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beam-losses

      
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MOPLT005 An Improved Collimation System for the LHC collimation, impedance, proton, insertion 536
 
  • R.W. Assmann, O. Aberle, A. Bertarelli, H.-H. Braun, M. Brugger, L. Bruno, O.S. Brüning, S. Calatroni, E. Chiaveri, B. Dehning, A. Ferrari, B. Goddard, E.B. Holzer, J.-B. Jeanneret, J.M. Jimenez, V. Kain, M. Lamont, M. Mayer, E. Métral, R. Perret, S. Redaelli, T. Risselada, G. Robert-Demolaize, S. Roesler, F. Ruggiero, R. Schmidt, D. Schulte, P. Sievers, V. Vlachoudis, L. Vos, G. Vossenberg, J. Wenninger
    CERN, Geneva
  • I.L. Ajguirei, I. Baishev, I.L. Kurochkin
    IHEP Protvino, Protvino, Moscow Region
  • D. Kaltchev
    TRIUMF, Vancouver
  • H. Tsutsui
    SHI, Tokyo
  The LHC design parameters extend the maximum stored beam energy 2-3 orders of magnitude beyond present experience. The handling of the high-intensity LHC beams in a super-conducting environment requires a high-robustness collimation system with unprecedented cleaning efficiency. For gap closures down to 2mm no beam instabilities may be induced from the collimator impedance. A difficult trade-off between collimator robustness, cleaning efficiency and collimator impedance is encountered. The conflicting LHC requirements are resolved with a phased approach, relying on low Z collimators for maximum robustness and hybrid metallic collimators for maximum performance. Efficiency is further enhanced with an additional cleaning close to the insertion triplets. The machine layouts have been adapted to the new requirements. The LHC collimation hardware is presently under design and has entered into the prototyping and early testing phase. Plans for collimator tests with beam are presented.  
 
MOPLT008 The Mechanical Design for the LHC Collimators alignment, simulation, collimation, vacuum 545
 
  • A. Bertarelli, O. Aberle, R.W. Assmann, E. Chiaveri, T. Kurtyka, M. Mayer, R. Perret, P. Sievers
    CERN, Geneva
  The design of the LHC collimators must comply with the very demanding specifications entailed by the highly energetic beam handled in the LHC: these requirements impose a temperature on the collimating jaws not exceeding 50°C in steady operations and an unparalleled overall geometrical stability of 25micro-m on a 1200 mm span. At the same time, the design phase must meet the challenging deadlines required by the general time schedule. To respond to these tough and sometimes conflicting constraints, the chosen design appeals to a mixture of traditional and innovative technologies, largely drawing from LEP collimator experience. The specifications impose a low-Z material for the collimator jaws, directing the design towards graphite or such novel materials as 3-d Carbon/Carbon composites. An accurate mechanical design has allowed to considerably reduce mechanical play and optimize geometrical stability. Finally, all mechanical studies were supported by in-depth thermo-mechanical analysis concerning temperature distribution, mechanical strength and cooling efficiency.  
 
MOPLT033 Experimental Studies of Controlled Longitudinal Emittance Blow-up in the SPS as LHC Injector and LHC Test-Bed emittance, synchrotron, scattering, pick-up 617
 
  • J. Tuckmantel, T. Bohl, T.P.R. Linnecar, E.N. Shaposhnikova
    CERN, Geneva
  The longitudinal emittance of the LHC beam must be increased in a controlled way both in the SPS and the LHC itself. In the first case a small increase is sufficient to help prevent coupled bunch instabilities but in the second a factor three is required to also reduce intra-beam scattering effects. This has been achieved in the SPS by exciting the beam at the synchrotron frequency through the phase loop of the main RF system using bandwidth-limited noise, a method that is particularly suitable for the LHC which will have only one RF system. We describe the tests that have been done in the SPS both for low and high intensity beams, the hardware used and the influence of parameters such as time of excitation, bandwidth, frequency and amplitude on the resulting blow-up. After taking into account intensity effects it was possible to achieve a controlled emittance increase by a factor of about 2.5 without particle loss or the creation of visible tails in the distribution.  
 
MOPLT051 Experimental Characterization of PEP-II Luminosity and Beam-beam Performance luminosity, simulation, betatron, background 665
 
  • W. Kozanecki
    CEA/DSM/DAPNIA, Gif-sur-Yvette
  • M.A. Baak
    NIKHEF, Amsterdam
  • J. Seeman, M.K. Sullivan, U. Wienands
    SLAC, Menlo Park, California
  The beam-beam performance of the PEP-II B-Factory has been studied by simultaneously measuring the instantaneous luminosity, the horizontal and vertical e+ and e- beam sizes in the two rings, and the spatial extent of the luminous region as extracted from BaBar dilepton data. These quantities, as well as ring tunes, beam lifetimes and other collider parameters are recorded regularly as a function of the two beam currents, both parasitically during routine physics running and in a few dedicated accelerator physics experiments. They are used to quantify, project, and ultimately improve the PEP-II performance in terms of achieved beam-beam parameters, dynamic-beta enhancement, and current-dependence of the specific luminosity.  
 
MOPLT114 Modeling of Beam Loss in Tevatron and Backgrounds in the BTeV Detector hadron, collimation, shielding, background 803
 
  • A. Drozhdin, N. Mokhov
    Fermilab, Batavia, Illinois
  Detailed STRUCT simulations are performed of beam loss rates in the vicinity of the BTeV detector in the Tevatron C0 interaction region due to beam-gas nuclear elastic interactions, outscattering from the collimator jaws and an accidental abort kicker prefire. Corresponding showers induced in the machine components and background rates on the BTeV Detector are modeled with the MARS14 code. It is shown that a steel mask located in front of the last four dipoles upstream the C0 can reduce the accelerator-related background rates in the detector by an order of magnitude.  
 
MOPLT130 Bunch Pattern with More Bunches in PEP-II luminosity, injection, electron, positron 842
 
  • F.-J. Decker, S. Colocho, A. Novokhatski, M.K. Sullivan, U. Wienands
    SLAC, Menlo Park, California
  The number of bunches in the PEP-II B-Factory has increased over the years. The luminosity followed roughly linear that increase or even faster since we also lowered the spot size at the interaction point. The recent steps from 933 in June of 2003 to about 1320 in February 2004 should have been followed by a similar rise in luminosity from 6.5·1033 1/cm2 1/s to 9.2·1033 1/cm2 1/s. This didn?t happen so far and a peak luminosity of only 7.3·1033 1/cm2 1/s was achieved. By filling the then partially filled by-3 pattern to a completely filled by-3 pattern (1133 bunches) should even give 7.9·1033 1/cm2 1/s with scaled currents of 1400 mA (HER) and 1900 mA (LER). We are typically running about 1300 mA and 1900 mA with 15% more bunches. The bunch pattern is typically by-2 with trains of 14 bunches out of 18. The parasitic beam crossings or electron cloud effects might play a role in about a 10% luminosity loss. Also the LER x-tune could be pushed further down to the ? integer in the by-3 pattern. On the other hand we might not push the beam-beam tune shift as hard as in June of 2003 since we started trickle injection and therefore might avoid the highest peak luminosity with a higher background. A mixed pattern with a by2-by3 setup (separation of 2, 3, 2, 3 ?) would give totally filled a slightly higher number of bunches (1360), but near the interaction point there would be only one parasitic crossing per beam lowering the tune shift by two.  
 
MOPLT162 Continuous Abort Gap Cleaning at RHIC background, ion, accumulation, heavy-ion 908
 
  • K.A. Drees, R.P. Fliller III, W. Fu, R. Michnoff
    BNL, Upton, Long Island, New York
  Since the RHIC Au-Au run in the year 2001 the 200 MHz cavity system was used at storage and a 28 MHz system during injection and acceleration.The rebucketing procedure potentially causes a higher debunching rate of heavy ion beams in addition to amplifying debunching due to other mechanisms. At the end of a four hour store, debunched beam can easily account for more than 30% of the total beam intensity. This effect is even stronger with the achieved high intensities of the RHIC run 2004. A beam abort at the presence of a lot of debunched beam bears the risk of magnet quenching and experimental detector damage due to uncontrolled beam losses. Thus it is desirable to avoid any accumulation of debunched beam from the beginning of each store, in particular to anticipate cases of unscheduled beam aborts due to a system failure. A combination of a fast transverse kicker and the new 2-stage copper collimator system is used to clean the abort gap continuously throughout the store with a repetition rate of 1 Hz. This report gives an overview of the new gap cleaning procedure and the achieved performance.  
 
MOPLT178 RHIC Pressure Rise ion, electron, background, luminosity 944
 
  • S.Y. Zhang, J. Alessi, M. Bai, M. Blaskiewicz, P. Cameron, K.A. Drees, W. Fischer, R.P. Fliller III, D. Gassner, J. Gullotta, P. He, H.-C. Hseuh, H. Huang, U. Iriso, R. Lee, Y. Luo, W.W. MacKay, C. Montag, B. Oerter, S. Peggs, F.C. Pilat, V. Ptitsyn, T. Roser, T. Satogata, L. Smart, P. Thieberger, D. Trbojevic, J. Van Zeijts, L. Wang, J. Wei, K. Zeno
    BNL, Upton, Long Island, New York
  Beam induced pressure rise remains an intensity limit at the RHIC for both heavy ion and polarized proton operations. The beam injection pressure rise at warm sections has been diagnosed due to electron cloud effect. In addition, pressure rise of heavy ion operation at the beam transition has caused experiment background problem in deuteron-gold run, and it is expected to take place in gold-gold run at high intensities. This type of pressure rise is related to beam momentum spread, and the electron cloud seems not dominant. Extensive approaches for both diagnosis and looking-for-remedies are undergoing in the current gold operation, RUN 4. Results of beam scrubbing, NEG pipe in RHIC ring, beam scraping test of ion desorption, beam momentum effect at the transition, beam gap effect, solenoid effect, and NEG pipe ion desorption test stand will be presented.  
 
TUXLH01 Machine Protection Issues and Strategies for the LHC injection, kicker, proton, insertion 88
 
  • R. Schmidt, J. Wenninger
    CERN, Geneva
  For nominal beam parameters at 7 TeV/c, each of the two LHC proton beams has a stored energy of 350 MJ threatening to damage accelerator equipment in case of uncontrolled beam loss. Since the beam dump blocks are the only element of the LHC that can withstand the impact of the full beam, it is essential for the protection of the LHC that the beams are properly extracted onto the dump blocks in case of emergency. The time constants for failures leading to beam loss extend from 100 microseconds to few seconds. Several protection systems are designed to ensure safe operation, such as beam instrumentation, collimators and absorbers, and magnet protection. Failures must be detected at a sufficiently early stage and transmitted to the beam interlock system that triggers the beam dumping system. The strategy for the protection of the LHC will be illustrated starting from some typical failures.  
Video of talk
Transparencies
 
TUYLH02 Low and Medium Energy Beam Acceleration in High Intensity Linacs linac, rfq, quadrupole, lattice 108
 
  • J. Stovall
    LANL, Los Alamos, New Mexico
  In the past two years accelerator builders have published papers describing mature designs of no fewer than 7 new high-performance proton linacs. These machines are typically designed to deliver multi-megawatt beams for applications in pure and applied research. All of these machines use the radio-frequency quadrupole (RFQ) linac for the first stage of acceleration to reach an energy of a few MeV. In essentially all cases, superconducting elliptical cavities have been adopted as the technology of choice for acceleration above ~100 MeV. Between the RFQ and the high-energy elliptical cavities, designers have proposed no fewer than 6 different types of accelerating structures. In many cases these structures are reaching maturity as a result of active development programs. In this paper, we review the design architectures of the ?low and medium energy? portions of these machines emphasizing recent experience and developments applicable to high-current linac designs.  
Video of talk
Transparencies
 
TUPKF003 Industrial Production of the Eight Normal-conducting 200 MHz ACN Cavities for the LHC vacuum, simulation, electron, controls 956
 
  • R. Losito, E. Chiaveri, R. Hanni, T.P.R. Linnecar, S. Marque, J. Tuckmantel
    CERN, Geneva
  The LHC-ACN RF system consists of 8 normal-conducting cavities and is designed to reduce beam losses in the LHC when injecting beams with longitudinal emittance > 0.7 eVs from the CERN SPS. The cavity design took into account the possibility of recuperating all the "ancillary" equipment (tuners, fundamental mode damper, High Order Mode (HOM) couplers) from the old CERN SPS 200MHz system. The cavities are made from OFE copper. The original ingots, procured in Austria, have been forged and pre-formed by pressing them with a 20 tons press, following a procedure defined and adapted for the unusual dimensions of these pieces. The raw components thus obtained were machined and then welded together with an electron beam. In order to get a good repeatability of the fundamental mode frequency across the eight cavities, a procedure has been established with the contractor for the final machining and welding leading to a spread in frequencies below ±20 kHz (< 0.01%). The cavities will be installed in the LHC when losses at high intensities become significant. In the meantime they are undergoing a surface treatment to clean the RF surface and will be stored.  
 
TUPKF031 Non-resonant Accelerating System at the KEK-PS Booster booster, impedance, power-supply, synchrotron 1027
 
  • S. Ninomiya, M. Muto, M. Toda
    KEK, Ibaraki
  The non-resonant accelerating system for the KEK-PS booster accelerator has been constructed. The system has been operating since October 2003 without trouble. The accelerating gap in the system is loaded with magnetic cores of high permeability. The cores produce high resistive impedance at the gap. The power dissipated in the cores amounts to 50kW at 16kV accelerating voltage. It is removed by forced-air cooling system. At the last operation of the accelerator, with the help of new COD-correction system, the average beam intensity of the booster increased to 2.6E+12ppp, which is 30% higher than before.  
 
TUPKF032 COD Correction by Novel Back-leg at the KEK-PS Booster power-supply, injection, booster, closed-orbit 1030
 
  • S. Ninomiya, K. Satoh, H. Someya, M. Toda
    KEK, Ibaraki
  The COD correction is performed by using new driving system of back-leg windings. Two back-leg coils of the separate magnets are connected to make a closed circuit in which the induced voltages of the two magnets have opposite phases to each other. When the current source is inserted into the closed loop, the current drives the two magnets with opposite polarities. If the pair of magnets is properly selected, the current effectively corrects the orbit distortion. The selection rule of the pair is as follows; one is the magnet at the maximum distortion and the second magnet is that separated with the betatron phase of -90deg. The correction system at the KEK-PS Booster reduced the COD to less than 1/5 of that without correction, and increased the capture efficiency. The average beam intensity of our Booster is increased from 2E+12 to 2.6E+12ppp.  
 
TUPKF079 A Low Noise RF Source for RHIC instrumentation, acceleration, controls, luminosity 1123
 
  • T. Hayes
    BNL, Upton, Long Island, New York
  The Relativistic Heavy Ion Collider requires a low noise rf source to ensure that beam lifetime during a store is not limited by the rf system. The beam is particularly sensitive to noise from power line harmonics. Additionally, the rf source must be flexible enough to handle the frequency jump required for rebucketing (transferring bunches from the acceleration to the storage rf systems). This paper will describe the design of a Direct Digital Synthesizer (DDS) based system that provides both the noise performance and the flexibility required.

Work performed under the auspices of the US Department of Energy

 
 
TUPLT020 High Intensity Uranium Operation in SIS18 ion, injection, septum, acceleration 1180
 
  • P.J. Spiller, K. Blasche, P. Hülsmann, A. Kraemer, H. Ramakers, H.R. Sprenger
    GSI, Darmstadt
  For the present experiment program and the planned international accelerator facility at GSI, the space charge limit of SIS18 for highly(4x1010) and intermediate (2.7x1011) charged uranium ions shall be reached within the next four years. Furthermore, measures to increase the repetition- and ramp rate up to 4 Hz with 10 T/s have been progressed. The present state of intensities per cycle and the limitations will be described. In connection with the planned enhancement of heavy ion intensities, protection, interlock and diagnostic systems, especially for the injection- and extraction devices have been prepared. Special attention is drawn on the insights which were achieved with respect to the operation at dynamic vacuum conditions. Results of R&D work with the goal to increase the intensity threshold and to improve the beam life time will be summarized. Furthermore, the specific upgrade program and schedule for the SIS18 booster mode will be presented.  
 
TUPLT030 Numerical Simulations for the Frankfurt Funneling Experiment rfq, simulation, ion, emittance 1210
 
  • J. Thibus, A. Schempp
    IAP, Frankfurt-am-Main
  High beam currents are necessary for heavy ion driven fusion (HIF) or XADS. To achieve these high beam currents several ion beams are combined at low energies to one beam using the funneling technique. In each stage a r.f. funneling deflector bunches two accelerated beam lines to a common beam axis. The Frankfurt Funneling Experiment is a scaled model of the first stage of a HIF driver consisting of a Two-Beam RFQ accelerator and a funneling deflector. Our two different deflectors have to be enhanced to reduce particle losses during the funneling process. This is done with our new developed 3D simulation software DEFGEN and DEFTRA. DEFGEN generates the structure matrix and the potential distribution matrix with a Laplace 3D-solver. DEFTRA simulates ion beam bunches through the r.f. deflector. The results of the simulations of the two existing deflectors and proposals of new deflector structures will be presented.  
 
TUPLT057 Beam Dynamics Studies for the Fault Tolerance Assessment of the PDS-XADS Linac Design linac, quadrupole, target, simulation 1282
 
  • J.-L. Biarrotte
    IPN, Orsay
  • M. Novati, P. Pierini
    INFN/LASA, Segrate (MI)
  • H. Safa, D. Uriot
    CEA/DSM/DAPNIA, Gif-sur-Yvette
  In order to meet the high availability/reliability required by the PDS-XADS design the accelerator needs to implement, to the maximum possible extent, a fault tolerance strategy that would allow beam operation in the presence of most of the envisaged faults that could occur in its beamline components. In this work we report the results of beam dynamics simulations performed to characterize the effects of the faults of the main linac components (cavities, deflecting and focusing magnets, …) on the beam parameters. The outcome of this activity is the definition of the possible corrective and preventive actions that could be conceived (and implemented in the system) in order to guarantee the fault tolerance characteristics of the accelerator.  
 
TUPLT098 Vertical Beam Motion in the AGOR Cyclotron proton, resonance, cyclotron, betatron 1384
 
  • M.A. Hofstee, S. Brandenburg, H. Post, W.K. van Asselt
    KVI, Groningen
  Large-scale vertical excursions have been observed in the AGOR cyclotron for light ionbeams at energies close to the focussing limit (E/A =200 Q/A MeV per nucleon). With increasing radius the beam gradually moves down out of the geometrical median plane by several mm, leading to internal beamlosses. It was concluded that this effect is caused by a vertical alignment error of the coils combined with the weak vertical focussing for the beams concerned. Moving the main coils by a total of 0.37 mm has significantly improved the situation at large radii, but results in internal beamlosses for certain beams at small radii due to a large upward excursion. A systematic study of the vertical beam dynamics as a function of beam particle and energy will be presented. Possible causes and solutions will be discussed.  
 
TUPLT112 Radiation Damage to the Elements of the Nuclotron-type Dipole of SIS100 ion, dipole, vacuum, proton 1408
 
  • E. Mustafin, G. Moritz, G. Walter
    GSI, Darmstadt
  • L. Latysheva, N. Sobolevskiy
    RAS/INR, Moscow
  Radiation damage to various elements of the Nuclotron-type dipole of SIS100 sensitive to irradiation was calculated. Among the elements of consideration were the superconducting cables, insulating materials, ceramic insertions and high-current by-pass diodes. The Monte-Carlo particle transport code SHIELD was used to simulate propagation of the lost ions and protons together with the products of nuclear interactions in the material of the elements. The results for the proton projectiles were cross-checked using the particle transport code MARS, and a good agreement between the codes were found. It was found that the lifetime of the organic materials under irradiation are much more restrictive limit for the tolerable level of beam particle losses than the danger of the quench events.  
 
TUPLT143 Studies of Beam Loss Control on the ISIS Synchrotron proton, simulation, synchrotron, collimation 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.  
 
TUPLT147 Multiple-charge-state Beam Steering in High-intensity Heavy-ion Linacs linac, emittance, heavy-ion, focusing 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)

 
 
TUPLT172 Measurement of Halo Mitigation Schemes for the Spallation Neutron Source Linac optics, emittance, linac, simulation 1533
 
  • D.-O. Jeon
    ORNL/SNS, Oak Ridge, Tennessee
  A series of emittance measurements were performed at the end of Drift Tube Linac tank 1 of the Spallation Neutron Source to verify experimentally the previously proposed halo generation mechanism and its mitigation schemes [1]. The emittance measurements clearly showed a visible reduction in the halo as well as a significant reduction in the rms emittance when the proposed round beam optics is employed. This confirms experimentally the halo generation mechanism we identified.  
 
TUPLT173 Experimental Test of Transverse Matching Routine for the SNS Linac emittance, linac, optics, quadrupole 1536
 
  • D.-O. Jeon, S. Assadi
    ORNL/SNS, Oak Ridge, Tennessee
  • J. Stovall
    LANL, Los Alamos, New Mexico
  Transverse matching for a high intensity linac was proposed based on minimizing rms emittances. A MATLAB routine was developed and applied during the SNS linac commissioning. The result was also compared with the simulations.  
 
TUPLT192 Transition Crossing for the BNL Super Neutrino Beam lattice, proton, injection, chromatic-effects 1583
 
  • J. Wei, N. Tsoupas
    BNL, Upton, Long Island, New York
  The super neutrino beam facility proposed at the Brookhaven National Laboratory requires proton beams to cross the transition energy in the AGS to reach 1 MW beam power at top energy. High intensity beams are accelerated at a fast repetition rate. Upon transition crossing, such high intensity bunches of large momentum spreads suffer from strong nonlinear chromatic effects and self-field effects. Using theoretical and experimental methods, we determine the impact of these effects and the effectiveness of transition-jump compensation schemes, and determine the optimum crossing scenario for the super neutrino beam facility.  
 
WEPKF018 Beam-loss Induced Pressure Rise of LHC Collimator Materials Irradiated with 158 GeV/u In49+ Ions at the CERN SPS ion, vacuum, heavy-ion, linac 1633
 
  • E. Mahner, I. Efthymiopoulos, J. Hansen, E. Page, H. Vincke
    CERN, Geneva
  During heavy ion operation, large pressure rises, up to a few orders of magnitude, were observed at CERN, GSI, and BNL. The dynamic pressure rises were triggered by lost beam ions that impacted onto the vacuum chamber walls and desorbed about 104 to 107 molecules per ion. The deterioration of the dynamic vacuum conditions can enhance charge-exchange beam losses and can lead to beam instabilities or even to beam abortion triggered by vacuum interlocks. Consequently, a dedicated measurement of heavy-ion induced molecular desorption in the GeV/u energy range is important for LHC ion operation. In 2003, a desorption experiment was installed at the SPS to measure the beam-loss induced pressure rise of potential LHC collimator materials. Samples of bare graphite, sputter coated (Cu, TiZrV) graphite, and 316 LN stainless steel, were irradiated under grazing angle with 158 GeV/u indium ions. After a description of the new experimental set-up, the results of the pressure rise measurements are presented, and the derived desorption yields are compared with data from other experiments.  
 
WEPKF041 Permanent Magnet Generating High and Variable Septum Magnetic Field and its Deterioration by Radiation permanent-magnet, radiation, septum, booster 1696
 
  • T. Kawakubo, E. Nakamura, M. Numajiri
    KEK, Ibaraki
  • M. Aoki, T. Hisamura, E. Sugiyama
    NEOMAX Co., Ltd., Mishima-gun, Osaka
  Conventional high field septum magnet is fed by DC current or pulse current. In the case of DC, the problem of coil support is not very important, but the cooling of the coil is serious problem. While, in the case of pulse, the problem of support is much important than that of cooling. However, if the septum magnet is made of permanent magnet, those problems are dissolved. And the cost for electricity and cooling water can be exceedingly decreased. Therefore, we made the model septum magnet which has 1/4 scale of the real size and generates 1[T] with the variable range of ± 10%. The magnetic field distribution in the gap by changing the representative field is reported. When this permanent magnet is set in an accelerator, the deterioration of the permanent magnet by radiation will be serious problem. We also report the dependence of the magnetic fields generated by permanent magnet samples on accumulated radiation by various types of radiation source.  
 
WEPLT002 Shielding Design Study for CANDLE Facility shielding, radiation, electron, storage-ring 1816
 
  • K.N. Sanosyan, M. Aghasyan, R.H. Mikaelyan
    CANDLE, Yerevan
  • V.M. Vartanian
    Stanford University, Stanford, Califormia
  The radiation shielding design study for the third generation synchrotron light source CANDLE is carried out. The electron beam loss estimates have done for all the stages from linac to storage ring. A well-known macroscopic model describing the dose rate for point losses has been used to calculate the shielding design requirements of the facility.  
 
WEPLT035 Capture Loss of the LHC Beam in the CERN SPS injection, impedance, feedback, simulation 1906
 
  • E.N. Shaposhnikova, T. Bohl, T.P.R. Linnecar, J. Tuckmantel
    CERN, Geneva
  The matched voltage of the LHC beam at injection into the SPS is 750 kV. However, even with RF feedback and feed forward systems in operation, the relative particle losses on the flat bottom for nominal LHC parameters with this capture voltage can reach the 30% level. With voltages as high as 2 MV these losses are still around 15% pushing the intensity in the SPS injectors to the limit to obtain nominal intensity beam for the LHC. Beam losses grow with intensity and are always asymmetric in energy (lost particles are seen main in front of the batch). The asymmetry can be explained by the energy loss of particles due to the SPS impedance which is also responsible for a non-zero synchronous phase on the flat bottom leading to large gaps between buckets. In this paper the measurements of the dependence of particles loss on the beam and machine parameters are presented and discussed together with possible loss mechanisms.  
 
WEPLT043 Detecting Failures in Electrical Circuits Leading to Very Fast Beam Losses in the LHC extraction, simulation, insertion, septum 1930
 
  • M. Zerlauth, B. Goddard, V. Kain, R. Schmidt
    CERN, Geneva
  Depending on the beam optics, failures in the magnet powering at locations with large beta functions could lead to very fast beam losses at the collimators, possibly within less than 10 turns. Beam loss monitors would normally detect such losses and trigger a beam dump. However, the available time for detection with beam loss monitors before reaching the damage level of a collimator might not be sufficient, in particular for beams with few particles in the tails. This has always been of concern and becomes even more relevant since very fast losses have been observed recently at HERA. In this paper, we present particle tracking studies for the LHC to identify failures on critical magnets. We propose a fast detection of such failures in the electrical circuit, either with highly precise hall probes for current measurement or measurements of the induced inductive voltage during the current decay. In combination with a small and simple interlock electronics such detection system can provide reliable and fast interlock signals for critical magnets in the LHC main ring but could also be used to monitor injection and extraction magnets. Depending on the properties of the electrical circuit an increase of the natural time constant of the current decay using a serial superconducting magnet is also considered.  
 
WEPLT045 Experiments on LHC Long-range Beam-beam Compensation in the CERN SPS emittance, simulation, closed-orbit, betatron 1936
 
  • F. Zimmermann, J.-P. Koutchouk, J. Wenninger
    CERN, Geneva
  Long-range beam-beam collisions may limit the dynamic aperture and the beam lifetime in storage-ring colliders. Their effect can be compensated by a current-carrying wire mounted parallel to the beam. A compensation scheme based on this principle has been proposed for the Large Hadron Collider (LHC). To demonstrate its viability, a prototype wire was installed at the CERN SPS in 2002. First successful machine experiments explored the dependence of beam loss, beam size, and beam lifetime on the beam-wire distance and on the wire excitation. They appear to confirm the predicted effect of the long-range collisions on the beam dynamics. In 2004, two further wires will become available, by which we can explicitly demonstrate the compensation, study pertinent tolerances, and also compare the respective merits of different beam-beam crossing schemes for several interaction points.  
 
WEPLT059 Beam Loss Modeling for the SIS100 space-charge, resonance, lattice, synchrotron 1978
 
  • G. Franchetti, I. Hofmann
    GSI, Darmstadt
  In long term storage dynamic aperture is typically regarded as the quantity which has to be maintained sufficiently large in order to prevent beam loss. In the SIS100 of the GSI future project, a beam size occupying a large fraction of the beam pipe is foreseen. This circumstance requires a careful description of the lattice magnetic imperfections. The dynamic aperture is estimated in relation with an optimization of the SIS100 working point. For a space-charge-free bunched beam, estimates of beam loss are computed and compared with dynamic aperture. The impact of space charge will be discussed, and preliminary results on its effect on dynamic aperture and beam loss are presented.  
 
WEPLT073 VDHL Design and Simulation of a Fast Beam Loss Interlock for TTF2 single-bunch, linac, simulation, electron 2020
 
  • A. Hamdi
    CEA/Saclay, Gif-sur-Yvette
  • M. Luong
    CEA/DSM/DAPNIA, Gif-sur-Yvette
  • M. Werner
    DESY, Hamburg
  The TTF2 fast beam loss interlock provides different modes of protection. Based on the differential beam charge monitoring over a macropulse, a pulse slice or bunch-by-bunch, the signal processing time should be as short as the bunch repetition period (110 ns). The signal delivered by the toroid-like inductive current transformer always shows an envelope droop due to its self-inductance to resistance ratio. When the macropulse length is comparable to this ratio, the charge of each bunch must be derived from the difference of the top to the bottom level on the signal. This necessity combined to the various protection modes leads to a digital implementation. All the processing functionalities are designed with VHDL for a Xilinx FPGA. Because the interlock involves other control signals in addition to the toroid signal with specific shapes, which cannot be easily reproduced for the design validation before the TTF2 completion, VHDL provides meanwhile the possibility for an exhaustive validation of the system with a software test bench including all timing information.  
 
WEPLT086 Non Gaussien Transverse Distributions in a Stochastic Model for Beam Halos space-charge, emittance, simulation, linac 2056
 
  • N. Cufaro Petroni
    INFN-Bari, Bari
  • S. De Martino, S. De Siena, F. Illuminati
    Universita' degli Studi di Salerno, Dipartimento di Fisica E.R. Caianiello, Baronissi
  The formation of the beam halo in charged particle accelerators is studied in a dynamical stochastic model for the collective motion of the particle beam. The density and the phase of the charged beam obey a set of coupled nonlinear hydrodynamic equations with time-reversal invariance. The linearized theory for this collective dynamics is given in terms of a classical Schroedinger equation. Self-consistent solutions with space-charge effects lead to quasi-stationary beam configurations with enhanced transverse dispersion and transverse emittance growth. In the limit of a frozen space-charge core it is possible to determine and study the properties of stationary, stable core-plus-halo beam distributions. We explore the effect of non-Gaussian transverse distributions. In this case the underling stochastic process is allowed to jump, and the transverse distribution tails are heavier than in the Gaussian case giving rise to a halo effect. The stationary transverse distribution plays the role of an attractor for every other distribution, and we give an estimation of the time needed by a non stationary, halo-free distribution to relax toward the stationary distribution with a halo.  
 
WEPLT090 Nonlinear Evolution of the Beam in Phase Space at Elettra resonance, betatron, coupling, dynamic-aperture 2059
 
  • S. Di Mitri, L. Tosi
    ELETTRA, Basovizza, Trieste
  Phase space in the Elettra storage ring has been investigated. The beam is kicked and the coordinates of the bunch centroid are acquired for at least 1000 turns. A Hilbert transform has been used to deduce the evolution of beam phase space from position coordinates. Several nonlinear effects have been detected, such as the amplitude dependence of the betatron tune, the presence of high order and coupling resonances. Fixed points have been evidenced as well as the behaviour of the beam in their neighbourhood. Scans in lifetime versus tune confirm the limiting effect of the observed resonances on the region of regular motion.  
 
WEPLT115 A Study of Transverse Resonance Crossing in FFAG resonance, simulation, emittance, acceleration 2119
 
  • M. Aiba
    University of Tokyo, Tokyo
  • S. Machida, Y. Mori
    KEK, Ibaraki
  A study of "resonance crossing" in FFAG accelerator is described in this paper. A deviation of FFAG guiding field in actual magnet breaks zero chromaticity condition, and tunes cross resonance while acceleration. In order to avoid a critical beam loss or emittance growth, nominal tune should be chosen so as not to cross low-order resonances. However, crossing higher order resonance can be critical and that depends on the parameters such as crossing speed, excitation magnitude and initial beam emittance. We will present analytical model and simulation study in various parameter space.  
 
WEPLT145 Beam Loss Studies in High-intensity Heavy-ion Linacs linac, simulation, emittance, ion 2176
 
  • 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

 
 
WEPLT149 Image-charge Effects on the Beam Halo Formation and Beam Loss in a Small-aperture Alternating-gradient Focusing System focusing, lattice, quadrupole, heavy-ion 2188
 
  • J. Zhou, C. Chen
    MIT/PSFC, Cambridge, Massachusetts
  The image-charge effects on an intense charged-particle beam propagating through an alternating-gradient focusing channel with a small aperture, circular, perfectly conducting pipe are studied using a test-particle model. For a well-matched elliptical beam with the Kapchinskij-Vladimirskij (KV) distribution, it is found that halo formation and beam loss is induced by nonlinear fields due to image charges on the wall. The halo formation and chaotic particle motion dependent sensitively on the system parameters: filling factor of the quadrupole focusing field, vacuum phase advance, beam perveance, and the ratio of the beam size to the aperture. Furthermore, the percentage of beam loss to the conductor wall is calculated as a function of propagating distance and aperture. The theoretical results are compared with PIC code simulation results.  
 
THOACH03 Top-up Operation at SPring-8 - Towards Maximizing the Potential of a 3rd Generation Light Source injection, storage-ring, target, single-bunch 222
 
  • H. Tanaka, T. Aoki, T. Asaka, S. Daté, K. Fukami, Y. Furukawa, H. Hanaki, N. Hosoda, T. Kobayashi, N. Kumagai, M. Masaki, T. Masuda, S. Matsui, A. Mizuno, T. Nakamura, T. Nakatani, T. Noda, T. Ohata, H. Ohkuma, T. Ohshima, M. Oishi, S. Sasaki, J. Schimizu, M. Shoji, K. Soutome, M. Suzuki, S. Suzuki, S. Takano, M. Takao, T. Takashima, H. Takebe, K. Tamura, R. Tanaka, T. Taniuchi, Y. Taniuchi, K. Tsumaki, A. Yamashita, K. Yanagida, H. Yonehara, T. Yorita
    JASRI/SPring-8, Hyogo
  • M. Adachi, K. Kobayashi, M. Yoshioka
    SES, Hyogo-pref.
  Top-up operation maximizes research activities in a light source facility by an infinite beam lifetime and photon beam stability. We have been improving the SPring-8 accelerators to achieve the ideal top-up operation. For the perturbation-free injection, we adjusted the magnetic field shape of four bump magnets to close the bump orbit, and introduced a scheme to suppress the stored beam oscillation induced by the nonlinearlity of sextupole magnets. These reduced the horizontal oscillation down to a third of the stored beam size. For the loss-free injection, beam collimators were installed upstream of the injection line. This realized the injection efficiency of ~100% under the restricted gap condition of in-vacuum insertion devices (ID). Since autumn 2003, we have been injecting the beams keeping the photon beam shutters opened and ID gaps closed. We developed a bunch-by-bunch feedback system to reduce the beam loss further with all the ID gaps fully closed by lowering the operating chromaticity. The operation with constant stored current is scheduled in June 2004. We present the overview and progress of the SPring-8 top-up operation focusing on our developments and results.  
Video of talk
Transparencies
 
THPKF012 Operation of the Swiss Light Source: Top-up for Highest Performance injection, linac, booster, feedback 2281
 
  • A. Lüdeke
    PSI, Villigen
  The Swiss Light Source (SLS) is now in its third year of user operation. Right from the beginning Top-up has been the standard mode of operation. Operation at a fixed beam current makes many applications easier to implement and allows to push several systems to higher performance. It enabled us to reach an excellent orbit stability and reproducibility and it made our users less sensitive to shortened beam lifetimes. We succeeded to satisfy the high demands on the availability of the injector system and our flexible timing system allows for a parallel usage of the Linac for experiments during Top-up operation. The impact of Top-up operation on the overall performance of the SLS is documented in this paper.  
 
THPKF023 Studies using Beam Loss Monitors at ANKA vacuum, electron, storage-ring, injection 2314
 
  • F. Pérez, I. Birkel, K. Hertkorn, E. Huttel, A.-S. Müller, M. Pont
    FZK-ISS-ANKA, Karlsruhe
  ANKA is a synchrotron light source that operates in the energy range from 0.5 to 2.5 GeV. In order to investigate the electron beam losses, two kind of beam loss monitors have been installed: 24 Pin Diode from Bergoz distributed around the storage ring, and one Pb-glass calorimeter located in a high dispersion region. The Pin Diodes are used to obtain information about the distribution of the losses while the Pb-glass detector provides higher sensitivity. The Pin Diodes allow to locate and distinguish the regions of higher losses due to Touschek and Elastic scattering. Furthermore, regions of higher losses at injection have been identified. The Pb-glass detector has been used to determine the beam energy with the resonant spin depolarisation technique. A strong spin orbit resonance has been observed with both detectors.  
 
THPKF025 Commissioning Report of the CLS Booster Synchrotron booster, synchrotron, injection, lattice 2320
 
  • G. Georgsson
    Danfysik A/S, Jyllinge
  • L. Dallin
    CLS, Saskatoon, Saskatchewan
  • S.P. Møller
    ISA, Aarhus
  • L. Præstegaard
    Århus Sygehus, Århus
  A full energy booster is produced and taken into operation for the Canadian Light Source. The Booster accelerates the beam from the injection energy of 200 MeV to a maximum of 2.9GeV. The results of the commissioning and the characterized beam parameters are reported  
 
THPLT008 A Beam Condition Monitor for the Experimental Areas of the LHC radiation, proton, monitoring, luminosity 2475
 
  • L. Fernandez-Hernando, L. Fernandez-Hernando, C. Ilgner, A. Oh, H. Pernegger
    CERN, Geneva
  • A. Macpherson
    PSI, Villigen
  • T. Pritchard
    CCLRC/RAL/ASTeC, Chilton, Didcot, Oxon
  • R. Stone
    Rutgers University, The State University of New Jersey, Piscataway, New Jersey
  The CERN Large Hadron Collider (LHC) will store 2808 bunches per colliding beam, with each bunch consisting of 1·1011 protons at an energy of 7 TeV. If there is a failure in an element of the accelerator, the resulting beam losses could cause damage not only to the machine but also to the experiments. A Beam Condition Monitor (BCM) is foreseen to monitor fast increments of fluence rate near the interaction point and, if necessary, to generate an abort signal to the LHC accelerator control to dump the beams. The system is being developed initially for the CMS experiment, but is sufficiently general to find potential applications elsewhere. Due to its high radiation hardness, CVD diamond was chosen for investigation as the BCM sensor. Various samples of CVD diamond have been characterised extensively with both a Sr-90 source and in a high intensity testbeam in order to assess the capabilities of such sensors and to study whether this detector technology is suitable for a BCM system. A selection of results from these investigations is presented.  
 
THPLT011 Longitudinal Loss Distribution along the LHC quadrupole, dipole, simulation, proton 2484
 
  • 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 quadrupole, proton, collimation, monitoring 2487
 
  • 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  
 
THPLT039 SVD Based Orbit Correction Incorporating Corrector Limitations at DELTA dipole, synchrotron, storage-ring, multipole 2568
 
  • M. Grewe, P. Hartmann, G. Schmidt, K. Wille
    DELTA, Dortmund
  Singular Value Decompostion (SVD) of the orbit response matrix has become an invaluable tool for orbit correction at storage rings worldwide. SVD based orbit correction has now been realised at DELTA, a 1.5 GeV electron storage ring. However, due to special orbit demands at DELTA and possibly by magnetic imperfections within the storage ring, we frequently have to face corrector limitations during the process of orbit correction. This work focuses on presenting an analytic algorithm on how to treat these limitations when seeking for an optimal SVD based orbit correction. In contrast to previously published methods, this approach is fairly easy to implement and does not afford an numerical solver. Concepts and results will be presented.  
 
THPLT052 Measurement of Relative Gas Chamber Pressure in Narrow Straight Section Vacuum Vessels by Observing Gas Bremstrahlung radiation, vacuum, electron, background 2601
 
  • G.A. Naylor, B. Joly, D. Robinson
    ESRF, Grenoble
  The measurement of gas pressure inside long, small cross section, vacuum vessels is difficult due to the distance between the centre of the vacuum vessel and vacuum gauges (leading to a low vacuum conductance). Following initial chamber installation, significant out-gassing is observed leading to a significant pressure bump within the chamber. A modified beam loss detector has been developed in order to monitor the gamma radiation produced by the collision of the 6GeV electrons in the storage ring with residual gas atoms. The narrow beam of gamma radiation is intercepted at various points by high Z materials in the beam line front-end allowing a radiation shower to be detected outside the vacuum vessel proportional to the gas pressure in the corresponding storage ring straight section. Various locations are considerred and results shown.  
 
THPLT069 High Speed Beam Loss Monitor and its Deterioration by Radiation radiation, kicker, septum, booster 2652
 
  • T. Kawakubo, T. Ishida, T. Sanami
    KEK, Ibaraki
  High speed loss monitor is very useful for tuning and operating the beam in an accelerator, especially in the injection and extraction period. We made a new type loss monitor by connecting a fiber to a photo-multiplier (PMT). In the case that the fiber is made of quartz, the source of the signal is Cherenkov effect. And in the case of scintillation fiber, the signal comes from the scintillation effect. The quartz is much stronger than the scintillator to the radiation, but generating light in the quartz is weaker than scintillator, especially in low energy beam. It is very easy to make this monitor and the fabrication cost is cheap. The monitor can observe the bunch loss with an order of 10 ns. After long time use under high irradiation, the signal of the monitor will decrease. Therefore, we also report the dependence of the signal strength on accumulated radiation in various types of material.  
 
THPLT073 Numerical Methods for the Orbit Control at the KEK 12 GeV PS injection, synchrotron, closed-orbit, vacuum 2664
 
  • Y. Hitaka, H. Sato, M.J. Shirakata
    KEK, Ibaraki
  • M.K. Kono, Y.M. Yokomichi
    Miyazaki University, Miyazaki
  At the KEK 12GeV-PS main ring, when the least square method is applied to correct whole beam orbit all at once, it remains unacceptable beam loss and it is necessary to adjust the local positions of the beam orbit by hands with the beam loss monitors until the beam loss is suppressed under an acceptable level. However, the orbit does not realize the minimum-loss condition. In this paper, a new method is proposed. It focuses a fact that the beam loss distribution depends on the shape of the beam orbit and formulates this relationship to a functional approximation by using a nural network algorithm. Then, solving an optimization problem for generated network system, data of the beam shape which is more suitable for the beam loss of the accelerator can be obtained. The description of the system construction and experimental results are presented.  
 
THPLT074 The Beam Loss Monitor System of the J-parc LINAC, 3 GEV RCS and 50 GEV MR linac, extraction, radiation, injection 2667
 
  • S. Lee, T. Toyama
    KEK, Ibaraki
  • J. Kishiro
    JAERI/LINAC, Ibaraki-ken
  • M. Tanaka
    JAERI, Ibaraki-ken
  The high intensity beam accelerator complex itself requires the significant progress of design study and hardware R&D. Operational beam intensity should be limited by the beam loss and activation level of the equipment. Once the beam loss exceeds a criterion at outer environment, beam intensity has to be decreased to prevent the further activation. In order to investigate loss mechanism and suppress the beam loss, a beam loss monitor system have been developed for the J-PARC linac, 3 GeV RCS and 50GeV MR. The system will be essential component for beam commissioning, tuning and machine protection in high intensity beam accelerators. The loss monitor system is composed of scintillator, argon-methane/3He gas filled proportional counter and air filled coaxial cable ionization chamber, which detect g-ray, neutron and charged particles induced by lost particle. It is necessary to measure wide dynamic range of loss intensity for various beam energies. To prevent the activation and heat load by intense beam loss, fast time response of loss signals is required. In this paper, construction and application of loss monitor system are described in detail. Preliminary result of demonstration in the KEK-PS and calibration with cobalt 60 g-ray radiation source are also discussed.  
 
THPLT148 Beam Loss Monitoring on the CLIC Test Facility 3 linac, simulation, monitoring, electron 2804
 
  • T. Lefevre, M. Velasco, M. Wood
    NU, Evanston
  • H.-H. Braun, R. Corsini, M. Gasior
    CERN, Geneva
  The CLIC test facility 3 (CTF3) provides a 3.5A, 1.5s electron beam pulse of 150MeV at the end of the linac. The average beam power is 4 kW. Beam loss will be monitored all along the linac in order to keep the radiation level as low as possible. The heavy beam loading of the linac can lead to time transients of beam position and size along the pulse. To compensate these transients effectively a beam loss monitor (BLM) technology has to be chosen with a time response faster than a few nanoseconds. In this context, two different tests have been performed in 2003 on the already existing part of the CTF3 accelerator. Several detectors based on different technologies were first tested in parallel to determine which one was the most appropriate. A second test, in which the beam was intentionally lost in well defined conditions, was then made with the aim of comparing the measurements with simulation results. We present here the results of these tests and our conclusion for the new system to be developed.  
 
THPLT153 Commissioning and Initial Operation of the Isotope Production Facility at the Los Alamos Neutron Science Center target, kicker, isotope-production, diagnostics 2816
 
  • K.F. Johnson, H.W. Alvestad, W.C. Barkley, D.B. Barlow, D.S. Barr, G.A. Bennett, L.J. Bitteker, E. Bjorklund, W. Boedeker, M.J. Borden, R.A. Cardon, G. Carr, J.L. Casados, S. Cohen, J.F. Cordova, J.A. Faucett, M. Fresquez, F.R. Gallegos, J.D. Gilpatrick, F. Gonzales, F.W. Gorman, M.S. Gulley, M.J. Hall, D.J. Hayden, R.C. Heaton, D. Henderson, D.B. Ireland, G. Jacobson, G.D. Johns, D.M. Kerstiens, A.J. Maestas, A.R. Martinez, D. Martinez, G.C. Martinez, J. Martinez, M.P. Martinez, R. Merl, J.B. Merrill, J. Meyer, M.L. Milder, E.A. Morgan, F.M. Nortier, J.F. O'Hara, F.R. Olovas, M.A. Oothoudt, T.D. Pence, E.M. Perez, C. Pillai, F.P. Romero, C. Rose, L. Rybarcyk, G. Sanchez, J.B. Sandoval, S. Schaller, F.E. Shelley, R.B. Shurter, W. Sommer, M.W. Stettler, J.L. Stockton, J. Sturrock, T.L. Tomei, V.P. Vigil, P.L. Walstrom, P.M. Wanco, J. Wilmarth
    LANL/LANSCE, Los Alamos, New Mexico
  • R.E. Meyer, E.J. Peterson, F.O. Valdez
    LANL, Los Alamos, New Mexico
  The recently completed 100-MeV H+ Isotope Production Facility (IPF) at the Los Alamos Neutron Science Center (LANSCE) will provide radioisotopes for medical research and diagnosis, for basic research and for commercial applications. A change to the LANSCE accelerator facility allowed for the installation of the IPF. Three components make up the LANSCE accelerator: an injector that accelerates the H+ beam to 750-KeV, a drift-tube linac (DTL) that increases the beam energy to 100-MeV, and a side-coupled cavity linac (SCCL) that accelerates the beam to 800-MeV. The transition region, a space between the DTL and the SCCL, was modified to permit the insertion of a kicker magnet (23o kick angle) for the purpose of extracting a portion of the 100-MeV H+ beam. A new beam line was installed to transport the extracted H+ beam to the radioisotope production target chamber. This paper will describe the commissioning and initial operating experiences of IPF.