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MOPLT042 Interaction of the CERN Large Hadron Collider (LHC) Beam with Solid Metallic Targets lepton, wiggler, feedback, extraction 641
 
  • N.A. Tahir, D.H. Hoffmann
    GSI, Darmstadt
  • V. Fortov, I. Lomonosov, A. Shutov
    IPCP, Chernogolovka, Moscow region
  • B. Goddard, V. Kain, R. Schmidt
    CERN, Geneva
  • R. Piriz, M. Temporal
    Universidad de Castilla-La Mancha, Ciudad Real
  The LHC will operate at 7 TeV with a luminosity of 1034 cm-2s-1. This requires two beams, each with 2808 bunches. The nominal intensity per bunch is 1.1 1011 protons. The energy stored in each beam of 350 MJ could heat and melt 500 kg of copper. Protection of machine equipment in the presence of such powerful beams is essential. In this paper the mechanisms causing equipment damage in case of a failure of the machine protection system are discussed. An energetic heavy ion beam induces strong radial hydrodynamic motion in the target that drastically reduces the density in the beam heated region [*], leading to a much longer range for particles in the material. For the interaction of the LHC proton beams with a target a similar effect is expected. We carried out two-dimensional hydrodynamic simulations of the heating of a solid copper block with a face area of 2cm x 2cm irradiated by the LHC beam with nominal parameters. We estimate that after an impact of about 100 bunches the beam heated region has expanded drastically. The density in the inner 0.5 mm decreases by about a factor of 10. The temperature in this region is about 10 eV and the pressure about 15 GPa. The material in the heated region is in plasma state while the rest of the target is in a liquid state. The bulk of the following beam will not be absorbed and continue to tunnel further and further into the target. The results allow estimating the length of a sacrificial absorber, if such device should be installed for an LHC upgrade. A very interesting "spinoff" from this work would be the study of high-energy-density states of matter induced by the LHC beam, because a specific energy deposition of 200 kJ/g is achieved after 2.5 micros.

* N.Tahir et al., Phys. Rev. E, 63, 2001

 
 
MOPLT044 Longitudinal Positron Polarisation in HERA-II lepton, wiggler, feedback, extraction 644
 
  • E. Gianfelice-Wendt, D.P. Barber, F. Brinker, W. Decking, J. Keil, M. Vogt, F.J. Willeke
    DESY, Hamburg
  Following the installation of two more pairs of spin rotators in the course of the HERA Luminosity Upgrade, longitudinal positron spin polarisation has now been generated simultaneously at all three positron(electron) interaction points in HERA at the routine energy of 27.5 GeV. The maximum attained so far is 54 percent. The theoretical maximum for this configuration and in the presence of realistic errors is 57.0 percent. This is the first time in the history of high energy electron storage ring physics that the naturally occurring vertical polarisation has been, with the aid of spin rotators, converted to longitudinal polarisation at three interaction points simultaneously. We describe the measures needed to attain polarisation in light of the HERA Upgrade and the resulting recent performance.  
 
MOPLT045 Vacuum Induced Backgrounds in the New HERA Interaction Regions background, wiggler, feedback, extraction 647
 
  • M. Seidel, M.G. Hoffmann
    DESY, Hamburg
  After the rebuild of the HERA interaction regions the experimental detectors were limited by beam induced backgrounds. Four types of background mechanisms were observed and identified - proton gas scattering, lepton gas scattering, synchrotron radiation and proton beam-halo losses. With some refined beam steering methods it was possible to tune the synchrotron radiation background to acceptable limits. The remaining most important effect was the scattering of the beam particles, mostly the protons, at the residual gas. In this contribution we describe our systematic attempts to investigate the complex behavior of the beam gas background and the measures taken to improve the situation. This includes dynamic pressure profile simulations and measurements, experimental determination of the background sensitivity profile along the beamline, the pressure development with current and time, and residual gas analysis. The background conditions were finally improved due to long term conditioning with beam, modifications of internal masks which were heated by higher order mode losses and moderate improvements of the pumping speed at strategic locations.  
 
MOPLT046 Overcoming Performance Limitations due to Synchrobetatron Resonances in the HERA Electron Ring background, wiggler, extraction, undulator 650
 
  • F.J. Willeke
    DESY, Hamburg
  The HERA Electron Ring was suffering from strong synchrobetatron resonances which have been particularly detrimental after the HERA luminosity upgrade because of a reduced sychrotron tune due to stronger transverse focusing and a shift in the damping distribution in favor of transverse damping. It turned out to be most difficult to store a beam at the preferred working point for high electron spin polarization between the 2nd and the 3rd synchro-betatron satellite of the horizontal integer resonance. A comparative study of the resonance strength did not reveal any significant additional disadvantage of the new beam optics. However, a mechanism driven by closed orbit distortions was discovered which can increase the width of the resonance Qx+2Qs=0 by a large factor. This explains the operational difficulties. The remedy against this effect is quite straight forward. The Fourier component of the closed orbit near the horizontal tune must be avoided. This is enforced in HERA operations by rigerous orbit corrections and an orbit feedback system which reproduces well-corrected orbits reliably. Synchrobetatron resonances do not constitute a performance limitation of polarized lepton proton collisions in HERA any more.  
 
TUPLT010 Aperture and Stability Studies for the CNGS Proton Beam Line plasma, laser, booster, focusing 1150
 
  • M. Meddahi, W. Herr
    CERN, Geneva
  The knowledge of the beam stability at the CNGS target is of great importance, both for the neutrino yield and for target rod resistance against non-symmetric beam impact. Therefore, simulating expected imperfections of the beam line elements and possible injection errors into the CNGS proton beam line, the beam spot stability at the target was investigated. Moreover, the mechanical aperture of the CNGS proton beam line was simulated and the results confirmed that the aperture is tight but sufficient.  
 
TUPLT011 The LHC Lead Ion Injector Chain ion, 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. ion, 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 ion, 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 ion, 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.  
 
TUPLT015 The Bunch Compressor System for SIS18 at GSI plasma, laser, electron, booster 1165
 
  • P. Hülsmann, G. Hutter, W. Vinzenz
    GSI, Darmstadt
  For bunch compression down to pulse durations of 50 ns, a dedicated rf system is under development for the SIS12/18 heavy ion synchrotron upgrade and will be described in this paper. Due to space restrictions in SIS12/18 the rf system consists of very short cavities which provide a very large voltage gradient (50 kV/m) at a very low frequency of approximately 800 kHz and rf final stages which provide a short rise time. The only possibilty to meet the requirements is the application of a cavity heavily inductively loaded by metallic alloy (MA) ring cores. This new rf system will be a prototype for the advanced acceleration and compression system needed in SIS100, which is the most important part for the proposed International Acceleration Facility at GSI. In order to gain experience with different MA ring core materials two of the four compressor cavities are loaded differently, which gives us an opportunity to learn the operational advantages of both materials. It is expected that the experimental results will support the final judgement for the future rf system in SIS100.  
 
TUPLT016 Improved Performance of the Heavy Ion Storage Ring ESR plasma, laser, electron, booster 1168
 
  • M. Steck, K. Beckert, P. Beller, B. Franczak, B.  Franzke, F. Nolden
    GSI, Darmstadt
  The heavy ion storage ring ESR at GSI allows experiments with stable and radioactive heavy ions over a large range of energies. The energy range available for operation with completely stripped ions has recently been extended to energies as low as 3 MeV/u. Even for bare uranium such low energies can be provided by deceleration of the ions which are stripped to high charge states in a foil at energies of 300-400 MeV/u. After injection the beam is cooled and decelerated in an inverse synchrotron mode interspersed with electron cooling at an intermediate energy. At the lowest energy of 3 MeV/u some hundreds of thousands ions could be electron cooled after deceleration. At energies of 10-20 MeV/u physics experiments with stored and slowly extracted beam have been performed with some million decelerated cooled ions. The cooling of radioactive ions by a combination of stochastic pre-cooling and final electron cooling has been demonstrated. The hot fragment beam, which was injected at an energy of 400 MeV/u, was cooled in about 6 s to a quality useful for precision experiments.  
 
TUPLT017 Achievements of the High Current Beam Performance of the GSI Unilac plasma, laser, electron, booster 1171
 
  • W. Barth, L. Dahl, J. Glatz, L. Groening, S.G. Richter, S. Yaramishev
    GSI, Darmstadt
  The present GSI-accelerator complex is foreseen to serve for the future synchrotron SIS100 as an injector for up to 1012 U28+ particles/sec. The High Current Injector of the Unilac was successfully commissioned five years ago. An increase of more than two orders of magnitude in particle number for the heaviest elements in the SIS had to be gained. Since that time many different ion species were accelerated in routine operation. In 2001 a physics experiment used 2×109 Uranium ions per spill. In order to meet this request the MEVVA ion source provided for the first time in routine operation a high intense Uranium beam. The main purpose for the machine development program during the last two years was the enhancement of the intensity for Uranium beams. Different hardware measures and a huge investigation program in all Unilac-sections resulted in an increase of the uranium intensity by a factor of 7. The paper will focus on the measurements of beam quality, as beam emittance and bunch structure for Megawatt-Uranium beams. Additionally the proposed medium- and long-term hardware measures will be described, which should gain in the required uranium intensity to fill the SIS up to the space charge limit.  
 
TUPLT052 GANIL Status Report ion, emittance, 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) ion, emittance, 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 ion, 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 ion, 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.  
 
TUPLT136 Proton Beam Line for the ISIS Second Target Station linac, electron, booster, bunching 1443
 
  • D.J. Adams
    CCLRC/RAL/ASTeC, Chilton, Didcot, Oxon
  The ISIS facility, based at the Rutherford Appleton Laboratory in the UK, is an intense pulsed source of Muons and Neutrons used for condensed matter research. The accelerator facility delivers an 800 MeV proton beam of 2.5x1013 protons per pulse at 50 Hz. As part of the facility upgrade, which includes increasing the source intensity to 3.7x1013 protons per pulse using a dual harmonic RF system, it is planned to share the source with a second, 10 Hz, target station. A beam line supplying this target will extract from the existing target station beam line. Measurements and models characterising the optical functions around the extraction point of the existing line are discussed. The optical design, diagnostics and beam correction systems for second target station beam line are presented.  
 
TUPLT137 Comparative Simulation Studies of Electron Cloud Build-up for ISIS and Future Upgrades linac, bunching, optics, injection 1446
 
  • G. Bellodi
    CCLRC/RAL/ASTeC, Chilton, Didcot, Oxon
  Electron cloud effects currently limit the performance of several proton accelerators operating with high beam current. Although ISIS, the 160 kW 70-800 MeV proton synchrotron at the Rutherford Appleton Laboratory (UK), has never appeared to be affected by the problem in its 15 years of operations, e-p instabilities could potentially be a cause of concern for future machine upgrades to higher beam powers. In this paper we review the present status of simulations for ISIS and compare it to preliminary results for two upgrade options: a 0.5MW 180-800 MeV scheme and a 1MW 0.8-3 GeV scheme with an additional synchrotron using ISIS as a booster (see C. Prior et al., ISIS megawatt upgrade plans, in Proceedings of the 2003 Particle Accelerator Conference PAC 2003, Portland, Or, USA).  
 
TUPLT138 A Fast Beam Chopper for Next Generation High Power Proton Drivers bunching, optics, injection, focusing 1449
 
  • M.A. Clarke-Gayther
    CCLRC/RAL/ASTeC, Chilton, Didcot, Oxon
  The identification and development of a successful beam chopper design is regarded as key for the European Spallation Source (ESS), and for all next generation high intensity proton driver schemes that adopt the linac-accumulator ring configuration. A description is given of refinements to the beam line design of a 'Tandem' chopper system, developed to address the requirements of the ESS. Particle tracking using the 'General Particle Tracer' (GPT) code has enabled efficient optimisation of beam apertures, and the analysis of beam power density distributions on chopper beam dumps. Preliminary results of 'proof of principle' testing on prototype fast, and slower transition high voltage pulse generators, are presented.  
 
TUPLT139 Extending the Duty Cycle of the ISIS H Minus Ion Source, Thermal Considerations bunching, optics, injection, ion 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 bunching, optics, injection, ion 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.  
 
TUPLT141 The Effect of Extraction Geometry on the Measured ISIS H Minus Ion Source Beam bunching, injection, beamloading, lattice 1458
 
  • J.W.G. Thomason, D.C. Faircloth, R. Sidlow, C.M. Thomas, M. Whitehead
    CCLRC/RAL/ISIS, Chilton, Didcot, Oxon
  Recent Finite Element Analysis (FEA) electromagnetic modelling of the extraction region of the ISIS H minus source has suggested that the present set up of extraction electrode and 90 degree sector magnet is sub-optimal, with the result that the beam profile is asymmetric, the beam is strongly divergent in the horizontal plane and there is severe aberration in the focusing in the vertical plane. The FEA model of the beam optics has demonstrated that relatively simple changes to the system should produce a dramatic improvement in performance. These changes have been incorporated on the Ion Source Development Rig (ISDR) at Rutherford Appleton Laboratory (RAL), and their effects on the H minus beam are presented here.  
 
TUPLT142 Status of Design of Muon Beamline for the Muon Ionisation Cooling Experiment bunching, injection, beamloading, lattice 1461
 
  • K. Tilley
    CCLRC/RAL/ISIS, Chilton, Didcot, Oxon
  The MICE collaboration proposes to install a Muon Ionisation Cooling Experiment at the ISIS facility, at Rutherford Appleton Laboratory. This experiment will be the first demonstration of ionisation cooling as a means to reduce the large transverse emittance of the muon beam, produced during the early stages of a neutrino factory. In order to permit a realistic demonstration of cooling, a source of muons must be produced, possessing particular qualities, notably in emittance and momenta. This paper describes the present design for the muon beamline source, and the plans for its implementation at RAL.  
 
TUPLT143 Studies of Beam Loss Control on the ISIS Synchrotron bunching, injection, beamloading, lattice 1464
 
  • C.M. Warsop
    CCLRC/RAL/ISIS, Chilton, Didcot, Oxon
  The ISIS Facility at the Rutherford Appleton Laboratory in the UK produces intense neutron and muon beams for condensed matter research. The ISIS 800 MeV Proton Synchrotron presently provides up to 2.5·1013 protons per pulse at 50 Hz, corresponding to a mean power of 160 kW. A dual harmonic RF system upgrade is expected to increase the intensity and power by about 50%. The tighter constraints expected for higher intensity running are motivating a detailed study of beam loss distributions and the main factors affecting their control. Main aims are maximising the localisation of activation in the collector straight, and minimising risk of damage to machine components. The combination of experimental work, developments of the loss measurement systems, and simulation studies are summarised. Key factors considered include: the effects of primary collector geometry and material; the nature of the beam loss; and methods for experimentally determining spatial loss distributions.  
 
TUPLT144 Upgrade of the ISIS Main Magnet Power Supply bunching, injection, beamloading, lattice 1467
 
  • S. West, J.W. Gray, A. Morris
    CCLRC/RAL/ISIS, Chilton, Didcot, Oxon
  ISIS, situated at the Rutherford Appleton Laboratory (RAL) is the world?s most powerful pulsed neutron source. At the heart of the ISIS accelerator is a proton synchrotron which uses a ring of magnets connected in series and configured as a ?White Circuit?. The magnets are connected in series with capacitor banks so that they form a resonant circuit with a fundamental frequency of 50 Hz. The circuit allows the magnets to be fed with an AC current superimposed on a DC current. The AC is currently provided by a 1MVA Motor-Alternator set and it is now proposed to replace this by a solid state UPS (Uninterruptible Power Supply) system. Tests on a smaller 80kVA unit have shown that it is possible to control the magnet current with a modified UPS system in such a way that both the frequency, phase and output voltage are under the direct influence of the control system. This paper discusses the issues surrounding the upgrading of AC supply to the main magnets with a view to improving the system reliability, improving magnet current stability and reducing the risk of mains failure.  
 
TUPLT145 Transverse Coupling Measurement using SVD Modes from Beam Histories bunching, injection, beamloading, antiproton 1470
 
  • C.-X. Wang
    ANL, Argonne, Illinois
  • R. Calaga
    BNL, Upton, Long Island, New York
  In this report we investigate the measurement of local transverse coupling from turn-by-turn data measured at a large number of beam position monitors. We focus on a direct measurement of coupled lattice functions using the Singular Value Decomposition (SVD) modes and explore the accuracy of this method. The advantages and shortcomings of this model-independent method for coupling measurement will be also discussed.  
 
TUPLT146 Techniques to Extract Physical Modes in Model-independent Analysis of Rings bunching, injection, beamloading, antiproton 1473
 
  • C.-X. Wang
    ANL, Argonne, Illinois
  SVD mode analysis is a basic techinique in Model-Independent Analysis of beam dynamics. It decomposes the spatial-temporal variation of a beam centroid into a small set of orthogonal modes based on statistical analysis. Although such modes have been proven to be rather informative, each orthogonal mode may not correspond to an individual physical source but a mix of several in order to be orthogonal. Such mixing makes it difficult to quantitatively understand the SVD modes and thus limits their usefulness. Here we report a new techinique to untangle the mixed modes in storage ring analysis based on the fact that most of the physical modes in a ring have identifiable characteristics in frequency domain.  
 
TUPLT147 Multiple-charge-state Beam Steering in High-intensity Heavy-ion Linacs bunching, injection, beamloading, antiproton 1476
 
  • E.S. Lessner, P.N. Ostroumov
    ANL/Phys, Argonne, Illinois
  An algorithm suitable for correction to steering of multiple-charge-state beams in heavy-ion linacs operating at high currents has been developed [*]. It follows a four-dimensional minimization procedure that includes coupling of the transverse beam motions. A major requirement is that it obeys the restricted lattice design imposed by the acceleration of multiple-charge-state heavy-ion beams [**]. We study the algorithm efficiency in controlling the beam effective emittance growth in the presence of random misalignments of cavities and focusing elements. Limits on misalignments are determined by quantifying beam losses and effective steering requirements are selected by examining several correcting schemes within the real-state constraints. The algorithm is used to perform statistically significant simulations to study beam losses under realistic steering.

* E. S. Lessner and P. N. Ostroumov, Proc. Part. Accel. Conf. (2003)** P. N. Ostroumov, Phys. Rev. STAB Vol. 5, 0030101 (2002)

 
 
TUPLT149 Beam Manipulation and Compression Using Broadband RF Systems in the Fermilab Main Injector and Recycler bunching, injection, beamloading, antiproton 1479
 
  • G.W. Foster, C.M. Bhat, B. Chase, J.A. Mac Lachlan, K. Seiya, P. Varghese, D. Wildman
    Fermilab, Batavia, Illinois
  Successful tests of new method for beam manipulation, compression, and stacking using the broadband RF systems in the Fermilab Recycler and Main Injector are described. Under usual conditions an unbunched beam can be confined to a fraction of the azimuth of the ring by a set of "Barrier Pulses" which repel particles trying to escape from the ends of the segment of beam. One way to compress or expand the azimuthal extent of the segment of beam is to slowly change the distance between barrier pulses. However when it is desired to rapidly compress or expand the length of the segment, a linear ramp can be superimposed on the waveform between barrier pulses. This causes particles at the front and back of the beam segment to be accelerated or decelerated by differing amounts, and the velocity correlation along the length of the beam segment causes it to expand or contract. When the expansion or contraction is halfway completed, the ramp voltage is reversed so the all particles will come relatively to rest at the end of the process. With the Barrier pulses following appropriately, no particles leak out the ends of the beam segment and the emittance is preserved.  
 
TUPLT150 Vector Sum Control of an 8 GeV Superconducting Proton Linac bunching, injection, beamloading, antiproton 1482
 
  • M. Huening, G.W. Foster
    Fermilab, Batavia, Illinois
  Fermilab is investigating the feasibility of an economical 8 GeV superconducting linac for H-. In order to reduce the construction costs it is considered to fan out the rf power to a string of accelerating structures per klystron. Below 1 GeV the individual fluctuations of the cavities will be compensated by high power phase shifters, above 1 GeV the longitudinal dynamics are sufficiently damped to consider omitting the phaseshifters. The impact of this setup on the field stability of individual cavities and ultimately the beam energy has been studied.  
 
TUPLT151 Status of the Fermilab Electron Cooling Project electron, bunching, injection, beamloading 1485
 
  • J.R. Leibfritz, D.R. Broemmelsiek, A.V. Burov, K. Carlson, B. Kramper, T. Kroc, M. McGee, S. Nagaitsev, L. Nobrega, G. Saewert, C.W. Schmidt, A.V. Shemyakin, M. Sutherland, V. Tupikov, A. Warner
    Fermilab, Batavia, Illinois
  • G. Kazakevich
    BINP SB RAS, Novosibirsk
  • S. Seletsky
    Rochester University, Rochester, New York
  Fermilab has constructed and commissioned a full-scale prototype of a multi-MV electron cooling system to be installed in the 8.9 GeV/c Fermilab Recycler ring. This prototype was used to test all of the electron beam properties needed for cooling. However, because the prototype is not located within proximity of the Recycler ring, the actual electron cooling of antiprotons can not be demonstrated until it is relocated. The Fermilab electron cooling R&D project is scheduled to be completed in May, 2004 at which time it will be disassembled and relocated to a newly constructed facility where it will be installed in the Recycler. This paper describes the experimental results obtained with the prototype cooler system, gives an overview of the new electron cooling facility, and discusses the overall status of the project.  
 
TUPLT153 Orbit Response Matrix Analysis Applied at PEP-II electron, lattice, bunching, injection 1488
 
  • C. Steier, A. Wolski
    LBNL/AFR, Berkeley, California
  • S. Ecklund, J.A. Safranek, P. Tenenbaum, A. Terebilo, J.L. Turner, G. Yocky
    SLAC, Menlo Park, California
  Beam-based techniques to study lattice properties have proven to be a very powerful tool to optimize the performance of storage rings. The analysis of orbit response matrices has been used very successfully to measure and correct the gradient and skew gradient distribution in many accelerators. The first applications were mostly in synchrotron light sources, but the technique is also used increasingly at colliders. It allows determination of an accurately calibrated model of the coupled machine lattice, which then can be used to calculate the corrections necessary to improve coupling, dynamic aperture and ultimately luminosity. At PEP-II, the Matlab version of LOCO has been used to analyze coupled response matrices for both the LER and the HER. The large number of elements in PEP-II and the very complicated interaction region present unique challenges to the data analysis. The orbit response matrix analysis will be presented in detail, as well as results of lattice corrections based on the calibrated machine model.  
 
WEOCCH01 A New 180 MeV H- Linac for Upgrades of ISIS radiation, focusing, kicker, bunching 153
 
  • F. Gerigk
    CCLRC/RAL/ASTeC, Chilton, Didcot, Oxon
  Several options have been studied to raise the beam power of the ISIS spallation neutron source to a level of 1 MW with the possibility of going to 4-5 MW in the longer term. All scenarios can operate in 2 modes, where the beam power is either delivered to a spallation target or, alternatively, to a target suitable to produce muons via pion decay for a neutrino factory. A more recent upgrade option takes an intermediate step and uses a 180 MeV H- linac, which is also foreseen for the 4-5 MW upgrade, as a replacement for the current 70 MeV injector. First estimates indicate that, due to the lower space charge forces, the ring would be able to carry twice as many particles, thus doubling the final beam power to 0.5 MW. This paper presents a first design for the 180 MeV linac, using a triple frequency jump from 234.8 to 704.4 MHz. The design profits from the development of 704.4 MHz cavities and RF equipment within the framework of the European HIPPI collaboration. The low frequency for the front-end was chosen to ease the DTL design as well as the development of a low energy beam chopper, which will be necessary to reduce beam losses at injection into the synchrotron.  
Video of talk
Transparencies
 
WEOCCH02 Construction Status and Issues of the Spallation Neutron Source Ring radiation, focusing, kicker, bunching 156
 
  • J. Wei
    BNL, Upton, Long Island, New York
  (For the Spallation Neutron Source collaboration) The Spallation Neutron Source (SNS) accelerator complex is now in its sixth year of a seven-year construction cycle. The design, fabrication, test, and assembly of the accumulator ring and its transport lines is approaching the final stage. In order to reach the design goal of this high-power ring to deliver 1.5 MW beam power (1.5$× 1014 protons of 1 GeV kinetic energy at a repetition rate of 60 Hz), stringent measures have been implemented to ensure the quality of the accelerator systems. This paper reviews the progress of the ring and transport systems with emphasis on the challenging technical issues and their solutions inccurred during the construction period.  
Video of talk
Transparencies
 
WEPLT077 DESIGN OF A FULL-CUSTOM ACCURATE I-Q MODULATOR antiproton, damping, booster, focusing 2026
 
  • M. Luong, M. Desmons
    CEA/DSM/DAPNIA, Gif-sur-Yvette
  The I-Q modulator is a key component in a digital Low Level RF (LLRF) system for amplitude and phase feedbacks. Its residual errors in offset or gain have a strong impact on the dynamic and accuracy of the feedback loops. For some frequencies, commercial I-Q modulators are available on the market. But even in that case, these components are usually designed for broadband communication purposes, and their performances in term of residual errors may not fit the strict requirements on the final amplitude and phase loop stability. Since LLRF systems for accelerators are typically narrow-banded, i.e. limited to few MHz, it is possible to achieve a high directivity and a very accurate coupling for hybrids, and an excellent matching for all subcomponents in a fully custom design. This approach guarantees the lowest residual errors for an I-Q modulator. The principle for the design and the process for the optimization are presented in this paper.  
 
WEPLT078 The IFMIF High Energy Beam Transport Line antiproton, damping, booster, focusing 2029
 
  • D. Uriot, R. Duperrier, J. Payet
    CEA/DSM/DAPNIA, Gif-sur-Yvette
  The IFMIF project (International Fusion Materials Irradiation Facility) requests two linacs designed to accelerate 125 mA deuteron beams up to 40 MeV. The linac has to work in CW mode and uses one RFQ and 10 DTL tanks. After extraction and transport, the deuteron beams with strong internal space charge forces have to be bunched, accelerated and transported to target for the production of high neutron flux. This paper presents the high energy beam transport line which provides a flat rectangular beam profile on the liquid lithium target. Transverse uniformisation is obtained by using non-linear mutipole lenses (octupoles and duodecapoles). Beam dynamics with and without errors has been study.  
 
WEPLT079 Non Linear Beam Dynamics and Lifetime on the SOLEIL Storage Ring antiproton, damping, booster, beamloading 2032
 
  • P. Brunelle, A. Loulergue, A. Nadji, L.S. Nadolski
    SOLEIL, Gif-sur-Yvette
  The incidence of several non-linear effects on the energy acceptance and beam lifetime has been investigated, using the BETA and TRACY II tracking codes. The effect of all magnets multipolar components has been checked on the working point (18.20; 10.30), especially the decapolar component induced by the H-corrector. The dipolar field, which is created by additional coils in the sextupoles, generates a significant decapolar component which, associated to the distributed dispersion, can reduce significantly the dynamic acceptance at large energy deviations. This effect depends on the natural closed orbit to be corrected: corrector strengths and cross talk between the different decapolar components. Moreover, the sensitivity to the number of correctors, used for correction, has been evaluated. The effect of insertions devices has also been studied, integrating field maps generated by the RADIA code into the tracking codes. With undulators, such as an in-vacuum U20 and an Apple II type HU80 (with different polarization modes), it was shown that the transverse field in-homogeneity and the focusing effects generating beta-beat can affect severely the energy acceptance and the beam lifetime because of resonance excitation.  
 
WEPLT080 Study of Resistive-wall Effects on SOLEIL antiproton, damping, booster, beamloading 2035
 
  • R. Nagaoka
    SOLEIL, Gif-sur-Yvette
  The presence of low-gap chambers for insertion devices, along with a relatively small vertical gap of 25 mm chosen for the standard vacuum chambers, implies a significant influence of the resistive-wall on the beam in the future SOLEIL storage ring. A systematic approach was taken to quantify the net contribution by taking into account all local variations of the non-circular chamber cross-sections as well as beta functions. Low multibunch instability thresholds were found in both transverse planes, indicating the necessity of cures, by means of transverse feedback and/or chromaticity shifts. An effort was made to evaluate the effect of metallic coating, particularly that of NEG, which was adopted in all straight sections. The dependence on both resistivity and thickness of NEG was followed. It is found that, the NEG coating nearly doubles the reactive part of the impedance in the frequency range seen by the beam. Implication on the reduction of the transverse mode-coupling instability threshold is discussed. Incoherent tune shifts arising from the non-circular chamber cross-section were also evaluated, including a non-negligible NEG contribution in the short-range wakes.  
 
WEPLT081 Numerical Evaluation of Geometric Impedance for SOLEIL impedance, antiproton, damping, booster 2038
 
  • R. Nagaoka
    SOLEIL, Gif-sur-Yvette
  Good knowledge and minimisation of the coupling impedance is of great importance for the future storage ring SOLEIL, envisaged to operate in both high current multibunch and high bunch intensity modes. Three-dimensional computations of the geometric impedance of various vacuum chamber components have been made with the code GdfidL, which allows parallel processing with a cluster of computers, rendering the computation with a small mesh size and a long integrated distance feasible. Many treated objects were found to exhibit large asymmetry in the two transverse planes, as well as resonant behaviour at high frequencies, both of which being non-straightforward to follow with the conventional analytical methods and 2-dimensional calculations. In particular, strongly trapped modes found for the flange impedance resulted in an unacceptably low vertical multibunch instability threshold, which urged a modification of the original cavity-like structure. The dependence of the dipole chamber impedance on the vertical slot size was followed to determine the optimal slot opening. Characteristics of the total broadband impedance obtained, along with relative contributions are also presented.  
 
WEPLT083 Coherent and Incoherent Tune Shifts Deduced from Impedance Modelling in the ESRF-Ring injection, antiproton, damping, booster 2044
 
  • T.F. Günzel
    ESRF, Grenoble
  In single bunch the detuning of the transverse modes m=0,1 and -1 are calculated on the base of an impedance model contructed from element-wise wakefield calculation and the resistive wall impedance of the ESRF-ring. As the vacuum chambers of the ESRF storage ring have notably flat cross sections incoherent wake fields have an impact on the tune shifts as well as coherent wake fields. Compared to tune shift measurements in single bunch the calculated transverse mode detuning can explain half of the tune shift in the vertical plane and almost completely the tune shift in horizontal plane.  
 
WEPLT084 Experimental Frequency Maps for the ESRF Storage Ring injection, antiproton, damping, booster 2047
 
  • Y. Papaphilippou, L. Farvacque, E. Plouviez, J.-L. Revol, A. Ropert
    ESRF, Grenoble
  • J. Laskar
    IMCCE, Paris
  • Ch. Skokos
    Academy of Athens, Athens
  Experimental frequency maps have already revealed many unknown characteristics of the ESRF storage ring non-linear dynamics. In the past year, several efforts were undertaken in order to establish this technique as an operational on-line tool. The acquisition time was significantly reduced by collecting data from a dedicated fast BPM system. The problem of beam decoherence was limited by establishing a method for accurate tune determination in a small number of turns, using the information from all the BPMs around the ring. The possibility to explore the off-momentum dynamics by exciting the beam, with synchronous transverse and longitudinal kicks was also investigated. Finally, measurements of resonance driving term amplitudes and phase advances were used to identify the efficiency of resonance corrections.  
 
WEPLT095 Modified Polarizabilities and Wall Impedance for Shielded Perforated Beam Pipes with General Shape antiproton, damping, vacuum, booster 2071
 
  • S. Petracca, T. Demma
    U. Sannio, Benevento
  We extend previous results [*] concerning the modified polarizability of (electrically small) holes/slots in the wall of a circular beam liner surrounded by a coaxial circular tube to the most general liner and cold bore geometries. We obtain an equivalent wall impedance to describe the electromagnetic boundary conditions at perforated walls for this most general case, and use a general perturbational approach [**] for computing the pertinent longitudinal and transverse coupling impedances.

* R.L. Gluckstern, CERN SL 92-06 (AP), 1992, CERN SL 92-31 (AP), 1992; R.L. Gluckstern, B. Zotter, CERN SL 96-56 (AP), 1996.** S. Petracca, Part. Acc., {\bf 50}, 211, 1995; id., Phys. Rev. E, 60 (3),1999.

 
 
WEPLT097 Beam Loading in the RF Deflector of the CTF3 Delay Loop antiproton, damping, vacuum, booster 2074
 
  • D. Alesini, F. Marcellini
    INFN/LNF, Frascati (Roma)
  In this paper we describe the impact of the beam loading in the RF deflectors on the transverse beam dynamics of the CTF3 Delay Loop. The general expression for the single passage wake field is obtained. A dedicated tracking code has been written to study the multi-bunch multi-turn effects on the transverse beam dynamics. A complete analysis for different machine parameters and injection errors is presented and discussed. The numerical simulations show that the beam emittance growth due to the wake field in the RF deflectors is small.  
 
WEPLT098 Experience with Long Term Operation with Demineralized Water Systems at DAFNE antiproton, damping, vacuum, booster 2077
 
  • L. Pellegrino
    INFN/LNF, Frascati (Roma)
  During eight years operation of the Dafne water cooling system we coped with several critical situations and managed successfully specific upgrades to the demineralized water system. Here we revise critically the collected data and the experience gained in the field of copper corrosion and related water treatment.  
 
WEPLT102 Electron Cooling Experiments at HIMAC Synchrotron antiproton, plasma, vacuum, booster 2086
 
  • K. Noda, T. Furukawa, T. Honma, S. Shibuya, D. Tan, T. Uesugi
    NIRS, Chiba-shi
  • T. Iwashima
    AEC, Chiba
  • I.N. Meshkov, E. Syresin
    JINR, Dubna, Moscow Region
  • S. Ninomiya
    RCNP, Osaka
  In the HIMAC synchrotron, the electron cooling experiments have been carried out since 2000 in order to develop new technologies in heavy-ion therapy and related research. Among of them, especially, the cool-stacking method has been studied to increase the intensity of heavy ions such as Fe and Ni in order to study the risk estimation of the radiation exposure in space. The simulation was carried out in order to optimize the stacking intensity under various the injection periods. In addition, the beam heating by the RF-KO and the clearing the secondary ion in the cooler were applied to avoid the instability occurred when the beam density became high. We will report the experiment results.  
 
WEPLT123 Engineering Design of High-current 81.36 MHz RFQ with Elliptic Coupling Windows radiation, sextupole, antiproton, resonance 2140
 
  • D. Kashinskiy, A. Kolomiets, S. Minaev, V. Pershin, B.Y. Sharkov, T. Tretyakova
    ITEP, Moscow
  Four-vane RFQ structure with elliptic coupling windows has been originally developed at ITEP for injection into ITEP-TWAC synchrotron/storage ring complex, being lately adapted for RIA project too. As the electrodynamics simulations show, this structure combines the high efficiency with the operating mode stability against asymmetric detuning and electrode misalignment. A considerable reduction of structure diameter due to coupling windows becomes important for low frequency range which is necessary for the heavy ion acceleration. At the same time, the electrode configuration allows the efficient cooling and high duty factor operation. A mechanical design of 81 MHz, 1.6 MeV/u, 6 m long heavy ion RFQ section is discussed. The outer tank is made of two layers, steel and copper, joined by using the thermal diffusion technology. Each electrode is supplied with the alignment mechanism and connected to the tank by the flexible conducting insert. The whole setup is in manufacturing now.  
 
WEPLT136 Lattice Studies For The MAX-IV Storage Rings sextupole, antiproton, resonance, beamloading 2152
 
  • H. Tarawneh, M. Eriksson, L.-J. Lindgren, S. Werin
    MAX-lab, Lund
  • B. Anderberg
    AMACC, Uppsala
  • E.J. Wallén
    ESRF, Grenoble
  The lattice for the future MAX-IV storage rings at MAX-Lab has been studied, The MAX IV facility consists of two similar rings operated at 1.5 GeV and 3 GeV electron energies, The ring consists of 12 supercells each built up by 5 unit cells and matching sections. The high periodicity of the lattice combined with the high gradients in the small gap dipole magnets yield a small emittance of 1 nm.rad, good dynamic aperture and momentum acceptance. In the matching section, a soft end dipole magnet is introduced to reduce the synchrotron radiation power hitting the upstream straight section.  
 
WEPLT137 Higher Order Modes in the New 100 and 500 MHz Cavities at MAX-lab sextupole, antiproton, resonance, beamloading 2155
 
  • H. Tarawneh, Å. Andersson, M. Bergqvist, M. Brandin, M. Eriksson, L. Malmgren
    MAX-lab, Lund
  The MAX-II electron storage ring operates exclusively in multi-bunch mode with all buckets filled. Damping of the longitudinal higher order mode (HOM) instabilities has successfully been provided by passive third harmonic 1.5 GHz cavities. With a new RF employing three 100 MHz capacity loaded cavities and a fifth harmonic Landau cavity installed, a study of the HOM impedances, and related threshold instability currents, is necessary. Measurements and calculations so far, are being presented.  
 
WEPLT143 Simulation Calculations of Stochastic Cooling for Existing and Planned GSI Facilities sextupole, laser, resonance, emittance 2167
 
  • I. Nesmiyan
    National Taras Shevchenko University of Kyiv, Radiophysical Faculty, Kiev
  • F. Nolden
    GSI, Darmstadt
  The process of longitudinal stochastic cooling is simulated using a Fokker-Planck model. The model includes the sensitivities of pick-up and kicker electrodes as calculated from field theoretical models. The effect of feedback through the beam is taken into account. Intra beam scattering is treated as an additional diffusive effect. The calculations cover the existing system of the ESR storage ring at GSI as well as the cooling system for secondary heavy ion and antiproton beams at the proposed new accelerator facility. The paper discusses the resulting cooling times. Requirements on the system layout as amplification factors and electrical power can be derived from the simulations.  
 
WEPLT144 New Characteristics of a Single-bunch Instability Observed in the APS Storage Ring sextupole, laser, resonance, emittance 2170
 
  • C.-X. Wang
    ANL, Argonne, Illinois
  • K. Harkay
    ANL/APS, Argonne, Illinois
  In the Advanced Photon Source storage ring, a transverse single-bunch instability has long been observed that appears unique to this ring. Many of its features have been previously reported. New results have recently been obtained using beam centroid history measurements and analysis. These preliminary results provide more detailed information regarding the characteristics of this instability and could provide insight into the physics mechanism.  
 
WEPLT145 Beam Loss Studies in High-intensity Heavy-ion Linacs sextupole, linac, laser, resonance 2173
 
  • P.N. Ostroumov, V.N. Aseev, E.S. Lessner, B. Mustapha
    ANL/Phys, Argonne, Illinois
  A low beam-loss budget is an essential requirement for high-intensity machines and represents one of their major design challenges. In a high-intensity heavy-ion machine, losses are required to be below 1 W/m for hands-on-maintenance. The driver linac of the Rare Isotope Accelerator (RIA) is designed to accelerate beams of any ion to energies from 400 MeV per nucleon for uranium up to 950 MeV for protons with a beam power of up to 400 kW. The high intensity of the heaviest ions is achieved by acceleration of multiple-charge-state beams, which requires a careful beam dynamics optimization to minimize effective emittance growth and beam halo formation. For beam loss simulation purposes, large number of particles must be tracked through the linac. Therefore the computer code TRACK [P.N. Ostroumov and K.W. Shepard, PRST AB 11, 030101 (2001)] has been parallelized and calculations is being performed on the JAZZ cluster [*] recently inaugurated at ANL. This paper discusses how this powerful tool is being used for simulations for the RIA project to help decide on the high-performance and cost-effective design of the driver linac.

* The Jazz Cluster, http://www.lcrc.anl.gov/jazz

 
 
WEPLT146 Mismatch Oscillations in High-current Accelerators sextupole, linac, laser, resonance 2176
 
  • O.A. Anderson
    LBNL, Berkeley, California
  Strong space charge challenges the designers of modern accelerators such as those used in Heavy Ion Inertial Fusion. Simple, accurate design tools are useful for predicting beam behavior, such as phase advances and envelope oscillation periods, given the beam emittance and charge and the lattice parameters. Along with the KV beam model, the smooth approximation [*] is often used. It is simple but not very accurate in many cases. Although Struckmieir and Reiser [**] showed that the stable envelope oscillations of unbalanced beams could be obtained accurately, they used a hybrid approach where the phase advances σ0 and σ were already known precisely. When starting instead with basic quantities–quadrupole dimensions, field strength, beam line charge and emittance–the smooth approximation formulas give substantial errors (10% or more). We previously described an integration method [***] for matched beams that yields fairly simple third-order formulas for σ0, σ, beam radius and ripple. Here we extend the method to include small-amplitude mismatch oscillations. We derive a simple modification of the smooth approximation formulas and show that it improves the accuracy of the predicted envelope frequencies significantly–for example, by a factor of five when σ0 is 83 degrees.

* M. Reiser, Particle Accelerators 8, 167 (1978) ** J. Struckmeier and M. Reiser, Particle Accelerators 14, 227 (1984)*** O. A. Anderson, Particle Accelerators 52, 133 (1996)

 
 
WEPLT147 Lattice Studies for CIRCE (Coherent InfraRed CEnter) at the ALS sextupole, linac, laser, resonance 2179
 
  • H. Nishimura, D. Robin, F. Sannibale, W. Wan
    LBNL, Berkeley, California
  CIRCE (Coherent InfraRed Center) at the Advanced Light Source is a proposal for a new electron storage ring optimized for the generation of coherent synchrotron radiation (CSR) in the terahertz frequency range. One of the main requirement for this special mode of operation is the capability of the ring of operating at very small momentum compaction values. In this regime, the longitudinal dynamics becomes strongly nonlinear and an accurate control of the higher order energy dependent terms of the momentum compaction is necessary. The lattice for CIRCE allows controlling these terms up to the third order. The paper describes the lattice and presents the calculated performances in terms of momentum acceptance, dynamic aperture, lifetime and momentum compaction tune capabilities.  
 
WEPLT148 Dynamical Map for Combined Function Magnets with Solenoid, Dipole and Quadrupole Fields sextupole, linac, laser, resonance 2182
 
  • A. Wolski, M. Venturini
    LBNL, Berkeley, California
  The interaction regions of colliders invariably include strong solenoid fields. Where quadrupoles and dipoles are embedded in the solenoid, the beam dynamics in the combined fields can be complicated to model using the traditional approach of interleaving slices of different fields. The complexity increases if the design trajectory is offset from the magnetic axis; this is the case, for example, in PEP-II. In this paper, we present maps for combined solenoid, dipole and quadrupole fields that provide a much simpler alternative to the traditional approach, and show that the deviation of the design trajectory from the magnetic axis can be handled in a straightforward manner. We illustrate the techniques presented by reference to the PEP-II interaction region.  
 
THPKF034 Design of a Photoneutron Source based on a 5 MeV Electron Linac electron, booster, beamloading, damping 2344
 
  • L. Auditore, R.C. Barnà, D. De Pasquale, A. Trifirò, M. Trimarchi
    INFN & Messina University, S. Agata, Messina
  • A. Italiano
    INFN - Gruppo Messina, S. Agata, Messina
  A photoneutron source, based on a 5 MeV electron linac was designed by means of the MCNP simulation code. Although higher electron energies are required to produce acceptable neutron fluxes, the availability of a 5 MeV electron linac developed at the Dipartimento di Fisica (Università di Messina) has suggested this project, in sight of a future development and testing of the studied neutron source. Be and BeD2 targets were considered, whose neutron production was studied optimizing two sequential steps: the bremsstrahlung production in a suitable e-gamma converter and the (gamma,n) production in an properly designed photoneutron target-reflector-moderator system. As a result of a comparative study of different materials performances, a 0.88 mm-thick W layer was chosen as e-gamma converter. A natural graphite reflector was designed, surrounding the target, enhancing the neutron flux of two order of magnitude. The final neutron flux, at 50 cm from the photoneutron target, thermalized by a 12.2 cm-thick PE layer, was estimated to be 8.48E+07 n/cm2/sec/mA with Be target and 1.23E+08 n/cm2/sec/mA with BeD2 target.  
 
THPKF035 Design of the Super-SOR Light Source synchrotron, booster, beamloading, damping 2347
 
  • N. Nakamura
    ISSP/SRL, Chiba
  The Super-SOR light source is a Japanese VUV and soft X-ray third-generation synchrotron radiation source, which is to be operated for nation-wide and world-wide users. The University of Tokyo has proposed to construct the facility in Kashiwa new campus and we have designed the light source intensively for more than two years. The light source consists of an electron storage ring, booster synchrotron and pre-injector linac. The 1.8-GeV storage ring has a circumference of about 280 m and 14 DBA cells with two 17-m and twelve 6.2-m long straight sections, which are used for twelve insertion devices and RF and injection systems. The booster synchrotron is compact, one third of the ring in circumference, and can achieve a low emittance of about 50 nmrad at 1.8 GeV. The 200-MeV linac is made up of S-band accelerating structures powered by two 50-MW klystrons and a SLED cavity and capable of changing the beam current widely in both single- and multi-bunch operation modes. These accelerators are designed so as to fully meet requirements for top-up injection. We describe the design of the Super-SOR accelerators here.

on behalf of the Super-SOR accelerator design group

 
 
THPKF036 Developments of the FZP Beam Profile Monitor booster, beamloading, beamlosses, linac 2350
 
  • N. Nakamura, M. Fujisawa, H. Kudo, H. Sakai, K. Shinoe, H. Takaki, T. Tanaka
    ISSP/SRL, Chiba
  • H. Hayano, T. Muto
    KEK, Ibaraki
  A beam profile monitor based on two Fresnel Zone Plates (FZPs) has been developed at the KEK-ATF damping ring. This monitor can perform real-time imaging of the electron beam with an X-ray imaging optics and the synchrotron radiation and measure the horizontal and vertical beam sizes with a high spatial resolution. A clear electron-beam image with the vertical beam size less than 10 microns was already obtained in the early measurements [*]. Thereafter some of the optical elements, the crystal monochromator, X-ray CCD camera and FZP holders, were improved and an X-ray pinhole mask was installed between the two FZPs for reducing the background of X-rays passing through the MZP (the second FZP). Aberrations due to alignment errors of the FZPs were studied with an analytical approach and a ray-tracing method and vibrations of the optical elements were measured in order to estimate their effects on the system performance. In this paper, we will present developments of the beam profile monitor with results of some beam-size measurements.

* K. Iida et al., Nucl. Instrum. Methods A506, p.41-49 (2003); N. Nakamura et al., Proc. of PAC2003, p.530-532

 
 
THPKF037 Quasi-isochronus Operation at NewSUBARU booster, beamloading, beamlosses, linac 2353
 
  • Y. Shoji, S.H. Hisao, T. Matsubara
    LASTI, Ako-gun, Hyogo
  Quasi-isochronus operation is one of the operation modes of NewSUBARU, a 1.5 GeV VUV storage ring. NewSUBARU has six invert bending magnets to control the momentum compaction factor. The aim of this research is to explore the extreme reduction of electron bunch length by reducing the linear momentum compaction factor. We experimentally reduced the momentum compaction factor from 0.0014 down to less than 10-5, keeping the beam in the ring. The second-order momentum compaction factor was adjusted to almost zero, while keeping the third-order momentum compaction factor positive. The ring was operated at 1.0 GeV. Using a streak camera, the shortest bunch length we observed was 4 ps FWHM. With such a low momentum compaction factor, we expect an energy spreading by betatron oscillation even at the extremely low beam current.  
 
THPKF038 Radiation Damage of Magnet Coils due to Synchrotron Radiation radiation, booster, beamloading, beamlosses 2356
 
  • K. Tsumaki, S. Matsui, M. Oishi, T. Yorita
    JASRI/SPring-8, Hyogo
  • T. Shibata, T. Tateishi
    KOBELCO, Hyogo
  Radiation damage of the equipment in the SPring-8 storage ring tunnel has become a serious problem. In the storage ring, the unnecessary radiation from bending magnets is shielded by absorbers. The equipment around the absorbers was damaged by the scattered radiation from the absorbers. Last year, cooling water leaked from the rubber hose of magnets. It was due to the deterioration of rubber hose caused by synchrotron radiation. We measured the radiation distribution around the storage ring and found that the most high intensity spot was on the magnet coil near the absorbers. If the coils are damaged and the magnets do not work correctly, we need to shut down the storage ring to exchange the magnet coils. To avoid such a situation, we needed to clarify the relation between the radiation damage of the coils and the dose of radiation. We did an acceleration test of the radiation damage of magnet coils. The magnet coils were exposed to the radiation from the bending magnet directly. We observed the degree of damage with changing the doses of radiation. In this paper, we describe about these acceleration tests and test results.  
 
THPKF039 Study of Photo-cathode RF Gun for a High Brightness Electron Beam radiation, cathode, booster, beamloading 2359
 
  • Y. Yamazaki
    JNC/OEC, Ibaraki-ken
  • S. Araki, H. Hayano, M. Kuriki, T. Muto, N. Terunuma, J. Urakawa
    KEK, Ibaraki
  • M.K. Fukuda, K. Hirano, M. Nomura, M. Takano
    NIRS, Chiba-shi
  We are going to develop a compact high-brightness electron beam system to adopt industrial and medical applications. A multi-bunch photo-cathode RF gun has been developed to generate 100 bunches beam with 2.8ns spacing and 5nC charge per bunch. We will report details of the development, especially photo-cathode production and emission characteristics from cathode by the laser.  
 
THPKF040 Development of a Femtosecond Pulse Radiolysis for Reaction Analysis in Nano-space cathode, laser, electron, booster 2362
 
  • Y. Yoshida, T. Kozawa, S. Tagawa, J. Yang
    ISIR, Osaka
  A new femtosecond pulseradiolysis system was developed in Osaka University for the study of radiation-induced ultrafast physical and chemical reactions in femtosecond time regions. In the pulseradiolysis system, a femtosecond electron beam produced by a photocathode RF gun is used as an irradiation source, while a mode-locked Ti:Sapphire femtosecond laser was used as a probe light source. A time jitter between the electron pulse and the femtosecond laser was compensated by a jitter compensation technique used a femtosecond streak camera. An oblique incidence of the probe light is considered in the system to reduce the degradation of velocity difference between the electron and the laser light in samples. A time resolution of <100 fs is expected in the pulse radiolysis system for the analysis of utrafast physical and chemical reactions in nano-space.  
 
THPKF041 SSRF: A 3.5GeV Synchrotron Light Source for China cathode, laser, booster, beamloading 2365
 
  • Z. Zhao, H. Xu
    SINR, Jiading, Shanghai
  The Shanghai Synchrotron Radiation Facility (SSRF) is an intermediate energy light source that will be built at Zhang-Jiang Hi-Tech Park in Shanghai. The SSRF consists of a 432 m circumference storage ring with an operating energy of 3.5GeV and a minimum emittace of 2.95 nm-rad, a full energy bosster, a 100MeV electron Linac and dozens of beamlines and experimental stations. The design of the SSRF accelerator complex evolves timely along the technological progress such as top-up injection, mini-gap undulator, superconducting RF system and etc. This paper reports the design progress and status of the SSRF project.  
 
THPKF043 Accelerators Use for Irradiation of Fresh Medicinal Herbs cathode, laser, booster, beamloading 2368
 
  • R.D. Minea, M.M. Brasoveanu, M.R. Nemtanu, C. Oproiu
    INFLPR, Bucharest - Magurele
  • E. Mazilu, N. Radulescu
    Hofigal S.A., Bucharest - Magurele
  The paper presents the results regarding the electron beam irradiation of fresh Salvia Officinalis and Calendula Officinalis. Irradiation is already a well-known decontamination method, but it received less attention for medicinal plants, especially on fresh herbs. Microbial load behavior, antioxidant activity, and enzymatic inhibition activity were measured for doses between 1 and 50 kGy. Up to 5 kGy, herbs are decontaminated without any important alteration in the active principles, but they loose their fresh aspect easier than non-irradiated ones. The last effect could be useful for the extracting process in which herbs are stressed anyway.  
 
THPKF044 The Improvement of NSRRC Linac for Top-up Mode Operation cathode, laser, booster, beamloading 2371
 
  • J.-Y. Hwang, J. Chen, J.-P. Chiou, K.-T. Hsu, S.Y. Hsu, K.H. Hu, T.C. King, C.H. Kuo, K.-K. Lin, C.-J. Wang, Y.-T. Yang
    NSRRC, Hsinchu
  • C.T. Pan
    NTHU, Hsinchu
  The performance of the 50 MeV linac at the National Synchrotron Radiation Research Center (NSRRC) was examined and has been improved recently. The major improved items were 1) adopting a command-charging scheme to replace the resonance charging for the linac modulator; and 2) gun electronics. As a result, the beam quality was improved in terms of its energy spectrum and stability. The correlation between the improvement of beam quality and component upgrading is analyzed. The influence of the beam quality improvement to the recently proposed top-up mode operation in 2005 will also be discussed in this report.  
 
THPKF045 Accelerator Physics Issues at NSRRC cathode, laser, booster, beamloading 2374
 
  • C.-C. Kuo, H.-P. Chang, P.J. Chou, K.-T. Hsu, G.-H. Luo, H.-J. Tsai, M.-H. Wang
    NSRRC, Hsinchu
  Over the past decade, NSRRC has served the synchrotron light users with its 1.5 GeV third-generation storage ring. To provide stable hard x-ray for the x-ray community, two strong-field superconduting wigglers have been installed and three more will be put in such a low energy ring. A superconduting rf cavity is to replace the conventional ones and the beam current will be double too. Top-up injection study is underway. This paper presents the accelerator physics issues at NSRRC such as single particle dynamics and collective effects.  
 
THPKF046 Feasibility Study of Constant Current Operation at TLS Storage Ring cathode, laser, injection, beamloading 2377
 
  • G.-H. Luo, H.-P. Chang, J. Chen, C.-C. Kuo, K.-B. Liu, R.J. Sheu, H.-J. Tsai, M.-H. Wang
    NSRRC, Hsinchu
  Several top-up experiments were carried out at various upgrade path of Taiwan Light Source. However, there were too many obstacles laid ahead of various stages to prevent the realization of top-up injection routinely. The small gap undulators, the requirement of small emittance operation and high current operation by SC cavity have promoted the top-up injection project to hightest priority. During last one and half years, a series of beam parameters measurement, subsystem checkout, installing various sensors, control program modification and hardware upgrade made the top-up injection more likely in routine operation. Discussions on the results of some measurements of booster and storage ring, the requirement of hardware upgrade and the future executable plan will be presented in this paper.  
 
THPKF050 Electron Accelerator for Energy up to 5.0 MeV and Beam Power up to 50 KW with X-ray Converter electron, cathode, laser, injection 2380
 
  • V. Auslender, A.A. Bryazgin, B.L. Faktorovich, E.N. Kokin, I. Makarov, S.A. Maximov, V.E. Nekhaev, A.D. Panfilov, V.M. Radchenko, M.A. Tiunov, V.O. Tkachenko, A.F.A. Tuvik, L.A. Voronin
    BINP SB RAS, Novosibirsk
  In recent time the new powerful industrial electron accelerators appear on market. It caused the increased interest to radiation technologies using high energy X-rays due to their high penetration ability. One of the promising directions is the creation of the irradiation installations for treatment of wide variety of food products. The report describes the industrial electron accelerator ILU-10 for electron energy up to 5 MeV and beam power up to 50 kW specially designed for use in industrial applications. The ILU-10 accelerator generates the vertical electron beam. The beam line turns the beam through an angle of 90 degrees and transports the beam to the vertically posed X-ray converter to generate the horizontal beam of X-rays. In the work presented results of measurements of the dose distribution profiles on the surface of treated products.  
 
THPKF051 The Status-2004 of the KURCHATOV Center of SR cathode, laser, beamloading, beamlosses 2383
 
  • V. Korchuganov, V. Korchuganov, Y.V. Krylov, V.V. Kvardakov, D.G. Odintsov, V. Ushkov, A.G. Valentinov, Y.L. Yupinov, S.I. Zheludeva
    RRC Kurchatov Institute, Moscow
  • M.V. Kovalchuk
    RAS/A.V.Shubnikov, Moscow
  Kurchatov Synchrotron Radiation Source (KCSR) began the work as a first dedicated synchrotron radiation facility in Russia in 1999. The facility includes two storage rings: 450 MeV SIBERIA-1 and 2.5 GeV SIBERIA-2 and is intended for experiments in the range of SR from VUV up to hard X-ray. Large progress was achieved in increasing SIBERIA-2 stored current during last year. Now maximum current at injection energy is more than 220 mA and it equals to 140 mA at operation energy. The SR dose is rising fast and the life time is also grown because of the outgassing of vacuum chamber by SR. Consequently, after the only one electrons accumulation the work during 24 hours on experimental stations becomes possible with SR beams unbroken. Eight experimental stations with SR beam lines and hutches were mounted and are now in routine operation with SR from bending magnets in experimental hall of Siberia-2. We are installing next beam lines there. SIBERIA-1 also has experimental hall with three beam lines and three experimental stations being in operation. The report describes the current work and the plans on the storage rings. It informs about achieved consumer parameters of an electron beam and status of SR stations.  
 
THPKF052 The Project of Accelerator Mass-Spectrometer at BINP cathode, laser, beamloading, beamlosses 2386
 
  • M. Petrichenkov, N. Alinovsky, V. Klyuev, E. Konstantinov, S.G. Konstantinov, A. Kozhemyakin, A. Kryuchkov, V.V. Parkhomchuk, A. Popov, S. Rastigeev, V.B. Reva, B. Sukhina
    BINP SB RAS, Novosibirsk
  The project of creation of first Russian accelerator mass-spectrometer at BINP is described. The scheme of spectrometer includes two types of ion sources (sputter and gaseous ones), low energy beam line with analysers, electrostatic tandem accelerator with accelerating voltage up to 2 MV and magnesium vapours stripper and also includes the high energy beam line with analysers. The results of first experiments with ion sources are given also.  
 
THPKF056 The MAX IV Facility cathode, laser, beamloading, beamlosses 2389
 
  • M. Eriksson, Å. Andersson, M. Bergqvist, M. Brandin, M. Demirkan, G. Georgsson, G. LeBlanc, L.-J. Lindgren, L. Malmgren, H. Tarawneh, E.J. Wallén, S. Werin
    MAX-lab, Lund
  • B. Anderberg
    AMACC, Uppsala
  • S. Biedron, S.V. Milton
    ANL, Argonne, Illinois
  The MAX IV facility is a planned successor of the existing MAX facility. The planned facilty is described below. It consists of two new synchrotron storage rings operated at different electron energies to cover a broad spectral region and one linac injector. The linac injector is also meant to be operated as a FEL electron source. The two rings have similar low emittance lattices and are placed on top of each other to save space. A third UV light source, MAX III, is planned to be transfered to the new facility.  
 
THPKF058 Experimental Experience with a Thermionic RF-gun cathode, laser, gun, beamlosses 2391
 
  • S. Werin, Å. Andersson, M. Bergqvist, M. Brandin, L. Malmgren, S. Werin
    MAX-lab, Lund
  • G. Georgsson
    Danfysik A/S, Jyllinge
  An RF-gun structure developed at MAX-lab, and thus different from the most common BNL-structure, is in operation as a thermionic RF-gun at MAX-lab. The properties of the gun have been investigated. Especially aspects such as extractable energy range, emittance properties at various beamloading conditions and extracted current.  
 
THPKF059 Adaption of an RF-gun from Thermionic to Photo Cathode gun, beamlosses, linac, laser 2394
 
  • S. Werin, M. Berglund, M. Brandin, T. Hansen
    MAX-lab, Lund
  The current electron source for the injector at MAX-lab is a thermionic RF-gun. This gun produces a several ns long pulse with a significant beamloading. To allow for ?few bucket? operation and emittance reduction the gun will be adapted for operation with a ns laser system. The system to be installed during the spring 2004 is a 3 or 4th harmonic injection seeded Nd:YAG laser. The thermionic BaO cathode already in use will be used at a temperature just below thermal emission where a quantum efficiency of around 1* 10-4 is expected.  
 
THPKF060 Singapore Synchrotron Light Source– Helios 2 and Beyond gun, beamlosses, laser, brilliance 2397
 
  • H.O. Moser, B.D.F. Casse, E.P. Chew, M. Cholewa, C. Diao, S.X.D. Ding, M. Hua, J.R. Kong, Z. Li, S.bin. Mahmood, M.L. Ng, B.T. Saw, S.V.S. Vidyaraj, O. Wilhelmi, J.H.W. Wong, P. Yang, X.J. Yu
    SSLS, Singapore
  SSLS is operating a superconducting 700 MeV electron storage ring to produce synchrotron radiation over a useful spectral range from 10 keV to the far infrared for micro/nanofabrication, phase contrast imaging, surface and nano science with soft X-rays, and hard X-ray diffraction and absorption spectroscopy. An Infrared spectro/microscopy beamline is under construction. Latest results from all beamlines will be presented. SSLS is also working on a conceptual study of a Linac Undulator Light Installation (LIULI) that includes a superconducting miniundulator. Pursuing earlier work* a prototype built by ACCEL is being tested at SSLS and will later serve for FEL studies in cooperation with SSRF at Shanghai.

* A. Geisler, A. Hobl, D. Krischel, H.O. Moser, R. Rossmanith, M. Schillo, First Field Measurements and Performance Tests of a Superconductive Undulator for Light Sources with a Period Length of 14 mm, ASC Conference, Houston, TX, August 2002

 
 
THPKF061 RT-office for Electron Beam, X-ray, and Gamma-ray Dosimetry radiation, gun, beamlosses, laser 2400
 
  • G.F. Popov, V.T. Lazurik, V.M. Lazurik, Y.V. Rogov
    KhNU, Kharkov
  An absorbed dose of electron beam (EB),X-ray (bremsstrahlung), and gamma-ray within the irradiated product is one of the most important characteristic for all industrial radiation-technological processes. The conception for design of the Radiation-Technological Office (RT-Office) - software tools for EB, X-ray, and gamma-ray dosimetry for industrial radiation technologies was developed by authors. RT-Office realize computer technologies at all basic stages of works execution on the RTL using irradiators of EB, X-ray, and gamma-ray in the energy range from 0.1 to 25 MeV. The specialized programs for simulation of EB, X-ray, and gamma-ray processing and for decision of special tasks in dosimetry of various radiation technologies were designed on basis of the RT-Office modules. The use of the developed programs as predictive tools for EB,X-ray, and gamma-ray dose mapping, for optimization of regimes irradiation to receive minimum for dose uniformity ratio, for reducing the volume of routine dosimetry measurements of an absorbed dose within materials at realization of the radiation-technological processes are discussed in the paper.  
 
THPKF062 Comparison of Dose Distribution Prediction in Targets Irradiated by Electron Beams with Dosimetry gun, simulation, beamlosses, laser 2403
 
  • G.F. Popov, V.T. Lazurik, V.M. Lazurik, Y.V. Rogov
    KhNU, Kharkov
  • I. Kalushka, Z. Zimek
    Institute of Nuclear Chemistry and Technology, Warsaw
  The features of the absorbed depth-dose distribution (DDD) on boundaries of two contacting materials and material with air irradiated with an electron beam (EB) were predicted by simulation with the software ModeRTL (Modeling of the radiation-technological lines (RTL)). Validation of DDD prediction with dosimetry was fulfilled on the industrial RTL with linear electron accelerator LAE 13/9 at the INCT, Warsaw. Simulation and measurement of boundary effects of DDD were carried out for targets irradiated by scanning EB with energy 10 MeV on moving conveyer. The irradiated materials were represented as parallelepipeds with all sizes greater than range of electrons in material. Cellulose Triacetate (CTA) dosimetric film (FTR-125) in form of strips inserted between materials and air in parallel with an axis of EB was used for dosimetry. Such irradiation setup allows to receive the complete curve of DDD on the boundary of contacting materials by one dosimetric film. The physical regularities for DDD on the boundary of contacting materials predicted by simulation methods were experimentally confirmed. Investigation of those anomalies is necessary in practice to estimate the quality of an irradiation performed on RTL at realization of various industrial EB processing.  
 
THPKF063 Parameters of X-ray Radiation Emitted by Compton Sources gun, simulation, beamlosses, brilliance 2406
 
  • E.V. Bulyak, V. Skomorokhov
    NSC/KIPT, Kharkov
  Presented are results of analytical study on X–ray beam parameters generated in the Compton storage rings. A model with the given circulating electron bunch parameters and the laser splash as well is considered. For this model, the total yield of x–ray quanta is derived as a function of the crossing angle and geometric dimensions of both the bunch and splash. Also spectral characteristics of emitting x–ray beam are evaluated with account for the collimating conditions and both the angular and energy spreads in the bunch. As is shown the width of x–ray energy spectrum is narrowest for the x-ray beam collimated along the bunch orbit. With increasing the scattering angle (with respect to the bunch orbit) the spectrum of emitting quanta is widening. Problems of x-ray beam generation with required energy and brightness with the Compton storage rings are discussed.  
 
THPKF064 Status of Kharkov X-ray Generator based on Compton Scattering NESTOR vacuum, gun, simulation, beamlosses 2409
 
  • A.Y. Zelinsky, V.P. Androsov, E.V. Bulyak, I.V. Drebot, P. Gladkikh, V.A. Grevtsev, V.A. Ivashchenko, I.M. Karnaukhov, V. Lapshin, V. Markov, N.I. Mocheshnikov, A. Mytsykov, F.A. Peev, A.V. Rezaev, A.A. Shcherbakov, V.L. Skirda, V.A. Skomorokhov, Y.N. Telegin, V.I. Trotsenko
    NSC/KIPT, Kharkov
  • A. Agafonov, A.N. Lebedev
    LPI, Moscow
  • J.I.M. Botman
    TUE, Eindhoven
  • T.R. Tatchyn
    SLAC/SSRL, Menlo Park, California
  Nowadays the sources of the X-rays based on a storage ring with low beam energy and Compton scattering of intense laser beam are under development in several laboratories. In the paper the state-of-art in development and construction of cooperative project of a Kharkov advanced X-ray source NESTOR based on electron storage ring with beam energy 43 - 225 MeV and Nd:YAG laser is described. The layout of the facility is presented and main results and constructing timetable are described. The designed lattice includes 4 dipole magnets with combined focusing functions, 20 quadrupole magnets and 19 sextupoles with octupole component of magnetic field. At the present time a set of quadrupole magnet is under manufacturing and bending magnet reconstruction is going on. The main parameters of developed vacuum system providing residual gas pressure in the storage ring vacuum chamber up to 10-9 torr are presented along with testing measurement at NSC KIPT vacuum bench. The facility is going to be in operation in the middle of 2006 and generated X-rays flux is expexted to be of about 1013 phot/s.  
 
THPKF066 Conception of X-ray Source Based on Compact Wakefield Undulator vacuum, gun, simulation, undulator 2412
 
  • A. Opanasenko
    NSC/KIPT, Kharkov
  Study of interaction of bunched charged ultrarelativistic particles with own wakefields in periodic rf structures detects new applications in the area of accelerator physics and technology. Conception of monochromatic X-ray source based on wakefield undulator, WFU, with very short period is presented. In the base of photon generation by the WFU lies a new mechanism of undulator-type radiation emitted by an ultrarelativistic electron bunch that undulates due to non-synchronous spatial harmonics of its wakefields while the bunch moves along a periodic waveguide. The features of the hard radiation and yield of photons depending on waveguide sizes and charge distribution are considered. The creation of the WFU with sub-millimetre periods due to advanced accelerator technology, such as deep X-ray lithography, opens possibilities to obtain high brightness X-rays at employing comparatively low electron energies without external alternative fields. That can have commercial significance for technological and medical applications.  
 
THPKF067 Progress of the DIAMOND Storage Ring and Injector Design. vacuum, gun, simulation, undulator 2415
 
  • S.L. Smith, D.J. Holder, J.K. Jones, J.A. Varley, N.G. Wyles
    CCLRC/DL/ASTeC, Daresbury, Warrington, Cheshire
  • R. Bartolini, I.P.S. Martin, B. Singh
    Diamond, Oxfordshire
  DIAMOND is a state of the art 3 GeV synchrotron light source that will be available to users in 2007. Considerable further progress has been made on the accelerator physics design of the storage ring, booster and other associated injector systems. Detailed analysis of injection processes, lifetime, coupling, instabilities, feedback systems and dynamic aperture have been undertaken driven by the procurement activity and the desire to fully understand all aspects of the accelerator's performance.  
 
THPKF068 An Advanced Light Source Proposed for the South Eastern USA lattice, vacuum, gun, emittance 2418
 
  • V.P. Suller, M.G. Fedurin, J. Hormes
    LSU/CAMD, Baton Rouge, Louisiana
  • D. Einfeld
    CELLS, Bellaterra (Cerdanyola del Vallès)
  • G. Vignola
    SESAME, Amman
  At this time CAMD, a 1.3 GeV second generation storage ring, is the only synchrotron radiation facility in the Southeastern USA. To cater for the increasing demand for synchrotron light in this region a study is being made for a new high performance source. In keeping with its role as a regional source, it must be economical to construct and operate yet provide high brightness beams from its Insertion Devices. These will need to span both the soft X-ray region (1-2 keV) and the X-ray region up to at least 13 keV. A high brightness 3rd generation source is described which exhibits a beam emittance less than 10 nm rads at an energy of 2.5 GeV. By using a lattice cell derived from the Theoretical Minimum Emittance type, this performance is achieved in a circumference of only approximately 160 m. The economical, yet flexible, lattice uses vertically focusing gradient in the dipoles. The lattice functions and other parameters are presented of both a 12 cell double bend design and a 10 cell triple bend. The 12 cell gives a horizontal emittance of 8.5 nm rads and the 10 cell 4.6 nm rads. The dynamical stability of both lattices is described together with the beam performance from the anticipated insertion devices. The current status of the proposal is explained.  
 
THPKF069 Improvements to, and Current Status of, the CAMD Light Source lattice, vacuum, gun, emittance 2421
 
  • V.P. Suller, M.G. Fedurin, P. Jines, D.J. Launey, T.A. Miller, Y. Wang
    LSU/CAMD, Baton Rouge, Louisiana
  Throughout 2003 a sustained program of modifications and improvements has been applied to the CAMD light source. These affected the 7 Tesla wiggler, the RF system, the magnet power supplies, the control system, the diagnostics and the injector linac. These modifications and their impact on the storage ring performance are described, together with an analysis of where future improvements should be directed. The present performance and limitations of CAMD are described.  
 
THPKF070 A Beam Based Alignment System at the CAMD Light Source vacuum, gun, emittance, simulation 2424
 
  • V.P. Suller, E.J. Anzalone, A.J. Crappell, M.G. Fedurin, T.A. Miller
    LSU/CAMD, Baton Rouge, Louisiana
  Beam based alignment is being applied to the CAMD light source. It is implemented by a flexible and versatile system of electronic shunts which are applied to each of the storage ring lattice quadrupoles. The essential design features of the electronic shunts are described as is the routine operation of the full system. The improvement to the corrected closed orbit from using the system is shown. Preliminary results are presented of the use of the shunts for correcting the lattice functions.  
 
THPKF071 Linear Coupling and Lifetime Issues in the DIAMOND Storage Ring vacuum, coupling, gun, simulation 2427
 
  • R. Bartolini
    Diamond, Oxfordshire
  • N.G. Wyles
    CCLRC/DL/ASTeC, Daresbury, Warrington, Cheshire
  In synchrotron light sources the correction of the linear coupling is an important issue related to the brightness of the photon beam and to the beam lifetime. The vertical emittance of the electron beam in the DIAMOND storage ring will be controlled using 168 skew quadrupoles embedded in the sextupoles of the ring. In this paper we report the linear coupling estimates for the expected misalignment errors and we compare the results of coupling correction with different correction strategies. The effect on lifetimes is also discussed.  
 
THPKF072 Progress with the Diamond Light Source coupling, gun, simulation, insertion 2430
 
  • R.P. Walker
    Diamond, Oxfordshire
  Construction of Diamond, the UK?s new 3 GeV, 3rd generation synchrotron light source, is well underway and progressing in-line with the original target of starting storage ring commissioning in January 2006 and being operational for users in January 2007. Having completed the foundations, the main building works are now proceeding at their maximum rate. Most of the major machine components are also under construction, aiming towards the key target date of starting machine installation in September 2004. As well as reporting on the overall status, detailed design developments and component choices will be summarised. The results of tests of various prototype components, including magnets, vacuum vessels and girders, will also be presented.  
 
THPKF073 CIRCE, the Coherent InfraRed CEnter at the ALS coupling, gun, simulation, insertion 2433
 
  • J.M. Byrd, S. De Santis, J.-Y. Jung, M.C. Martin, W.R. McKinney, D.V. Munson, H. Nishimura, D. Robin, F. Sannibale, R.D. Schlueter, M. Venturini, W. Wan, M.S. Zolotorev
    LBNL, Berkeley, California
  CIRCE (Coherent InfraRed Center) is a new electron storage ring to be built at the Advanced Light Source (ALS) of the Lawrence Berkeley National Laboratory (LBNL). The ring design is optimized for the generation of coherent synchrotron radiation (CSR) in the terahertz frequency range. CIRCE operation includes three possible modes: ultra stable CSR, femtosecond laser slicing CSR and broadband SASE. CSR will allow CIRCE to produce an extremely high flux in the terahertz frequency region. The many orders of magnitude increase in the intensity is the basis of our project and enables new kinds of science. The characteristics of CIRCE and of the different modes of operation are described in this paper.  
 
THPLT004 Toroidal Cavity Loaded with an Electron Beam linac, laser, simulation, insertion 2460
 
  • E.D. Gazazyan, T. Harutyunyan, D. Kalantaryan
    YSU, Yerevan
  • V. Kocharyan
    DESY, Hamburg
  Three problems have been considered in this paper: the development of Maxwell's equations strict solution method to define the electromagnetic own values and own functions of the toroidal cavity; the radiation of the charged bunch rotating along the average radius, and, at last, the consideration of the case of a toroid filled with dielectric medium. The peculiarities of this radiation have been investigated as well. We suppose to consider the case when toroid is filled with plasma like a disperse medium.  
 
THPLT005 Ultra-high Frequency Scanning Cavities for Non-relativistic Electron Beam linac, laser, simulation, insertion 2463
 
  • G.G. Oksuzyan, E.D. Gazazyan, A.T. Margaryan, A.D. Ter-Poghosyan
    YerPhI, Yerevan
  • M. Ivanyan
    CANDLE, Yerevan
  The different scanning schemes based on the RF cavities for non-relativistic electron beam are examined. Optimization criteria for various types of cavities were developed. A complete picture of the beamscanning at a given point of interest is obtained.  
 
THPLT006 A Comparison of COSY DA Maps with Analytic Formulae for Orbit Functions of a Non-scaling FFAG Accelerator linac, laser, simulation, insertion 2466
 
  • S.R. Koscielniak
    TRIUMF, Vancouver
  Fixed Field Alternating Gradient (FFAG) magnetic lattices with fixed, possibly high, radio-frequency proposed for muon acceleration have unusual requirements: relative momentum swing dp/p of ± 30% and relative spread of revolution frequencies < 10-3. It is not evident whether the existing accelerator optical design codes are sufficiently accurate for such a large momentum range. Analytic expressions for orbit displacements, tunes and path length have been derived for thick-element models of doublet, F0D0 and FDF triplet lattices; it is this paper's purpose to compare these with values computed by SYNCH and COSY, and truncated Taylor maps constructed by Lie algebra. The mutual agreement of results from independent sources will serve to validate them all. A mathematical necessity is that one at least of the magnets be of the combined-function type, and with entrance and exit faces disposed in a sector layout. It is sufficient to consider the triplet case because in the limit that the two F quadrupoles are combined, the cell reduces to the simpler F0D0. We use as our example a "nonscaling" FFAG ring proposed for accelerations of muons over the momentum range 10-20 GeV/c.  
 
THPLT010 Limiting High Frequency Longitudinal Impedance of an Inductive Pick-up by a Thin Metallic Layer antiproton, laser, simulation, insertion 2478
 
  • M. Gasior
    CERN, Geneva
  An Inductive Pick-Up (IPU) was developed to measure the position and current of an electron beam of the CTF3 Drive Beam Linac. The pick-up construction is similar to a wall current monitor, but the pick-up inner wall is divided into 8 electrodes, each of which forms the primary winding of a toroidal transformer. The beam image current component flowing along each electrode is transformed to a secondary winding, connected to an output. The continuity of the vacuum chamber is taken care of by a ceramic insertion surrounded by the electrodes. The insertion is titanium coated on the inside and the end-to-end resistance of the layer is chosen in such a way that within the IPU bandwidth the image current flows over the electrodes. For higher frequencies the current is conducted by the coating to limit the longitudinal impedance of the device in the GHz range. This paper describes a simple electric network model, which was used to simulate the influence of the coating and to optimize its resistance. The model is built from sections of ideal transmission lines and resistors and is suitable for SPICE simulations. Results of measurements and simulations are compared.  
 
THPLT011 Longitudinal Loss Distribution along the LHC antiproton, laser, simulation, lattice 2481
 
  • E.B. Holzer, B. Dehning
    CERN, Geneva
  For the design and calibration of the LHC beam loss monitoring system it is essential to have good predictions of the expected longitudinal loss distributions. For this purpose a complete and detailed aperture model of one LHC sector was compiled and included with the tracking code MAD. The positions of all beam pipe bellows are included in the model as well. Therefore, it allows investigating the loss pattern due to misalignment effects, in addition to steady beam losses (beam halo, beam-beam and beam-rest gas interactions) and orbit errors. Loss maps of halo particles originating from the betatron cleaning insertion have been created for proton and ion beams. The distribution of particle losses along the beam pipe is folded with the result of GEANT simulations of the shower development through the magnets and cold masses. They link the loss of a beam particle on the aperture to particle fluencies outside of the cryostats, where the beam loss monitors will be installed. These simulations determine the positioning of the loss monitors, the longitudinal distance one detector has to cover to achieve the required resolution as well as all calibration factors for the individual detectors. The model also serves to identify hot spots, which can limit the performance of the LHC.  
 
THPLT012 Design of the Beam Loss Monitoring System for the LHC Ring antiproton, laser, simulation, lattice 2484
 
  • E.B. Holzer, B. Dehning, E. Effinger, G. Ferioli, J.L. Gonzalez, E. Gschwendtner, G. Guaglio, M. Hodgson, V. Prieto, C. Zamantzas
    CERN, Geneva
  The beam loss monitoring (BLM) system of the LHC is one of the most critical elements for the protection of the LHC. It must prevent the super conducting magnets from quenches and the machine components from damages, caused by beam losses. It helps in the identification of the loss mechanism by measuring the loss pattern. Special detectors will be used for the setup and control of the collimators. Furthermore, it will be an important tool during machine setup and studies. The specification requirements of the BLM system include a very high reliability  
 
THPLT013 Simulation of Multi-bunch Multi-turn Instabilities in High Energy Proton Rings: Algorithms and Results antiproton, laser, lattice, undulator 2487
 
  • A. Koschik
    CERN, Geneva
  A simulation code to study collective effects in multi-bunch proton machines has been developed and applied to the CERN SPS and LHC. The 3D simulation program allows the exploration of long-range effects due to resistive-wall and HOMs in circular, elliptic and rectangular vacuum chambers also for uneven filling schemes. The code has been benchmarked with measurements in the SPS. Results obtained for LHC, including beam stability and emittance growth, are presented and discussed.  
 
THPLT014 Coupler Structures for the LHC Beam-pipe Waveguide Mode Reflectometer antiproton, laser, lattice, undulator 2490
 
  • T. Kroyer
    TU Vienna, Vienna
  • F. Caspers
    CERN, Geneva
  The LHC reflectometer will be used to detect and localize obstacles and other kinds of discontinuities in the LHC beam screen. An important part of this device is the RF coupler element, which provides the interface between the circular beam screen and the measurement equipment. Two different scenarios of operation are considered. The first option consists in carrying out measurements during assembly by directly branching a coupler to the end of the beam screen. The other one is a permanent installation to be used in situ requiring a different kind of coupler to keep the aperture free. The goal is to achieve a reasonably well-matched spurious mode-free excitation over a 25% bandwidth for the TM01 and the T·1011 mode, respectively. The fulfillment of the required features is severely complicated by space and material restrictions arising mainly from vacuum and installation constraints.  
 
THPLT015 Accuracy of Profile Monitors and LHC Emittance Measurements antiproton, laser, lattice, undulator 2493
 
  • F. Roncarolo, G. Arduini, B. Dehning, G. Ferioli, J. Koopman, D. Kramer
    CERN, Geneva
  The monitoring and controlling of the beam transverse emittance is essential to allow high luminosity performances in a collider operation. The profile monitors in the LHC injection chain are exploited to determine their precision. A fit strategy was developed to reduce the fitting procedure error and make it negligible compared to instrumentation errors. The method proved to be robust against non-Gaussian tails and can estimate the fraction of non-Gaussian distributed beam intensity. The procedure was applied to the 2003 SPS Wire Scanner measurements with different kind of LHC type beams. The reproducibility of the six available monitors was determined by choosing one as a reference and making synchronized measurements. Several instrumental errors were discovered and corrected to the one per cent level. The demanding small LHC transverse emittances were determined under different beam conditions in terms of intensity, bunch spacing and length in the PS Booster, PS and SPS.  
 
THPLT016 LHC Orbit Feedback Tests at the SPS feedback, antiproton, laser, lattice 2496
 
  • J. Wenninger, J. Andersson, L.K. Jensen, R.O. Jones, M. Lamont, R. Steinhagen
    CERN, Geneva
  The real-time orbit feedback system foreseen for the LHC will be an essential component for reliable and safe machine operation. A test setup including a number of beam position monitors equipped with the LHC acquisition and readout system have been installed in the SPS ring to perform prototyping work on such an orbit feedback. A closed loop digital feedback was implemented and tested with LHC beams on the SPS during the 2003 machine run. The feedback loop was tested successfully at up to 100 Hz. The performance of the feedback loop and of its constituents will be described.  
 
THPLT017 Review and Comparison of Simulation Codes Modeling Electron-Cloud Build Up and Instabilities feedback, antiproton, laser, lattice 2499
 
  • F. Zimmermann, E. Benedetto, F. Ruggiero, D. Schulte
    CERN, Geneva
  • G. Bellodi
    CCLRC/RAL/ASTeC, Chilton, Didcot, Oxon
  • M. Blaskiewicz, L. Wang
    BNL, Upton, Long Island, New York
  • Y. Cai, M.T.F. Pivi
    SLAC, Menlo Park, California
  • V.K. Decyk, W. Mori
    UCLA, Los Angeles, California
  • M.A. Furman
    LBNL/AFR, Berkeley, California
  • A.F. Ghalam, T. Katsouleas
    USC, Los Angeles, California
  • K. Ohmi, S.S. Win
    KEK, Ibaraki
  • G. Rumolo
    GSI, Darmstadt
  Several computer codes written at various laboratories are employed for modelling the generation and the consequences of an electron cloud. We review the most popular of these programs, which simulate either the build of an electron cloud or the instabilities it produces, and we compare simulation results for identical, or similar, input parameters obtained from the various codes.  
 
THPLT018 Electron Beam Dynamics Simulations for the Low Emittance Gun feedback, antiproton, gun, electron 2502
 
  • M. Dehler, S.C. Leemann
    PSI, Villigen
  • A.E. Candel
    ETH, Zürich
  We report on theoretical simulation performed for the development of a high brightness, field emitter based electron gun suitable for an Angstrom wavelength free electron laser\cite{LEG}. First simulations have been done with available codes in 2 1/2D and 3D for basic gun configurations showing the global and local (due to the granularity of the emitter array) effects on the emittance dilution.Design and construction started on a test setup consisting of a 100 keV electron gun with solenoidal focusing and a diagnostics module. In addition to solenoid focussing, anode shaping will be investigated in order to compensate for non-linear fields leading to space charge blow-up. For advanced simulations of field emitter based guns allowing to resolve individual emitters and to capture the influence of mechanical imperfections, a massive parallel code for 3D particle-in-cell simulations is in development. The electromagnetic field solver is fully functional and the particle tracker has been completed in its basic structures.  
 
THPLT019 Commissioning Results of the Multi Bunch Feedback System at SLS antiproton, gun, electron, lattice 2505
 
  • M. Dehler, R. Kramert, P. Pollet, T. Schilcher
    PSI, Villigen
  • D. Bulfone, M. Lonza
    ELETTRA, Basovizza, Trieste
  Within the frame of the project for a multi bunch feedback system for the Swiss Light Source (SLS), a new family of 500 MS/s analog to digital and digital to analog conversion boards with an 8 bit resolution has been developed, containing on board MUX and DEMUX circuitry to reduce data rates to approximately 20 MS/s using up to ten Front Panel Data Port (FPDP) ports. Using six quad processor DSP boards, full bandwidth bunch by bunch feedbacks in the transverse and longitudinal planes are set up to provide bunch by bunch correction kicks with a 2 nsec resolution. We report on the hardware setup and properties as well as feedback performance in the SLS storage ring.  
 
THPLT020 The DSP-based Betatron Tune Feedback of the Ramped 1.5 GeV Electron Storage Ring BoDo antiproton, feedback, gun, electron 2508
 
  • B. Keil
    PSI, Villigen
  • K. Wille
    DELTA, Dortmund
  The ramped storage ring BoDo is the full energy injector of the 1.5 GeV synchrotron light source DELTA. All ramped booster magnet power supplies, RF power and beam diagnostics of BoDo are handled by a distributed VME-based DSP (digital signal processor) multiprocessing system developed at DELTA. The VME DSP boards of this system are interconnected by DeltaNet, a novel reflective memory ring network. DeltaNet transmits the measurement data from each DSP board to all other boards in real-time via fibre optic links. The generic hardware and software architecture of the system allows the implementation of different kinds of global real-time feedbacks with correction rates in the range from some 100 Hz to some 10 kHz. This paper presents architecture and performance of a real-time betatron tune feedback that was implemented with the DSP system. The betatron tune is measured and corrected in both planes at a rate of typically 700 Hz for arbitrary beam optics and energy ramps of BoDo. In combination with the global Bodo orbit feedback, the tune feedback increases the performance of Bodo both as an injector and as a testbed for machine studies and newly developed accelerator components.  
 
THPLT021 A DSP-Based Fast Orbit Feedback System for the Synchrotron Light Source DELTA antiproton, feedback, gun, electron 2511
 
  • B. Keil
    PSI, Villigen
  • K. Wille
    DELTA, Dortmund
  A DSP-based Fast Orbit Feedback (FOFB) system has been designed for the synchrotron light facility DELTA. DELTA consists of a 60 MeV linac, the ramped storage ring BoDo as full-energy injector and the 1.5 GeV storage ring Delta. BoDo and Delta have the same dipole, quadrupole and corrector magnet design, the same beam pipe design and the same BPM RF frontends, therefore BoDo was used as a testbed for the newly developed FOFB hardware and software. Using the fast corrector magnet power supplies of BoDo, the FOFB could damp orbit perturbations up to 90 Hz. The envisaged future use of the FOFB for the Delta storage ring will require either the partial or full replacement of the present slow (1 Hz bandwidth) Delta corrector power supplies, or additional fast power supplies with dedicated FOFB corrector magnets. A first test of the FOFB in Delta for local orbit stabilization at one beamline is in preparation. This paper presents the results of a successful test of the FOFB at BoDo, where it achieves a correction rate of 4 kHz for a global SVD-based feedback in both planes. The FOFB is based on the "DeltaDSP" VMEbus DSP boards that are also used for the BoDo betatron tune feedback.  
 
THPLT022 The Generic VME PMC Carrier Board: A Common Digital Hardware Platform for Beam Diagnostics and Feedbacks at PSI antiproton, gun, lattice, undulator 2514
 
  • B. Keil, C. Buehler, P.-A. Duperrex, U. Greuter, R. Kramert, P. Pollet, V. Schlott, N. Schlumpf, P. Spuhler
    PSI, Villigen
  Rapid progress in digital electronics allows digitization of monitor signals at a very early stage of the signal processing chain, providing optimum performance and maximum flexibility for today's accelerator instrumentation. While the analog front-ends of such systems are usually specific for each monitor type, the subsequent digital part of the processing chain can be unified for many different measurement tasks. The "VME generic PMC Carrier board" (VPC) was developed to achieve this unification at the PSI electron and proton accelerator diagnostics and fast data acquisition and feedback systems. The core of the VME64x board consists of two Virtex2Pro FPGAs with two PowerPCs each, a floating point DSP and RAM. The FPGAs can acquire and process measurement data from the VMEbus P0/P2 connectors or from two application-dependent PMC mezzanine modules. Two 2 GBaud fibre optics transceivers may also be used to aquire or distribute measurement data. Envisaged applications include digital beam position (DBPM) and current monitors for proton beams, data processing for a muon decay experiment, and general beam diagnostics as well as global feedbacks at SLS accelerators and beamlines.  
 
THPLT023 The Use of Photon Monitors at the Swiss Light Source antiproton, photon, gun, lattice 2517
 
  • J. Krempasky, M. Böge, T. Schilcher, V. Schlott, T. Schmidt
    PSI, Villigen
  The photon beam position monitors (PBPM) in a synchrotron radiation facility are important tools for beam-line and machine diagnostics since they deliver position and angle information directly from the radiation source point. In the last two years a number of PBPMs have been installed and commissioned at the Swiss Light Source (SLS). Their readouts have been systematically studied and the results have been correlated with data from the digital beam position monitor (DBPM) system. It turns out that the PBPMs help understanding the influence of insertion device gap changes on photon beam position and thus on photon flux and/or energy resolution near the beam-line experimental stations. In addition to the global fast orbit feedback (FOFB), a local slow feedback based on PBPM data has been implemented to remove the remaining systematic effects of the DBPM system and to stabilize the photon beam to a micron level at the experimental station.  
 
THPLT024 Commissioning and Operation of the SLS Fast Orbit Feedback antiproton, photon, gun, lattice 2520
 
  • T. Schilcher, M. Böge, B. Keil, P. Pollet, V. Schlott
    PSI, Villigen
  The SLS Fast Orbit Feedback (FOFB) was successfully commissioned in 2003. Since November 2003 it runs during user operation of the accelerator. Taking into account 72 Digital Beam Position Monitors (DBPMs), the FOFB applies SVD-based global orbit corrections for 72 horizontal (x) and 72 vertical (y) correctors at a rate of 4 kHz, compared to ~0.5 Hz for the Slow Orbit Feedback (SOFB) that was used so far. While the SOFB was important for the elimination of orbit drifts due to temperature changes and slowly moving insertion device (ID) gaps, the FOFB is also able to damp orbit oscillations that are caused by fast changes of ID gaps or magnets, by ground and girder vibrations, 3 Hz booster crosstalk and power supply noise. This report presents experience from commissioning and user operation of the FOFB.  
 
THPLT025 Using Visible Synchrotron Radiation at the SLS Diagnostics Beamline antiproton, gun, lattice, undulator 2523
 
  • V. Schlott, M. Dach, Ch. David, B. Kalantari, M. Pedrozzi, A. Streun
    PSI, Villigen
  A diagnostics beamline has been set-up at the BX05 bending magnet of the SLS storage ring. It is equipped with a standard bending magnet front end, including two photon beam position monitors (PBPM) for determination of photon beam angle and position as well as a pinhole array monitor for online monitoring of beam size. The visual part of the dipole radiation is transported to an optical lab, where the temporal profile of the storage ring bunches can be measured with a minimal time resolution of 2 ps using a dual sweep, synchrocan streak camera. Simultaneously, beam size and coupling can be measured at 1.8 keV radiation energy with a zome plate monitor overcoming diffraction limitations. This paper describes the beamline design and summarizes the first experimental results.  
 
THPLT026 Beam Profile Measurements at PETRA with the Laserwire Compton Scattering Monitor antiproton, positron, laser, gun 2526
 
  • T.  Kamps
    BESSY GmbH, Berlin
  • K. Balewski, H.-C. Lewin, S. Schreiber, K. Wittenburg
    DESY, Hamburg
  • G.A. Blair, G. Boorman, J. Carter, F. Poirier
    Royal Holloway, University of London, Surrey
  • S.T. Boogert
    UCL, London
  • T. Lefevre
    CERN, Geneva
  The vertical beam profile at the PETRA positron storage ring has been measured using a laserwire scanner. A laserwire monitor is a device which can measure high brilliant beam profiles by scanning a finely focused laser beam non-invasively across the charged particle beam. Evaluation of the Compton scattered photon flux as a function of the laser beam position yields the transverse beam profile. The aim of the experiment at PETRA is to obtain the profile of the positron beam at several GeV energy and several nC bunch charge. Key elements of laserwire systems are currently being studied and are described in this paper such as laser beam optics, a fast scanning system and a photon calorimeter. Results are presented from positron beam profile scans using orbit bumps and a fast scanning scheme.  
 
THPLT027 Optical Transition Radiation Based Beam Diagnostics at the BESSY Synchrotron Radiation Source and FEL Accelerators antiproton, positron, gun, lattice 2529
 
  • T.  Kamps, K. Holldack, P. Kuske
    BESSY GmbH, Berlin
  Optical Transition Radiation (OTR) based diagnostics tools are widely used in linear accelerators to measure beam parameters like transverse beam size and emittance. Design ideas for OTR stations in the linac section of the BESSY FEL facility are presented. Several key components will be tested in the transfer lines of the BESSY storage ring. Furthermore a novel type of OTR monitor is introduced which enables the measurement of the transverse overlap of seed laser and electron beam in the undulator sections of the linac based FEL facility. Here a special radiator screen will be used allowing simultaneous imaging of both beams in the same optical readout channel.  
 
THPLT028 High Precision Cavity Beam Position Monitor antiproton, positron, gun, lattice 2532
 
  • A. Liapine, H. Henke
    TET, Berlin
  A cavity beam position monitor is proposed for measuring the beam deflection in the TESLA energy spectrometer. The precision of the measurement has to be better than 1 micrometer. A slotted cavity is chosen as pick-up in order to reject the background signals and enhance the precision and the dynamic range of the monitor. The paper gives the design overview for two prototypes with operating frequencies of 1.5 GHz and 5.5 GHz, respectively. The results obtained on the test bench with direct conversion electronics are presented. A resolution of about 100 nm was achieved.  
 
THPLT029 Parallel Particle in Cell Computations with GdfidL antiproton, positron, gun, lattice 2535
 
  • W. Bruns
    WBFB, Berlin
  The electromagnetic field solver GdfidL has been extended to compute with free moving charges. For computing in parallel, GdfidL partitions the computational volume in many small subvolumes. Each processor computes the electromagnetic field in its part of the whole volume. In addition to the normal field update equations, the movement of the particles must be computed from the Lorentz-force, and the convection current due to the moving charges must be computed and be used to change the electric field near the particle. For each particle, these computations are performed by the processor which is responsible for the volume where the particle is in. Details of the parallel implementation of the used algorithm, Particle in Cell, are given.  
 
THPLT030 A Novel Device for Non-intersecting Bunch Shape Measurement at the High Current GSI-Linac antiproton, positron, gun, lattice 2538
 
  • P. Forck, C. Dorn, M.H. Herty, P. Strehl
    GSI, Darmstadt
  • V. Peplov
    RAS/INR, Moscow
  • S. Sharamentov
    ANL, Argonne, Illinois
  Due to the high current of heavy ions accelerated at the UNILAC at GSI, non-intersecting beam diagnostics are mandatory. For bunch length and bunch structure determination in the range of 0.3 to 5 ns a novel device has been realized. It uses the time spectrum of secondary electrons created by atomic collisions between beam ions and residual gas molecules. These electrons are accelerated by an electric field of 400 V/mm toward an electro-static energy analyzer. The analyzer is used to restrict of the effective source region. Then the electrons are deflected by an rf-resonator running in phase with the acceleration frequency (36 or 108 MHz) to transform the time spectrum into spatial separation. The detection is done with a multi-channel plate equipped with a phosphor screen and observed by a digital CCD camera. The achieved time resolution is at least 50 ps, corresponding to 2 degree of rf frequency. The general layout of the device and first results will be presented.  
 
FRXCH01 Development of High Power Targets plasma, laser, polarization, booster 276
 
  • G.S. Bauer
    FZJ/ESS, Jülich
  High power targets are at the very heart of most applications of accelerators to science and technology. With many projects aiming to utilize beams in the multi-megawatt power range, solid targets, in particular stationary ones, become increasingly difficult. Liquid metal targets have become the concept of choice. Designs cover a variety of concepts ranging from free jets to allow extraction of low energy ? highly ionizing radiation (pions and muons) to fully enclosed systems if neutron generation is the main goal. Mercury is often the preferred target material due to its liquid state at room temperature and other favourable properties. Designs aiming at high temperature operation depending on small neutron absorption rely on PbBi as target material. Liquid lithium is proposed for a deuteron stripping target for the IFMIF project. Questions that need to be solved include solid-liquid metal reactions, radiation effects, general liquid metal technology, handling of spallation products as well as design of components and subsystems. In addition, short pulse operation leads to the generation of pressure waves inside the targets and the need to control their consequences.  
Video of talk
Transparencies
 
FRXBCH01 Novel Ideas and R&D for High Intensity Neutrino Beams plasma, laser, polarization, booster 281
 
  • K.J. Peach
    CCLRC/RAL/ASTeC, Chilton, Didcot, Oxon
  Recent developments in neutrino physics, primarily the conclusive demonstration of neutrino oscillations in both atmospheric neutrinos and solar neutrinos, provide the first conclusive evidence for physics beyond the Standard Model of particle physics. The phenomenology of neutrino oscillations, for three generations of neutrino, requires six parameters - two squared mass differences, 3 mixing angles and a complex phase that could, if not 0 or pi, contribute to the otherwise unexplained baryon asymmetry observed in the Universe. Exploring the neutrino sector will requires very intense beams of neutrinos, and needs novel solutions.  
Video of talk
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FRXBCH02 Towards Higher Luminosities in B and Phi Factories plasma, laser, polarization, booster 286
 
  • P. Raimondi
    INFN/LNF, Frascati (Roma)
  A brief review of the performances of the existing Factories will be presented. Such machines have been proved extremely successful, for both particle and accelerator physics. To further extend their physics reach, several plans are under way to upgrade the existing colliders, in order to increase their luminosity up to an order of magnitude. Will also be described several new schemes and ideas to realize full ?Second Generation Factories? aimed at luminosities two order of magnitude higher then what achieved so far.  
Video of talk
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FRYACH01 HICAT - The German Hospital-Based Light Ion Cancer Therapy Project plasma, laser, polarization, booster 290
 
  • H. Eickhoff, T. Haberer, B. Schlitt, U. Weinrich
    GSI, Darmstadt
  At the University Clinics at Heidelberg /Germany the realization of a cancer Therapy facility using light and medium ions (from protons up to oxygen) has started. This facility will be capable to treat about 1000 patients per year by means of the 'intensity controlled rasterscan technique', that has been already successfully applied to about 200 patients since 1998 at the GSI therapy pilot project. The presentation will give an overview of the facility layout and especially the accelerator- and beam transport systems, capable to provide 3 treatment places with light ions between 50 and 430 MeV/u. Two treatment places are located after horizontal beam lines and one after an isocentric gantry. A further horizontal beam line for research and development activities is foreseen. Besides the technical description and the status and schedule for the project realization organizational aspects of this project will be discussed with the project leadership at the University Clinics, the strong technical assistance of GSI and the role of industrial partners.  
Video of talk
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FRYBCH01 Clean Energy and the Fast Track to Fusion Power laser, polarization, booster, plasma 295
 
  • C. Llewellyn Smith
    UKAEA Culham, Culham, Abingdon, Oxon
  The theoretical attractions of fusion are clear: used as fuel in a fusion power plant, the lithium in one laptop battery together with 40 litres of water would produce 200,000 kW hours of electricity in an environmentally benign manner. The Joint European Torus (JET), which has produced 16MW, has shown that fusion can work in practice. ITER (the International Tokamak Experimental Reactor) is now essential to test integration of the components at the heart of a fusion reactor, and confirm that a burning plasma, in a fusion device scaled up in all dimensions by a factor of two from JET, to power plant size, has the expected behaviour. ITER should confirm that a fusion power plant can be built. The challenge will then be to build a power plant that would be sufficiently reliable and robust to be economically viable. This will require intensive research and development on the materials needed to construct the plasma vessel and surrounding blanket. These materials will have to be tested under reactor conditions at a dedicated facility called IFMIF (International Fusion Materials Facility). Construction of IFMIF in parallel with ITER would put fusion firmly on the 'fast track' (strongly advocated by the British Government) to the construction of a commercial fusion power plant, which could in principle be in operation within 30 years. I shall describe how a fusion power plant would work, the advantages and disadvantages of fusion, and the challenges that lie ahead.  
Video of talk
Transparencies