Keyword: focusing
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MOPEA026 X-ray Powder Diffraction Beamline for the Iranian Light Source Facility photon, electron, synchrotron, brilliance 130
 
  • H. Khosroabadi, S. Amiri, H. Ghasem, A. Gholampour
    ILSF, Tehran, Iran
  • H. Ghasem
    IPM, Tehran, Iran
  
  Iranian Light Source Facility (ILSF) project has been initiated since 2010 in order to design and construction of a synchrotron facility in Iran. In parallel with the machine’s activities, scientific committee, users community and beamline technical group are working on different aspects of the scientific and beamline design issues for the operating phase after construction*. X-ray powder diffraction beamline is one of the most priorities in ILSF due to wide range of applications and big potential user community in Iran. Conceptual design report of this beamline operating in other worldwide synchrotrons have been studied and compared in details. The light source and schematic design of the beamline has been prepared in this study. Then, the parameters have been calculated and have been optimized by employing computational software such as XOP and SHADOW**. The optical properties of the optical elements such as reflectivity, absorbance, Bragg diffraction, rocking curve, aberration, etc have been studied at this design, and the results have been compared with the other published results. The outcome and final results of this design progress will be discussed in details.
References:
* Conceptual Design Report (2011, summer), ILSF, http://ilsf.ipm.ac.ir/.
** http://www.esrf.eu/UsersAndScience/Experiments/TBS/SciSoft/xop2.3.
 
 
MOPEA063 The First Results of the NESTOR Commissioning injection, storage-ring, dipole, electron 225
 
  • A.Y. Zelinsky, V.P. Androsov, O. Bezditko, V.N. Boriskin, P. Gladkikh, A.N. Gordienko, V.A. Grevtsev, A. Gvozd, V.E. Ivashchenko, A.A. Kalamayko, I.I. Karnaukhov, I.M. Karnaukhov, D. Korzhov, V.P. Kozin, V.A. Kushnir, V.P. Lyashchenko, M.P. Maksim, V.S. Margin, N.I. Mocheshnikov, V.V. Mytrochenko, A. Mytsykov, F.A. Peev, O.V. Ryezayev, V.P. Sergienko, A.A. Shcherbakov, S. Sheyko, V.L. Skirda, Y.N. Telegin, V.I. Trotsenko, O.P. Zolochevskij, O.D. Zvonarjova
    NSC/KIPT, Kharkov, Ukraine
  
  In the paper the first results of the NESTOR facility are presented. 60 MeV electron linac injector has been tested and the first electron beam with project parameters was registered at the screen monitors. Electron beam was passed through the transportation channel and injection system. As a result, the first turn of the storage ring was closed.  
 
MOPEA073 Current Status of the LBNE Neutrino Beam target, proton, shielding, simulation 255
 
  • C.D. Moore, K.R. Bourkland, C.F. Crowley, P. Hurh, J. Hylen, B.G. Lundberg, A. Marchionni, M.W. McGee, N.V. Mokhov, V. Papadimitriou, R.K. Plunkett, S.D. Reitzner, A.M. Stefanik, G. Velev, K.E. Williams, R.M. Zwaska
    Fermilab, Batavia, USA
  
  Funding: Work supported by the Fermilab Research Alliance, under contract DE-AC02-07CH11359 with the U.S. Dept of Energy.
The Long Baseline Neutrino Experiment (LBNE) will utilize a neutrino beamline facility located at Fermilab. The facility is designed to aim a beam of neutrinos toward a detector placed in South Dakota. The neutrinos are produced in a three-step process. First, protons from the Main Injector hit a solid target and produce mesons. Then, the charged mesons are focused by a set of focusing horns into the decay pipe, towards the far detector. Finally, the mesons that enter the decay pipe decay into neutrinos. The parameters of the facility were determined by an amalgam of the physics goals, the Monte Carlo modeling of the facility, and the experience gained by operating the NuMI facility at Fermilab. The initial beam power is expected to be ~700 kW, however some of the parameters were chosen to be able to deal with a beam power of 2.3 MW. The LBNE Neutrino Beam has made significant changes to the initial design through consideration of numerous Value Engineering proposals and the current design is described. 		 
 
MOPFI018 Design Study of a New Large Aperture Flux Concentrator positron, target, simulation, solenoid 318
 
  • L. Zang, M. Akemoto, S. Fukuda, K. Furukawa, T. Higo, K. Kakihara, T. Kamitani, Y. Ogawa, H. Someya, T. Takatomi
    KEK, Ibaraki, Japan
  
  For high luminosity electron-positron colliders, intense positron beam production is one of the key issues. Flux Concentrator (FC) is a pulsed solenoid that can generate high magnetic field of several Tesla and is often used for focusing positrons emerged from a production target. It works as an optical matching device in a positron capture section. With this device, high capture efficiency is achieved. In this paper, we will introduce a new design of a FC for the SuperKEKB positron source. The advantages of the new design are: 1. the aperture could be doubled of the previous design, 2. the transverse components are only 1/10 of the previous design, 3. maintain the same high peak longitudinal field. The new FC modeling has been done in CST Studio and we will report the results of new FC field evaluation. In order to calculate the positron yield and capture efficiency, a tracking simulation to the end of capture section has also been carried out, which is also included in this paper.  
 
MOPME010 Transverse Beam Profile Diagnostics using Point Spread Function Dominated Imaging with Dedicated De-focusing radiation, electron, target, background 488
 
  • G. Kube, S. Bajt
    DESY, Hamburg, Germany
  • W. Lauth
    IKP, Mainz, Germany
  • Yu.A. Popov, A. Potylitsyn, L.G. Sukhikh
    TPU, Tomsk, Russia
  
  Transverse beam profile diagnostics in electron accelerators is usually based on direct imaging of a beam spot via optical radiation (transition or synchrotron radiation). In this case the fundamental resolution limit is determined by radiation diffraction in the optical system. A method to achieve resolutions beyond the diffraction limit is to perform point spread function (PSF) dominated imaging, i.e. the recorded image is dominated by the resolution function of a point source (single electron), and with knowledge of the PSF the true image (beam spot) may be reconstructed. To overcome the limited dynamical range of PSF dominated imaging, a dedicated de-focusing of the optical system can be introduced. In order to verify the applicability of this method, a proof-of-principle experiment has been performed at the Mainz Microtron MAMI (University of Mainz, Germany) using optical transition radiation. Status and results of this experiment will be presented.  
 
MOPWA058 Cavity Beam Position Monitor at Interaction Point Region of Accelerator Test Facility 2 cavity, feedback, quadrupole, optics 807
 
  • Y.I. Kim, D.R. Bett, N. Blaskovic Kraljevic, P. Burrows, G.B. Christian, M.R. Davis, A. Lyapin
    JAI, Oxford, United Kingdom
  • S.T. Boogert
    Royal Holloway, University of London, Surrey, United Kingdom
  • J.C. Frisch, D.J. McCormick, J. Nelson, G.R. White
    SLAC, Menlo Park, California, USA
  • Y. Honda, T. Tauchi, N. Terunuma, J. Urakawa
    KEK, Ibaraki, Japan
  
  Nanometre resolution cavity beam position monitors (BPMs) have been developed to measure the beam position and linked to a feedback system control the beam position stability within few nanometres in the vertical direction at the focus, or interaction point (IP), of Accelerator Test Facility 2 (ATF2). In addition, for feedback applications a lower-Q and hence faster decay time system is desirable. Two IPBPMs have been installed inside of IP chamber at the ATF2 focus area. To measure the resolution of IPBPMs two additional C-band cavity BPMs have been installed one upstream and one downstream of the IP. One cavity BPM has been installed at an upstream image point of IP. The performance of the BPMs is discussed and the correlation between IP and image point positions is presented along with a discussion of using these BPMs for position stabilisation at the IP.  
 
MOPWO020 Space Charge Dominated Envelope Dynamics using GPUs space-charge, simulation, controls, luminosity 924
 
  • N.V. Kulabukhova
    St. Petersburg State University, St. Petersburg, Russia
  
  High power accelerator facilities lead to necessity to consider space charge forces. It is therefore important to study the space charge dynamics in the corresponding channels. To represent the space charge forces of the beam we have developed special software based on some analytical models for space charge distributions. Because calculations for space charge dynamics become extremely time consuming, we use a special algorithm for predictor-corrector method for evaluation scheme for beam map evaluation including the space charge forces. This method allows us to evaluate the map along the references trajectory and to create the beam envelope dynamics. The corresponding computer codes are realized using CUDA implementation of maps for particle dynamics. Some numerical results for different types of the beam channels are discussed. The survey of advantages and disadvantages of using different methods of parallelization and some parallel approaches will be done.  
 
TUOCB103 Quasi Traveling Wave Side Couple RF Gun for SuperKEKB gun, cavity, emittance, cathode 1117
 
  • T. Natsui, Y. Ogawa, M. Yoshida, X. Zhou
    KEK, Ibaraki, Japan
  
  We are developing a new RF gun for SuperKEKB. High charge low emittance electron and positron beams are required for SuperKEKB. We will generate 7.0 GeV electron beam at 5 nC 20 mm-mrad by J-linac. In this linac, a photo cathode S-band RF gun will be used as the electron beam source. For this reason, we are developing an advanced RF gun. We have tested a Disk and Washer (DAW) type RF gun. Additionally, another new RF gun which has two side coupled standing wave field is developed. We call it quasi traveling wave side couple RF gun. This gun has a strong focusing field at the cathode and the acceleration field distribution also has a focusing effect. The design of RF gun and experimental results will be shown.  
slides icon Slides TUOCB103 [2.959 MB]  
 
TUPEA012 Rebunching Ultracold Neutrons by Magnetic Deceleration for the neutron EDM experiment at J-PARC neutron, resonance, coupling, power-supply 1187
 
  • S. Imajo
    Kyoto University, Kyoto, Japan
  • Y. Arimoto
    KEK, Ibaraki, Japan
  • P.W. Geltenbort
    ILL, Grenoble, France
  • Y. Iwashita
    Kyoto ICR, Uji, Kyoto, Japan
  • M. Kitaguchi
    Kyoto University, Research Reactor Institute, Osaka, Japan
  • Y. Seki
    RIKEN Nishina Center, Wako, Japan
  • H.M. Shimizu
    Nagoya University, Nagoya, Japan
  • T. Yoshioka
    Kyushu University, Fukuoka, Japan
  
  Ultra cold neutrons (UCN) - neutrons with energies less than 300 neV - can be accelerated or decelerated by means of static magnetic and RF fields. Neutron have a magnetic dipole moment, and hence their kinetic energies vary depending on their spin in magnetic fields. Their kinetic energies are restored when they get out from the magnetic field area if their spin did not flip. A spin flip can be triggered by applying an RF field whose frequency coincides with the spin precession frequency of a neutron in this magnetic field. This allows to tune the kinetic energy of neutrons. This method can be used to rebunch a pulsed beam of neutrons to a storage bottle that can store UCN. By open and close the storage bottle synchronously with the rebuncher, high UCN densities can be achieved for precision measurements of neutron properties such as the Electric Dipole Moment. The method and experimental setup are described in detail and the results of a recent first test experiments are presented.  
 
TUPEA055 Quasistatic Field Influence on Bunches Focusing by Wakefields in the Plasma-dielectric Waveguide plasma, wakefield, electron, acceleration 1256
 
  • R.R. Kniaziev
    KhNU, Kharkov, Ukraine
  • G.V. Sotnikov
    NSC/KIPT, Kharkov, Ukraine
  
  Funding: The research is supported in part by Global Initiatives for Proliferation Prevention (GIPP) program, project ANL-T2-247-UA (STCU Agreement P522).
Acceleration of charged particles by wakefields, excited by a drive electron bunch in the dielectric waveguide, is a perspective method in accelerator physics. We have previously proposed using plasma, filling the drift channel of the dielectric structure (DS), for focusing of the accelerated bunch*. The analytical expressions, obtained for the components of the electromagnetic field, considered only the propagating wake field, and did not consider quasi-static fields of electron bunches that are important for calculating bunches dynamics. In this paper we report the result of numerical calculations of the influence of quasistatic field of bunches on focusing by wake fields in the plasma-dielectric accelerator. We refine analytical expressions for the electromagnetic field by adding components of bunch quasi-static fields and show the correlation of total force and their quasi-static components.
* R.R. Knyazev, G.V. Sotnikov. Focusing of accelerated particles by wakefields of a drive bunch in a plasma-dielectric waveguide. Proc. of IPAC2012, New Orleans, Louisiana, USA, paper weppp003.pdf 		 
 
TUPEA062 Advanced Gabor Lens Lattice for Medical Applications laser, ion, proton, space-charge 1277
 
  • J.K. Pozimski, M. Aslaninejad, P.A. Posocco
    Imperial College of Science and Technology, Department of Physics, London, United Kingdom
  
  The widespread introduction of Hadron therapy for cancer treatment is inhibited by the large costs for the accelerator and treatment facility and the subsequent maintenance costs which reflects into the cost per treatment. In the long term future (laser) plasma wakefield accelerated hadrons could offer compact treatment devices with significantly reduced treatment costs. In the moment the particle distributions produced by such accelerators do not fulfill the medical requirements. Beside the reliable production of a sufficient number of ions at the required energy the formation of a particle beam suitable for treatment from the burst of ions created in the acceleration process is one of the major challenges. While conventional optical systems will be operating at the technical limits which would be contradictory to the cost argument, space charge lenses of the Gabor type might be a cost effective alternative. An advanced beam line consisting of Gabor lenses, a few cavities and an dipole will be presented together with results from particle transport simulations.  
 
TUPEA066 Metamaterial-based Accelerating, Bending and Focusing Structures electron, quadrupole, vacuum, resonance 1286
 
  • I. McGregor
    The University of Liverpool, Liverpool, United Kingdom
  • K.M. Hock
    Cockcroft Institute, Warrington, Cheshire, United Kingdom
  
  We report on the progress of our research into metamaterial-based accelerating, bending and focusing structures at the Cockcroft Institute. The effort during the last year has been directed towards designing and investigating practical RF structures that are suitable for industrial and medical applications. We have shown that, by introducing structures based on metamaterial resonators, RF accelerating structures can be made more compact and higher gradient. This year, we will concentrate on focusing and bending structures.  
 
TUPEA085 Optics Tuning and Compensation in LCLS-II quadrupole, undulator, lattice, optics 1313
 
  • Y. Nosochkov, T.O. Raubenheimer, M. Woodley
    SLAC, Menlo Park, California, USA
  
  Funding: Work supported by the US Department of Energy contract DE-AC02-76SF00515.
The LCLS-II is a future upgrade of the Linear Coherent Light Source (LCLS) at SLAC. It will include two new Free Electron Lasers (FELs) to generate soft and hard X-ray radiation. The 2.9 km LCLS-II lattice will include 1/3 of the SLC linac located just before the existing LCLS, the 1.2 km bypass line, the bend section, the beam separation and diagnostic regions, and the FEL undulators and dump. The LCLS operation showed that occasionally the beam phase space may be significantly mismatched due to various errors in the beamline. This requires correction to ensure good beam quality in the undulators. Similarly, the LCLS-II must have lattice correction system with a large tuning range to cancel such errors. Since the various LCLS-II regions are connected using matching sections, the latter naturally can be used for correction of the mismatched lattice functions. In addition, the large tuning capability is required to provide a wide range of focusing conditions at the FEL undulators. The compensation and tuning abilities of the LCLS-II lattice have been studied for incoming beam errors equivalent to 160% of beta beat and for a factor of 5 in the range of undulator quadrupole strengths. 		 
 
TUPFI043 Matching Antisymmetric Arc Optics to Symmetric Interaction Region optics, quadrupole, collider, hadron 1445
 
  • J.L. Abelleira, F. Zimmermann
    CERN, Geneva, Switzerland
  • J.L. Abelleira
    EPFL, Lausanne, Switzerland
  
  Funding: Work supported by the European Commission under the FP7 Research Infrastructures project Eu- CARD, grant agreement no. 227579.
Considering a generic double-ring collider, we discuss the matching from an antisymmetric optics in the arcs to a symmetric optics in the interaction region (IR) by means of an antisymmetric matching section (MS). As an example, we present an application to the LHC, for which a symmetric IR with extremely flat beams is under study. 		 
 
TUPFI086 A Tapered Six Dimensional Cooling Lattice for a Muon Collider emittance, collider, lattice, simulation 1547
 
  • D. Stratakis, R.C. Fernow, R.B. Palmer
    BNL, Upton, Long Island, New York, USA
  
  Designs for Neutrino Factories and Muon Colliders use ionization cooling to reduce the emittance of the muon beam prior to acceleration. Two lattices based on the original RFOFO ring design representing different configurations of the magnetic field are considered. One is with a flip magnetic field and one with a non-flip magnetic field configuration that is used to eliminate for possible space-charge effects. The details of the G4Beamline tracking studies of both channels are presented and compared to the independent ICOOL code.  
 
TUPFI087 Alternative Muon Cooling Options based on Particle-Matter-Interaction for a Neutrino Factory lattice, cavity, solenoid, proton 1550
 
  • D. Stratakis
    BNL, Upton, Long Island, New York, USA
  • A. Alekou
    CERN, Geneva, Switzerland
  • D.V. Neuffer, P. Snopok
    Fermilab, Batavia, USA
  • J. Pasternak
    STFC/RAL, Chilton, Didcot, Oxon, United Kingdom
  • J. Pasternak
    Imperial College of Science and Technology, Department of Physics, London, United Kingdom
  • C.T. Rogers
    STFC/RAL/ASTeC, Chilton, Didcot, Oxon, United Kingdom
  • P. Snopok
    Illinois Institute of Technology, Chicago, Illinois, USA
  
  Funding: This work is funded by US Dept. of Energy grant numbers DE AC02-98CH10886
An ionization cooling channel is a tightly spaced lattice containing absorbers for reducing the momentum of the muon beam, rf cavities for restoring the momentum and strong solenoids for focusing the beam. Such a lattice is an essential feature of most designs for Neutrino Factories and Muon Colliders. Here, we explore three different approaches for designing ionization cooling channels with periodic solenoidal focusing. Key parameters such as the engineering constraints that are arising from the length and separation between the solenoidal coils are systematically examined. In addition, we propose novel approaches for reducing the peak magnetic field inside the rf cavities by using either a magnetic shield system or a bucked coils configuration. Our lattice designs are numerically examined against two independent codes: The ICOOL and G4BL code. The feasibility of our proposed cooling channels to muon accelerators is examined by applying the proposed lattices to the front-end of a Neutrino Factory. 		 
 
TUPME066 CESR Low Emittance Upgrade with Combined Function Bends wiggler, quadrupole, emittance, damping 1718
 
  • D. L. Rubin, Y. Li, A.A. Mikhailichenko, S. Wang
    CLASSE, Ithaca, New York, USA
  
  Funding: Work supported by the National Science Foundation and Department of Energy under contract numbers PHY-1002467, DMR-0936384 and DE-SC0006505
The Cornell Electron Storage Ring is the laboratory for the CESR Test Accelerator damping ring R&D program, and the source of x-rays for CHESS. A peculiarity of the layout of the storage ring is that horizontal emittance is generated predominantly by the strong bends in the sextant of the ring that was designed with a long straight to accommodate the interaction region required for operation as an electron-positron collider. By reconfiguring that single sextant we reduce the emittance by 60% to 20 nm-rad at 5.3 GeV for x-ray production and with damping wigglers to 1.3 nm-rad at 2.1 GeV for investigations of low emittance phenomena. The 35 meter radius of curvature, 3.2 meter long dipoles are refitted as combined function (vertically focusing) magnets to create simple achromats. The layout can accommodate six, 3 meter long undulators, in addition to the six existing superconducting damping wigglers. With reduced horizontal emittance and energy spread, the reconfiguration enhances the sensitivity of CESR to the emittance diluting effects that are the subject of the CesrTA study. Capability of the x-ray source is significantly improved with six new undulator beam lines. 		 
 
TUPWA007 Method and Results of Systematic Beam Matching to a Periodic DTL emittance, DTL, resonance, quadrupole 1733
 
  • L. Groening, W.A. Barth, P. Forck, I. Hofmann, S.G. Yaramyshev
    GSI, Darmstadt, Germany
  • D. Jeon
    IBS, Daejeon, Republic of Korea
  
  Systematic investigations on high current 3d-beam matching to a periodic Alvarez-type DTL are reported. Twiss parameters at the entrance of a matching section to the periodic structure were concluded from transverse and longitudinal measurements. Periodic solutions in 3d were calculated including space charge using the measured rms emittances. The matching was performed by rms beam size tracking and employing a numerical routine to set the matching section, which comprises five quadrupoles and two bunchers. Matching allowed for significant emittance growth reduction and for verification of non-linear beam dynamics effects along the DTL.  
 
TUPWA018 Local Compensation-Rematch for Element Failures in the Low Energy Section of C-Ads Accelerator solenoid, cavity, emittance, linac 1760
 
  • B. Sun, Z. Li, J.Y. Tang, F. Yan
    IHEP, Beijing, People's Republic of China
  
  Due to the requirement of high reliability and availability for the C-ADS accelerators, a fault tolerance design is pursued. The effects of transverse focusing element failures in different locations have been studied and the schemes of compensation by means of local compensation have been investigated. After one transverse element failure especially in the low energy section happens, some new methods have been purposed by which the new settings of the neighbouring solenoids and the cavities can be set, and the Twiss parameters and energy can be approximately recovered to that of the nominal ones at the matching point. We find that the normalized RMS emittance in transverse and longitudinal planes have no obvious growth after applying the compensation in each section of the main linac. When we make study on the compensation-rematch for the RF cavity failures, the TraceWin code has been used that doesn’t consider the phase change during the cavity resetting, so a code named LOCCOM, which is based on MATLAB, is developed and used to compensate the error on arrival-time at the matching point.  
 
TUPWA064 Suppression of Halo Formation in FODO Focusing Channel with Nonlinear Focusing quadrupole, multipole, space-charge, emittance 1850
 
  • Y.K. Batygin, A. Scheinker
    LANL, Los Alamos, New Mexico, USA
  
  Averaging method was applied to analyze focusing properties of a quadrupole FODO channel with inserted multipole lenses. General expression for averaged focusing potential is obtained as a function of position of multipole lenses with respect to FODO quadrupole lenses. Obtained results were applied to the problem of intense beam transport in combined FODO structure. Numerical and analytical treatments of high-brightness beam dynamics with suppressed space-charge induced halo formation are presented.  
 
TUPWA065 Design Issues of Low Energy Beam Transport solenoid, space-charge, emittance, ion 1853
 
  • Y.K. Batygin
    LANL, Los Alamos, New Mexico, USA
  
  Low energy beam transport (LEBT) is an important element of ion accelerator facilities to provide beam matching between ion source and accelerator structure, perform required beam diagnostics measurements, dispose extra particle components, and create necessary time structure of the beam. Most of existing ion LEBT are based on solenoid focusing. Design criteria for ion LEBT with magnetostatic focusing are discussed. Dynamics in LEBT is optimized in terms of maximizing acceptance of the channel and transported beam current, and minimizing spherical aberrations in solenoids and space charge induced beam emittance growth.  
 
TUPWO008 High-Current Beam Transport Simulations Including Gabor Lenses in Varying Non-Neutral Plasma States electron, simulation, plasma, space-charge 1892
 
  • M. Droba, H. Dinter, O. Meusel, D. Noll, U. Ratzinger, K. Schulte
    IAP, Frankfurt am Main, Germany
  
  The Gabor space charge lens has theoretically and experimentally been investigated at IAP for many years. Especially the application in high current, Low Energy Beam Transport (LEBT) sections seems efficient and attractive. The focusing properties and imaging quality of this lens type depend on the transverse and longitudinal confinement of the electron column. Different non-neutral plasma states have been observed and calculated. In general, they can be disturbed by the interaction with ion beams. This results in a shift and in a modification of the work function with a rise of aberrations and beam emittance growth. It is necessary to understand such processes for transport channels using intense ion beams to preserve the high beam brilliance. The beam transport simulations including Gabor lenses in various non-neutral plasma states will be presented and compared with experimental results.  
 
TUPWO010 Optimal Twiss Parameters for Emittance Measurement in Periodic Transport Channels emittance, betatron, simulation, beam-transport 1898
 
  • N. Golubeva, V. Balandin, W. Decking
    DESY, Hamburg, Germany
  
  From the point of view of the optimality criteria introduced in *, we study in this paper the procedure of emittance measurement in periodic beam transport channels.
* V.Balandin, W.Decking, N.Golubeva. “Invariant Criteria for the Design of Multiple Beam Profile Emittance and Twiss Parameters Measurement Sections”, These Proceedings.
 		 
 
TUPWO013 Non-linear Beam Transport Optics for a Laser Wakefield Accelerator undulator, radiation, electron, optics 1907
 
  • C. Widmann, V. Afonso Rodriguez, T. Baumbach, A. Bernhard, N. Braun, B. Härer, P. Peiffer, R. Rossmanith, W. Werner
    KIT, Karlsruhe, Germany
  • O. Jäckel, M. Kaluza, M. Reuter
    HIJ, Jena, Germany
  • M. Kaluza, M. Nicolai, T. Rinck, A. Sävert
    IOQ, Jena, Germany
  • M. Scheer
    HZB, Berlin, Germany
  
  Funding: This work is funded by the German Federal Ministry for Education and Research under contract no. 05K10VK2 and no. 05K10SJ2
The transport and matching of electron beams generated by a Laser Wakefield Accelerator (LWFA) is a major challenge due to their large energy spread and divergence. The divergence in the range of one milli-radian at energies of some 100 MeV calls for strong focusing magnets. At the same time a chromatic correction of the magnets is needed due to the relative energy spread of a few percent. This contribution discusses in particular the layout of the beam transport optics for a diagnostic beam-line at the LWFA in Jena, Germany. The aim of this optics is to match the betatron functions and the non-zero dispersion to the x-dependent flux density amplitude of a non-planar undulator such that monochromatic undulator radiation is generated despite the large energy spread. The transport line is realized as a dogleg chicane involving several strong focusing quadrupoles. The chromatic error is compensated by additional sextupoles. To keep the setup as compact as possible the magnets are designed as combined function magnets. In this contribution the design and optimization of the transport optics, as well as its realization are presented. 		 
 
TUPWO034 Focusing Magnetic Field Design for a FEL Linac linac, electron, space-charge, solenoid 1949
 
  • Q.S. Chen, Q. Fu, T. Hu, B. Qin, B. Wu, H. Zeng
    HUST, Wuhan, People's Republic of China
  • J. Li, Y.J. Pei
    USTC/NSRL, Hefei, Anhui, People's Republic of China
  
  A linac-based Free Electron Laser is planned to be built in Huazhong University of Science and Technology (HUST). As an important part of the whole project, the focusing magnetic field is carefully designed. Space-charge force is calculated at first to give a rough evaluation about the focusing field. Start-to-end simulation shows that the magnetic field has only great effect on spot size and phase space. With the final designed field, 10-ps-length pulse containing 200pC electrons can be got and the corresponding RMS emittance and RMS radius are 7 πmm•mrad and 0.25 mm, respectively. Finally, a new idea (double-peak scheme) is discussed and excitation current is proposed as the evaluation index.  
 
TUPWO042 Modeling Results from Magnetic and Beam Based Measurements of the ALBA Gradient Dipoles dipole, lattice, quadrupole, storage-ring 1967
 
  • X. Gavaldà
    SOLEIL, Gif-sur-Yvette, France
  • G. Benedetti, J. Marcos, Z. Martí
    CELLS-ALBA Synchrotron, Cerdanyola del Vallès, Spain
  
  The ALBA lattice is a DBA-like structure where most of vertical focusing is provided by gradient dipoles. In the first year of machine operation, the model parameters describing the focusing strength of the 32 dipoles have been calibrated by fitting the measured closed orbit response matrix. The mean k-value obtained from this analysis differs by -0.3% with respect to the value taken from the magnetic measurements previous to the magnet installation, while the k variation within the 32 dipoles is of the same order of magnitude. The optics results (tunes, beta beating, dispersion) obtained with the beam based model are compared with the predicted ones from the magnetic measurement model.  
 
WEPWA024 Study of an Electron Gun for Terahertz Radiation Source gun, electron, cathode, radiation 2184
 
  • J. Li, C. Li, Y.J. Pei, L. Shang
    USTC/NSRL, Hefei, Anhui, People's Republic of China
  • Q.S. Chen, T. Hu
    HUST, Wuhan, People's Republic of China
  • G. Feng
    DESY, Hamburg, Germany
  
  With the aim to obtain short-pulse bunches with high peak current for a terahertz radiation source, an RF gun with independently tunable cells (ITC) was employed. As the electron source of the ITC RF gun, a grid-control DC gun plays a key role, the performance of which determines the beam quality in the injector and transport line. In order to make the beam well compressed in the ITC RF gun, the energy of the electrons acquired from the grid-control DC gun should be 15 KeV at most. A proper structure of the grid-gun is shown to overcome the strong space charge force on the cathode, which is able to generate 1us beam with 4.5A current successfully. Simulations considering the grid net are also introduced.  
 
WEPWA030 Using the Power Spectral Density Method to Characterize and Evaluate the X-ray Mirrors Surfaces synchrotron, simulation, optics, brilliance 2196
 
  • W.Q. Hua, F.G. Bian, Y.M. He, W.H. Lin, L. Song, J. Wang, N. Zhao
    SINAP, Shanghai, People's Republic of China
  
  Rapid progress in synchrotron X-ray beams’ coherence and X-ray optics performance places a high demand on characterization and evaluation of optical surface figure and slope errors and roughness on meter-long optics over spatial frequencies as short as 0.1mm. In this paper, the propagation model of hard X-ray beams through reflecting mirror surface is proposed based on wave-front propagation, and numerical simulations are performed for predicting the hard X-ray focusing performance of different imperfect mirrors using a Fresnel diffraction calculation. The imperfect mirror surface height maps synthesized from power spectral functions are used to analyze and evaluate the influences of different mirror surface errors on the reflected hard X-ray beam properties.  
 
WEPWA036 The Magnetic Performance of a Double Elliptically Polarized Undulator undulator, polarization, photon, quadrupole 2208
 
  • Q.G. Zhou, H.F. Wang, M. Zhang, W. Zhang
    SINAP, Shanghai, People's Republic of China
  
  A pair of elliptically polarized undulators with APPLE-II type which will be used in a soft X-ray beam line for ARPES and PEEM at SSRF has been built and installed in the storage ring. The undulators can cover the energy range from 20eV to 2000eV of arbitrary polarized light including the horizontal, vertical, elliptical and circular polarization. The quasi-periodic design of the low energy undulator minimizes the contributions of the higher harmonics to be less than 20%. The magnet design and the measured magnetic field performance will be presented in this paper.  
 
WEPWA044 Electron Trajectories in a Three-dimensional Undulator Magnetic Field undulator, electron, radiation, simulation 2223
 
  • N.V. Smolyakov, S.I. Tomin
    NRC, Moscow, Russia
  • G. Geloni
    XFEL. EU, Hamburg, Germany
  
  In this contribution we present an analysis of electron trajectories in the three dimensional magnetic field from a planar undulator. The electron trajectory is influenced by the focusing properties of the undulator field. In the European XFEL case, long segmented undulators (21 segments for the SASE3 beamline to 35 for SASE1 and SASE2) are planned to be installed, with quadrupole lenses between different segments. These focusing properties should be taken into account in simulations of spontaneous radiation, which constitutes the background signal of the FEL. The ideal magnetic field of an undulator can be described by a sinusoidal vertical magnetic field on the undulator axis, and by horizontal and longitudinal field components that appear out of axis. Exploiting this description for the ideal case, an experimentally measured magnetic field is accounted for by solving the differential equations of motion. The electrons' trajectories for the experimentally measured magnetic field were also simulated numerically. To that aim, a computer code was written, which relies on the Runge-Kutta algorithm. The analytical and numerical methods show a good agreement.  
 
WEPWA072 Design and Commissioning of Chasman-­Green Double Bend Achromatic Lattice Linear Transport Line at the University of Hawai'i MkV Accelerator Facility dipole, quadrupole, electron, diagnostics 2280
 
  • B.T. Jacobson, J. Madey, P. Niknejadi
    University of Hawaii, Honolulu, HI, USA
  
  The design of the Double Bend Achromat (DBA) lattice was originally motivated by the desire to increase the brightness of a synchrotron ring by storing a low emittance electron beam*. Alternating the direction of the bends in the DBA lattice turns the ring into a linear transport line, which has advantages over the straight transport lines typically used in linac FEL's. The dipoles in the DBA cells provide synchrotron images of the electron beam, a real-time non-destructive diagnostic during operation. As in circular machines, sections between DBA cells provide a low-emittance dispersion free beam for insertion devices such as FEL's and inverse Compton backscattering sources. This paper describes an example linear DBA, which has been designed and commissioned as part of the MkV 40 MeV electron accelerator facility at the University of Hawaii.
* Renate Chasman and G. Kenneth Green "Preliminary Design of a Dedicated Synchrotron Radiation Facility", IEEE Transactions on Nuclear Science, NS­22(3):1765-­1767, June 1975 		 
 
WEPEA025 Chromatic Sextupole Pair Optimization Methods for Enlarging Dynamic Aperture sextupole, lattice, dynamic-aperture, storage-ring 2555
 
  • Z. Bai, Q.K. Jia, W. Li, L. Wang, Q. Zhang
    USTC/NSRL, Hefei, Anhui, People's Republic of China
  
  Based on the step-by-step chromaticity compensation method [1] and artificial intelligence algorithms, we propose new numerical methods, called chromatic sextupole pair optimization methods, for enlarging the dynamic aperture of electron storage rings. In the new methods, the decision variables related to chromatic sextupole pairs are optimized using artificial intelligence algorithms to enlarge the dynamic aperture. We demonstrate that the new methods are equivalent to the recently used numerical method, in which the decision variables, sextupole strengths, are optimized using artificial intelligence algorithms.
[1] E. Levichev, P. Piminov, Proceedings of EPAC 2006, p. 2116. 		 
 
WEPEA043 Working Point and Resonance Studies at the CERN PS resonance, injection, controls, octupole 2597
 
  • A. Huschauer, M. Benedikt, H. Damerau, P. Freyermuth, S.S. Gilardoni, R. Steerenberg, B. Vandorpe
    CERN, Geneva, Switzerland
  
  The increase of luminosity demanded by the High Luminosity LHC (HL-LHC) requires an increase of beam intensity, which might result in instabilities appearing at injection energy in the CERN PS. Transverse head-tail instabilities have already been observed on operational LHC beams and a stabilizing mechanism as an alternative to linear coupling is currently being studied. It consists of reducing the mode number of the transverse oscillation by changing linear chromaticity and in succession completely suppressing the instability by a transverse damper system with appropriate bandwidth. Therefore, a chromaticity correction scheme at low energy exploiting the intrinsic possibilities offered by special circuits mounted on top of the main magnet poles, the Pole Face Windings (PFW), has been examined. The presence of destructive betatron resonances, which restrict the choice of the injection working point and the maximum acceptable tune spread, forms an additional limitation for high-brightness and high-intensity beams in the CERN PS. To improve the current working point control scheme, the influence of the P F W on the machine resonances is presented in this paper.  
 
WEPEA059 Study of the Impact of Fringe Fields of the Large Aperture Triplets on the Linear Optics of the HL-LHC optics, quadrupole, luminosity, collider 2642
 
  • B.J. Holzer, R. De Maria, S. Russenschuck
    CERN, Geneva, Switzerland
  • R. Appleby, S. Kelly, M.B. Thomas, L.N.S. Thompson
    UMAN, Manchester, United Kingdom
  • L.N.S. Thompson
    Cockcroft Institute, Warrington, Cheshire, United Kingdom
  
  Funding: The HiLumi LHC Design Study is included in the HL-LHC project and is partly funded by the European Commission within the Framework Programme 7 Capacities Specific Programme, Grant Agreement 284404
High-luminosity hadron colliders such as the High Luminosity LHC (HL-LHC) project place demanding requirements on existing and new magnet technology. The very low β* achieved by the Achromatic Telescopic Squeeze (ATS) optics scheme* for the HL-LHC in particular, requires large apertures in the high gradient Nb3Sn final focusing inner triplet triplet. Such magnets have extended fringe fields which perturb the linear and non-linear optics. This paper presents results of studies into the liner optics of the LHC using a range of fringe field models, including measurements of fringe fields from prototype magnets, and presents calculations of the beta-beating in the machine. Furthermore a similar study is presented on the nominal LHC optics, which uses final focus quadrupoles of higher gradient but significantly smaller aperture.
* S. Fartoukh, ‘’An Achromatic Telescopic Squeezing (ATS) Scheme for
LHC Upgrade’’, in proceedings of IPAC11, p. 2088. 		 
 
WEPEA072 Experimental Studies of Resonance Crossing in Linear Non-scaling FFAGs With the S-POD Plasma Trap resonance, dipole, ion, betatron 2675
 
  • S.L. Sheehy, D.J. Kelliher, S. Machida, C.R. Prior
    STFC/RAL/ASTeC, Chilton, Didcot, Oxon, United Kingdom
  • K. Fukushima, K. Ito, K. Moriya, H. Okamoto
    HU/AdSM, Higashi-Hiroshima, Japan
  
  In a linear non-scaling FFAG the betatron tunes vary over a wide range during acceleration. This naturally leads to resonance crossing including first order integer resonances. The S-POD (Simulator for Particle Orbit Dynamics) plasma trap apparatus at Hiroshima University represents a physically equivalent system to a charged particle beam travelling in a strong focusing accelerator lattice. The S-POD system can be used as an ‘experimental simulation’ to investigate the effects of resonance crossing and its dependence on dipole errors, tune crossing speed and other factors. Recent developments and experiments are discussed.  
 
WEPEA079 A New Method to Integrate s-dependent Hamiltonian insertion, insertion-device, undulator, beam-transport 2693
 
  • W. Guo
    BNL, Upton, Long Island, New York, USA
  
  Funding: Work supported by U.S. DOE, Contract No. DE-AC02-98CH10886
The present theory to obtain higher order terms of beam dynamics is mostly through Taylor expansion and differentiation, for example, the Lie transformation. When 3-dimensional Hamiltonian is being considered the operation of integration becomes necessary. In this paper we will present a new integration theory, which leads to transfer maps for common accelerator elements based on 3-d Hamiltonians. Some physics insight was also gained from this theory, for example, the kick-map theory which is used for insertion device design and modeling, is a first-order approximation in our approach. 		 
 
WEPFI024 Anisotropic Ferrite Magnet Focusing System for Klystrons klystron, cathode, permanent-magnet, simulation 2756
 
  • Y. Fuwa, H. Ikeda, Y. Iwashita, R. Kitahara, Y. Nasu, H. Tongu
    Kyoto ICR, Uji, Kyoto, Japan
  • S. Fukuda, T. Matsumoto, S. Michizono
    KEK, Ibaraki, Japan
  
  The permanent magnet beam focusing for klystrons can eliminate the solenoid coil with the water cooling system and the power supply that consumes electricity. Hence the failure rate and the operating cost of RF systems should decrease. This feature is suitable for a large facility that requires a lot of klystrons such as ILC. Since the required magnetic field for klystron beam is moderate, inexpensive anisotropic ferrite magnets can be applied. The test model is fabricated for a 1.3 GHz klystron whose output power is 800 kW. Each magnet block in the model is movable for magnetic field adjustment and the iron yoke in the oil tank improves magnetic field distribution around cathode area. The result of a klystron power test will be presented.  
 
WEPME034 Motion Control of the Mirror Chamber EPICS, controls, target 2998
 
  • Z.H. Zhang, L.F. Zheng
    SSRF, Shanghai, People's Republic of China
  • W.H. Jia, P. Liu
    SINAP, Shanghai, People's Republic of China
  
  Funding: Shanghai Institute of Applied Physics (SINAP), CAS, Shanghai 201800, P. R. China
The initial beamlines of SSRF have several mirror chambers. The motion mechanism of the mirror chamber consists of six step motors. Three vertical motors are used to achieve the height translation, the roll adjustment and the pitch adjustment. Two horizontal motors are used to achieve the horizon translation and the yaw adjustment. The mirror bending is achieved by a single motor. Except the bending, every motion needs two or three motors to work simultaneously. The VME systems are used in the control system. The EPICS (Experimental Physics and Industrial Control System) toolkits [1] are adopted to develop the control software. This paper describes how to use motor records, transform records and the EPICS database linking mechanism to form soft loops, which solve the difficulties of the complex motions perfectly. The system has been successfully applied in the mirror chambers at SSRF. 		 
 
WEPME063 Progress Report on Development of a 5-μm Drive Laser for Dielectric Laser Acceleration laser, acceleration, HOM, alignment 3079
 
  • G. Xu, I. Jovanovic, S.F. Wandel
    Penn State University, University Park, Pennsylvania, USA
  • E.R. Arab
    PBPL, Los Angeles, USA
  • P.D. Hoang, P. Musumeci, B.D. O'Shea, J.B. Rosenzweig
    UCLA, Los Angeles, USA
  • A.Y. Murokh, A.G. Ovodenko
    RadiaBeam, Santa Monica, USA
  • I. Pogorelsky
    BNL, Upton, Long Island, New York, USA
  
  Funding: This work has been sponsored by Defense Advanced Research Project Agency.
A simple and robust ultrafast, high-peak-power 5-μm laser source for pumping a dielectric photonic structure for high-gradient electron acceleration has been designed and is being constructed. The use of long wavelength drive lasers can mitigate the problem of dielectric structure breakdown caused by multiphoton ionization. In addition, structure fabrication requirements are relaxed, and greater energy can be stored in the structure. The 5-μm laser source consists of two components: (1) a type-II-beta-barium borate-based 2-μm optical parametric amplifier (OPA) as a pump source, and (2) a type-I-zinc-germaniu-phosphate-based 5-μm OPA to produce mJ-class, <100 fs pulses. Our supercontinuum seeded two-stage 2-μm OPA is pumped by a Ti:sapphire amplifier and produces pulse energy of ~1.4 mJ with a pulse duration of 42 fs (~6 optical cycles). Carrier-envelope phase (CEP) stabilization is passively established for 2 μm pulses in our OPA design. An modified design of seed pulse generation for the 5-μm OPA based on several cascaded parametric processes can also result in CEP-stable operation for 5-μm amplified pulses. 		 
 
THPFI016 DESIGN CONSIDERATION OF BEAM DUCTS FOR QUADRUPOLE CORRECTORS IN J-PARC RCS quadrupole, vacuum, synchrotron, injection 3327
 
  • J. Kamiya, N. Hayashi, H. Hotchi, M. Kinsho, N. Ogiwara, N. Tani, Y. Watanabe
    JAEA/J-PARC, Tokai-mura, Japan
  
  which rapidly correct the tunes, are planned to be installed during the summer shutdown in 2013. The characteristic of the excitation pattern of such quadrupoles (quadrupole corrector) is their fast change of magnetic field, which are more than 200T/s at the fastest point. In this report, we describe a deliberation flow about the design of a vacuum chamber, which is installed in the quadrupole corrector. The effect of eddy current was calculated in the case of the current titanium vacuum chamber. The results showed that the temperature rise was too much (up to ~350oC) and the magnetic field in the vacuum chamber is largely distorted by the eddy current. Therefore we decided to employ an alumina ceramics vacuum chamber, for which we have a past achievement in RCS*. We estimated the displacement and stress, which is caused by the atmospheric pressure, for the alumina ceramics vacuum chamber and vacuum component around it by making the calculation model for the finite element method. It was found that there was no large displacement and stress by installing the alumina ceramics vacuum chamber.
*M. Kinsho, et al. Vacuum 81 (2007) 808. 		 
 
THPFI017 Development of Harmonic Field Measurement System with Higher Resolution ADC background, dipole, multipole, quadrupole 3330
 
  • R. Kitahara, Y. Fuwa, Y. Iwashita, Y. Nasu
    Kyoto ICR, Uji, Kyoto, Japan
  
  Quadrupole magnets for ILC final focus should be enough strong with the limitation on the external radius, while the vibration of the magnetic center has to be highly avoided to keep the nm sized beam focusing stable at the interaction point a few m downstream from the lens. Gluckstern's 5-ring PMQ singlet seems a good candidate for the purpose, which is under investigation. The precise magnetic harmonic field measurement system is also under development for adjusting each magnet ring and evaluation of the assembled singlet. A rotating magnet system and a rotating coil system are prepared for the former and the latter purposes, respectively. Both systems have 24-bit ADC's for higher resolution. For the rotation coil, a flexible print circuit sheet, where a pair of one turn coils is printed on, is glued on a quartz rod. The two coils located on the quarts rod with the angle difference of 180 degree can separate the odd and even harmonics components by recording both the signals simultaneously to get their sum and difference. The two digitized signals are integrated digitally.  
 
THPFI056 Design Study for a Future LAGUNA-LBNO Long-baseline Neutrino Facility at CERN target, secondary-beams, site, hadron 3418
 
  • I. Efthymiopoulos, J. Alabau-Gonzalvo, A. Alekou, F. Antoniou, M. Benedikt, M. Calviani, A. Ferrari, R. Garoby, F. Gerigk, S.S. Gilardoni, B. Goddard, A. Kosmicki, C. Lazaridis, J.A. Osborne, Y. Papaphilippou, A.S. Parfenova, E.N. Shaposhnikova, R. Steerenberg, P. Velten, H. Vincke
    CERN, Geneva, Switzerland
  
  A design study for a long baseline neutrino oscillation experiment (LBNO) with a new conventional neutrino beamline facility (CN2PY) at CERN was initiated in September 2011, supported by EU/FP7 funds. The beam will be aimed at a next generation deep-underground neutrino observatory located at the Pyhasalmi (Finland) mine at a distance of 2300 km. In an initial phase the CN2PY facility will use a 400 GeV beam extracted from SPS up to a maximum power of 750 kW, and in a second phase a 2 MW beam of about 50 GeV produced by a new High-Power Proton Synchrotron accelerator using the LP-SPL as injector also under design. The paper will focus on the design challenges of this MW-class facility and on the optimization studies of the secondary beam elements (target and horns) to produce a neutrino beam spectrum that matches best the experimental requirements for neutrino flavor oscillations and CP-violation tests. The challenges and bottlenecks in the existing CERN accelerator complex to produce the high-intensity beams foreseen for this facility at the initial phase are discussed.  
 
THPME008 Experimental Study of Magnetic Properties for Magnet Material in CYCIAE-100 cyclotron, factory, vacuum, resonance 3525
 
  • J.Q. Zhong, T. Cui, M. Li, C. Wang, Z.H. Wang, J.J. Yang, T.J. Zhang
    CIAE, Beijing, People's Republic of China
  
  The magnetic property of magnet material is one of the key factors that influence the distribution of magnetic field in large scale cyclotrons, especially embody on the vertical focusing of field and the first harmonic field error in cyclotron. According to the requirements of the physical design of CYCIAE-100, we have studied the pivotal factors, which impact on the maximum permeability, coercivity and B-H curve of material of CYCIAE-100 magnet, including the cooling rate during magnetic annealing and residual stress. The study results will be shown in this paper.  
 
THPWA001 Design of X-Band Medical Linear Accelerator with Multiple RF Feeds and RF Phase Focusing linac, cavity, impedance, bunching 3627
 
  • Y. N. Nour El-Din, T.M. Abuelfadl
    Cairo University, Giza, Egypt
  
  Funding: Work supported by the Egyptian Science and Technology Development Fund (STDF) No. 953.
A design of 6 MeV X-band 9.3 GHz medical linear accelerator is presented. It is composed of four separate clusters of accelerating cavities, where a coherent RF excitation is provided separately to each cluster. The use of multiple accelerating sections with multiple RF feeds permits the use of inexpensive RF sources. The first cluster is Alternate Phase Focusing (APF) RF cavities, providing radial and longitudinal beam focusing without the use of heavy and bulky magnets or solenoids. The three other clusters used for acceleration are composed of multiple standing wave sections operating in the Pi-mode. Each section has been designed and optimized for high shunt impedance by means of 2D SUPERFISH code and 3D CST code. A two dimensional code, named PTCC, was developed to facilitate design and analysis of the different parts of the accelerating structure. 		 
 
THPWA030 Design and Prototype Test of C-band Standing-wave Accelerating Structure to Enhance RF Phase Focusing electron, coupling, bunching, simulation 3690
 
  • H. Yang, M.-H. Cho, W. Namkung, S.-G. Shin
    POSTECH, Pohang, Kyungbuk, Republic of Korea
  • S.H. Kim
    ANL, Argonne, USA
  • J.-S. Oh
    NFRI, Daejon, Republic of Korea
  
  Funding: This research was financially supported by the MOTIV, KIAT and Dongnam Institute for Regional Program Evaluation through the Leading Industry Development for Economic Region
A C-band standing-wave accelerator for X-ray and electron beam sources of medical radiotherapy is designed and being fabricated. The accelerator system is to be operated in two modes, using the X-ray and electron beams. Because of the energy loss in electron mode, the accelerator is capable of producing 6-MeV, 100-mA electron beams with peak 2-MW RF power, and 7.5-MeV, 20 mA electron beams with peak 2.5-MW RF power. The beam radius at the end of column was < 0.5 mm without focusing magnets in PARMELA simulations, because the bunching cells are designed to enhance the RF phase focusing. Each cavity in the bunching and normal cells was designed by the MWS code to maximize the effective shunt impedance with 3.8% inter-cell coupling in normal cells. The dimensions of normal cells were determined by the low power RF test of prototype cells with 5711.06-MHz resonant frequency and 3.5% inter-cell coupling. In this paper, we present details of the accelerator design and prototype test. 		 
 
THPWO012 High Gradient Room Temperature Cavity Development for 10 – 100 AMeV Beams cavity, linac, ion, DTL 3785
 
  • A. Almomani, U. Ratzinger
    IAP, Frankfurt am Main, Germany
  
  Funding: BMBF, 05P12RFRB9
These linac activities are aimed to increase the accelerating field gradient. In IAP – Frankfurt, a CH – design was proposed to post-accelerate a proton bunch, generated by an intense laser, from 10 – 15.2 MeV. The accelerating field gradient is expected to reach > 10 MV/m. Within a funded project, this cavity will be further developed towards a high gradient cavity. The availability of the GSI 3 MW klystron test stand will be very important for these investigations. The results will influence the rebuilt of the Unilac - Alvarez section, where the existing linac tunnel with 1 m thick concrete walls should house a powerful pulsed heavy ion linac, optimized for achieving finally the beam intensities specified for the GSI-FAIR project. The status of the cavity design will be presented. 		 
 
THPWO027 Lattice and Error Studies for J-PARC Linac Upgrade to 50mA/400MeV emittance, linac, simulation, lattice 3818
 
  • Y. Liu
    KEK/JAEA, Ibaraki-Ken, Japan
  • M. Ikegami
    J-PARC, KEK & JAEA, Ibaraki-ken, Japan
  
  Equi-partitioning (EP) setting is applied as base-line design for the J-PARC linac upgrade from present 15mA/181MeVto 50mA/400MeV H− beam. We also studied the possibility of mitigating the intra-beam stripping (IBSt) with constant-envelop setting for the frequency jump from 324MHz to the 972MHz ACS section. Since the constant-envelop setting here for the frequency jump is away from equi-partitioning and close to the resonances kz=3kx, kz=2kx and so on, considerable emittance exchange and mismatch were found in the simulation. It is natural to continue the work to explore the parameter space around the above two typical settings. Three key points are to be checked. The first is the tradeoff between the envelopes big enough to suppress the IBSt and tunes not to be too depressed to the space charge region. The second point is the sensitivity of these lattices vs. errors. The third is about the criterion of mismatch in the presence of emittance exchange. When emittance exchange is serious the mismatch can be unavoidable. So it is crucial to ensure the settings are in the safe region free from un-controlled mismatch.  
 
THPWO043 Progress on the Physics Design of the C-ADS Injector Scheme I rfq, linac, cavity, ion-source 3863
 
  • Z. Li, P. Cheng, H. Geng, C. Meng, H.F. Ouyang, B. Sun, J.Y. Tang, F. Yan, Z. Yang
    IHEP, Beijing, People's Republic of China
  
  Funding: Surported by China ADS Project
The China ADS (C-ADS) driver linac is composed of two parallel 10 MeV injectors and a main linac which boosts the beam further to 1.5 MeV. There are two design schemes for the injectors based on different working frequency and superconducting cavity structures and are under developing at the same time on IHEP and IMP. The Injector Scheme I, which is proposed by IHEP, works at 325 MHz, the same frequency of the main linac, and superconducting Spoke cavities with geometry beta of 0.12, the same type of cavity as the main linac too, are applied after the RFQ. In this paper, the latest progress on physics design will be presented. 		 
 
THPWO056 A 5.3 MeV/U, 200MHz APF DTL for Carbon Ions as an Injector of Medical Synchrotron synchrotron, cavity, emittance, DTL 3890
 
  • P. Jiang, Y.J. Yuan
    IMP, Lanzhou, People's Republic of China
  
  A new low energy medium frequency DTL for 12C5+ with alternative phase focusing method (APF), which has advantage in compact space and low cost, was designed as an injector of medical synchrotron. There is no conventional focusing elements in the APF DTL, and transversal focusing is realized using RF field by varying synchronous phase instead. The envelopes of beam size are presented and the emittance change of six-dimension phase space is shown. The simple method proposed by Y. Iwata was used to create synchronous phase array. Since the motion between transversal and longitudinal plains are coupled, the longitudinal acceptance of the DTL is not large.