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MOPLT153 Electron-Ion Collider at CEBAF: New Insights and Conceptual Progress luminosity, acceleration, vacuum, quadrupole 893
 
  • Y.S. Derbenev, A. Afanasev, K. Beard, S.A. Bogacz, P. Degtiarenko, J.R. Delayen, A. Hutton, G.A. Krafft, R. Li, L. Merminga, M. Poelker, B.C. Yunn, Y. Zhang
    Jefferson Lab, Newport News, Virginia
  • P.N. Ostroumov
    ANL/Phys, Argonne, Illinois
  We report on progress in conceptual development of the proposed high luminosity (up to 1035/cm2s) and efficient spin manipulation (using figure 8 boosters and collider rings) Electron-Ion Collider at CEBAF based on use of polarized 5-7 GeV electrons in superconduction energy recovering linac (ERL with circulator ring, kicker-operated) and 30-150 GeV ion storage ring (polarized p, d. He3, Li and unpolarized nuclei up to Ar, all totally stripped). Ultra-high luminosity is envisioned to be achievable with short ion bunches and crab-crossing at 1.5 GHz bunch collision rate interaction points. Our recent studies concentrated on simulation of beam-beam interaction, preventing the electron cloud instability, calculating luminosity lifetime due to Touschek effect in ion beam and background scattering of ions, experiments on energy recovery at CEBAF, and other. These studies have been incorporated in the development of the luminosity calculator and in formulating minimum requirements to the polarized electron and ion sources  
 
MOPLT155 Study of Beam-beam Effects at PEP-II luminosity, acceleration, vacuum, quadrupole 896
 
  • I.V. Narsky, F.C. Porter
    CALTECH, Pasadena, California
  • Y. Cai, J. Seeman
    SLAC, Menlo Park, California
  • W. Kozanecki
    CEA/DSM/DAPNIA, Gif-sur-Yvette
  Using a self-consistent, three-dimensional simulation program running on parallel supercomputers, we have simulated the beam-beam interaction at the PEP II asymmetric e+e- collider. In order to provide guidance to luminosity improvement in PEP-II, we have scanned the tunes and other machine parameters in both rings, and computed their impact on the luminosity and particle loss. Whenever possible, the code has been benchmarked against experimental measurements, at various beam currents, of luminosity and luminous-region size using the BaBar detector. These studies suggest that three-dimensional effects such as bunch lengthening may be important to understand a steep drop of luminosity near the peak currents.  
 
MOPLT156 High Brightness Electron Guns for Next-Generation Light Sources and Accelerators gun, luminosity, acceleration, vacuum 899
 
  • H. Bluem, M.D. Cole, J. Rathke, T. Schultheiss, A.M.M. Todd
    AES, Princeton, New Jersey
  • I. Ben-Zvi, T. Srinivasan-Rao
    BNL, Upton, Long Island, New York
  • P. Colestock, D.C. Nguyen, R.L. Wood, L. Young
    LANL, Los Alamos, New Mexico
  • D. Janssen
    FZR, Dresden
  • J. Lewellen
    ANL, Argonne, Illinois
  • G. Neil, H.L. Phillips, J.P. Preble
    Jefferson Lab, Newport News, Virginia
  Advanced Energy Systems continues to develop advanced electron gun and injector concepts. Several of these projects have been previously described, but the progress and status of each will be updated. The project closest to completion is an all superconducting RF (SRF) gun, being developed in collaboration with the Brookhaven National Laboratory, that uses the niobium of the cavity wall itself as the photocathode material. This gun has been fabricated and will shortly be tested with beam. The cavity string for a closely-coupled DC gun and SRF cavity injector that is expected to provide beam quality sufficient for proposed ERL light sources and FELs will be assembled at the Jefferson Laboratory later this year. We are also collaboration with Los Alamos on a prototype CW normal-conducting RF gun with similar performance, that will undergo thermal testing in late 2004. Another CW SRF gun project that uses a high quantum efficiency photocathode, similar to the FZ-Rossendorf approach, has just begun. Finally, we will present the RF design and cold test results for a fully axisymmetric, ultra-high-brightness x-band RF gun.  
 
MOPLT158 Cost Optimization of Non-Scaling FFAG Lattices for Muon Acceleration gun, luminosity, vacuum, quadrupole 902
 
  • J.S. Berg, R. Palmer
    BNL, Upton, Long Island, New York
  Fixed Field Alternating Gradient (FFAG) accelerators are a promising idea for reducing the cost of acceleration for muon accelerators as well as other machines. This paper presents an automated method for designing these machines to certain specifications, and uses that method to find a minimum cost design. The dependence of this minimum cost on various input parameters to the system is given. The impact of the result on an FFAG design for muon acceleration is discussed.  
 
MOPLT170 eRHIC, Future Electron-ion Collider at BNL gun, electron, vacuum, quadrupole 923
 
  • V. Ptitsyn, L. Ahrens, M. Bai, J. Beebe-Wang, I. Ben-Zvi, M. Blaskiewicz, J.M. Brennan, R. Calaga, X. Chang, E.D. Courant, A. Deshpande, A.V. Fedotov, W. Fischer, H. Hahn, J. Kewisch, V. Litvinenko, W.W. MacKay, C. Montag, S. Ozaki, B. Parker, S. Peggs, T. Roser, A. Ruggiero, B. Surrow, S. Tepikian, D. Trbojevic, V. Yakimenko, S.Y. Zhang
    BNL, Upton, Long Island, New York
  • D.P. Barber
    DESY, Hamburg
  • M. Farkhondeh, W. Franklin, W. Graves, R. Milner, C. Tschalaer, J. Van der Laan, D. Wang, F. Wang, A. Zolfaghari, T. Zwart
    MIT/BLAC, Middleton, Massachusetts
  • A.V. Otboev, Y.M. Shatunov
    BINP SB RAS, Novosibirsk
  The paper reviews the progress made lately in the design of eRHIC, proposed future electron-ion collider on the basis of the existing RHIC machine. The eRHIC aims to provide collisions of electrons and positrons on ions and protons in center mass energy range of 25-70 GeV. The goal luminosities are in 1032-1033 1/(s*cm2) values for e-p and in 1030-1031 1/(s*cm2) values for e-Au collisions. An essential design requirement is to provide longitudinally polarized beams of electrons and protons (and, possibly lighter ions) at the collision point. The eRHIC ZDR has been recently developed which considers various aspects of the accelerator design. An electron accelerator, which delivers about 0.5A polarized electron beam current in the electron energy range of 5 to 10 GeV, should be constructed at the BNL near existing ion rings of the RHIC collider and should intersect an ion ring at least in one of the available ion ring interaction regions. In order to reach the luminosity goals some upgrades in ion rings also would be required. Ways to reach lower beam emmittances (electron cooling) and higher beam intensities have to be realized.  
 
MOPLT178 RHIC Pressure Rise gun, vacuum, focusing, beamloading 944
 
  • S.Y. Zhang, J. Alessi, M. Bai, M. Blaskiewicz, P. Cameron, K.A. Drees, W. Fischer, R.P. Fliller III, D. Gassner, J. Gullotta, P. He, H.-C. Hseuh, H. Huang, U. Iriso, R. Lee, Y. Luo, W.W. MacKay, C. Montag, B. Oerter, S. Peggs, F.C. Pilat, V. Ptitsyn, T. Roser, T. Satogata, L. Smart, P. Thieberger, D. Trbojevic, J. Van Zeijts, L. Wang, J. Wei, K. Zeno
    BNL, Upton, Long Island, New York
  Beam induced pressure rise remains an intensity limit at the RHIC for both heavy ion and polarized proton operations. The beam injection pressure rise at warm sections has been diagnosed due to electron cloud effect. In addition, pressure rise of heavy ion operation at the beam transition has caused experiment background problem in deuteron-gold run, and it is expected to take place in gold-gold run at high intensities. This type of pressure rise is related to beam momentum spread, and the electron cloud seems not dominant. Extensive approaches for both diagnosis and looking-for-remedies are undergoing in the current gold operation, RUN 4. Results of beam scrubbing, NEG pipe in RHIC ring, beam scraping test of ion desorption, beam momentum effect at the transition, beam gap effect, solenoid effect, and NEG pipe ion desorption test stand will be presented.  
 
MOPLT179 Beam Scrubbing for RHIC Polarized Proton Opearation gun, vacuum, focusing, proton 947
 
  • S.Y. Zhang, W. Fischer, H. Huang, T. Roser
    BNL, Upton, Long Island, New York
  One of the intensity limiting factor of RHIC polarized proton beam is the electron cloud induced pressure rise. During the 2003 polarized proton run, a beam scrubbing study was performed. Actual beam scrubbing time was much less than the planned 2 hours. However, a non-trivial beam scrubbing effect was observed not only in the locations with highest pressure rise, but also in most of the single beam straight sections. This not only confirmed that beam scrubbing is indeed a countermeasure to the electron cloud, but also showed the feasibility of applying beam scrubbing in RHIC proton beam operation to allow for higher beam intensities. In this article, the results will be reported.  
 
TUXCH01 Review of ISOL-type Radioactive Beam Facilities gun, vacuum, focusing, beamloading 45
 
  • M. Lindroos
    CERN, Geneva
  The ISOL technique was invented in Copenhagen over 50 years ago and eventually migrated to CERN where a suitable proton drive beam was available at the Syncho-Cyclotron. The quick spread of the technique from CERN to many other laboratories has resulted in a large user community, which has assured the continued development of the method, physics in the front-line of fundamental research and the application of the method to many applied sciences. The technique is today established as one of the main techniques for on-line isotope production of high intensity and high quality beams. The thick targets used allows the production of unmatched high intensity radioactive beams. The fact that the ions are produced at rest makes it ideally suitable for low energy experiments and for post acceleration using well established accelerator techniques. The many different versions of the technique will be discussed and the many facilities spread all over the world will be reviewed. The major developments at the existing facilities and the challenges encountered will be presented. Finally, the possibility of using the resulting high intensity beams for the production of intense neutrino beams will be briefly discussed.  
Video of talk
Transparencies
 
TUXCH02 FAIR - An International Accelerator Facility for Research with Ions and Antiprotons gun, vacuum, focusing, beamloading 50
 
  • W.F. Henning
    GSI, Darmstadt
  This presentation describes the conceptual design for the accelerator facility and the physics research program, and discusses the status and the new challenges in accelerator physics and technology.  
Video of talk
Transparencies
 
TUPLT011 The LHC Lead Ion Injector Chain target, plasma, laser, electron 1153
 
  • K. Schindl, A. Beuret, A. Blas, J. Borburgh, H. Burkhardt, C. Carli, M. Chanel, T. Fowler, M. Gourber-Pace, S. Hancock, C.E. Hill, M. Hourican, J.M. Jowett, K. Kahle, D. Kuchler, A.M. Lombardi, E. Mahner, D. Manglunki, M. Martini, S. Maury, F. Pedersen, U. Raich, C. Rossi, J.-P. Royer, R. Scrivens, L. Sermeus, E.N. Shaposhnikova, G. Tranquille, M. Vretenar, T. Zickler
    CERN, Geneva
  A sizeable part of the LHC physics programme foresees heavy ion (lead-lead) collisions with a design luminosity of 1027 cm-2 s-1. This will be achieved after an upgrade of the ion injector chain comprising Linac3, LEIR, PS and SPS machines. Each LHC ring will be filled in ~10 minutes with ~600 bunches, each of 7 107 Pb ions. Central to the scheme is the Low Energy Ion Ring (LEIR), which transforms long pulses from Linac3 to high-brilliance bunches by means of 6D multi-turn injection and accumulation via electron cooling. Major limitations along the chain, including space charge, intra-beam scattering, vacuum issues, and emittance preservation are highlighted. The conversion from LEAR (Low Energy Antiproton Ring) to LEIR includes new magnets and power converters, high-current electron cooling, broad-band RF cavities, upgraded beam diagnostics, and UHV vacuum equipment relying on beam scrubbing to achieve a few 10-12 mbar. Major hardware changes in Linac3 (Electron Cyclotron Resonance source, repetition rate, energy ramping cavity), PS (new injection hardware, elaborate RF gymnastics, stripping insertion), and SPS (100 MHz system) are described. An early beam scenario, using fewer bunches but the same bunch intensity to deliver a lower luminosity, reduces the work required for LHC ion operation in spring 2008.  
 
TUPLT012 Adjusting the IP Beta-functions in RHIC. target, plasma, laser, electron 1156
 
  • W. Wittmer, F. Zimmermann
    CERN, Geneva
  • F.C. Pilat, V. Ptitsyn, J. Van Zeijts
    BNL, Upton, Long Island, New York
  The beta- functions at the IP can be adjusted without perturbation of other optics functions via several approaches. In this paper we describe a scheme based on a vector knob, which assigns fixed values to the different tuning quadrupoles and scales them by a common multiplier. The values for the knob vector were calculated for a lattice without any errors using MADX. Previous studies for the LHC have shown that this approach can meet the design goals. A specific feature of the RHIC lattice is the nested power supply system. To cope with the resulting problems a detailed response matrix analysis has been carried out and different sets of knobs were calculated and compared. The knobs are tested at RHIC during the 2004 run and preliminary results maybe discussed. Simultaneously a new approach to measure the beam sizes of both colliding beams at the IP, based on the tune ability provided by the knobs, was developed and tested.  
 
TUPLT013 Calculating LHC Tuning Knobs using Various Methods target, plasma, laser, electron 1159
 
  • W. Wittmer, D. Schulte, F. Zimmermann
    CERN, Geneva
  By measuring and adjusting the beta-functions at the IP the luminosity is being optimized. In LEP this was done with the two closest doublet magnets. This approach is not applicable for the LHC due to the asymmetric lattice and common beam pipe through the triplet magnets. To control and change the beta-functions quadrupole groups situated on both sides further away from the IP have to be used where the two beams are already separated. The quadrupoles are excited in specific linear combinations, forming the so-called tuning knobs for the IP beta-functions. We compare the performance of such knobs calculated by different methods: (1) matching in MAD, (2) inversion of the re-sponse matrix and singular value decomposition inversion and conditioning and (3) conditioning the response matrix by multidimensional minimization using Hessian method.  
 
TUPLT014 Comparative Design Studies of a Super Buncher for the 72 MeV Injection Line of the PSI Main Cyclotron target, plasma, laser, electron 1162
 
  • J.-Y. Raguin, A. Adelmann, M. Bopp, H. Fitze, M. Pedrozzi, P. Schmelzbach, P. Sigg
    PSI, Villigen
  The envisaged current upgrade from 2 to 3 mA of the PSI 590-MeV main cyclotron requires an increase of the global accelerating voltage of the 50-MHz cavities which leads to a nearly unacceptable RF requirement for the 150-MHz flattop cavity. In order to preserve the longitudinal acceptance and transmission of the machine while relaxing the high demands on the flattop system, it is conceivable to install a buncher in the 72-MeV injection line. To this end, normal-conducting 150-MHz half-wave resonators and 500-MHz two-gap drift-tube cavities have been designed and optimised for minimum input power and peak surface fields. The dependence of the RF properties (Q0, shunt impedances and peak fields) with beam apertures and gap voltages compatible with beam-dynamics requirements are presented.  
 
TUPLT021 Heavy Ion Beam Transport in Plasma Channels laser, beamloading, antiproton, betatron 1183
 
  • S. Neff, D.H. Hoffmann, R. Knobloch
    TU Darmstadt, Darmstadt
  • C. Niemann, D. Penache, A. Tauschwitz
    GSI, Darmstadt
  • S. Yu
    LBNL, Berkeley, California
  The transport of heavy ion beams in high current discharge channels is a promising option for the final beam transport in a heavy ion fusion reactor. The channel provides space-charge neutralization and an azimuthal magnetic field of several tesla, thereby allowing for transporting high current ion beams. The possibility to heat the hohlraum target with only two ion beams simplifies the reactor design significantly. Therefore channel transport is studied as part of the US fusion reactor study as an alternative to neutralized ballistic focusing. We have created 1 m long discharge channels and studied the channel development and stability. In addition, we have carried out proof-of-principle transport experiments using the UNILAC facility at the Gesellschaft für Schwerionenforschung. The experiments demonstrate the feasibility of plasma channel transport. Our transport experiments with low current beams are supplemented by simulations for high current beams. These simulations show the possibility of transporting particle currents of up to 60 kA.  
 
TUPLT022 Beam Dynamics Simulations at the S-DALINAC for the Optimal Position of Beam Energy Monitors beamloading, antiproton, betatron, cathode 1186
 
  • B. Steiner, W.F.O. Müller, T. Weiland
    TEMF, Darmstadt
  • A. Richter
    TU Darmstadt, Darmstadt
  The S-DALINAC is a 130 MeV superconducting recirculating electron accelerator serving several nuclear and radiation physics experiments as well as driving an infrared free-electron laser. For the experiments an energy stability of 1·10-4 should be reached. Therefore noninvasive beam position monitors will be used to measure the beam energy. For the measurement the different flight time of the electrons to the ideal particle are compared, that means in the simulations the longitudinal dispersion of the beam transport system is used for the energy detection. The results of the simulations show that it is possible to detect an energy difference of 1·10-4 with this method. The results are also proven by measurements.  
 
TUPLT023 A New Ion Beam Beam Facility for Slow Highly Charged Ions electron, beamloading, antiproton, betatron 1189
 
  • G. Zschornack, S. Landgraf
    TU Dresden, Dresden
  • S. Facsko, D. Kost, W. Möller, H. Tyrroff
    FZR, Dresden
  • F. Grossmann, U. Kentsch, V.P. Ovsyannikov, M. Schmidt, F. Ullmann
    Leybold Vacuum Dresden, Dresden
  A new ion beam facility for slow highly charged ions is presented. It will provide slow highly charged ions from an Electron Cyclotron Resonance (ECR) ion source as well as very highly charged ions at lower ion currents from an Electron Beam Ion Trap (EBIT). As ECR ion source a SUPERNANOGAN source* is applied. The Dresden EBIT**, a room-temperature EBIT, is used to produce comparatively low currents of very highly charged ions. This very compact and long-term stable device is producing highly charged ions at ultimate low costs. The Dresden EBIT working with electron energies up to 15 keV at electron currents up to 50 mA is able to produce bare nuclei up to nickel as Fe26+ or Ni28+, helium-like ions for medium Z such as Ge30+ or Kr34+ and neon-like ions for elements of the high-Z region such as Xe44+ or Ir67+. The ion currents extracted from the Dresden EBIT are typically in the range of some nA per pulse. With the new ion beam facility outstanding possibilities for a wide range of investigations are opened up in areas such as surface analysis, materials science and nanotechnology as well as for basic research in different fields as for instance in atomic and solid state physics.

*The Pantechnik Catalogue, August 2001 Edition, Caen 2001, France **V.P.Ovsyannikov, G.Zschornack; Review of Scientific Instruments, 70 (1999) 2646

 
 
TUPLT024 A Comparison of High Current Ion Beam Matching from an Ion Source to a RFQ by Electrostatic and by Magnetic Lenses electron, beamloading, antiproton, betatron 1192
 
  • R. Becker, R.A. Jameson, A. Schempp
    IAP, Frankfurt-am-Main
  • T. Hata, N. Hayashizaki, H. Kashiwagi, K. Yamamoto
    RLNR, Tokyo
  • T. Hattori, M. Okamura, A. Sakumi
    RIKEN, Saitama
  In order to improve the ?direct? injection scheme of the Riken Nd-YAK-laser driven ion source into a RFQ rf-accelerator, several basic methods have been investigated and compared, in order to transform the initially divergent ion beam into a convergent one, needed for matching the high current (100 mA C6+) ion beam at an energy of 100 keV to a RFQ. From the point of power supplies and break down characteristics, the simplest solution is a decelerating electrostatic lens, with the decelerating electrode operated on ion source potential. Due to the strong divergence of the ions beam after acceleration, this lens will be filled to an aperture, which causes strong aberrations. Therefore, we also investigated to use an accelerating potential on the lens electrode. This reduces significantly the filling of the lens and the emittance growth is only a factor of 3, as compared to the decelerating lens with a factor of 30! Finally we have been looking also into a magnetic matching system, which can match the ion beam to the RFQ with virtually no emittance growth.  
 
TUPLT025 Matching of a C6+ Ion Beam from a Laser Ion Source to a RFQ electron, beamloading, antiproton, betatron 1195
 
  • R. Becker, R.A. Jameson, A. Schempp
    IAP, Frankfurt-am-Main
  • T. Hattori
    RIKEN, Saitama
  • N. Hayashizaki, H. Kashiwagi
    RLNR, Tokyo
  • M. Okamura
    RIKEN/RARF/CC, Saitama
  • K. Yamamoto
    RIKEN/RARF/BPEL, Saitama
  A laser ion source, driven by a Nd-YAG laser can provide more than 100 mA of C6+ ions for a duration of about 1 μs, which is well matching the task of single-turn injection into synchrotrons for hadron tumor therapy with light ions. The ?direct? injection scheme has been improved by providing a design, which reduces the surface field strength to less than 30 kV/cm on all critical parts on relative negative potential. The new design keeps the advantage of divergent ion emission and acceleration, which seems to be the only way to keep the surface fields in limits, but includes a decelerating electrostatic lens on birth potential of the ions to refocus the emerging ion beam to the RFQ entrance. The whole design is very compact and allows for electrostatic steering between the ion source and the RFQ.  
 
TUPLT030 Numerical Simulations for the Frankfurt Funneling Experiment electron, linac, focusing, beamloading 1210
 
  • J. Thibus, A. Schempp
    IAP, Frankfurt-am-Main
  High beam currents are necessary for heavy ion driven fusion (HIF) or XADS. To achieve these high beam currents several ion beams are combined at low energies to one beam using the funneling technique. In each stage a r.f. funneling deflector bunches two accelerated beam lines to a common beam axis. The Frankfurt Funneling Experiment is a scaled model of the first stage of a HIF driver consisting of a Two-Beam RFQ accelerator and a funneling deflector. Our two different deflectors have to be enhanced to reduce particle losses during the funneling process. This is done with our new developed 3D simulation software DEFGEN and DEFTRA. DEFGEN generates the structure matrix and the potential distribution matrix with a Laplace 3D-solver. DEFTRA simulates ion beam bunches through the r.f. deflector. The results of the simulations of the two existing deflectors and proposals of new deflector structures will be presented.  
 
TUPLT040 CSR - a Cryogenic Storage Ring at MPI-K beamloading, antiproton, damping, betatron 1237
 
  • C.P. Welsch, J. Crespo López-Urrutia, M. Grieser, D. Orlov, C.D. Schroeter, D. Schwalm, J. Ullrich, A. Wolf, R. von Hahn
    MPI-K, Heidelberg
  • X. Urbain
    UCL CRC, Louvain-la-Neuve
  • D. Zajfman
    Weizmann Institute of Science, Physics, Rehovot
  A small cryogenic storage ring is planned to be developed at MPI-K, Heidelberg. The energy in the machine will be variable from 300 keV > down to 20 keV. Electron cooling will be applied to produce a high quality ion beam. The ring shall accommodate slow, vibrationally and rotationally cooled molecular ions and highly charged ions from the EBIT ion source. Moreover, it will serve as a test facility for the low-energy antiproton ring planned within the FLAIR collaboration to be installed at the future GSI facility. A number of technological challenges have to be handled: Especially highly charged ions require a vacuum in the order below 10-13 mbar to achieve reasonable lifetimes. Therefore - and for enabling experiments with rotationally cold molecules - the complete machine will be cooled down to below 10 K. Moreover, experiments with reaction microscopes to determine the full kinematics of ion- (antiproton-) atom or molecule collisions require a bunched operation with a bunch length below 2 ns. The optical elements of the machine and the lattice functions are given and first ideas about the vacuum chamber design are described in this paper.  
 
TUPLT041 Ultra-low Energy Antiprotons at FLAIR beamloading, antiproton, damping, betatron 1240
 
  • C.P. Welsch, M. Grieser, D. Orlov, J. Ullrich, A. Wolf, R. von Hahn
    MPI-K, Heidelberg
  The Future Accelerator Facility for Beams of Ions and Antiprotons at Darmstadt will produce the highest flux of antiprotons in the world. So far it is foreseen to accelerate the antiprotons to high energies (3-15 GeV) for meson spectroscopy and other nuclear and particle physics experiments in the HESR (High Energy Storage Ring). Within the planned complex of storage rings, it is possible to decelerate the antiprotons to about 30 MeV kinetic energy, opening up the possibility to create low energy antiprotons. In the proposed FLAIR facility the antiprotons shall be slowed down in a last step from 300 keV to 20 keV in an electrostatic storage ring (USR) for various in-ring experiments as well as for their efficient injection into traps. In this energy range - especially if one thinks about realizing a real multi-purpose facility with not only antiprotons, but also various highly-charged radioactive ions to be stored and investigated - electrostatic storage rings have clear advantages compared to their magnetic counterparts. In case one envisions to even approach the eV range, electrostatic machines are the only possible choice. This contribution presents the layout and design parameters of the USR.  
 
TUPLT042 Ring of FIRE beamloading, antiproton, damping, betatron 1243
 
  • C.P. Welsch, J. Ullrich
    MPI-K, Heidelberg
  • R. Doerner, H. Schmidt-Boecking
    IKF, Frankfurt-am-Main
  • C. Glaessner, K.-U. Kuehnel, A. Schempp
    IAP, Frankfurt-am-Main
  A small electrostatic storage ring is the central machine of the Frankfurt Ion stoRage Experiments which will be build up at the new Stern-Gerlach-Center of Frankfurt university. With ion energies up to 50 keV it will allow new methods to analyze complex many-particle systems from atoms to very large bio molecules. The high luminosity of the beam allows measurements with many orders of magnitude better resolution compared to traditional measurements. It will be combined with existing experiments, like the reaction microscope COLTRIMS and the ECR ion source. In comparison to earlier designs, the ring lattice was modified in many details: Problems in earlier designs were related with e.g. the detection of light particles and highly charged ions with different charge states. Therefore, the deflectors were redesigned completely, allowing a more flexible positioning of the diagnostics. In this contribution the final design of the storage ring is presented and the layout of all elements given. First results from vacuum measurements in the recently assembled quarter ring section are summarized.  
 
TUPLT043 Status of the Cooler Synchrotron COSY-Juelich beamloading, antiproton, damping, betatron 1246
 
  • B. Lorentz, U. Bechstedt, J. Dietrich, R. Eichhorn, R. Gebel, A. Lehrach, R. Maier, D. Prasuhn, A. Schnase, H. Schneider, R. Stassen, H. Stockhorst, R. Tölle
    FZJ/IKP, Jülich
  The cooler synchrotron COSY accelerates and stores unpolarized and polarized protons and deuterons in the momentum range between 300 MeV/c to 3.65 GeV/c. To provide high quality beams, an Electron Cooler at injection and a Stochastic Cooling System from 1.5 GeV/c up to maximum momentum are available. Vertically polarized proton beams with a polarization of more than 0.80 are delivered to internal and external experimental areas at different momenta. Externally, the maximum momentum is up to date restricted to approximately 3.4 GeV/c by the extraction elements installed in COSY. In 2003 deuteron beams with different combinations of vector and tensor polarization were made available for internal and external experiments. An rf dipole was installed, which is used to induce artificial depolarizing resonances. It can be used for an accurate determination of the momentum of the stored beams. The status of the cooler synchrotron COSY is presented and future plans are discussed.  
 
TUPLT044 Delta-T Procedure for Superconducting Linear Accelerator linac, beamloading, antiproton, damping 1249
 
  • A. Bogdanov, R. Maier, Y. Senichev
    FZJ/IKP, Jülich
  Development of the tune-up procedure for a linear accelerator is the next important stage after the design is complete. Conventional delta-T procedure developed for tuning of a normal-conducting linear accelerator by Crandall allows setting up of accelerating field amplitude and phase in cavity with known phase velocity. However, application of the delta-T procedure to a superconducting linac meets some difficulties. In particular, the synchronous phase velocity in superconducting linac is determined by RF phase shift between cavities, but not by geometrical size of accelerating cells as in normal conducting linac. Additionally, in superconducting linac the smaller phase advance leads to an insensibility of particles at the cavity exit to the variation of the electric field inside the cavity. In the paper we consider the modified delta-T procedure adjusted for superconducting linac. Numerical simulations prove that by proposed technique both tasks of preservation of necessary stable region motion and providing the beam with required final energy can be successfully solved.  
 
TUPLT045 Separatrix Formalism Applied to Linacs Accelerating Particles with Different Charge to Mass Ratio beamloading, antiproton, damping, betatron 1252
 
  • A. Bogdanov, R. Maier, Y. Senichev
    FZJ/IKP, Jülich
  We have developed separatrix formalism for superconducting linear accelerators. This method allows optimizing the quasi-synchronous velocity behavior along a linac. It gives a great advantage in acceleration of particles with different charge to mass ratio. In the article design optimization of structure supposed to accelerate different particles is presented. As an example for numerical simulation superconducting injector COSY is taken.  
 
TUPLT046 Luminosity Considerations for Internal and External Experiments at COSY beamloading, antiproton, damping, betatron 1255
 
  • A. Lehrach, U. Bechstedt, J. Dietrich, R. Eichhorn, R. Gebel, B. Lorentz, R. Maier, D. Prasuhn, H. Schneider, R. Stassen, H. Stockhorst, R. Tölle
    FZJ/IKP, Jülich
  • A. Schnase
    JAERI/J-PARC, Tokai-Mura, Naka-Gun, Ibaraki-Ken
  The future physics program at the Cooler-Synchrotron COSY in Jülich requires intense beams to provide high luminosities up to 1032cm-2s-1 for internal and external experiments. In 2003 the number of unpolarized protons could significantly be increased up to the theoretical space charge limit of COSY. This was achieved by careful study and adjustment of all subsystems in the accelerator chain of COSY. The intensities for polarized proton beams are at best an order of magnitude lower compared to one for unpolarized beams, depending on the beam current provided the injector cyclotron. Still there is some potential for further enhancement of polarized beam intensities. In this paper, luminosity considerations for polarized and unpolarized beams at COSY are presented taking into account different machine cycles and operation modes for internal and external experimental set-ups.  
 
TUPLT047 First Results of Pulsed Superconducting Half-wave Resonators beamloading, antiproton, damping, betatron 1258
 
  • R. Stassen, R. Eichhorn, F.M. Esser, B. Laatsch, R. Maier, G. Schug, R. Tölle
    FZJ/IKP, Jülich
  A pulsed linac for the cooler synchrotron COSY was projected based on superconductive half-wave resonators (HWRs). The concept of single phased resonators is a great challenge related to the requirement of accelerating protons and deuterons up to a similar energy. A cryomodule, which houses four cavities was designed in Cooperation with FZJ-ZAT, taking into account the restricted space and the special requirements of a linear accelerator. Two prototypes of the 160MHz Half-Wave Resonators (HWRs) were built at different companies. The fabrication differs slightly concerning the top and bottom parts of the cavity as well as the welding of the inner and outer conductor. First results of warm and cold measurements will be presented. The behaviour of the adjustable 4kW main coupler as well as the mechanical tuner can be tested together with the HWR in a new vertical test-cryostat.  
 
TUPLT049 Triple-spoke Cavities in FZJ beamloading, antiproton, damping, betatron 1261
 
  • E. Zaplatin, W. Braeutigam, R. Maier, M. Pap, M. Skrobucha, R. Stassen, R. Tölle
    FZJ/IKP, Jülich
  We report the situation with superconducting triple-spoke cavity activities at the research center FZJ in Juelich. The Nb prototype of the 700 MHz, beta=0.2 cavity is already in fabrication and should be tested this year. This work has been initiated for the European Spallation Source project. In the frames of the new European project of High Intensity Pulsed Proton Injector the 352 MHz, beta=0.48 cavity is under developments. This cavity should be designed, built and tested in the Lab within next few years.  
 
TUPLT050 Lattice for CELLS emittance, beamloading, antiproton, damping 1264
 
  • M. Muñoz, D. Einfeld
    CELLS, Bellaterra (Cerdanyola del Vallès)
  The CELLS is an approved project to build a national synchrotron light source in Spain. The main goals of the project are to provide a medium energy machine (3 GeV) with low emittance and top up operation, a circumference of ~280 m and at least 12 straight sections available for experiments. At present, two lattices are being considered. The first one is based in QBA optics and provides and emittance of 5 nm-rad, using existing technologies. The second one is a TBA one, with an emittance of 2 nm, where physical aperture are reduced by at least a factor 2 and gradients in the bending magnets are up to 10 T/m. We present the selected lattice, and review the main beam dynamics (energy acceptance, errors) issues.  
 
TUPLT052 GANIL Status Report emittance, target, beamloading, antiproton 1270
 
  • F. Chautard, J.L. Baelde, C. Barue, C. Berthe, A. Colombe, L. David, P. Dolegieviez, B. Jacquot, C. Jamet, P. Leherissier, R. Leroy, M.H. Moscatello, E. Petit, A. Savalle, G. Sénécal, F. Varenne
    GANIL, Caen
  The GANIL facility (Caen, France) is dedicated to the acceleration of heavy ion beams for nuclear physics, atomic physics, radiobiology and material irradiation. The production of radioactive ion beams for nuclear physics studies represents the main part of the activity. The in-flight fragmentation method was already used, since 1994, with the SISSI device. Since September 2001, SPIRAL, the Radioactive Ion Beam Facility at GANIL, delivers radioactive species produced by the ISOL method. The heavy ion beams of GANIL are sent onto a target and source assembly, and the radioactive beams are accelerated up to a maximum energy of 25 MeV/u by the cyclotron CIME. The operation and the running statistics of GANIL-SPIRAL are presented, with particular attention to the first SPIRAL beams. Few results about the cyclotron CIME, as the mass selection and tuning principle are summarized. The recent developments for increasing stable beams intensities, up to a factor 13 for argon, for use with SPIRAL, SISSI, or the LISE spectrometer, are presented. Considering the future of GANIL, SPIRAL II projects aims to produce high intensity secondary beams, by fission induced with a 5 mA deuteron beam in an uranium target.  
 
TUPLT053 Recent Evolutions in the Design of the French High Intensity Proton Injector (IPHI) emittance, target, beamloading, antiproton 1273
 
  • P.-Y. Beauvais
    CEA/DSM/DAPNIA, Gif-sur-Yvette
  In 1997, the two French National Research Agencies (CEA and CNRS) decided to collaborate in order to study and construct a prototype of the low energy part of a High Power Proton Accelerator (HPPA). The main objective of this project (the IPHI project), is to allow the French team to master the complex technologies used and the control concepts of the HPPAs. Recently, a collaboration agreement was signed with the CERN and led to some evolutions in the design and in the schedule. The IPHI design current was maintained at 100 mA in Continuous Wave mode. This choice should allow to produce a high reliability beam at reduced intensity (typically 30 mA) tending to fulfill the Accelerator Driven System requirements. The output energy of the Radio Frequency Quadrupole (RFQ), originally set to 5 MeV, was reduced to 3 MeV, allowing then the adjunction and the test in pulsed mode of a chopper line developed by the CERN for the Superconducting Proton Linac (SPL). In a final step, the IPHI RFQ and the chopper line should become parts of the SPL injector. In this paper, the IPHI project evolutions are reported as well as the construction and operation schedule.  
 
TUPLT060 Production of Radioactive Ion Beams for the EXCYT Facility target, beamloading, antiproton, damping 1291
 
  • M. Menna, G. Cuttone, M. Re
    INFN/LNS, Catania
  The EXCYT facility (EXotics with CYclotron and Tandem) at the INFN-LNS is based on a K-800 Superconducting Cyclotron injecting stable heavy-ion beams (up to 80 MeV/amu, 1 emA) into a target-ion source assembly to produce the required nuclear species, and on a 15 MV Tandem for post-accelerating the radioactive beams. After thermal ANSYS simulations, during May 2003 the Target-Ion Source assembly (TIS) was successfully tested at GANIL under the same operational conditions that will be initially used at EXCYT. Yields and production efficiencies for 8,9Li were compatible with the ones obtained at SPIRAL. Following suggestions by the Referees and the LNS Research Division, we decided to deliver 8Li as the first EXCYT radioactive beam (primary beam 13C). This choice also takes in account the availability of MAGNEX in 2004 as well as the requests and the first results obtained by the Big Bang collaboration. The commissioning of the EXCYT facility is foreseen by the end of 2004 together with the start of nuclear experiments program. In this poster we also report prospective ion beams currently in development.  
 
TUPLT061 Production and Transport of Radioactive Francium for Magneto-optical Trapping target, beamloading, antiproton, damping 1294
 
  • G. Stancari, R. Calabrese, B. Mai, G. Stancari, L. Tomassetti
    INFN-Ferrara, Ferrara
  • S.N. Atutov, V. Guidi
    UNIFE, Ferrara
  • V. Biancalana, A. Burchianti, A. Khanbekyan, C. Marinelli, E. Mariotti, L. Moi, S. Veronesi
    UNISI, Siena
  • L. Corradi, A. Dainelli
    INFN/LNL, Legnaro, Padova
  • P. Minguzzi, S. Sanguinetti
    UNIPI, Pisa
  An innovative facility for the production and trapping of francium isotopes is operating at the INFN laboratories in Legnaro, Italy. The goal is to obtain a dense cloud of cold and possibly polarized radioactive atoms for a wide range of fundamental studies. Among them are high-resolution laser spectroscopy, alpha-decay asymmetries from deformed nuclei, and tests of the standard model at low transferred momenta. The production of francium is achieved by sending a 100-MeV oxygen-18 beam from the Tandem-XTU accelerator on a thick gold target. The extraction of Fr+ is enhanced by heating the target to 1200 K and by biasing it at +3 kV. The ions are transported to the magneto-optical trap (MOT) through a 7-m electrostatic beam line. The diagnostic systems for monitoring the beam intensity (105 ions/s) are based on silicon detectors sensitive to the alpha particles from Fr decays. Beams of stable Rb+ can also be used for optimizing the transport and trapping processes. Prior to injection into the MOT the beam is neutralized and released in atomic form by a heated yttrium or zirconium foil. Details on the production, transport and neutralization processes are presented.  
 
TUPLT062 Design of the Proton Beam Line for the Trade Experiment beamloading, antiproton, damping, betatron 1297
 
  • C. Ronsivalle, L. Picardi
    ENEA C.R. Frascati, Frascati (Roma)
  • S. Monti, F. Troiani
    ENEA C.R. Rome, Rome
  The TRADE (Triga Accelerator Driven Experiment)experiment, to be performed in the TRIGA reactor of the ENEA-Casaccia centre consists in the coupling of a 140-300 MeV, 0.5 mA proton beam produced by a cyclotron to a target hosted in the central thimble of the reactor scrammed to sub-criticality. A 30 m long beamline has been designed to transfer the beam injecting it from the top of the pool with special care of having low losses in TRIGA building where a limited shielding of the line is possible. A particular attention was paid to reduce the number and size of elements in the last part of the beamline that are immersed in the pool's water. The paper presents a description of the beam line, the design criteria and the results of beam dynamics calculations.  
 
TUPLT063 Laser Temporal Pulse Shaping Experiment For SPARC Photoinjector laser, beamloading, antiproton, damping 1300
 
  • C. Vicario, A. Ghigo
    INFN/LNF, Frascati (Roma)
  • I. Boscolo, C. Vozzi
    Universita' degli Studi di Milano, MILANO
  • S. Cialdi, A.F. Flacco
    INFN-Milano, Milano
  • M. Nisoli, G. Sansone, S. Stagira
    Politecnico/Milano, Milano
  • M. Petrarca
    INFN-Roma, Roma
  Laser for driving high brightness photoinjector have to produce UV square pulse which is predicted to be the optimum profile for emittance compensation in advanced photoinjectors. The longitudinal laser pulse distribution, according to numerical simulations for the SPARC photoinjector, must be square with rise and fall time shorter than 1 ps and flat top variable up to 10 ps FWHM. In this paper we report the results of pulse shaping obtained using an acousto-optic (AO) programmable dispersive filter (DAZZLER). The DAZZLER was used to perform spectral amplitude and phase modulation of the incoming 100 fs Ti:Sapphire pulses. Because of the finite length of the crystal the maximum duration of the shaped pulse is 6 ps. To overcome this limitation we used a configuration in which the laser pulses passed twice through the AO filter. A dispersive glass section was also used to lengthen the pulse with a single pass in the DAZZLER. In this paper we report the experimental setup, hardware description and time and frequency domain measurements.  
 
TUPLT088 Beam Cooling at S-LSR septum, sextupole, gun, booster 1360
 
  • A. Noda, H. Fadil, S. Fujimoto, M. Ikegami, T. Shirai, M. Tanabe, H. Tongu
    Kyoto ICR, Uji, Kyoto
  • M. Grieser
    MPI-K, Heidelberg
  • I.N. Meshkov, E. Syresin
    JINR, Dubna, Moscow Region
  • K. Noda, T. Takeuchi
    NIRS, Chiba-shi
  • H. Okamoto, Y. Yuri
    HU/AdSM, Higashi-Hiroshima
  S-LSR is an ion accumulation and cooler ring with the circumference and maximum magnetic rigidity of 22.589 m and 1.0T.m, respectively. Electron beam cooling will be applied for laser-produced hot ion beam after phase rotation. Electron cooler for S-LSR is now under construction and the beam simulation is also going on. Laser cooling of Mg ion with low energy (35 keV) is also planned in 3-dimensional way with use of Synchro-Betatron coupling.so as to realize ultra cold beam. Cancellation of shear force due to orbit-length difference in the dipole section is to be studied with use of overlapping of the radial electric field inversely proportional to the curvature radius with the uniform vertical magnetic field. Possible experiments to approach to ultra-cold beam is also to be studied by computer simulation  
 
TUPLT089 Status of PEFP 3MeV RFQ Development septum, sextupole, gun, booster 1363
 
  • Y.-S. Cho, B.-H. Choi, S.-H. Han, J.-H. Jang, Y.H. Kim, H.-J. Kwon, C.-B. Shim
    KAERI, Daejon
  In the PEFP (Proton Engineering Frontier Project), a 350MHz, 3MeV RFQ (Radio Frequency Quadrupole) has been developed and tested. The tuning results showed that the resonant frequency is somewhat higher than 350MHz and other methods in addition to slug tuners should be used to tune the cavity correctly. To check the cavity characteristics, high power RF test has been done. The required peak RF power is 600kW and pulse width, repetition rate for initial test are 100 micro-s, 10Hz respectively. To solve the problems in PEFP RFQ, the upgrade design of 3MeV RFQ has been decided. The main concept of this upgrade design is constant vane voltage profile with the same length of RFQ. The other parameters (350MHz, 3MeV, 20mA) are the same with the previous RFQ. With constant vane voltage profile, fabrication of RFQ can be easier, and with the same mechanical dimension, other parts such as vacuum pumping station can be re-used. In this paper, the test results of the PEFP RFQ, and the details of beam dynamics design/engineering design of upgrade RFQ will be presented.  
 
TUPLT091 Fabrication Status of the PEFP 20 MeV DTL septum, sextupole, gun, booster 1369
 
  • M.-Y. Park, Y.-S. Cho, J.-H. Jang, Y.H. Kim, H.-J. Kwon
    KAERI, Daejon
  The PEFP (Proton Engineering Frontier Project) 20 MeV DTL have been constructed in KAERI site. The fabrication of the first tank is finished and the DT installation is in the process. We choose the pool-type electromagnets as the focusing magnet and 50 DTs will be installed on first tank. We tested the winding schemes of copper coils on the iron core and measured the magnetic field saturation.In this paper, the results of the tank fabrication and quadrupole magnet test are presented.  
 
TUPLT103 Possibilities for Experiments with Rare Radioactive Ions in a Storage Ring Using Individual Injection septum, gun, booster, optics 1393
 
  • A.O. Sidorin, I.N. Meshkov, A.O. Sidorin, A. Smirnov, E. Syresin, G.V. Troubnikov
    JINR, Dubna, Moscow Region
  • T. Katayama
    CNS, Saitama
  • W. Mittig, P. Roussel-Chomaz
    GANIL, Caen
  A radioactive ion beam produced at a target bombarded with a primary beam has after a fragment separator a relatively large emittance and small production rate. For instance, typical flux of 132Sn isotope at the exit of fragment-separator is about 5×105 ions/s. Conventionally used scheme of the ion storage in a ring based on multitutrn injection and (or) RF stacking and stochastic cooling application can not provide a high storage rate at so pure intensity especially for short lived isotopes. In this report we discuss an alternative storage scheme which is oriented to the continuous ion beam from fragment separator at production rate of 104 ions/s or even less. It is based on the fact, that at low production rate the parameters of each particle can be measured individually with rather high accuracy. The particle trajectory can be individually corrected in a transfer channel from fragment separator to the storage ring using system of fast kickers. A fast kicker in the ring synchronized with a circulating bunch provides continuous injection of the ions. The scheme permits to store the ion number required for precise mass measurements and internal target experiment. A hope to obtain large luminosity of ion-electron collisions is related with a possibility of the ion beam crystallization at small particle number.  
 
TUPLT104 Particle Dynamics in the Low Energy Positron Toroidal Accumulator: First Experiments and Results electron, gun, booster, optics 1396
 
  • G.V. Troubnikov, V. Antropov, E. Boltushkin, V. Bykovsky, A.I. Ivanov, S. Ivashkevich, A. Kobets, I.I. Korotaev, V. Lohmatov, I.N. Meshkov, D. Monahov, V. Pavlov, R. Pivin, I.A. Seleznev, A.O. Sidorin, A. Smirnov, E. Syresin, S. Yakovenko
    JINR, Dubna, Moscow Region
  The project of Low Energy Particle Toroidal Accumulator (LEPTA) is dedicated to construction of a positron storage ring with electron cooling of positrons circulating in the ring. Such a peculiarity of the LEPTA enables it automatically to be a generator of positronium (Ps) atoms, which appear in recombination of positrons with cooling electrons inside the cooling section of the ring. The project has a few goals: to study electron and positron dynamics in the ring (particle motion in the horizontal and vertical planes are coupled contrary to of classic cycle accelerators), to set up first experiments with Ps in flight; Magnetic measurements of main LEPTA elements are performed. Several elements : kicker, injection system of electron beam, helical quadrupole, septum magnet are tested and expected design parameters were achieved for those elements. The investigations of electron beam dynamics are started. First results of experiments with circulating electron beam are presented and discussed in this article. Several beam diagnostic methods for studying of strong coupled motion of charged particles are proposed and tested.  
 
TUPLT105 Measurement of Activation Induced by an Argon Beam in a Copper Target at the SIS18 electron, gun, booster, optics 1399
 
  • A. Fertman, A. Golubev, M. Prokuronov, B.Y. Sharkov
    ITEP, Moscow
  • G. Fehrenbacher, R.W. Hasse, I. Hofmann, E. Mustafin, D. Schardt, K. Weyrich
    GSI, Darmstadt
  Results of the measurement of activation induced by Argon beam with energies of E=100,200,800 MeV/u in the copper target are presented. The densities of various radioactive isotopes are derived from the measurements. Long-time prediction of radioactivity and accumulated doses in the accelerator equipment is calculated.  
 
TUPLT113 Technicalities for a Novel Medium Energy Ion Accelerator electron, focusing, linac, gun 1411
 
  • V. Gorev
    RRC Kurchatov Institute, Moscow
  Transmutation of radioactive waste,high-intensity pulsed sources of fast neutrons,problem of inertially-confined fusion and a lot of different problems of science and technology put increased demands on the linear high power medium energy proton and heavy ion accelerators.But these accelerators are presently massive,huge and very expansive,which restrict now and in a near future their wide use and motivates the study of altenetive methods to achieve the design current,power and economic characteristics.This report decribes the present reseach on attaining high power medium energy ion beams,using novel idea for accelerator design.Theoretical proposal and preliminary conceptual design for the accelerator,based on a principle of free flying ion emitter("ballistic anode"),were discussed first a few years ago.The principle involves a high potencial difference generated only for a short time in the special vacuum chamber,but not steady-state conditions.Now,we would like to discuss next problems:1.technicalities of the ballistic anode design,both for proton and heavy ion beams generation.2 pulse power multiplication.3.high current sources for charge pumping of the ballistic anode.4 experimental modelling.  
 
TUPLT117 Test of Materials for the High Temperature Intense Neutron Target Converter focusing, linac, gun, booster 1413
 
  • K. Gubin, M. Avilov, S. Fadeev, A. Korchagin, A. Lavrukhin, P.V. Logatchev, P. Martyshkin, S.N. Morozov, S. Shiyankov
    BINP SB RAS, Novosibirsk
  • J. Esposito, L.B. Tecchio
    INFN/LNL, Legnaro, Padova
  Nowadays in LNL INFN (Italy) the project for gain and study of short-lived radioactive isotopes is in progress [1]. The intense neutron target is required for these goals. In BINP, Russia, the design of high temperature target cooled by radiation is proposed. Presented paper describes the results of preliminary test of materials for the target converter: MPG6-brand graphite, graphite material on the basis of 13C, boron carbide, glassy carbon. Test included the distributed heating over volume of samples with the electron beam up to conditions, simulating the converter working regime (heating power density up to 1300 W/cm2, temperature up to 20000C, temperature gradient up to 1000C/mm). Graphite materials show its adaptability under conditions specified.  
 
TUPLT118 Test of Construction for High Temperature Intense Neutron Target Prototype focusing, linac, gun, booster 1416
 
  • K. Gubin, M. Avilov, D. Bolkhovityanov, S. Fadeev, A. Lavrukhin, P.V. Logatchev, P. Martyshkin, A.A. Starostenko
    BINP SB RAS, Novosibirsk
  • O. Alyakrinsky, L.B. Tecchio
    INFN/LNL, Legnaro, Padova
  Within the framework of the creation of the high temperature intense neutron target prototype, the thermal tests of the preliminary design were done in BINP. Tests were aimed at experimental definition of temperature and heat flux distribution over the construction, heat transfer via the contact areas between materials selected, specifying the properties of these materials. This paper presents the experimental test results as well as the comparison of experimental data with the results of numerical simulation of the working regimes of the construction.  
 
TUPLT120 Commissioning of Electron Cooler EC-300 electron, focusing, linac, gun 1419
 
  • V.B. Reva, E.A. Bekhtenev, V.N. Bocharov, A.V. Bubley, Y. Evtushenko, A.D. Goncharov, A.V. Ivanov, V.I. Kokoulin, V.V. Kolmogorov, M.N. Kondaurov, S.G. Konstantinov, V.R. Kozak, G.S. Krainov, Ya.G. Kruchkov, E.A. Kuper, A.S. Medvedko, L.A. Mironenko, V.M. Panasyuk, V.V. Parkhomchuk, K.K. Schreiner, B.A. Skarbo, A.N. Skrinsky, B.M. Smirnov, M.A. Vedenev, R. Voskoboinikov, M.N. Zakhvatkin, N.P. Zapiatkin
    BINP SB RAS, Novosibirsk
  • J. Li, W. Lu, L.J. Mao, Z.X. Wang, X.B. Yan, X.D. Yang, J.H. Zhang, W. Zhang, H.W. Zhao
    IMP, Lanzhou
  The article deals with the commissioning of electron cooler EC-300. It was designed and manufactured for CSR experiment (IMP, Lanzhou, China) by BINP, Russia. The energy of electron beam is up to 300 keV, the electron current is up to 3 A, the magnetic field in the cooling section is up to 1.5 kG. The major innovation of the cooler is the variable profile of electron beam, the electrostatic bends of the electron beam and the system of the magnetic field correction. During commissioning the linearity of the magnetic field 10-6 was obtained, the recuperation efficiency was observed up 10-6 , the pressure of residual gas in the vacuum chamber was 5? 10-11 torr during operation with the electron beam. The CSRe cooler for IMP is a new step at cooling technique and the first results achieved during commissioning are very interesting for accelerator physics.  
 
TUPLT139 Extending the Duty Cycle of the ISIS H Minus Ion Source, Thermal Considerations target, bunching, optics, injection 1452
 
  • D.C. Faircloth, J.W.G. Thomason
    CCLRC/RAL/ISIS, Chilton, Didcot, Oxon
  The ISIS H minus ion source is currently being developed on the Ion Source Development Rig (ISDR) at Rutherford Appleton Laboratory (RAL) in order to meet the requirements for the next generation of high power proton drivers. One key development goal is to increase the pulse width and duty cycle, but this has a significant effect on ion source temperatures if no other changes are made. A Finite Element Analysis (FEA) model has been produced to understand the steady state and dynamic thermal behavior of the source, and to investigate the design changes necessary to offset the extra heating.  
 
TUPLT140 Redesign of the ISIS Main Magnet Power Supply Storage Choke target, bunching, optics, injection 1455
 
  • A.J. Kimber, J.W. Gray, A. Morris
    CCLRC/RAL/ISIS, Chilton, Didcot, Oxon
  The ISIS facility, based at the Rutherford Appleton Laboratory in the UK, provides intense pulsed neutron and muon beams for condensed matter studies. As part of the facilities upgrade and refurbishment program, the 1MJ storage choke which forms part of the main magnet power supply system, will be replaced with a number of smaller units. The present storage choke, which consists of a split secondary winding transformer, is incorporated into a series-parallel resonant circuit known as the 'white circuit'. This circuit ensures that each magnet receives identical currents, but is not subjected to excessive voltages. Although the storage choke is essentially a transformer, its secondary magnetising inductance is relatively low and a precisely defined value. This paper discusses the design and development of ten smaller units which will eventually replace the present equipment, and the testing of a one fifth scale model, which will be used to prove the technology.  
 
TUPLT175 Operation of the SNS Ion Source at High Duty-Factor focusing, bunching, betatron, beamloading 1538
 
  • R.F. Welton, T.A. Justice, S.N. Murray, M.P. Stockli
    ORNL/SNS, Oak Ridge, Tennessee
  • R. Keller
    LBNL/AFR, Berkeley, California
  The ion source for the Spallation Neutron Source* (SNS) is a radio frequency, multi-cusp, source designed to deliver ~ 45 mA of H- with a normalized rms emittance of less than 0.2 pi mm mrad to the SNS accelerator. Once the SNS is fully operational a beam current duty factor of 6% (1 ms pulse length, repetition rate of 60 Hz) will be required from the ion source. To date, the source has been utilized in the early commissioning of the SNS accelerator and has already demonstrated stable, satisfactory operation at beam currents of ~30 mA with duty factors of ~0.1% for operational periods of several weeks. This work summarizes the results of a series of lifetime tests performed at a dedicated ion source test facility where the source was pushed closer to the operational goal of 6% duty factor.  
 
TUPLT177 RHIC Optics Measurements at Different Working Point focusing, bunching, betatron, beamloading 1541
 
  • R. Calaga, M. Bai, S. Peggs, T. Roser, T. Satogata
    BNL, Upton, Long Island, New York
  Working point scans at RHIC were performed during 2004 to determine the effect on lifetime and luminosity. Linear optics were measured for different working point tunes by exciting coherent oscillations with the aid of RHIC AC dipoles. Two methods to measure the beta functions and phases are presented and compared: a conventional technique, and a new method based on singular value decomposition (SVD). The performance of a 3-bump beta wave algorithm to identify quadrupole error sources is also presented.  
 
TUPLT179 Mini-bunched and Micro-bunched Slow Extracted Beams from the AGS focusing, bunching, betatron, beamloading 1544
 
  • K.A. Brown, L. Ahrens, J.M. Brennan, J. Glenn, M. Sivertz, N. Tsoupas
    BNL, Upton, Long Island, New York
  • S.R. Koscielniak
    TRIUMF, Vancouver
  BNL's AGS has a long history of providing slow extracted proton beams to fixed target experiments. This program of providing high quality high intensity beams continues with two new experiments currently being designed for operation at the AGS; both of these new experiments require slow extracted beam, but with an added requirement of those beams experiments require slow extracted beam, but with an added requirement of those beams experiments and initial tests have been performed. In this report we will describe the beam requirements for the two experiments, and present results of detailed simulations and initial beam tests.  
 
TUPLT180 Results of the NASA Space Radiation Laboratory Beam Studies Program at BNL focusing, bunching, betatron, radiation 1547
 
  • K.A. Brown, L. Ahrens, R.H. Beuttenmuller, I.-H. Chiang, D.C. Elliott, D. Gassner, Z. Li, I. Marneris, J. Mead, J. Morris, D. Phillips, V. Radeka, A. Rusek, N. Tsoupas, B. Yu, K. Zeno
    BNL, Upton, Long Island, New York
  The NASA Space Radiation Laboratory (NSRL) was constructed in collaboration with NASA for the purpose of performing radiation effect studies for the NASA space program. The NSRL makes use of heavy ions in the range of 0.05 to 3 GeV/n slow extracted from BNL's AGS Booster. The purpose of the NSRL beam studies program is to develop a clear understanding of the beams delivered to the facility, to fully characterize those beams, and to develop new capabilities in the interest of understanding the radiation environment in space. In this report we will describe the first results from this program.  
 
WEODCH02 Interaction of Stored Ions with Electron Target in Low Energy Electrostatic Ring electron, radiation, focusing, kicker 162
 
  • E. Syresin
    JINR, Dubna, Moscow Region
  • K. Noda
    NIRS, Chiba-shi
  • T. Tanabe
    KEK, Ibaraki
  The KEK electrostatic ring is used for investigations of molecular, bimolecular and DNA ions. The electron target installed in this ring has same construction as usual electron cooler. The interaction of stored ions with the electrons increases the ion lifetime at electron cooling caused by a suppression of the ion scattering on the residual gas atoms. The proton lifetime of 2 s was increased in the experiments by factor 2 at the electron cooling with the electron beam current of 0.2 mA, the proton energy of 20 keV and the residual gas pressure of 0.04 nTorr. However the electron-ion interaction can decrease the ion lifetime caused by an excitation of the transverse instability produced by an intensive electron beam. So in the KEK electrostatic ring the proton lifetime is reduced to 1.7 s at detuning of electron acceleration voltage from nominal cooler value on 0.4 V. The simulation of electron cooling and transverse instability of the light and DNA ions are discussed in this report.  
Video of talk
Transparencies
 
WEXLH01 Non-destructive Beam Measurements electron, radiation, focusing, kicker 165
 
  • M. Bai
    BNL, Upton, Long Island, New York
  In high energy accelerators especially storage rings, non-destructive beam measurements are highly desirable to minimize the impact on the beam quality. In principle, the non-destructive tools can be either passive detectors like Schottky, or active devices which excite either longitudinal or transverse beam motions for the corresponding measurements. An example of such a device is ac dipole, a magnet with oscillating field, which can be used to achieve large coherent betatron oscillations. It has been demonstrated in the Brookhaven AGS that by adiabatically exciting the beam, the beam emittance growth due to the filamentation in the phase space can be avoided. This paper overviews both techniques in general. In particular, this paper also presents the beam tune measurement with Schottky detector, phase advance measurement as well as non-linear resonance measurements with the ac dipoles in the Brookhaven RHIC.  
Video of talk
Transparencies
 
WEOALH01 Particle-in-cell Beam Dynamics Simulations electron, radiation, focusing, kicker 170
 
  • T. Lau, E. Gjonaj, T. Weiland
    TEMF, Darmstadt
  We describe the application of the Conformal Finite Integration Technique (CFIT) in the time-domain to beam dynamics simulations with the Particle-In-Cell (PIC) method. The conformal method results in a more accurate field solution for complicated geometries than the traditional FIT approach. For long-time simulations we investigate several methods for the suppression of the spurious noise, typically emerging in PIC simulations. The results are compared with the analytical solution for a bunch in a semi-infinite waveguide for each of the presented methods. As a realistic example simulations for the RF-Gun installed at Photo Injector Test Facility in DESY Zeuthen (PITZ) will be presented.  
Video of talk
Transparencies
 
WEOALH02 Multiturn Extraction Based on Trapping in Stable Islands at CERN PS: Recent Measurement Advances electron, radiation, focusing, kicker 173
 
  • M. Giovannozzi, R. Cappi, S.G. Gilardoni, M. Martini, E. Métral, A. Sakumi, R.R. Steerenberg
    CERN, Geneva
  • A.-S. Müller
    FZK-ISS-ANKA, Karlsruhe
  Recently a novel approach to perform multi-turn extraction was proposed based on beam splitting in the transverse phase space by means of trapping inside stable islands. During the year 2002 run, preliminary measurements at the CERN Proton Synchrotron with a low-intensity, single-bunch, proton beam, confirmed the possibility of generating various beamlets starting from a single Gaussian beam. The experimental campaign continued also in the year 2003 run to assess a number of key issues, such as feasibility of trapping with high-intensity beam, capture efficiency, and multi-turn extraction proper. The experimental results are presented and discussed in detail in this paper.  
Video of talk
Transparencies
 
WEOALH03 Installation Strategy for the LHC Main Dipoles electron, radiation, focusing, kicker 176
 
  • S.D. Fartoukh
    CERN, Geneva
  All positions in the LHC machine are not equivalent in terms of beam requirements on the geometry and the field quality of the main dipoles. In the presence of slightly or strongly out-of tolerance magnets, a well-defined installation strategy will therefore contribute to preserve or even optimize the performance of the machine. In view of present state of the production, we have anticipated a list of potential issues (geometry, transfer function, field direction and random b3) which, combined by order of priority, have been taken into account to define a robust installation algorithm for the LHC main dipoles. Among the different possible strategies, the proposed one has been optimised in terms of simplicity and flexibility in order not to slow down and complicate the installation process. Its output is a prescription for installing the available dipoles in sequence while reducing to an absolute minimum the number of holes required by geometry or field quality issues.  
Video of talk
Transparencies
 
WEYLH01 Emittance Control for Very Short Bunches electron, focusing, kicker, bunching 179
 
  • K.L.F. Bane
    SLAC, Menlo Park, California
  Many recent accelerator projects call for the production of high energy bunches of electrons or positrons that are simultaneously short, intense, and have small emittances. Two examples of such projects are linear colliders, such as the GLC/NLC, and Self-Amplified Spontaneous Emission (SASE) FEL's, such as the Linac Coherent Light Source (LCLS). A major challenge in such projects is keeping in check forces that increase short bunch emittances in accelerator components, such as: wakefields of accelerator structures, collimators, and surface roughness, and coherent synchrotron radiation (CSR). We describe such forces and their control.  
Video of talk
Transparencies
 
WEYLH02 Single Particle Linear and Non-linear Dynamics electron, focusing, kicker, bunching 184
 
  • Y. Cai
    SLAC, Menlo Park, California
  I will give a comprehensive review of existing particle tracking tools to assess long-term particle stability for small and large accelerators in the presence of realistic magnetic imperfections and machine misalignments. The emphasis will be given to the tracking and analysis tools based upon the differential algebra, Lie operator, and "polymorphism". Using these tools, a uniform linear and non-linear analysis will be outlined as an application to the normal form. Finally I will compare simulation results with observations in existing circular accelerators. "Model independent analysis" will be treated as an example for measuring machine optics.  
Video of talk
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WEYLH03 Collective Effects and Instabilities in Space Charge Dominated Beams focusing, kicker, bunching, beamloading 189
 
  • J.A. Holmes
    ORNL/SNS, Oak Ridge, Tennessee
  Significant progress in the detailed computational study of collective beam dynamics is being driven by the spectacular increase in computer power. To take advantage of this, sophisticated physics models are being applied to ever more realistic and detailed situations, so that it is no longer necessary to restrict computer studies to highly idealized depictions of beam dynamics questions. This presentation will illustrate the application of a number of collective beam dynamics models to a range of accelerator physics problems in high intensity proton rings. In particular, we will consider the effects of space charge, transverse and longitudinal impedances, and electron cloud formation on beam parameters, stability, halo formation, collimation and losses, and possible equilibrium configurations. Examples will be taken from PSR, the CERN PS Ring, and SNS.  
Video of talk
Transparencies
 
WEILH00 Industrial Involvement in EC Supported Accelerator R&D in the 6th Framework Programme and in Preparing Large Scale Accelerator Projects focusing, kicker, bunching, beamloading 194
 
  • D. Proch
    DESY, Hamburg
  The presentation will cover industrial involvement in EC supported accelerator R&D in the 6th framework programme and in preparing large scale accelerator projects (TESLA).  
Video of talk
Transparencies
 
WEILH01 Methods for Successful Technology Transfer in Physics focusing, kicker, bunching, beamloading 198
 
  • K.N. Hill
    Qi3, Cambridge
  The development of accelerators for scientific research generates significant technologies of interest to industry. As physicists and technologists we also require strong partnerships with industry in order that it may supply us with the instrumentation and systems we require for new apparatus. We will discuss the methods developed for the UK Particle Physics and Astronomy Research Council (PPARC) and applied on behalf of CERN to encourage successful knowledge transfer into industry. Case studies will illustrate the hurdles that must be surmounted and effective methods to build successful partnerships, licensing opportunities and spinout companies. Factors considered will include assessment of the commercial potential of technologies, personal motivations for academic/industrial collaboration, sources of funding, and effects on the academic groups involved in knowledge transfer activity.  
Video of talk
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WEILH03 Industrial Response to RF Power Requirements focusing, kicker, bunching, beamloading 202
 
  • M. Wilcox
    e2v technologies, Chelmsford, Essex
  Today, high-energy physics machines are broadly speaking of two kinds. Some machines are dedicated to providing a service using particle acceleration as an intermediate step (light sources, neutron spallation sources, cancer therapy equipment etc.)and occasionally, particle colliders are built in which the particles are used directly to probe the nature and origin of matter. The latter machines have developed to a point where the technology needed is often at the extreme edge of what is understood, let alone of what is currently achievable. In addition the scope of supply and the level of equipment integration demanded of industry is increasing as RF skills become scarcer. This reduces the supplier base so placing greater demands on those remaining. To help offset this problem, companies should be brought 'inside' the project team at an early stage of the machine design so that better account can be taken of limitations, preferences and competing obligations that the companies may have. A more collaborative approach should result in projects being completed in a shorter time, to a lower cost, and with a more certain outcome.  
Video of talk
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WEILH04 Industrial Involvement in the Construction of Synchrotron Light Sources focusing, kicker, bunching, beamloading 206
 
  • M.S. de Jong
    CLS, Saskatoon, Saskatchewan
  The design, construction and commissioning of a modern third-generation synchrotron light source facility is a major project, costing hundreds of millions of dollars. The delivery of these new facilities, usually on a fixed budget and schedule, requires an effective working relationship with all suppliers providing equipment and services to the project. This talk will examine some of the key issues in developing and maintaining such a relationship with industry during the construction of a third-generation synchrotron light facility. These issues include project planning, the contract specification, the tendering process, communication techniques over the contract term, and other aspects of contract control. Examples, primarily from our experience constructing the Canadian Light Source but also from other new facilities planned or under construction, will be used to examine the effectiveness of various approaches to working with industry.  
Video of talk
Transparencies
 
WEPKF001 Diffusion Welding of Heterogeneous Materials in Accelerator Technique focusing, kicker, bunching, beamloading 1586
 
  • V.S. Avagyan
    CANDLE, Yerevan
  • A. Babayan, N.M. Dobrovolski, I.V. Tunyan
    YerPhI, Yerevan
  The results of the joining of heterogeneous materials, such as titanium with stainless steel (serviceable at 4.2 K), copper with aluminum, titanium with niobium (this work has been carried out for TESLA project), stainless steel with aluminum, copper with stainless steel are presented in this work.  
 
WEPKF002 Magnets for the CANDLE Booster Synchrotron, Design and Prototyping focusing, kicker, bunching, beamloading 1588
 
  • V.G. Khachatryan, Y.L. Martirosyan, A. Petrosyan
    CANDLE, Yerevan
  CANDLE booster synchrotron magnetic lattice contains 48 dipoles of H-shape. Detailed magnetic and mechanical design of those magnets is performed within the framework of the project. In this report, the design considerations of the dipole magnet, including the magnetic field simulation is presented. The main features of the fabricated first prototype dipole magnet are discussed.  
 
WEPKF003 Design of the End Magnets for the IFUSP Main Microtron focusing, kicker, bunching, beamloading 1591
 
  • M.L. Lopes, A.A. Malafronte, M.N. Martins, J. Takahashi
    USP/LAL, Bairro Butantan
  • K.-H. Kaiser
    IKP, Mainz
  The Instituto de Física da Universidade de São Paulo (IFUSP) is building a two-stage 31 MeV continuous wave (cw) racetrack microtron. In this work we describe the characteristics of the end magnets for the IFUSP main microtron. The magnets are part of the main acceleration stage, which raises the energy from 4.9 to 31 MeV. We are studying the possibility of increasing the energy up to 38 MeV, so the magnets should have approximately 2x1 m2 region of useful field. The dipoles have a 0.1410 T magnetic field and 1 part in 1000 homogeneity without correcting devices. Using a 2D magnetic field code (FEMM), we illustrate the use of homogenizing gaps with different forms and non parallel pole faces to achieve the necessary homogeneity. The use of clamps to produce reverse fields to reduce the vertical defocusing strength on the beam is also described. In order to calculate the beam trajectories and to evaluate the magnetic field homogeneity within the useful region, a 3D magnetic field software (TOSCA) was used.  
 
WEPKF004 Magnetic Quadrupole Lenses for the IFUSP Microtron focusing, kicker, bunching, quadrupole 1594
 
  • T.F. Silva, M.L. Lopes, A.A. Malafronte, M.N. Martins, P.B. Rios, J. Takahashi
    USP/LAL, Bairro Butantan
  The Instituto de Física da Universidade de São Paulo (IFUSP) is building a two-stage 31 MeV continuous wave (cw) racetrack microtron. In this work, we describe the design of the magnetic quadrupole lenses for the IFUSP microtron. The design consists of a laminar structure divided in four equal pieces. Because each piece corresponds to an individual pole, it eases the assembling of the coils and the installation of the quadrupole on the beam transport line without breaking the vacuum. Due to the fact that the quadrupole is laminated along the longitudinal axis, it is possible to change the length of a given lens by adding or subtracting foils. We also present the magnetic field distribution calculated using the POISSON code. A prototype presented good mechanical rigidity and thermal performance, showing that a refrigeration system is not necessary. The magnetic measurements show that the field distribution within the region of interest agrees with the POISSON simulation.  
 
WEPKF005 Pressure Field Distribution in a Cylindrical Geometry with Arbitrary Cross Section focusing, kicker, bunching, vacuum 1597
 
  • F.T. Degasperi
    FATEC-SP, Sao Paulo, SP
  • M.N. Martins, J. Takahashi
    USP/LAL, Bairro Butantan
  • L.L. Verardi
    IBILCE - UNESP, Sao Jose do Rio Preto, SP
  This work presents analytical and numerical results for the pressure field distribution along the axis of tubular geometries with arbitrary axisymmetric cross sections with an arbitrary time- and position-dependent gas source. Several areas of applied physics deal with problems in high-vacuum and ultra high-vacuum technology that present tubular form. In many cases one finds tubes with non uniform cross sections, like parts of particle accelerators, colliders, storage rings, gravitational antennas, and electron devices, like klystrons, electron microscopes, and also parts of vacuum systems in general, for instance, bellows, conical pipes and others. In this work one can get the detailed pressure distribution is not determined. This work presents and describes in detail the pressure field in tubes with arbitrary axisymetric cross sections. Details of the mathematical and physical formulations and modeling are given; specific conductance and specific throughput are defined; and a detailed discussion about the boundary conditions is given. These concepts and approach are applied to usual realistic cases, like conical tubes and bellows, with typical laboratory dimensions.  
 
WEPKF006 Field Quality and Hysteresis of LHC Superconducting Corrector Magnets focusing, kicker, bunching, vacuum 1600
 
  • A. Santrich Badal, M. Allitt, C. Giloux, M. Karppinen, A.M. Lombardi, V. Remondino, W.  Venturini Delsolaro, R. Wolf
    CERN, Geneva
  • M. Bagre, P. Khare, T. Maurya, A. Puntambekar
    CAT, Indore (M.P.)
  The Large Hadron Collider (LHC) will use some 6400 superconducting corrector magnets. There are 19 corrector types. These are assembled 14 different types of magnets of which 4 are nested. They are being manufactured by 4 firms in Europe and 3 in India. The magnetic field quality is measured at room temperature by 12 magnetic measurement benches employed by the corrector manufacturers. CERN performs magnetic measurement at 4.2K and at 1.9K on a small subset of corrector magnets. The paper discusses the correlation between the warm and cold field measurements. The field quality is compared to the magnet design expectations and to the target field quality for LHC. Many corrector circuits will be powered in a way which cannot be predicted before LHC will start operation and which even then may change between physics runs. The measured magnetic hysteresis and its influence on possible setting errors during operation is discussed, in particular for the orbit correctors and the tuning/trim quadrupole magnet circuits.  
 
WEPKF007 Vacuum Characterisation of a Woven Carbon Fiber Cryosorber in Presence of H2 focusing, kicker, bunching, vacuum 1603
 
  • V. Baglin, H. Dupont, T. Garcin
    CERN, Geneva
  Some of the cryogenic components in the Large Hadron Collider (LHC) will operate at 4.5 K. The H2 desorption will rapidly increase to the saturated vapour pressure, 3 orders of magnitude larger than the design pressure. Therefore, the use of cryosorbers is mandatory to provide the required pumping capacity and pumping speed. The behaviour of a woven carbon fiber to be used as a cryosorber has been studied under H2 injection. The pumping speed and capacity measured in the range 6 to 30 K are described. Observations made with an electron microscope are shown. A proposed pumping mechanism and the implications to the LHC are discussed.  
 
WEPKF008 A Strategy for Sampling of the Field Quality of the LHC Dipoles focusing, kicker, bunching, vacuum 1606
 
  • L. Bottura, S.D. Fartoukh, V. Granata, E. Todesco
    CERN, Geneva
  We have measured the magnetic field of a considerable fraction of the superconducting LHC main dipoles, of the order of 300 in warm conditions and 100 in cold conditions. All LHC dipoles will be measured in warm conditions at the manufacturers to steer the production inside the acceptance limits imposed by beam dynamics. Using the available data we analysed the distributions of the main field and higher order field errors in warm and cold conditions, as well as the distribution of the warm-to-cold correlation. Based on this analysis we predict the minimum number of magnets that should be measured in cold conditions in order to guarantee that (1) the production is controlled within the specified limits (2) the field is known to a sufficient level for a sound installation and (3) the uncertainty on the knowledge of the magnetic field of the LHC dipoles is small enough for the commissioning of the accelerator and to insure operation of the machine in any condition, including higher energy. The main outcome of this analysis is that cold measurements on a fraction of the order of one third of the total production, i.e. approximately 400 dipoles, will be sufficient to achieve the above objectives.  
 
WEPKF009 A Scaling Law for Predicting Snap-back in Superconducting Accelerator Magnets focusing, kicker, bunching, vacuum 1609
 
  • T. Pieloni, L. Bottura, S. Sanfilippo
    CERN, Geneva
  • G. Ambrosio, P. Bauer
    Fermilab, Batavia, Illinois
  • M. Haverkamp
    METROLAB, Plan-les-Ouates
  The decay of the sextupole component in the bending dipoles during injection and the subsequent snap-back at particle acceleration are issues of common concern, albeit at different levels of criticality, for all superconducting colliders built (Tevatron, HERA, RHIC) or in construction (LHC) to date. The main difficulty is the correction of the relatively large and fast sextupole change during snap-back. Motivated by the above considerations, we have conducted an extended study of sextupole snap-back on two different magnet families, the Tevatron and the LHC bending dipoles, using the same measurement method. We show in this paper that it is possible to generalise all the results obtained by using a simple, exponential scaling law. Furthermore, we show that for magnets of the same family the parameters of the scaling law correlate linearly. This finding could be exploited during accelerator operation to produce accurate forecast of the snap-back correction based solely on beam-based measurements.  
 
WEPKF010 Design of an Automatic System for the Electrical Quality Assurance during the Assembly of the Electrical Circuits of the LHC focusing, kicker, bunching, vacuum 1612
 
  • D. Bozzini, V. Chareyre, A. Jacob, K.H. Mess, S. Russenschuck, R. Solaz Cerdan
    CERN, Geneva
  During the assembly of the LHC one of the challenges will be the correct wiring of the 1712 circuits powering the 10094 magnet units, for which all-together 70000 splices have to be done. Considering the complexity of the electrical scheme the risk of wrong wiring is high. Errors, if not detected during the assembly phase, will perturb the LHC operation. A method has been developed to verify automatically the cabling scheme. It first detects the continuity of a portion of circuit and then verifies the correct polarity and type of the magnets in the circuit. A 108-meter LHC cell is the shortest length that can be tested. The system is composed of a unit to be placed at the center of the cell and two de-multiplexers positioned at the extremities of the cell. The central unit contains a data acquisition system where in total 217 signals can be acquired and more than 3000 voltage combinations are possible. Pointing to different databases, a LabVIEW program automatically executes the test procedure, generates, and stores the reports. The hardware and software design, the data flow between databases, and the testing methodology applied to the different circuit types are described.  
 
WEPKF011 Performance of the Superconducting Matching Quadrupoles for the LHC Insertions focusing, kicker, bunching, vacuum 1615
 
  • N. Catalan-Lasheras, G. Kirby, R. Ostojic, J.C. Perez, H. Prin, W.  Venturini Delsolaro
    CERN, Geneva
  The optics flexibility of the LHC insertions is provided by the individually powered quadrupoles in the dispersion suppressors and matching sections. These units comprise special quadrupole magnets of the MQM and MQY type and range in length from 5.4 m to 11.4 m. In total, 82 insertion quadrupoles will be assembled at CERN. In this paper we present the advance in construction and report on the performance of the first series built quadrupoles. In particular, we present the quench performance of the individual magnets and alignment measurements of the cold masses, and discuss the field quality trends and possible implications.  
 
WEPKF012 LHC Dipole Axis, Spool Piece Alignment and Field Angle in Warm and Cold Conditions focusing, kicker, bunching, vacuum 1618
 
  • M. Coccoli, M. Buzio, J. Garcia Perez
    CERN, Geneva
  The installation and commissioning of the LHC dipoles requires the knowledge of the magnetic axis and of the spool piece corrector alignment at the operating conditions. The installation is based at present on the use of geometric information derived from mechanical measurements performed in warm conditions, with the assumption that the geometric and magnetic axis are coincident. Any discrepancies between mechanical and magnetic axis and unforeseen geometry variations from ambient to cold operating temperature can introuduce important uncertaintes in the prediction of the alignment at operational conditions. Such prediction is studied through correlations between measurements performed at room and liquid helium temperature. A statistic analysis of the measurement data available is presented showing uncertainties on the correctors alignment. They are compared with beam-based specifications of the positioning of the spool piece.  
 
WEPKF014 Magnetic Field Tracking Experiments for LHC focusing, kicker, bunching, vacuum 1621
 
  • V. Granata, J. Billan, F. Bordry, L. Bottura, P. Coutinho Ferreira, E. Effinger, G. Fernqvist, P. Galbraith, Q. King, J. Pett, A. Raimondo, A. Rijllart, H. Thiesen
    CERN, Geneva
  At the Large Hadron Collider (LHC) at CERN one of the fundamental requirements during the energy ramp is that the ratio between the field produced by the quadrupoles and the field in the dipoles remains constant in order to minimize the variation of the betatron tune that could induce particle loss. With a series of tracking experiments it has been demonstrated that this ratio can be maintained constant to better than 10-4 throughout the same current ramp as foreseen for the LHC. A technique has been developed to optimise the dipole and quadrupole current ramps to obtain the required ratio of B2/B1. Measurements performed by modulating the current with a harmonic function (so-called k-modulation) demonstrated that it is possible to modulate the strength of an individual quadrupole to determine the magnetic center through beam-based measurements.  
 
WEPKF015 The Design of Cold to Warm Transitions of the LHC focusing, kicker, bunching, alignment 1624
 
  • J. Knaster, B.J. Jenninger, D.R. Ramos, G. Ratcliffe, R. Veness
    CERN, Geneva
  The Large Hadron Collider (LHC) is the next accelerator being constructed on the CERN site to be operational in 2007. It will accelerate and collide 7 TeV protons and heavier ions up to lead. More than 2000 cryomagnets working at 1.9 or 4.5 k will form part of the magnetic lattice of the LHC. The transitions from cryogenic temperatures to room temperature zones will be achieved by 200 cold to warm transitions (CWTs). The CWTs will compensate for longitudinal and transversal displacements between beam screens and cold bores, ensuring vacuum continuity without limiting the aperture for the beam. The transverse impedance contribution is kept below the assigned total budget of 1 MΩ/m by means of a 5 μm thick Cu coating that also minimises the dynamic heat load through image currents. Tests have been performed that confirm that the static heat load per CWT to the cryomagnets remains below 2.5 W, hence validating the design.  
 
WEPKF016 Instrumental Uncertainty in Measuring the Geometry of the LHC Main Dipoles. focusing, kicker, bunching, alignment 1627
 
  • M. La China, G. Gubello, W. Scandale
    CERN, Geneva
  In the Large Hadron Collider 1232 superconducting dipoles will bend the two 7 TeV energy beams along a 27 km-circumference trajectory. The series production (assigned to three European firms) will require a well-defined procedure to check, in every magnet, the respect of the dimensional specifications. To verify the tolerances of few tenths of millimeter over the 15-meter length in each cold mass, a laser tracker is necessarily used. To access the two beam apertures and to increase the measurement accuracies, the laser tracker is placed in different stations around the dipole defining a 'multi-station measuring procedure'. The noise affecting all the data taken so far suggested a careful analysis of the procedure itself. Through the computer modeling (based on a Monte Carlo algorithm), the statistical error was quantified and compared to the experimental error. From this comparison the critical aspects of low accuracy rooted in the multi-station procedure were better understood, allowing the optimization of the procedure itself for the forthcoming series production.  
 
WEPKF018 Beam-loss Induced Pressure Rise of LHC Collimator Materials Irradiated with 158 GeV/u In49+ Ions at the CERN SPS focusing, kicker, undulator, bunching 1633
 
  • E. Mahner, I. Efthymiopoulos, J. Hansen, E. Page, H. Vincke
    CERN, Geneva
  During heavy ion operation, large pressure rises, up to a few orders of magnitude, were observed at CERN, GSI, and BNL. The dynamic pressure rises were triggered by lost beam ions that impacted onto the vacuum chamber walls and desorbed about 104 to 107 molecules per ion. The deterioration of the dynamic vacuum conditions can enhance charge-exchange beam losses and can lead to beam instabilities or even to beam abortion triggered by vacuum interlocks. Consequently, a dedicated measurement of heavy-ion induced molecular desorption in the GeV/u energy range is important for LHC ion operation. In 2003, a desorption experiment was installed at the SPS to measure the beam-loss induced pressure rise of potential LHC collimator materials. Samples of bare graphite, sputter coated (Cu, TiZrV) graphite, and 316 LN stainless steel, were irradiated under grazing angle with 158 GeV/u indium ions. After a description of the new experimental set-up, the results of the pressure rise measurements are presented, and the derived desorption yields are compared with data from other experiments.  
 
WEPKF019 Magnetic Measurement Systems for the LHC Dipole Assembly Firms focusing, kicker, undulator, bunching 1636
 
  • H. Reymond, J. Billan, J. Garcia Perez, D. Giloteaux, A. Raimondo, V. Remondino, A. Rijllart
    CERN, Geneva
  The LHC lattice superconducting dipole magnets are actually under construction in three European industries. Due to the extremely high magnet performance required for the LHC, these magnets have to be built with high accuracy during all the steps of their assembling. In order to detect defects in the earliest production phases and to ensure the quality of the magnetic field as specified by the CERN contracts, dedicated measurement benches have been built and installed in each industry to validate the magnetic field quality at two important production stages. This paper describes the initial requirements and the implementation of the magnetic measurement systems. Details on the technical solutions, the present status and measurement results are presented.  
 
WEPKF027 R&D Vacuum Issues of the Future GSI Accelerator Facilities kicker, undulator, bunching, beamloading 1657
 
  • H.R. Sprenger, M.C. Bellachioma, M. Bender, H. Kollmus, A. Krämer, J. Kurdal, P.J. Spiller
    GSI, Darmstadt
  The new GSI accelerator facilities are planned to deliver heavy ion beams of increased energy and highest intensity. Whereas the energy is planned to be increased roughly by a factor of 10, the ion beam intensities are planned to be enlarged by three orders of magnitude. To achieve highest beam intensities, medium charged heavy ions (e.g. U28+) are accelerated. Since the ionization cross sections for these ions are comparably high, a UHV-accelerator system with a base pressure in the low 10-12mbar regime is required, even under the influence of ion beam loss induced desorption processes. An intensive program was started to upgrade the UHV system of the existing synchrotron SIS18 (bakeable) and to design and lay out the UHV systems of the future synchrotron SIS100 and SIS300 (mainly cryogenic). The strategy of this program includes basic research on the physics of the ion induced desorption effects as well as technical developments, design and prototyping on bakeable UHV components (vacuum chambers, diagnostics, bakeout-control, pumping speed), collimator for controlled ion beam loss, NEG coating and cryogenic vacuum components.  
 
WEPKF028 High Charge Transfer Operation of Light Trigged Thrystor Crowbars kicker, undulator, bunching, beamloading 1660
 
  • W. Merz
    DESY, Hamburg
  High power klystrons are protected by the application of crowbar switches. The closing switch approach is most commonly used. It is characterized by establishing a short circuit path to bypass the klystron fault current. During short circuit operation the crowbar switch must be capable to carry both puls current of the filter capacitor and follow through current of the high voltage dc power supply. Depending on the main circuit parameters both the capacitor charge and the follow through charge can achieve significant amounts. The application of line controlled and uncontrolled hvdc power converters requires special attention regarding the follow through current charge transfer. This paper presents first practical results of series connected Light Triggered Thyristors (LTT) operating as closing crowbar switches. Measured data are discussed, which have been obtained from the DESY-II installation operating with thyristor controllers and the PETRA installation operating with uncontrolled rectifiers. Beside the puls operation the follow through current capability of the crowbar is pointed out.  
 
WEPLT055 Observation of Ultracold Heavy Ion Beams with Micrometer Size by Scraping focusing, electron, bunching, impedance 1963
 
  • M. Steck, K. Beckert, P. Beller, B.  Franzke, F. Nolden
    GSI, Darmstadt
  The existence of an ordered beam state for low intensity, electron cooled heavy ion beams has been evidenced by a sudden reduction of the momentum spread. The detection of a similar effect in the transverse degree of freedom by non-destructive diagnostics is ruled out by the limited resolution of beam profile detectors. A method to probe the horizontal beam size of an electron cooled beam in a dispersive section has been developed. It is based on beam scraping and allows a resolution on the order of micrometers. This good transverse resolution for the cooled ion beam is achieved by precise changes of the ion energy which is varied by changes of the electron beam energy. The lower resolution limit due to power supply ripple is estimated to be below 1 micrometer. This method evidenced that the reduction of the momentum spread by one order of magnitude coincides with a reduction of the transverse beam emittance by 2-3 orders of magnitude, at least. A horizontal beam radius of a few micrometer could be demonstrated for electron cooled heavy ion beams with less than 1000 particles. This gives new evidence for the formation of an ordered beam arranged as a linear string of ions.  
 
WEPLT056 An Electron Cooling System for the Proposed HESR Antiproton Storage Ring focusing, bunching, impedance, optics 1966
 
  • M. Steck, K. Beckert, P. Beller, A. Dolinskii, B.  Franzke, F. Nolden
    GSI, Darmstadt
  • V.V. Parkhomchuk, V.B. Reva, A.N. Skrinsky, V.A. Vostrikov
    BINP SB RAS, Novosibirsk
  The HESR storage ring in the proposed new international accelerator facility will provide high quality antiproton beams for experiments with an internal target. In order to achieve the design luminosity for collisions with a hydrogen target powerful beam cooling is required. For dedicated experiments ultimate resolution is demanded. Therefore it is foreseen to provide cooled antiproton beams in the energy range 0.8-14 GeV with an energy spread of 100 keV or better. According to computer simulations the required cooling rates can be achieved by electron cooling with an electron current of 1 A. The conceptual design of an electron beam device which is based on electrostatic acceleration of the electrons and their transport in longitudinal magnetic fields into a cooling section with a strong magnetic field of up to 0.5 T will be presented. This design will allow cooling in the magnetized regime in order to reach the required high cooling rates. Some novel features for the generation and regulation of the accelerating voltage and for the beam transport are proposed.  
 
WEPLT118 Performance of the TU/e 2.6 Cell Rf-photogun in the 'Pancake' Regime radiation, sextupole, antiproton, resonance 2125
 
  • S.B. van der Geer, G.J.H. Brussaard, O.J. Luiten, M.J. Van der Wiel
    TUE, Eindhoven
  • G. Pöplau
    Rostock University, Faculty of Engineering, Rostock
  • M.J. de Loos
    PP, Soest
  The 2.6 cell rf-photogun currently in operation at Eindhoven University of Technology has been designed as a booster for a 2 MeV semi-DC accelerator with a field of 1 GV/m. In this paper we present GPT simulation results of the TU/e gun, operated without its pre-accelerator, in the low-charge short-pulse regime. The main part of the paper describes detailed calculations of bunch lengthening due to path-length differences and space-charge effects, making use of high-precision field-maps and the newly developed 3D mesh-based space-charge model of GPT. It is shown that with the present set-up bunches can be produced that are well suited for injection into a planned experiment for controlled acceleration in a plasma-wakefield accelerator.  
 
WEPLT119 Beam Instabilitiy Studies of BEPC and BEPCII radiation, sextupole, antiproton, resonance 2128
 
  • J.Q. Wang, Z.Y. Guo, Y.D. Liu, Q. Qin, Z. Zhao, D.M. Zhou
    IHEP Beijing, Beijing
  BEPC has been well operated for more then 10 years, and it will be upgraded to a double ring electron positron collider using the existing tunnel, namely BEPCII. This paper describes the recent studies on beam instabilities in BEPC for the improvement of its performance as well as for BEPCII. The instabilities caused by impedance and two-stream effect are investigated. The experimental and simulation results are reported.  
 
WEPLT122 Investigation of Microwave Instability on Electron Storage Ring TLS radiation, sextupole, antiproton, resonance 2137
 
  • M.-H. Wang
    NSRRC, Hsinchu
  • A. Chao
    SLAC, Menlo Park, California
  With the planned installation of a superconducting rf system, the new operation mode of TLS, the electron storage ring at NSRRC, is expected to double the beam intensity. Several accelerator physics topics need to be examined. One of these topics concerns the beam instability of single-bunch longitudinal microwave instability. We consider different approaches to measure the effective broad band impedance. We compare these measurement results with each other and to the old data [*]. The new measurements of effective broad band impedance are higher than the old measurement since between these two sets of measurements several narrow gap insertion devices were installed into the storage ring. We calculate the threshold current of microwave instability with a mode-mixing analysis code written by Dr. K. Oide of KEK [**]. We also develop a multi-particle tracking code to simulate the instability. The results of simulation and measurement are compared and discussed. We conclude that the doubling of beam current will not onset the microwave instability even without a Landau cavity to lengthen the bunch.

* M.H. Wang, et al.,"Longitudinal Beam Instability Observation with streak Camera at SRRC", proceeding of 1996 European Particle Accelerator Conference, pp. 1120** K. Oide, "Longitudinal Single-Bunch Instability in Electron Storage Rings", KEK Preprint 90-10

 
 
THPLT033 The Heavy Ion Gantry of the HICAT-facility antiproton, positron, gun, lattice 2547
 
  • U. Weinrich, R. Fuchs
    GSI, Darmstadt
  • P. Emde
    MAN Technologie AG, Mainz
  The Heavy Ion Cancer Therapy Project HICAT at the University Hospital of Heidelberg is under construction. One unique feature of the treatment facility is the first heavy ion gantry in the world. The Gantry will allow the patient treatment with different ion species up to 430 MeV/u with full geometrical flexibility. This functionality has to be maintained for up to 300 000 rotations over the envisaged life cycle of 15 years. GSI has taken the responsibility to coordinate the design and construction of all the different required components. At the time of the conference the design will be finished and the construction started. The contribution will report on challenging construction items like the survey and alignment strategy, safety aspects, flexibility of the ion optics. In order to gain confidence on the principle a test bench with the last part of the gantry was already mounted in a fixed manner at GSI and beam measurements were performed. The results of these tests will also be reported.  
 
THPLT034 Implementation of Higher Order Moments for Beam Dynamics Simulation with the V-Code antiproton, positron, gun, lattice 2550
 
  • W. Ackermann, T. Weiland
    TEMF, Darmstadt
  Based on the moment approach V-Code is implemented to simulate charged particle beam dynamics in linear accelerators. Its main aim is to perform elementary studies in those cases when the beam can be considered as a whole and thus making the motion of individual particles negligible in the overall view. Therefore an ensemble of particles can be well described by the moments of its phase-space distribution and the regarded order influences naturally the achievable accuracy as well as the computational effort. Since the well known moment equations generally are not closed, a technique to limit the number of involved moments has to be applied. So far all moments up to the second order have been considered whereas higher order moments are truncated. As a further step towards higher accuracy the influence of higher order moments has to be investigated. For this reason additional third-order equations are implemented into the V-Code and the achieved results are compared with previous second-order-based ones as well as with higher order approximations.  
 
THPLT035 Development of a 3D-Gun-Code based on a Charge Conserving Algorithm antiproton, positron, electron, simulation 2553
 
  • E. Gjonaj, J. Mudiganti, T. Weiland
    TEMF, Darmstadt
  Recent efforts in the development of electron sources are aiming at high intensity electron beams, beyond the limitations posed by space-charge effects in conventional guns. Field emitter arrays, multi-beam and sheet-beam guns are a few examples of emerging technology, which require an accurate characterization of the limiting current in complicated 3D-geometry. The newly developed gun code at the Technische Universität Darmstadt, implements a novel approach to the numerical simulation of space-charge-limited electron emission, which is based on the local conservation of charge for arbitrary cathode surfaces. It is shown that, imposing exact charge conservation using the CAD-data of the geometry eliminates the spurious oscillations in the charge density, which typically arise when the piecewise-planar diode approximation is applied in the simulation. The accuracy of this approach is demonstrated in the validation study of a spherical diode and in the large-scale simulation of a Traveling Wave Tube amplifier.  
 
THPLT036 New Discretization Scheme for Wake Field Computation in Cylindrically Symmetric Structures antiproton, positron, electron, simulation 2556
 
  • R. Hampel, T. Weiland, I. Zagorodnov
    TEMF, Darmstadt
  Collective effects due to wake fields are a limiting factor in almost every new front line accelerator. Since the early 80's computer codes such as TBCI and MAFIA have been developed for computing wake fields in realistic accelerator structures. With the advent of linear collider studies and small wavelength FEL projects these codes had to face a severe limitation. For the very short bunches in these new accelerators combined with the need for an analysis of very long sections the discrete dispersion became a serious drawback. This effect of having only discrete field values rather than continous ones can be overcome by special algorithms such as semi-implicit integrators as used e.g. in the wake field code ECHO. In this paper we present a new explicit approach which combines the advantage of explicit algorithms (fast) with the absence of dispersion in beam direction.  
 
THPLT037 Investigation of Numerical Noise in PIC-Codes antiproton, positron, electron, simulation 2559
 
  • S. Schnepp, S. Setzer, T. Weiland
    TEMF, Darmstadt
  For a detailed analysis of the dynamics of space charge dominated beams a combination of Particle-in-Cell methods with efficient FDTD schemes is widely used. Besides the calculation of the forces acting on the particles the interaction of the beam itself with the surrounding geometries is taken into account. A drawback of this method is its sensitivity to numerical noise in the spectral range nearby the grid cutoff frequency. In this paper we will present results of detailed studies of the impact of the bunch shape on the level of the numerical noise. Furthermore an a priori scheme for efficient noise suppression is derived which does not affect the FDTD update algorithm.  
 
THPLT038 The Synchrotron Radiation Interferometer using Visble Light at DELTA antiproton, positron, synchrotron, simulation 2562
 
  • U. Berges, K. Wille
    DELTA, Dortmund
  Synchrotron radiation sources such as DELTA, the Dortmund electron accelerator, rely on a monitoring system to measure the beam size and emittance with sufficient resolution. The resolution limits of the different types of optical synchrotron light monitors at DELTA have been investigated. The minimum measurable beam size with the standard synchrotron light monitor using visible light at DELTA is appr. 80 μm. Due to this limitation an interferometer was built up and tested using the same beamline in the visible range. A minimum measurable beam size of appr. 8 μm could be obtained, which gives an increased resolution of one order of magnitude with the new system.  
 
THPLT039 SVD Based Orbit Correction Incorporating Corrector Limitations at DELTA antiproton, positron, synchrotron, simulation 2565
 
  • M. Grewe, P. Hartmann, G. Schmidt, K. Wille
    DELTA, Dortmund
  Singular Value Decompostion (SVD) of the orbit response matrix has become an invaluable tool for orbit correction at storage rings worldwide. SVD based orbit correction has now been realised at DELTA, a 1.5 GeV electron storage ring. However, due to special orbit demands at DELTA and possibly by magnetic imperfections within the storage ring, we frequently have to face corrector limitations during the process of orbit correction. This work focuses on presenting an analytic algorithm on how to treat these limitations when seeking for an optimal SVD based orbit correction. In contrast to previously published methods, this approach is fairly easy to implement and does not afford an numerical solver. Concepts and results will be presented.  
 
THPLT093 Particle-in-cell Numerical Simulations of Particle Dynamics in Beams and ECR Sources feedback, plasma, antiproton, emittance 2709
 
  • G. Shirkov, V. Alexandrov, V. Shevtsov
    JINR/PPL, Dubna, Moscow Region
  A summary of recent development of physical and mathematical basements and the first version of computer code library based on the particle-in-cell method are presented. The code library is aimed for the three-dimensional (3D) simulation of the ECR plasma and ion production in the ECR ion source. The particle-in-cell (finite particle) method is one of the most powerful methods for the numerical simulation of multicomponent ECR plasma and electron-ion beams. This method allows studying the detailed characteristics of plasma, taking into account the distribution functions of particles (spatial, velocity and energy distributions), real self and external fields, particle-particle interactions and many other effects. This technique promises to provide very precise numerical simulations and optimizations of ECR ion sources. The first results of simulations of ECR source plasma are presented. It has been shown that a complete and adequate description of ECR plasma requires the full-scale 3D model and computer codes. This is out of frames of existed project and could be an aim of some addition investigations.  
 
THPLT094 Ordered Ion Beam in Storage Rings feedback, plasma, antiproton, emittance 2712
 
  • A. Smirnov, I.N. Meshkov, A.O. Sidorin, E. Syresin, G.V. Troubnikov
    JINR, Dubna, Moscow Region
  • T. Katayama
    CNS, Saitama
  • H. Tsutsui
    SHI, Tokyo
  The using of crystalline ion beams can increase of the luminosity in the collider and in experiments with targets for investigation of rare radioactive isotopes. The ordered state of circulating ion beams was observed experimentally at several storage rings. In this report a new criteria of the beam orderliness are derived and verified with BETACOOL code with using molecular dynamics technique. The sudden reduction of momentum spread observed on a few rings is described with this code. The simulation shows a good agreement with the experimental results. The code has then been used to calculate characteristics of the ordered state of ion beams for ion rings which will have experimental programs for the study of crystalline beams. A new strategy of the cooling process is proposed which permits to increase the linear density of the ordered ion beam.  
 
THPLT095 Nuclotron Extracted Beam Spill Control plasma, antiproton, emittance, feedback 2715
 
  • V. Volkov, V. Andreev, E. Frolov, V. Karpinsky, A. Kirichenko, A.D. Kovalenko, V.A. Mikhaylov, S. Romanov, B. Vasilishin, A. Volnov
    JINR, Dubna, Moscow Region
  The first experiments with the Nuclotron Beam Slow Extraction System (BES) were carried out in December 1999. After the BES commissioning, the development of the system was continued together with experiments on relativistic nuclear physics. To realize the constant-current-beam or the constant-time-length spill and to suppress the low frequency spill structure in the range up to several hundred hertz, a spill control subsystem was designed and put into operation. It consists of a feedback loop in parallel with a feed-forward control. In the feedback loop the extracted particle flux is measured with beam current monitor and is compared with the request flux. The resulting error signal is fed into a feedback controller. The controller is an analog unit in which integration, differentiation and gain can be adjusted separately. The output control signal is added to the extraction quadrupoles power supply pattern generated by the corresponding function generator. The beam spill control subsystem has been improved in stages since its commissioning in 2000. The beam spill duration of more than 10s and the beam spill uniformity of about 0.9 were achieved in recent Nuclotron runs.