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focusing

   
Paper Title Other Keywords Page
MOPCH053 Towards Sub-picoseconds Electron Bunches: Upgrading Ideas for BESSY II optics, radiation, electron, storage-ring 157
 
  • G. Wuestefeld, J. Feikes, P. Kuske
    BESSY GmbH, Berlin
  Sub-picoseconds bunches were achieved with the BESSY low alpha optics, and their lengths were measured using Fourier Transform spectroscopy*. To avoid the coherent synchrotron radiation instability, the current in these short bunches has to be limited to theμampere level. An upgrade of the BESSY II rf gradient to much larger values is suggested to overcome this low current limitation by two orders of magnitude. Intense, picoseconds long bunches could then be achieved already at the regular user optics. The resulting short and very intense electron bunches are useful for generation of short x-ray pulses and powerful THz-radiation. Expected parameters of bunch length and current are discussed.

*J. Feikes et al. "Sub-Picoseconds Electron Bunches in the BESSY Storage Ring", EPAC'04, Luzerne (Switzerland), July 2004.

 
 
MOPCH115 Transverse Space Charge Studies for the ISIS Synchrotron resonance, space-charge, synchrotron, simulation 312
 
  • C.M. Warsop
    CCLRC/RAL/ISIS, Chilton, Didcot, Oxon
  The ISIS Facility at the Rutherford Appleton Laboratory in the UK produces intense neutron and muon beams for condensed matter research. It is based on a 50 Hz proton synchrotron which, once the commissioning of a new dual harmonic RF system is complete, will accelerate about 3.5·1013 protons per pulse from 70 to 800 MeV, corresponding to mean beam powers of 0.2 MW. Following this upgrade, transverse space charge is expected to be one of the main intensity limitations, and is also a key factor for further machine upgrades. A programme of R&D on transverse space charge is now under way, aiming not only to improve the ISIS ring but also to exploit it as an experimental tool for testing theory and codes. This paper summarises work so far, outlining calculations for coherent envelope modes on ISIS, using numerical solutions of the envelope equation to show the expected behaviour near half integer resonance. Progress on work linking these predictions with more realistic beam models in space charge codes, and extending calculations to images, coupling and non linear resonances will be described. Plans and preparations for experiments, along with initial results, will also be presented.  
 
MOPCH189 Calculating the Muon Cooling within a MICE Liquid Absorber scattering, emittance, cryogenics, factory 502
 
  • M.A. Green, S.P. Virostek
    LBNL, Berkeley, California
  • S.Q. Yang
    OXFORDphysics, Oxford, Oxon
  The key elements of the Muon Ionization Cooling Experiment (MICE) cooling channel are the absorbers that are a part of the MICE absorber focus coil modules (AFC modules). The boundaries of room temperature solid absorbers are well defined. The density of most solid absorber materials is also well understood. The properties of solid absorber are most certainly understood to 0.3 percent. The MICE liquid absorbers are different in that their dimensions are a function of the absorber temperature and the fluid pressure within the absorber. The second element in the liquid absorber is the variability of the liquid density with temperature and pressure. While one can determine the absorber boundary within 0.3 percent, the determination of the liquid density within 0.3 percent is more difficult (particularly with liquid helium in the absorber). This report presents a method of calculating absorber boundary and the cooling performance of the MICE absorbers as a function of fluid temperature and pressure.  
 
MOPLS040 Magnet Structure of the VEPP-2000 Electron-positron Collider sextupole, quadrupole, collider, dipole 628
 
  • P.Yu. Shatunov, D.E. Berkaev, A.A. Borisov, I. Koop, N.A. Mezentsev, E. Perevedentsev, Y.M. Shatunov, D.B. Shwartz
    BINP SB RAS, Novosibirsk
  • A. Valishev
    Fermilab, Batavia, Illinois
  Electron-positron collider VEPP-2000 with beam energy up to 1 GeV is under commissioning at Budker Institute. This paper presents magnetic elements of the storage ring including 13T focusing superconducting solenoids in interaction regions. Features of magnet elements design and magnetic measurements results are given together with comparison to previously calculated data.  
 
MOPLS075 Progress towards Crab Cavity Solutions for the ILC luminosity, quadrupole, electron, positron 724
 
  • G. Burt, A.C. Dexter
    Cockcroft Institute, Warrington, Cheshire
  • C.D. Beard, P. Goudket
    CCLRC/DL/ASTeC, Daresbury, Warrington, Cheshire
  • L. Bellantoni
    Fermilab, Batavia, Illinois
  In order to achieve acceptable luminosity for ILC crossing angles greater than a few mrad, RF deflection cavities must be used to rotate electron and position bunches leading up to the IP. A bunch that passes through a deflection cavity at a phase where the deflection averages to zero receives a crab kick leading to a finite rotation at the IP. For a beam energy of 500GeV and a crossing angle of 20mrad, the required crab kick is about 19.5MV at 1.3GHz and 6.5MV at 3.9GHz. Cavities are needed on both beams and are likely to be positioned about 12m before the IP. Any RF phase error between the bunch and the cavity leads to a deflection of the bunch in addition to a rotation of the bunch. Any differential phase error between the cavities leads to differing deflections and consequential loss in luminosity. Collaborative work with FNAL, being undertaken to develop a variant of their 3.9GHz CKM cavity optimised for an ILC solution, is described. Current analysis favours a solution with four nine-cell cavities on each beam. It is anticipated that the cavities will be run CW and driven from small Klystron/s (< 5kW) or solid state amplifiers.*

*We would like to thank Chris Adolphsen, SLAC, for his help in technical discussions, which were greatly appreciated.

 
 
TUXFI01 FFAG Accelerators and their Applications acceleration, proton, target, emittance 950
 
  • Y. Mori
    KURRI, Osaka
  This talk will give an introduction to the FFAG concept and review the present development of FFAG accelerators. It will also discuss the use of FFAGs for applications such as hadron therapy, neutron generation, BNCT, ADS, and muon acceleration.  
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TUPCH049 Proposal for a Fast Scanning System Based on Electro-optics for Use at the ILC Laser-wire laser, electron, positron, PETRA 1118
 
  • A. Bosco, G.A. Blair, S.T. Boogert, G.E. Boorman, L. Deacon, C. Driouichi, M.T. Price
    Royal Holloway, University of London, Surrey
  Electro-optic devices open the possibility of ultra-fast scanning systems for use in intra-train scanning at the ILC, where scanning rates in excess of 100 kHz may be required. A first study of the possibilities is presented together with the first results from a prototype system.  
 
TUPCH067 Time-resolved Beam Emittance Measurement of Dragon-I Linear Induction Accelerator emittance, radiation, induction, electron 1166
 
  • G.J. Yang, S. Chen, X. Jiang, Z. Zhang
    CAEP/IFP, Mainyang, Sichuan
  A beam emittance diagnostic system of an intense pulsed electron beam (20MeV, 2.6kA, 80ns) based on optical transition radiation is developed. A gated CCD camera is used to get time-resolved result. We develop a timing system to avoid the time jitter, an anti-interference system to avoid the electromagnetic interference, and a C++ code to deal with the experimental data. The measured emittance is about 2000¦Ð.mm.mrad, which is agree with the result of three gradient method.  
 
TUPCH089 Investigations of OTR Screen Surfaces and Shapes CTF3, radiation, diagnostics, electron 1220
 
  • C.P. Welsch, E. Bravin, T. Lefevre
    CERN, Geneva
  Optical transition radiation (OTR) has proven to be a flexible and effective tool for measuring a wide range of beam parameters, in particular the beam divergence and the transverse beam profile. It is today an established and widely used diagnostic method providing linear real-time measurements. Measurements in the CLIC Test Facility (CTF3) showed that the performance of the present profile monitors is limited by the optical acceptance of the imaging system. In this paper, two methods to improve the systems' performance are presented and results from measurements are shown. First, the influence of the surface quality of the OTR screen itself is addressed. Several possible screen materials have been tested to which different surface treatment techniques were applied. Results from the measured optical characteristics are given. Second, a parabolic-shaped screen support was investigated with the aim of providing an initial focusing of the emitted radiation and thus to reduce the problem of aperture limitation. Measured and calculated emission distributions are presented.  
 
TUPLS025 Racetrack Non-scaling FFAG for Muon Acceleration betatron, acceleration, lattice, linac 1544
 
  • D. Trbojevic
    BNL, Upton, Long Island, New York
  The non-scaling Fixed-Field Alternating Gradient (FFAG) machines have very strong focusing, large momentum acceptance, and small dispersion and betatron functions. This report is a study of using a compact non-scaling FFAG in combination with the superconducting linac to accelerate the muons. The drift space between two kinds of combined function magnets in the previous non-scaling FFAG is removed. The time of flight in the non-scaling FFAG has a parabolic dependence on momentum. The large energy acceptance of the machine requires matching between the linac and the non-scaling FFAG arcs for both the betatron and dispersion functions over the entire energy range.  
 
TUPLS044 The 3D Beam Dynamics with the Space Charge in the Low and Middle Energy Super-conducting Option of HIPPI emittance, quadrupole, simulation, proton 1594
 
  • N.E. Vasyukhin, R. Maier, Y. Senichev, R. Tölle
    FZJ, Jülich
  For the low and middle energy of the High Intensity Proton Pulse Injector (HIPPI), a superconducting option is considered.The 3D beam dynamics simulation results in the slot and the finger-slot sections covering the energy range from 3 to 160 MeV are presented. The optimization aim is the increase of beam current together with the reduction of emittance growth, beam losses and costs. The slot structure is compared with the conventional spoke structure.  
 
TUPLS058 New Prestripping Section of the MILAC Linear Accelerator Designed for Accelerating a High Current Beam of Light Ions ion, acceleration, heavy-ion, controls 1627
 
  • A.P. Kobets, V.A. Bomko, O.F. Dyachenko, Ye.V. Ivakhno, M.S. Lesnykh, Z.O. Ptukhina, V.N. Reshetnikov, S.S. Tishkin, V.P. Yashin, A.V. Zabotin, B.V. Zajtsev, V.G. Zhuravlev
    NSC/KIPT, Kharkov
  In the Kharkov Institute of Physics and Technology, the works on construction of a new prestripping section of the multicharge ion linear accelerator (MILAC) is performed. The task is set to provide acceleration of high current beams of light ions for research works on radiation material engineering and applied investigations. The new prestripping section is designed for accelerating ions with A/q=4 up to the energy of 1 MeV/u; after stripping they will be accelerated in the main section up to the energy of 8.5 MeV/u. Special operational mode will allow to increase noticeably the repetition rate with the same power consumption. The calculation results on beam dynamics in the structure with alternating phase focusing in the version with the stepped change of the synchronous phase, and calculations of electrodynamic characteristics of the accelerating structure of the interdigital type. The peculiarities of the construction of the accelerating structure are described.  
 
TUPLS069 Performance of Fermilab's 4.3 MeV Electron Cooler electron, antiproton, gun, cathode 1654
 
  • A.V. Shemyakin, A.V. Burov, K. Carlson, M. Hu, T.K. Kroc, J.R. Leibfritz, S. Nagaitsev, L.R. Prost, S.M. Pruss, G.W. Saewert, C.W. Schmidt, M. Sutherland, V. Tupikov, A. Warner
    Fermilab, Batavia, Illinois
  A 4.3 MeV DC electron beam is used to cool longitudinally an antiproton beam in the Fermilab's Recycler ring. The cooling rate is regulated either by variation of the electron beam current up to 0.5 A or by a vertical separation of beams in the cooling section. The paper will describe steps that provided a stable operation and present the status of the cooler.  
 
TUPLS070 Chromaticity Control in Linear-field Nonscaling FFAGs by Sextapoles quadrupole, lattice, betatron, LEFT 1657
 
  • S.R. Koscielniak
    TRIUMF, Vancouver
  Because of their high repetition rate and large apertures, FFAGs are proposed for high-current medical accelerators suitable for cancer therapy. The linear-field nonscaling FFAG is made from repeating cells containing D and F combined function magnets. The betatron tune profiles decrease with momentum; this leads to the crossing of resonances. We examine how sextapole magnets may be used to flatten the tune profile; in particular (i) whether it is better to place them at the D or F; (ii) what strength is required; and (iii) what is their effect on the closed orbits and path length? The orbit geometry is derived from a thin-element model and the tunes from power series in the quadrupole strength. Chromaticity is corrected by coupling focusing strength to dispersion, which is far stronger in the F element. The zeros of the orbit dispersion become the poles of the "sextapole strength to flatten the tune at some particular momentum". We demonstrate that a weak F sextapole can produce a substantial horizontal tune flattening, and has little impact on other optical properties. Contrarily, placing the sextapole at the D element may destroy the dynamic aperture and or vertical focusing.  
 
TUPLS088 Energy Distribution of H- Ions from the ISIS Ion Source ion, controls, ion-source, cathode 1708
 
  • D.C. Faircloth, J.W.G. Thomason
    CCLRC/RAL/ISIS, Chilton, Didcot, Oxon
  • G. Doucas, M. Haigh, I. Ho-ching Yiu, J. Morrison
    OXFORDphysics, Oxford, Oxon
  We have used a specially designed retarding field energy analyzer with a resolution (Δ E /E) of approximately 2 x 10 -4 in order to measure the energy distribution, under different operating conditions, of the H- beam of the ISIS ion source. The poster presents the details of the analyzer and the first results obtained on the Ion Source Test Facility at RAL.  
 
TUPLS132 Estimation of the Energy Deposited on the CNGS Magnetic Horn and Reflector target, shielding, secondary-beams, simulation 1813
 
  • L. Sarchiapone, A. Ferrari, M. Lorenzo Sentis
    CERN, Geneva
  In the CNGS installation two magnetic lenses, namely the horn and the reflector, focus the secondary beam generated in the target station. The gap between the horn and reflector is chosen to optimize a wide-band high-energy muon-neutrino beam. These two focusing elements are two coaxial lenses similar in length but different in shape: the outer conductor has a cylindrical shape whereas the inner conductor consists of a sequence of conical shapes to optimize the focusing capacity. The evaluation of the heat load on the support structures is crucial since modifications in the elements around the horn and reflector are under way and the support structures can be adapted to the heat load found. Furthermore, the heat load in the whole horn area has been evaluated to optimize the cooling-ventilation system. The FLUKA geometry input of the horn and reflector electrical connections has been notably improved in order to accommodate the detailed striplines design to the thermal expansion. The energy deposited on the horn and reflector as well as on their adjacent elements has been estimated using the FLUKA Monte Carlo package and results are presented in this document.  
 
WEOAPA03 MICE Overview - Physics Goals and Prospects emittance, scattering, radiation, photon 1870
 
  • M. Yoshida
    Osaka University, Osaka
  Ionization cooling, a technique in which muon beam is passed through a series of absorbers and followed by RF-acceleration, is a proposed method for cooling muon beam, i.e., phase-space reduction. The international Muon Ionisation Cooling Experiment (MICE), which will construct and operate a realistic cooling channel and measure the beam cooling performance, is the first essential step towardsrealization of nutrino factories and eventually muon colliders based on intense muon sources. The MICE have got approved to be constructedin Rutherford Appleton Laboratory (RAL) and the fist beam commissioning is scheduled in 2007. The physics goal and future prospects of the MICE together with the beamline and the instruments which is now being built will be described.  
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WEPCH054 Matrix Formalism for Current-independent Optics Design emittance, optics, space-charge, cathode 2044
 
  • C.-X. Wang, K.-J. Kim
    ANL, Argonne, Illinois
  Matrix formalism has been a powerful tool for beam optics designs. It not only facilitates computations but also plays an important role in formulating various design concepts. Here we extend the standard matrix formalism for the purpose of designing an optics that transports space-charge-dominated intense beam. Furthermore, we explore the concept of current-independent optics, which can be useful for systems such as high-brightness injectors and space-charge-dominated rings. Our discussion here is preliminary and limited to axisymmetric systems.  
 
WEPCH101 Ion Motion in the Adiabatic Focuser ion, electron, emittance, plasma 2149
 
  • A. Sessler, E. Henestroza, S. Yu
    LBNL, Berkeley, California
  The Adiabatic Focuser* works by having a focusing channel whose strength increases with distance down the channel. In this situation electrons of various energies and various transverse oscillation phase all are transversely focused. The concept works with external focusing, but would be very effective in a plasma ion focusing channel where the density of ions is simply increased as one goes down the channel. In the original work (Ref 1) motion of the ions was not included (as it was assumed to be a small effect). Recently, it has been suggested that ion motion in an adiabatic focuser would be significant and, even, preclude operation of the focuser as previously envisioned**. In this paper we numerically study the ion motion in the focuser. The ions clearly influence each other and, most importantly, are influenced by the electric field of the electrons being focused. It is shown that parameters can be selected such that the adiabatic focuser works as well as originally envisioned.

*P. Chen et al. Phys. Rev. Lett. 64, 1231 (1990).**J. R. Rosenzweig, et al. Phys. Rev. Lett. 95, 195002 (2005).

 
 
WEPCH106 Stationary Beam Electron Transport in AIRIX for the TRAJENV Code electron, space-charge, induction, target 2161
 
  • O. Mouton
    CEA, Bruyères-le-Châtel
  In the framework of the AIRIX program, the electron beam propagation between the injector and the X-conversion target is routinely simulated with the 2D TRAJENV code. We describe the physical models implemented in the code for a intense stationary beam. We present both the modeling of applied electromagnetic forces in induction cells and self generated ones. To avoid the cell damage due to target debris generated by the electron beam impact, a thin debris shield has been tested upstream the X-ray converter. Such a thin foil located in the beam pass, is taken into account in TRAJENV. We describe the modeling and the influence of the foil on the beam.  
 
WEPCH155 Tune-stabilized Linear-field FFAG for Carbon Therapy acceleration, extraction, injection, multipole 2290
 
  • C. Johnstone
    Fermilab, Batavia, Illinois
  • S.R. Koscielniak
    TRIUMF, Vancouver
  The simplicity, smaller aperture, and reduced ring size associated with linear-field, nonscaling FFAGs have made them attractive to investigate for a broad range of applications. Significant progress has recently been made towards understanding and modeling this new type of accelerator. The merits, drawbacks and challenges of the linear-field FFAG are discussed here, in particular its suitability for proton and carbon cancer therapy as compared with conventional synchrotrons and cyclotrons. Specifically, tune stabilization and dynamic aperture, a problem with both scaling and non-scaling FFAGs, will be addressed in detail.  
 
WEPCH178 Simulation Study of Compact Hard X-ray Source via Laser Compton Scattering electron, linac, simulation, laser 2346
 
  • R. Kuroda, M.K. Koike, H. Ogawa, N. Sei, H. Toyokawa, K. Y. Yamada, M.Y. Yasumoto
    AIST, Tsukuba, Ibaraki
  • N. Nakajyo, F. Sakai, T. Yanagida
    SHI, Tokyo
  The compact hard X-ray source via laser Compton scattering between high intensity electron beam and high power laser beam was developed at FESTA (The Femtosecond Technology Research Association) project in collaboration between AIST and SHI. According to completion of the project in March 2005, the compact hard X-ray source is being transferred from FESTA to AIST to upgrade and to apply the system to biological and medical uses. Our system consists of a laser-driven photocathode rf gun, two 1.5m-long S-band accelerator structures and a high power Ti:Sa Laser system. This system can generate a hard X-ray pulse which has variable energy of 12 keV – 33 keV with narrow bandwidth by changing electron energy and collision angle. Maximum X-ray photon yield at FESTA was accomplished about 107photons/s (@10Hz, MAX 33keV) in case of 165 degree collision angle. In the next phase, we are planning to make the total system much compact using X-band or C-band accelerator structures with permanent magnets. We have carried out the numerical simulations to investigate the possibility of these compact systems. In this conference, we will talk about results of the simulations and future plans.  
 
WEPCH180 A Dramatically Reduced Size in the Gantry design for the Proton-Carbon Therapy betatron, hadron, dipole, quadrupole 2352
 
  • D. Trbojevic, R.C. Gupta, B. Parker
    BNL, Upton, Long Island, New York
  • E. Keil
    CERN, Geneva
  • A. Sessler
    LBNL, Berkeley, California
  Gantries in the proton/carbon cancer therapy machines represent the major cost and are usually very large. This report explains a new way for the gantry design. The size and cost of the gantries are reduced, and their use is simplified by using the fixed magnetic field. The "new" gantry is made of a very large momentum acceptance non-scaling Fixed Field Alternating Gradient (FFAG) quarter and half arc beam lines. The gantry is made of combined function magnets with a very strong focusing and small dispersion function. Additional magnets with a fast response are required to allow adjustments of the beam position for different energies at the beginning of the gantry. The strong focusing magnets following the gantry have to be adjustable as well to provide the required spot size. The adjustable dipoles provide the radial scanning. The fixed field combined function magnets could be made of small permanent magnets for the proton machine, or of the high temperature superconductors or superconductors for the carbon machine, reducing dramatically the size.  
 
WEPLS012 Use of Gas-filled Cavities in Muon Capture for a Muon Collider or Neutrino Factory factory, emittance, target, collider 2421
 
  • D.V. Neuffer
    Fermilab, Batavia, Illinois
  • K. Paul
    Muons, Inc, Batavia
  Recent studies indicate that gas-filled cavities can provide high-gradient acceleration and simultaneous cooling for muons. In this paper we explore using these cavities in the front-end of the capture and cooling systems for muon colliders and neutrino factories. For a muon collider scenario we consider capturing the beam in a low-frequency cavity (~50 MHz) and cooling immediate after capture. For a neutrino factory, we consider capturing beam in high-frequency buckets and phase-energy rotating and cooling them using gas-filled rf cavities. Scenario variants are described and studied.  
 
WEPLS018 Optics for Phase Ionization Cooling of Muon Beams emittance, collider, resonance, space-charge 2430
 
  • R.P. Johnson
    Muons, Inc, Batavia
  • S.A. Bogacz, Y.S. Derbenev
    Jefferson Lab, Newport News, Virginia
  The realization of a muon collider requires a reduction of the 6D normalized emittance of an initially generated muon beam by a factor of more than 106. Analytical and simulation studies of 6D muon beam ionization cooling in a helical channel filled with pressurized gas or liquid hydrogen absorber indicate that a factor of 106 is possible. Further reduction of the normalized 4D transverse emittance by an additional two orders of magnitude is envisioned using Parametric-resonance Ionization Cooling (PIC). To realize the phase shrinkage effect in the parametric resonance method, one needs to design a focusing channel free of chromatic and spherical aberrations. We report results of our study of a concept of an aberration-free wiggler transport line with an alternating dispersion function. Resonant beam focusing at thin beryllium wedge absorber plates positioned near zero dispersion points then provides the predicted PIC effect.  
 
WEPLS047 3-1/2 Cell Superconducting RF Gun Simulations gun, cathode, emittance, simulation 2481
 
  • C.D. Beard, J.H.P. Rogers
    CCLRC/DL/ASTeC, Daresbury, Warrington, Cheshire
  • F. Staufenbiel, J. Teichert
    FZR, Dresden
  A 3-1/2 cell superconducting RF photocathode gun is being developed at Forschungszentrum Rossendorf to produce a high peak current, low emittance electron beam. This technology is essential to the realisation of many large scale facilities. The gun is designed for CW operation mode with 1 mA current and 9.5 MeV electron energy, and it will be installed at the ELBE superconducting electron linear accelerator. The gun will have a 3-1/2 cell niobium cavity operating at 1.3 GHz. The cavity consists of three cells with TESLA geometry and a specially designed half-cell in which the photocathode will be placed. Typical ERL-based projects require ~100 mA average current, and therefore suitable upgrade paths are required. Simulations have been carried out to evaluate the design and to determine suitable upgrades for higher current operation. Simulations of alternative cathode surface shapes are presented. Several couplers have been identified that can provide higher power to the cavity, whose integration and suitability has been verified. All the investigations that have identified possible solutions to higher current operation are discussed in this report.  
 
WEPLS056 R&D Status of the High-intense Monochromatic Low-energy Muon Source: PRISM simulation, impedance, lepton, synchrotron 2508
 
  • A. Sato, M. Aoki, Y. Arimoto, I. Itahashi, Y. Kuno, K. Kuriyama, T. Oki, T. Takayanagi, M. Yoshida
    Osaka University, Osaka
  • M. Aiba, C. Ohmori, T. Yokoi, K. Yoshimura
    KEK, Ibaraki
  • Y. Iwashita
    Kyoto ICR, Uji, Kyoto
  • S. Machida
    CCLRC/RAL/ASTeC, Chilton, Didcot, Oxon
  • Y. Mori
    KURRI, Osaka
  PRISM is a project of a future intense low-energy muon source, which combines monochromaticity and high purity. Its aimed intensity is about $1011-1012 muons per second. The muon beams will have a low kinetic energy of 20MeV so that it would be optimized for the stopped muon experiments such as searching the muon lepton flavor violating processes. PRISM consists of a pion capture section, a pion/muon transfer section and a phase rotation ssection. An FFAG is used as the phase rotator to achieve the monochromatic muon beams. This paper will describe design status of these sections as well as construction status of PRISM-FFAG.  
 
WEPLS064 Wiggler for ILC Cooler wiggler, emittance, quadrupole, dipole 2526
 
  • A.A. Mikhailichenko
    Cornell University, Department of Physics, Ithaca, New York
  We represented the concept of a wiggler with linear piecewise field dependence. This eliminates nonlinearities in wiggler. This type of wiggler can be recommended for usage in ILC cooler.  
 
WEPLS074 SESAME Magnets System dipole, quadrupole, sextupole, storage-ring 2553
 
  • S. Varnasseri
    SESAME, Amman
  In this paper the SESAME storage ring magnet system is described. The storage ring consists of 16 bending magnets with a maximum field of 1.455 T and vertical gradient of 2.79 T/m, 32 focusing quadrupoles with a maximum gradient of 16.92 T/m, 32 defocusing quadrupoles with a maximum gradient of 10.23 T/m, 32 focusing sextupoles with a maximum differential gradient of 200 T/m2 and 32 defocusing sextupoles with the maximum differential gradient of 300 T/m2. The horizontal/vertical correctors will be embedded inside focusing/defocusing sextupoles. For the quadrupole and sextupole, a design similar to ANKA has been adopted. The magnetic and electrical design of dipoles and correctors, field profile and higher order multipoles optimization will be presented.  
 
WEPLS077 Considerations on the Design of the Bending Magnet for Beam Extraction System of PEFP extraction, proton, dipole, target 2556
 
  • Y.-H. Kim, Y.-S. Cho, J.-H. Jang
    KAERI, Daejon
  The PEFP is designed to have two beam extraction lines at the 20 MeV end and 100MeV end for beam utilization. So, the bending magnet to extract the beam from the beam line is located among the MEBT. This implies that there is a long drift space between the focusing structures, while, from the beam dynamics study, it is recommended to make the drift space shorter. In this study, we design and compare some bending magnets to satisfy the beam dynamics requirements.  
 
WEPLS092 Computer Modeling of Magnetic System for C400 Superconducting Cyclotron cyclotron, extraction, simulation, injection 2589
 
  • Y. Jongen, D. Vandeplassche, S.E. Zaremba
    IBA, Louvain-la-Neuve
  • G.A. Karamysheva, N.A. Morozov, E. Samsonov
    JINR, Dubna, Moscow Region
  The superconducting cyclotron (C400) is designed at IBA (Belgium) able to accelerate carbon ions at 400 MeV/nucleon. By computer simulation with 3D TOSCA code, the cyclotron magnetic system principal parameters were estimated (pole radius 187 cm, outer diameter 606 cm, valley depth 60 cm, height 276 cm). The required isochronous magnetic field was shaped with an accuracy of ± 2 mT. Four-fold symmetry and spiralized sectors with elliptical gap (minimal 12 mm at extraction) provide the stable beam acceleration till 15 mm from the pole edge.  
 
THPPA03 The First CW Accelerator in USSR and a Birth of Accelerating Field Focussing rfq, proton, quadrupole, ion 2755
 
  • V.A. Teplyakov
    IHEP Protvino, Protvino, Moscow Region
  In the absence of Professor Teplyakov, Robert Jameson will present the work for which Professor Teplyakov is awarded the 2006 EPS-AG Prize for Achievement. The abstract of Professor Teplyakov's presentation follows: As CW linear accelerators became required, it appeared an absolute necessity to change the initial part of the accelerator. The initial part should prepare bunches of charged particles for the further acceleration in the main part. The CW accelerator should also be economic and reliable. The problem was solved using the principles of adiabatic capture of particles and low energy injection with focusing by means of the RF field. The acceleration of bunches with non-increasing charge density was the basic idea. It allowed reduction of the injection energy without reducing the current. By 1972, initial testing in IHEP Protvino was accomplished, and the first accelerated beam was obtained in an RFQ. The URAL-30 proton linac was commissioned in 1977 in IHEP. It applies RFQ-focusing from injection up to the top energy of 30 MeV. From 1985 until the present, this facility routinely operates as an injector to a booster proton synchrotron, this feeding the entire accelerator complex of ITEP. Development of the first RFQ in the Western world was started at Los Alamos in 1978 and performed a proof-of-principle test in 1980. After that there were many articles and reports and the RFQ became widely known in the world.  
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THPCH016 Transfer Matrix of Linear Focusing System in the Presence of Self-field of Intense Charged Particle Beam electromagnetic-fields, quadrupole, dipole, ion 2817
 
  • Yu. Kazarinov
    JINR, Dubna, Moscow Region
  Within the framework of moments method, the computation algorithm of the transfer matrix in the presence of self-field of the intense charged particle beam is given. The transfer matrix depends on both the linear external electromagnetic field parameters and the initial value of the second order moments of the beam distribution function. In the case of coupled degrees of freedom, the independent 2D subspaces of the whole phase space are found by means of the linear transformation of the phase space variables. The matrix of this transformation connects with second order moments of the beam distribution function. The momentum spread of the beam is taken into account also.  
 
THPCH023 Vlasov Equilibrium of a Periodically Twisted Ellipse-shaped Charged-particle Beam in a Non-axisymmetric Periodic Magnetic Focusing Field emittance, plasma, klystron, permanent-magnet 2826
 
  • J.Z. Zhou, C. Chen
    MIT/PSFC, Cambridge, Massachusetts
  A new Vlasov equilibrium is obtained for a periodically twisted ellipse-shaped charged-particle beam in a non-axisymmetric periodic permanent magnetic focusing field. The equilibrium distribution function is derived, and the statistical properties of the beam equilibrium are studied. The generalized envelope equations derived from the kinetic theory recovers the generalized envelope equations obtained in the cold-fluid theory when the temperature is taken to be zero*. Examples of periodically twisted elliptic beam equilibrium are presented and applications are explored.

*J. Zhou et al. “Exact Paraxial Cold-Fluid Equilibrium of a High-Intensity Periodically Twisted Ellipse-Shaped Charged-Particle Beam,” Phys. Rev. ST Accel. Beams, submitted for publication (2005).

 
 
THPCH028 Crystalline Beams at High Energies lattice, dipole, luminosity, quadrupole 2841
 
  • J. Wei
    BNL, Upton, Long Island, New York
  • S. Machida
    CCLRC/RAL/ASTeC, Chilton, Didcot, Oxon
  • S. Ochi, H. Okamoto
    HU/AdSM, Higashi-Hiroshima
  • A. Sessler
    LBNL, Berkeley, California
  • Y. Yuri
    JAEA, Takasaki, Takasaki
  Previously it was shown that by crystallizing each of the two counter-circulating beams, a much larger beam-beam tune shift can be tolerated during the beam-beam collisions; thus a higher luminosity can be reached for colliding beams*. On the other hand, crystalline beams can only be formed at energies below the transition energy of the circular accelerators**. In this paper, we investigate the formation of crystals in two types of high-transition-energy lattices, one realized by three-cell missing dipole modules and the other with negative bends. The latter type satisfies the maintenance condition for a crystalline beam***.

*J. Wei and A.M. Sessler, “Colliding crystalline beams”, EPAC98, p. 862. **J. Wei et al. Physical Review Letters, 73 (1994) p. 3089.***J. Wei et al. Physical Review Letters, 80 (1998) p. 2606.

 
 
THPCH040 Linac Focusing and Beam Break Up for 4GLS linac, BBU, quadrupole, TESLA 2871
 
  • E. Wooldridge, B.D. Muratori
    CCLRC/DL/ASTeC, Daresbury, Warrington, Cheshire
  As part of the design for 4GLS the linac focusing and its effect on the beam break up (BBU) threshold have been studied. The choice of graded gradient focusing scheme is discussed and initial models of the focusing, using a triplet of quadrupoles between each of the modules within the linac, are presented. The quadrupoles were set-up in a defocusing - focusing - defocusing format with strengths of -1/2k, k, -1/2k. Using these models the BBU threshold was computed using available codes assuming a 9-cell TESLA cavity within the linac and a 7-cell design with HOM dampers. A sweep of the magnet strength with respect to the BBU threshold showed that there is an optimum setting.  
 
THPLS037 Beam Position and Angular Monitor for Undulator by Using SR Monitor Technique electron, undulator, injection, radiation 3368
 
  • T. Mitsuhashi, M. Tadano
    KEK, Ibaraki
  We presented a beam position monitor by using SR monitor technique in the last PAC05. In this monitor, a visible SR in far tail of the undulator spectrum is extracted by a water-cooled beryllium mirror. We applied a focusing system to observe a beam position in the undulator through an optical image of beam. We continue further study of this monitor, and this time, we add the afocal system like a Kepler type telescope to measure the angular deviation of the beam. This system converts the angular deviation of optical axis of input ray into position deviation, and we can measure an angular deviation of the beam through its position deviation on the CCD. The results show us this method is applicable to monitor an angular deviation of beam in the undulator independent from position deviation, and gap change of undulator has no effect for the beam position monitoring.  
 
THPLS048 Beam-optics Analysis and Periodicity Restoration in the Storage Ring of the Pohang Light Source storage-ring, quadrupole, optics, dynamic-aperture 3395
 
  • S.H. Shin, M. Yoon
    POSTECH, Pohang, Kyungbuk
  • E.-S. Kim
    PAL, Pohang, Kyungbuk
  The PLS is a third-generation synchrotron radiation source, which provides intense light from ultraviolet to soft x-rays. Similar to other light sources, the PLS is characterized by a small emittance in order to achieve a very high spectral brightness and stably circulating electron beam. To guarantee these characteristics, a thorough understanding of the linear optics has to be carried out, and many storage rings employ LOCO (Linear Optics from Closed Orbits) to analyse the linear optics. This paper will describe the LOCO implementation at PLS and the results.  
 
THPLS069 Preliminary Design of the TPS Linac to Booster Transfer Line booster, linac, injection, electron 3448
 
  • Y.-C. Liu, H.-P. Chang, C.-S. Fann, K.-T. Hsu, S.Y. Hsu, K.-K. Lin, K.-B. Liu, G.-H. Luo
    NSRRC, Hsinchu
  The preliminary design of the LTB (linac to booster) transfer line of the proposed TPS (Taiwan Photon Source) project is considered in this study. The layout presented in this report is based on the booster lattice and the choice of linac parameters. These parameters are adopted from previous report of booster design and typical commercial available products of linac. The simulation result indicates that the desired optical functions at a given location can be readily obtained by varying the appropriate focusing strength of quadrupoles. It provides tuning capability to match various possible options of optical functions at injection location. This report is presented together with design consideration of a set of beam diagnostics instruments.  
 
THPLS126 Construction and Testing of a Pair of Focusing Undulators for ALPHA-X undulator, electron, insertion-device, insertion 3580
 
  • B.J.A. Shepherd, J.A. Clarke
    CCLRC/DL/ASTeC, Daresbury, Warrington, Cheshire
  ALPHA-X is a four-year project shared between several research groups in the UK to build a laser-plasma accelerator and produce coherent short-wavelength radiation in an FEL. A pair of undulators for the project have been designed and built by ASTeC at Daresbury Laboratory. The undulators are 1.5m long, 100 period permanent magnet devices with a minimum gap of 3.5mm, a peak field of 0.7T and a two-plane focusing design. The devices were modelled using RADIA, and data from the magnet block manufacturer was used to sort the blocks. To optimise the trajectory in the real devices, magnetic testing (using Hall probe and flipping coil techniques) and block swapping has been performed in Daresbury's dedicated insertion device test facility. The measurements agree well with the models, and the undulators will perform well within specification.