of a 1 GeV Isochronous Non-scaling FFAG Proton Driver 2715
 
  • S.L. Sheehy
    STFC/RAL/ASTeC, Chilton, Didcot, Oxon, United Kingdom
 
  The production of very high power proton drivers in the 10 MW range is a considerable challenge to the accelerator community. Non-scaling FFAGs have gained interest in this field, as they may be able to provide smaller, cheaper accelerators than existing options. The recent development of an isochronous non-scaling FFAG is a promising advance, but must be shown to have stable beam dynamics in the presence of space charge. Simulations of this design including space charge are presented and the implications discussed.  
 
WEPS090 The Myrrha Linear Accelerator 2718
 
  • D. Vandeplassche
    SCK-CEN, Mol, Belgium
  • J.-L. Biarrotte
    IPN, Orsay, France
  • H. Klein, H. Podlech
    IAP, Frankfurt am Main, Germany
 
  Funding: European Atomic Energy Community's (EURATOM) Seventh Framework Programme FP7/2007-2011, grant agreement no. 269565 (MAX project)
Accelerator Driven Systems (ADS) are promising tools for the efficient transmutation of nuclear waste products in dedicated industrial installations, called transmuters. The Myrrha project at Mol, Belgium, placed itself on the path towards these applications with a multipurpose and versatile system based on a liquid PbBi (LBE) cooled fast reactor (80 MWth) which may be operated in both critical and subcritical modes. In the latter case the core is fed by spallation neutrons obtained from a 600 MeV proton beam hitting the LBE coolant/target. The accelerator providing this beam is a high intensity CW superconducting linac which is laid out for the highest achievable reliability. The combination of a parallel redundant and of a fault tolerant scheme should allow obtaining an MTBF value in excess of 250 hours that is required for optimal integrity and successful operation of the ADS. Myrrha is expected to be operational in 2023. The forthcoming 4-year period is fully dedicated to R&D activities, and in the field of the accelerator they are strongly focused on the reliability aspects and on the proper shaping of the beam trip spectrum.
 
 
WEPS092 High Energy Beam Line Design of the 600MeV, 4 mA Proton Linac for the MYRRHA Facility 2721
 
  • H. Saugnac
    IPN, Orsay, France
 
  The general goal of the CDT project is to design a FAst Spectrum Transmutation Experimental Facility (FASTEF) able to demonstrate efficient transmutation and associated technology through a system working in subcritical and/or critical mode. A superconducting LINAC, part of the MYRRHA facility, will produce a 600 MeV, 4 mA proton beam and transport it to the spalation target located inside the reactor core. On this paper we focus on the final beam line design and describe optic simulations, beam instrumentation, integration inside the reactor building, mechanical and vacuum aspects as well as a preliminary design of the 2.4 MW beam dump located at the end of the accelerator tunnel.  
 
WEPS094 Dynamic Vacuum Stability in SIS100 2724
 
  • P. Puppel, U. Ratzinger
    IAP, Frankfurt am Main, Germany
  • P.J. Spiller
    GSI, Darmstadt, Germany
 
  SIS100 is the main synchrotron of the FAIR project. It is designed to accelerate high intensity intermediate charge state uranium beams from 200 MeV/u up to 2.7 GeV/u. Intermediate charge state heavy ions are exposed to a high probability of charge exchange due to collisions with residual gas molecules. Since the charge exchange process changes the magnetic rigidity, the involved ions are lost behind dispersive elements, and an energy-dependent gas desorption takes place. The StrahlSim code has been used to predict the stability of the residual gas pressure in SIS100 under beam loss driven dynamic conditions. The results show, that a stable operation at highest U28+ intensities is possible, under the constraint that the vacuum chambers of the ion catcher system are cold enough to pump hydrogen. Furthermore, in order to determine the load to the cryogenic system, the average beam energy deposition onto the ion catcher system has been calculated.  
 
WEPS095 Status of J-PARC Accelerator Facilities after the Great East Japan Earthquake 2727
 
  • K. Hasegawa, M. Kinsho, H. Oguri
    JAEA/J-PARC, Tokai-Mura, Naka-Gun, Ibaraki-Ken, Japan
  • T. Koseki
    KEK, Tokai, Ibaraki, Japan
 
  J-PARC was heavily affected by the March 11 Great East Japan Earthquake. When the earthquake struck, we had a beam study operation of the linac and the machine immediately stopped. Fortunately, we had no effects of tsunami that happened nearby and no one was injured. We can see subsidence at many places; about 1.5m over the wide area at the entrance of the linac building, about 50cm over the area of 1m x 10m at the main ring building, etc. Underground water is coming into the linac and the main ring tunnels. The water level at the linac reached a depth of 10 cm, but pumping with a diesel generator successfully saved from further flooding. At the RCS, the circulating road went wavy and the yard area for electricity and water devices was heavily distorted. Therefore, a high voltage power is not available on the date of abstract submission. We are investigating damages of each facility and also we are trying to estimate the beam restoration. The current status of the J-PARC accelerator facilities after the earthquake will be presented.  
 
WEPS096 Injection Energy Recovery of J-PARC RCS 2730
 
  • N. Hayashi, H. Hotchi, J. Kamiya, P.K. Saha, T. Takayanagi, K. Yamamoto, M. Yamamoto, Y. Yamazaki
    JAEA/J-PARC, Tokai-Mura, Naka-Gun, Ibaraki-Ken, Japan
 
  The J-PARC RCS is a high beam power Rapid-Cycling Synchrotron (RCS). The original designed injection energy is 400MeV, although presently it is 181MeV, and its beam power is limited to 0.6MW. Works to recover the Linac energy are ongoing and injection magnets power supplies upgrade are required in the RCS. In order to achieve 1MW designed beam power, new instrumentation is also planned simultaneously. Activities related injection energy recovery in the J-PARC RCS is presented.  
 
WEPS097 Performance of Multi-harmonic RF Feedforward System for Beam Loading Compensation in the J-PARC RCS 2733
 
  • F. Tamura, M. Nomura, A. Schnase, T. Shimada, M. Yamamoto
    JAEA/J-PARC, Tokai-Mura, Naka-Gun, Ibaraki-Ken, Japan
  • K. Hara, C. Ohmori, M. Toda, M. Yoshii
    KEK/JAEA, Ibaraki-Ken, Japan
  • K. Hasegawa
    KEK, Tokai, Ibaraki, Japan
 
  The beam loading compensation is a key part for acceleration of high intensity proton beams in the J-PARC RCS. In the wide-band MA-loaded RF cavity, the wake voltage consists of not only the accelerating harmonic component but also the higher harmonics. The higher harmonic components cause the RF bucket distortion. We employ the RF feedforward method to compensate the multi-harmonic beam loading. The full-digital feedforward system is developed, which compensates the first three harmonic components of the beam loading. We present the results of the beam test with a high intensity proton beam (2.5·1013 ppp). The impedance seen by the beam is greatly reduced, the impedance of the fundamental accelerating harmonic is reduced to less than 25 ohms in a full accelerating cycle, while the shunt resistance of the cavity is in the order of 800 ohms. The performance of the feedforward system is promising for achievement of the design beam power, 1 MW, in the future.  
 
WEPS098 Combined Momentum Collimation Method in High-intensity Rapid Cycling Proton Synchrotrons 2736
 
  • J.F. Chen, J. Tang, Y. Zou
    IHEP Beijing, Beijing, People's Republic of China
 
  A new momentum collimation method – so-called combined momentum collimation method in high-intensity synchrotrons is proposed and studied here, which makes use two-stage collimation in both the longitudinal and the transverse phase planes. The primary collimator is placed at a high-dispersion location of an arc, and the longitudinal and transverse secondary collimators are in the same arc and in the down-stream dispersion-free long straight section, respectively. The particles with positive momentum deviations will be scattered and degraded by a carbon scraper and then cleaned mainly by the transverse collimators, whereas the particles with negative momentum deviations will be scattered by a tantalum scraper and mainly cleaned by the longitudinal secondary collimators in the successive turns. Numerical simulation results using TURTLE and ORBIT codes show that this method gives high collimation efficiency for medium-energy synchrotrons. The studies have also shown two interesting effects: one is that the momentum collimation is strongly dependent on the transverse beam correlation; the other is that the material for the primary collimator plays an important role in the method.
This work was supported by the National Natural Science Foundation of China (10975150, 10775153), the CAS Knowledge Innovation Program-“CSNS R&D Studies”.
 
 
WEPS099 Physics Design of CSNS RCS Injection and Extraction System 2739
 
  • J. Qiu, N. Huang, J. Tang, S. Wang
    IHEP Beijing, Beijing, People's Republic of China
 
  In this paper, the injection and extraction system design for CSNS RCS are discussed. The injection system is designed to place all the injection devices in one uninterrupted long drift in one of the four dispersion free straight sections. Painting bumper magnets are used for both horizontal and vertical phase space painting. The beam extraction process from the CSNS RCS is a single turn two step process, requiring a group of kickers and a Lambertson septum magnet.  
 
WEPS100 Status of 100-MeV Proton Linac Development for PEFP 2742
 
  • Y.-S. Cho, S. Cha, I.-S. Hong, J.-H. Jang, D.I. Kim, H.S. Kim, H.-J. Kwon, K. Min, B.-S. Park, J.Y. Ryu, K.T. Seol, Y.-G. Song, S.P. Yun
    KAERI, Daejon, Republic of Korea
  • J.S. Hong
    KAPRA, Cheorwon, Republic of Korea
 
  Funding: This wok was supported through the Proton Engineering Frontier Project by the Ministry of Education, Science and Technology of Korea.
The Proton Engineering Frontier Project (PEFP) is developing a 100-MeV high-duty-factor proton linac, which consists of a 50-keV microwave ion source, a 3-MeV radio frequency quadrupole, a 100-MeV drift tube linac, a 20-MeV beam transport line, and a 100-MeV beam transport line. It will supply proton beams of 20-MeV and 100-MeV with peak current of 20 mA to users for proton beam applications. The beam duty factor will be 24% and 8% respectively. The 20-MeV front-end accelerator has been installed and operated at the KAERI Daejeon test stand for user service, and the rest part of the accelerator has been fabricated and will be installed at the new site of Gyeongju City in 2011. The detailed status of the 100-MeV proton linac will be presented.
 
 
WEPS101 Lattice Design of a RCS as Possible Alternative to the PS Booster Upgrade 2745
 
  • M. Fitterer, M. Benedikt, H. Burkhardt, C. Carli, R. Garoby, B. Goddard, K. Hanke, H.O. Schönauer
    CERN, Geneva, Switzerland
  • A.-S. Müller
    KIT, Karlsruhe, Germany
 
  In the framework of the LHC Injectors Upgrade (LIU) a new rapid cycling synchrotron as alternative to the PS Booster has been proposed. In this paper we present the lattice constraints and requirement as well as the current status of the RCS lattice design and beam dynamics studies.  
 
WEPS102 Latest News on the Beam Dynamics Design of SPL 2748
 
  • P.A. Posocco, M. Eshraqi, A.M. Lombardi
    CERN, Geneva, Switzerland
 
  SPL is a superconducting H− LINAC under study at CERN. The SPL is designed to accelerate the 160 MeV beam of LINAC4 to 5 GeV, and is composed of two fami¬lies of 704.4 MHz elliptical cavities with geometrical betas of 0.65 and 1.0. Two families of cryo-modules are considered: the low-beta cryo-module houses 3 low-beta cavities, whereas the high-beta one houses 8 cavities. The transverse focusing is performed with normal-conducting quadrupoles arranged in 2 different lattices: FD0 at lower and F0D0 at higher energies. The regular lattices are in-terrupted at the transition between low beta and high beta cryo-modules and for extracting medium energy beams at 1.4 and 2.5 GeV, where the change of the transverse lattice is performed. In this paper the latest beam dynamics studies will be presented together with the sensitivity of the SPL performance to RF errors, alignment tolerances and quadrupole high order components.  
 
WEPS103 Design of a Rapid Cycling Synchrotron for the Final Stage of Acceleration in a Common Proton Driver for a Neutrino Factory and a Spallation Neutron Source Based on Megawatt Upgrades to ISIS 2751
 
  • J. Pasternak
    STFC/RAL, Chilton, Didcot, Oxon, United Kingdom
  • L.J. Jenner, J. Pasternak
    Imperial College of Science and Technology, Department of Physics, London, United Kingdom
 
  Potential upgrades to the ISIS accelerators at RAL in the UK to provide proton beams in the few GeV and few MW range could be envisaged as the starting point for a proton driver shared between a short pulse spallation neutron source and the Neutrino Factory. The accelerator chain for the spallation neutron source, consisting of an 800 MeV H linac and a 3.2 GeV rapid cycling synchrotron (RCS), is currently being designed and optimised. The design of the RCS for the final stage of acceleration, which would increase the final beam energy of the dedicated pulses to feed the Neutrino Factory pion production target is presented. The feasibility of the final bunch compression to the necessary nanosecond range is also discussed.  
 
WEPS104 Transverse Beam Dynamics for the ISIS Synchrotron with Higher Energy Injection 2754
 
  • B.G. Pine, C.M. Warsop
    STFC/RAL/ISIS, Chilton, Didcot, Oxon, United Kingdom
 
  ISIS is the spallation neutron source at the Rutherford Appleton Laboratory in the UK. Operation centres on an 800 MeV rapid cycling synchrotron, which provides 3·1013 protons per pulse at 50 Hz, corresponding to a beam power of 200 kW. Studies are underway to increase the energy of the ISIS linac from 70 to 180 MeV. This would reduce space charge in the synchrotron, and enable a larger current to be accumulated, possibly up to 0.5 MW. As part of the study, transverse beam dynamics have been re-examined on ISIS, building up models from incoherent space charge tune shift, through smooth focusing models with space charge to 2D alternating gradient lattice simulations. These later simulations, using the in-house space charge code Set, include harmonic perturbations to the focusing lattice, closed orbits and images. A clearer picture of the dynamics is emerging, where there may be important constraints on the highest intensities, including half integer resonance, image induced structure resonances and transverse instabilities.  
 
WEPS105 A Common Proton Driver for a Neutrino Factory and a Spallation Neutron Source Based on Megawatt Upgrades to ISIS 2757
 
  • J.W.G. Thomason
    STFC/RAL/ISIS, Chilton, Didcot, Oxon, United Kingdom
  • J. Pasternak
    Imperial College of Science and Technology, Department of Physics, London, United Kingdom
 
  The Rutherford Appleton Laboratory (RAL) is home to ISIS, the world’s most productive spallation neutron source. Potential upgrades of the ISIS accelerators to provide beam powers of 2 – 5 MW in the few GeV energy range could be envisaged as the starting point for a proton driver shared between a short pulse spallation neutron source and the Neutrino Factory. The concept of sharing a proton driver between other facilities and the Neutrino Factory is an attractive, cost-effective solution which is already being studied in site-specific cases at CERN and FNAL. Although in the RAL case the requirements for the Neutrino Factory baseline proton energy and time structure are different from those for a spallation neutron source, an additional RCS or FFAG booster bridging the gap in proton energy and performing appropriate bunch compression seems feasible.  
 
WEPS106 Status of Injection Upgrade Studies for the ISIS Synchrotron 2760
 
  • C.M. Warsop, D.J. Adams, D.J.S. Findlay, I.S.K. Gardner, S.J.S. Jago, B. Jones, R.J. Mathieson, S.J. Payne, B.G. Pine, A. Seville, H. V. Smith, J.W.G. Thomason, R.E. Williamson
    STFC/RAL/ISIS, Chilton, Didcot, Oxon, United Kingdom
  • J. Pasternak
    Imperial College of Science and Technology, Department of Physics, London, United Kingdom
  • C.R. Prior, G.H. Rees
    STFC/RAL/ASTeC, Chilton, Didcot, Oxon, United Kingdom
 
  ISIS is the spallation neutron source at the Rutherford Appleton Laboratory in the UK. Operation centres on a high intensity proton accelerator, consisting of a 70 MeV linac and an 800 MeV rapid cycling synchrotron, which provides a beam power of 0.2 MW. Obsolescence issues are motivating plans to replace the ageing 70 MeV linac, and this paper summarises the status of studies looking at how a new, higher energy linac (~180 MeV) could be used to increase beam power in the existing synchrotron. Reduced space charge and optimized injection might allow beam powers in the 0.5 MW regime, thus providing a very cost effective upgrade. The key areas of study are: design of a practical injection straight and magnets; injection painting and dynamics; foil specifications; acceleration dynamics; transverse space charge; instabilities; RF beam loading; beam loss and activation; diagnostics and possible damping systems. Results from work on most of these topics suggest that beam powers of ~0.5 MW may well be possible, but a number of topics, particularly transverse stability, still look challenging. Conclusions so far are presented, as is progress on R&D on the main intensity limiting issues.  
 
WEPS107 Phase Space Coating in Synchrotrons: Some Applications* 2763
 
  • C.M. Bhat
    Fermilab, Batavia, USA
 
  Funding: Operated by Fermi Research Alliance, LLC under Contract No. DE-AC02-07CH11359 with the United States Department of Energy
Phase-space painting to produce very high intensity beam in synchrotrons is one of the widely studied topics in accelerator physics. A remarkable example of this is multi-turn beam injection by transverse phase-space painting in spallation sources. Use of barrier buckets at synchrotron storage rings has paved way for further advancements in this field. The Fermilab Recycler, antiproton storage ring, has been augmented with multipurpose broad-band barrier rf systems. Recently we have developed a longitudinal phase-space coating technique over already e-cooled high intensity low longitudinal antiproton beam and demonstrated with beam experiments. This method is extended to map the incoherent synchrotron tune of beam particles in a barrier bucket. Here I review various phase-space painting techniques being used in particle accelerators including some new schemes developed using barrier rf systems and possible new applications.