• F.-Z. Hsiao, S. H. Chang, W. S. Chiou, H.C. Li
  NSRRC, Hsinchu

• S.-P. Kao, C.R. Chen, F.-Z. Hsiao, J.P. Wang
  NSRRC, Hsinchu

• H.C. Li, S. H. Chang, W. S. Chiou, F.-Z. Hsiao, Z.-D. Tsai
  NSRRC, Hsinchu

• F. Casagrande, I.E. Campisi, P.A. Gurd, D.R. Hatfield, M.P. Howell, D. Stout, W.H. Strong
  ORNL, Oak Ridge, Tennessee
• D. Arenius, J.C. Creel, K. Dixon, V. Ganni, P.K. Knudsen
  Jefferson Lab, Newport News, Virginia

The Spallation Neutron Source (SNS) is under construction at Oak Ridge National Laboratory. The cold section of the Linac consists of 81 superconducting radio frequency cavities cooled to 2.1K by a 2400 Watt cryogenic refrigeration system. The major cryogenic system components include warm helium compressors with associated oil removal and gas management, 4.5K cold box, 7000L liquid helium dewar, 2.1K cold box (consisting of 4 stages of cold compressors), gaseous helium storage, helium purification and gas impurity monitoring system, liquid nitrogen storage and the cryogenic distribution transfer line system. The overall system commissioning strategy and status will be presented.

• R.H.A. Farias, J.F. Citadini, M.J. Ferreira, J.G.R.S. Franco, A.F.A. Gouveia, L.C. Jahnel, L. Liu, R.T. Neuenschwander, X.R. Resende, P.F. Tavares, G. Tosin
  LNLS, Campinas
• N.P. Abreu
  UNICAMP, Campinas, São Paulo

We present the results of the commissioning of a 28-pole 2 T Hybrid Wiggler at the 1.37 GeV electron storage ring of the Brazilian Synchrotron Light Source. The wiggler will be used mainly for protein crystallography and was optimized for the production of 12 keV photons. The very high field and relatively large gap (22 mm) of this insertion device led to a magnetic design that includes large main and side magnets and heavily saturated poles. We present the results of the commissioning with beam, with special attention to the correction of the large linear tune-shift perturbations produced by the wiggler as well as on the reduction of beam lifetime at full energy. Since the injection at the LNLS storage ring is performed at 500 MeV we also focus on the effects of non-linearities and their impact on injection efficiency.

• Y.-N. Rao, G.H. Mackenzie, T.C. Ries
  TRIUMF, Vancouver

• A. Coniglio, M.P. Pillon, S. Sandri
  ENEA C.R. Frascati, Frascati (Roma)
• M. D'Arienzo
  CNR/RFX, Padova

• S. Passarello, G. Cuttone, G. Gallo, D. Garufi, A. Grmek, G. Manno, M. Re, E. ZappalÃ
  INFN/LNS, Catania

During the last years big effort was devoted to increase the electrostatic deflectors’ reliability; this provided a better comprehension of the most significant effects concerning their working conditions. Deflectors were checked during the normal operation of the K800 Superconducting Cyclotron (CS) at LNS, at the operating pressure of 1 10^-6 mbar and a magnetic field of 3.5 T, the maximum cathodes voltage was –60kV (120 kV/cm). The maximum extracted beam power was, up to now, 100 W; it is foreseen to extract up to 500 W. In this contribution we present the study, the tests and the design of a new water cooled electrostatic deflector. Particular effort was applied to optimise the beam extraction efficiency, the thermal dissipation, and the mechanical stability. In particularly we implemented new insulators, new anodised aluminium cathodes, new Ta septum, new voltage and water feedthroughs and a more efficient cooling system. All these improvements were performed to increase the mean time between failure and the beam current stability.

• M. Kinsho, F. Masukawa, N. Ogiwara, O. Takeda, K. Yamamoto
  JAERI/J-PARC, Tokai-Mura, Naka-Gun, Ibaraki-Ken
• J. Kusano
  Japan Atomic Energy Institute, Linac Laboratory, Tokai-Mura

• K. Yamamoto
  JAERI/J-PARC, Tokai-Mura, Naka-Gun, Ibaraki-Ken
• M. Kinsho
  Japan Atomic Energy Institute, Linac Laboratory, Tokai-Mura

• M. Ikegami
  KEK, Ibaraki
• T. Ohkawa
  JAERI, Ibaraki-ken

• K.H. Gil, J.Y. Choi, C.W. Chung, Y.-C. Kim, H.-S. Lee
  PAL, Pohang, Kyungbuk

• K.-H. Park, C.W. Chung, S.-M. Hong, S.-H. Jeong, Y.G. Jung, D.E. Kim, H.-S. Lee, W.W. Lee
  PAL, Pohang, Kyungbuk
• B.-K. Kang
  POSTECH, Pohang, Kyungbuk

• S. Bartolome-Jimenez, G. Trinquart
  CERN, Geneva

• S. Mayer, D. Forkel-Wirth, M. Fuerstner, H.G. Menzel, S. Roesler, C. Theis, H. Vincke
  CERN, Geneva

• Y. Muttoni, J.-P. Corso, R. V. Valbuena
  CERN, Geneva

• A. Presland, B. Goddard, J.M. Jimenez, D.R. Ramos, R. Veness
  CERN, Geneva

• V. Parma, H. Prin
  CERN, Geneva
• fl. Lutton
  IPN, Orsay

The LHC insertions require 50 specific superconducting quadrupoles, operating in boiling helium at 4.5 K and housed in individual cryostats to form the MS Short Straight Sections (MS SSS). The quadrupoles and corrector magnets are assembled in 8 families of cold masses, with lengths ranging from 5 to 11 m and weights ranging from 60 to 140 kN. The MS SSS need to fulfil specific requirements related to the collider topology, its cryogenic layout and the powering scheme. Most MS SSS are standalone cryogenic and super-conducting units, i.e. they are not in the continuous arc cryostat, and therefore need dedicated cryogenic and electrical feeding. Specially designed cryostat end-caps are required to close the vacuum vessels at each end, which include low heat in-leak Cold-to-Warm transitions (CWT) for the beam tubes and 6 kA local electrical feedthrough for powering the quadrupoles. This paper presents the design of the MS SSS cryostats as an extension of the arc cryostat’s design to achieve a standard and consequently cost-effective solution, and the design solutions chosen to satisfy their specific functionalities.

• M.A.C. Cummings
  Northern Illinois University, DeKalb, Illinois
• S. Ishimoto
  KEK, Ibaraki

• C.K. Sinclair
  Cornell University, Department of Physics, Ithaca, New York
• Y. He, C.H. Smith
  Cornell University, Ithaca, New York

The electron beam exiting an Energy Recovery Linac (ERL) is dumped close to the injection energy. This energy is chosen as low as possible while allowing the beam quality specifications to be met. As ERLs are designed for high average beam current, beam dumps are required to handle high beam power at low energy. Low energy electrons have a short range in practical dump materials, requiring the beam size at the dump face be enlarged to give acceptable power densities and heat fluxes. Cornell University is developing a 100 mA average current ERL as a synchrotron radiation source. The 13 MeV optimum injection energy requires a 1.3 MW beam dump. We present a mature design for this dump, using an array of water-cooled extruded copper tubes. This array is mounted in the accelerator vacuum normal to the beam. Fatigue failure resulting from abrupt thermal cycles associated with beam trips is a potential failure mechanism. We report on designs for a 75 kW, 750 keV tube-cooled beryllium plate dump for electron gun testing, and a 500 kW, 5 to 15 MeV copper tube dump for use with the prototype injector under development. We expect to test the beryllium dump within a year, and the higher power copper dump within 2-1/2 years.

• T.K. Kroc, C.W. Schmidt, A.V. Shemyakin
  Fermilab, Batavia, Illinois

The Fermilab Electron Cooling Project requires the operation of a 4.35 MeV electron beam in the same enclosure that houses the 120 – 150 GeV Main Injector. Effective shielding of the magnetic fields from the ramped electrical buses and local static fields is necessary to maintain the high beam quality and recirculation efficiency required by the electron cooling system. This paper discusses the operational tolerances and the design of the beamline shielding, bus design, and bus shielding as well as experimental results from the prototype and final installation.

• E. Prebys
  Fermilab, Batavia, Illinois

The demands of the Fermilab neutrino program will require the 30 year old Fermilab 8 GeV Booster to deliver higher intensities than it ever has. Total proton throughput is limited by radiation damage and activation due to beam loss in the Booster tunnel. Of particular concern is the insulation in the 96 combined function lattice magnets. This poster describes a study of the potential radiation damage to these magnets from extended running at the planned intensities.

• V.D. Shiltsev, R.J. Hively, V. Kamerdzhiev, A. Klebaner, G.F. Kuznetsov, A. Martinez, H. Pfeffer, G.W. Saewert, A. Semenov, D. Wolff, X. Zhang
  Fermilab, Batavia, Illinois
• K. Bishofberger
  UCLA, Los Angeles, California
• I. Bogdanov, E. Kashtanov, S. Kozub, V. Sytnik, L. Tkachenko
  IHEP Protvino, Protvino, Moscow Region
• A.V. Kuzmin, M.A. Tiunov
  BINP SB RAS, Novosibirsk
• F. Zimmermann
  CERN, Geneva

The 2nd Tevatron electron lens (TEL2) is under the final phase of development and prepare for the installation in the Tevatron. In this report, we will describe the system and the main upgrades from the TEL1. We will also show the magnetic field measurement results, beam testing and plan for installation. The special operation consideration of the TEL2 under high radiation dose will also be discussed.

• Y. He, D.H. Rice
  Cornell University, Laboratory for Elementary-Particle Physics, Ithaca, New York
• Y. Li, M.A. Palmer
  Cornell University, Department of Physics, Ithaca, New York

A luminosity monitor using photons from radiative bhabha events at the CLEO interaction point (IP) has been installed in the Cornell Electron Storage Ring (CESR). A key vacuum and detector component is the photon window/converter whose uniformity and thickness are critical for determining the resolution of the total energy deposited in the segmented luminosity monitor. The window design must accommodate the operational requirements of the new monitor at CLEO-c beam energies of 1.5-2.5 GeV and also provide sufficient safety margin for operation at 5.3 GeV beam energies for Cornell High Energy Synchrotron Source (CHESS) running. During 5.3 GeV operation, intense stripes of synchrotron radiation from the interaction region superconducting quadrupole magnets as well as nearby bending magnets strike the window. During the course of window development, several materials and designs were evaluated. Thermal stresses were calculated using the finite element code ANSYS for various beam conditions to guide the cooling design. A window using aluminum alloy (6061-T6) was ultimately chosen to provide optimal performance for both CLEO-c and CHESS running conditions. The window has been in successful operation since September 2004.

• W. Stein, L. Ahle
  LLNL, Livermore, California
• D.L. Conner
  ORNL, Oak Ridge, Tennessee

• J.E. Spencer, S.D. Anderson, R. Wolf
  SLAC, Menlo Park, California
• A. Baldwin, D.E. Pellet
  UCD, Davis, California
• M. Boussoufi
  UCD/MNRC, McClellan, California
• J.T. Volk
  Fermilab, Batavia, Illinois

Many materials and electronics need to be tested for the radiation environment expected at linear colliders (LC) where the accelerator and detectors will be subjected to large fluences of hadrons, leptons and gammas over the life of the facility. Although the linacs will be superconducting, there are still many potential uses for NdFeB in the damping rings, injection and extraction lines and final focus. Our understanding of the radiation damage situation for rare earth permanent magnet materials was presented at PAC2003 and our first measurements of fast neutron, stepped doses at the UC Davis McClellan Nuclear Reactor Center (UCD MNRC) were presented at EPAC2004 where the damage appeared proportional to the distances between the effective operating points and Hc. Here we have extended those doses and included more commercial samples together with the induced radioactivities associated with their respective dopants. Hall probe data for the external induction distributions are compared with vector magnetization measurements for the different materials.

• Y.Y. Lee, G.J. Mahler, W. Meng, D. Raparia, L. Wang, J. Wei
  BNL, Upton, Long Island, New York

This paper describes the simulation studies on the motions of stripped electrons generated in the injection section of the Spallation Neutron Source (SNS) accumulator ring and the effective collection mechanism. Such studies are important for high intensity machines, in order to reduce beam loss and protect other components in the vicinity. The magnetic field is applied to guide electrons to a collector, which is located at the bottom of the beam chamber. Part of the study results with and without considering the interactions between electrons and materials are presented and discussed. The final engineering design of the electron collector (catcher) is also presented and described.

• R.C. McCrady
  LANL, Los Alamos, New Mexico

We have analyzed the requirements on alignment of the focusing elements (quadrupole doublets) in the Los Alamos Neutron Science Center (LANSCE) side coupled linac. The analysis is performed in terms of harmonics of the quardrupole spacing. This allows us to determine the effect of intentional deviations from a straight line, such as following the curvature of the Earth, and of unintentional deviations introduced by measurement and alignment errors. Results are compared to measured positions of the doublets.

• J.J. Error, D.R. Bruce, J.J. Fazekas, S.A. Helus, J.R. Maines
  ORNL, Oak Ridge, Tennessee

The SNS Project is a 1.4 MW accelerator-based neutron source located at Oak Ridge National Laboratory in Oak Ridge, Tennessee. For shielding purposes, a 17 foot berm of native soil has been constructed on top of the accelerator tunnel system. This backfill has caused ongoing settlement of the tunnels. The settlement has been monitored by the SNS Survey and Alignment Group at regular intervals, in order to discover the patterns of deformation, and to determine when the tunnels will be stable enough for precise alignment of beam line components. The latest monitoring results indicate that the settlement rate has significantly decreased. This paper discusses the techniques and instrumentation of the monitoring surveys, and provides an analysis of the results.

• P.E. Gibson, A.V. Aleksandrov, M.M. Champion, G.W. Dodson, J.P. Schubert, J.Y. Tang
  ORNL, Oak Ridge, Tennessee

The Spallation Neutron Source (SNS) is an accelerator-based neutron source being built at Oak Ridge National Laboratory. The warm linac portion, designed by Los Alamos, has been installed and commissioned. The warm linac is comprised of six Drift Tube Linac (DTL) tanks and four Coupled Cavity Linac (CCL) modules. For commissioning purposes the accelerating systems have been operated at less than the design 6% duty factor. During lower power operation there is less RF cavity heating. This decrease in heat load causes operational stability issues for the associated Resonance Control Cooling Systems (RCCSs) which were designed for full duty factor operation. To understand this effect operational results have been analyzed and tests have been performed. External system factors have been explored and the resulting impacts defined. Dynamic modeling of the systems has been done via a collaboration with the Institute for Nuclear Research (INR), Moscow, Russia. New RCCS operation code has been implemented. Increases in system performance achieved and solutions employed will be presented.

• S.A. Helus, D.R. Bruce, J.J. Error, J.J. Fazekas, J.R. Maines
  ORNL, Oak Ridge, Tennessee

Optical tooling has been a mainstay of the accelerator alignment community for decades. Even now in the age of electronic survey equipment, optical tooling remains a viable alternative, and at times the only alternative. At SNS, we combine traditional optical tooling alignment methods, instrumentation, and techniques, with the more modern electronic techniques. This paper deals with the integration of optical tooling into the electronic survey world.

• D.-O. Jeon
  ORNL, Oak Ridge, Tennessee

It is important to bring the cavity field amplitude and phase to the design values for a high intensity linac such as the Spallation Neutron Source (SNS)linac. A few techniques are available, such as the longitudinal acceptance scan and phase scan. During SNS linac commissioning, tuning of cavities was conducted using the acceptance scan and phase scan technique based on multiparticle simulations. The two techniques are compared.

• R.T. Roseberry, S. Assadi, G.R. Murdoch
  ORNL, Oak Ridge, Tennessee

The Spallation Neutron Source Project (SNS) is an accelerator-based neutron source currently under construction at Oak Ridge National Laboratory (ORNL). The availability of space along completed portions of the accelerator for the addition of beam diagnostic is limited. A new platform for mounting a variety of instruments has been created by replacing part of the Medium Energy Beam Transport (MEBT) section of the accelerator developed by Lawrence Berkeley National Laboratory. The design and current capabilities of this instrument platform will be presented along with plans for future enhancements.

• G.W. Dodson, M. Giannella, A.T. Ruffin, T.L. Williams
  ORNL, Oak Ridge, Tennessee

The SNS Front End, Drift Tube Linac and most of the Coupled Cavity Linac have been operated during commissioning. Beam loss data were taken with differential Beam Current Monitors, and Beam loss Monitors during commissioning. Residual activation data were taken at various times during and after the run. An analysis of beam loss trending, beam loss monitor data and residual activation will be shown.

• M. Emamian, M.D. Busch, S. Mikhailov
  DU/FEL, Durham, North Carolina
• N. Gavrilov
  BINP SB RAS, Novosibirsk

This paper presents the methodology and initial results for mechanical alignment of the booster synchrotron for the Duke FEL storage ring. The booster is a compact design and requires special considerations for alignment. The magnetic and vacuum elements of the arcs have been designed for alignment by a laser tracker system. A parametric 3D design package has been used to determine target coordinates. These target coordinates evolve from design goals to physically verified dimensions by modifying the parametric model to match mechanical measurement data after fabrication. By utilizing the functionality of the laser tracker system and a parametric 3D modeler, a direct and efficient measurement and alignment technique has been developed for a complex geometry.

• T. Morishita, H. Ao, T. Ito, A. Ueno
  JAERI/LINAC, Ibaraki-ken
• K. Hasegawa
  JAERI, Ibaraki-ken
• M. Ikegami, C. Kubota, F. Naito, E. Takasaki, H. Tanaka, K. Yoshino
  KEK, Ibaraki

• D. Li, M.A. Green, S.P. Virostek, M.S. Zisman
  LBNL, Berkeley, California
• W. Lau, A. E. White, S.Q. Yang
  OXFORDphysics, Oxford, Oxon

We describe the progress on the design of the RF coupling coil (RFCC) module for the international Muon Ionization Cooling Experiment (MICE) at Rutherford Appleton Laboratory (RAL) in the UK. The MICE cooling channel design consists of two SFOFO cells that is similar to that of the US Study-II of a neutrino factory. The MICE RFCC module comprises a superconducting solenoid, mounted around four normal conducting 201.25-MHz RF cavities. Each cavity has a pair of thin curved beryllium windows to close the conventional open beam irises, so thatnecessitating separate power feeds for each of the four cavities has to be separately powered. The coil package that surrounds the RF cavities sits is mounted on a vacuum vessel. The RF vacuum is shared between the cavities and the vacuum vessel around the cavities such that. Therefore there is no differential pressure on the thin beryllium windows. This paper discusses the design progress of the RFCC module, the fabrication progress of a prototype 201.25-MHz cavity, and the superconducting coupling coil that will be cooled using a single, small 4 K cooler.

• V.S. Avagyan
  CANDLE, Yerevan

This work presents technologies of copper accelarating structure diffusion joints. The formation conditions of copper diffusion joint with minimal residual plastic strain are determined experimentally.

• M. Fuerstner, I. Brunner, D. Forkel-Wirth, S. Mayer, H.G. Menzel, H. Vincke
  CERN, Geneva
• I. Floret
  Ecole d'ingénieurs de Genève, Genève

• J.L. Boles, L. Ahle, S. Reyes, W. Stein
  LLNL, Livermore, California

Heavy ion and radiation transport calculations are in progress for conceptual beam dump designs for the fragmentation line of the proposed Rare Isotope Accelerator (RIA). Using the computer code PHITS, a preliminary design of a motor-driven rotating wheel beam dump and adjacent downstream multipole has been modeled. Selected results of these calculations are given, including neutron and proton flux in the wheel, absorbed dose and displacements per atom in the hub materials, and heating from prompt radiation and from decay heat in the multipole.

• S. Reyes, L. Ahle, J.L. Boles, W. Stein
  LLNL, Livermore, California
• B.D. Wirth
  UCB, Berkeley, California

Within the scope of conceptual R&D activities in support of the Rare-Isotope Accelerator (RIA) facility, high priority is given to the development of high-power fragmentation beam dumps. A pre-study was made of a static water-cooled Cu beam dump that can meet requirements for a 400 MeV/u uranium beam. The issue of beam sputtering was addressed and found to be not a significant issue. Preliminary radiation transport simulations show significant damage (dpa) in the vicinity of the Bragg peak of uranium ions. Experimental data show that defects in Cu following neutron or high-energy particle irradiation tend to saturate at doses between 1 and 5 dpa, and this saturation in defect density also results in saturation of mechanical property degradation. However, effects of swift heavy ion irradiation and the production of gaseous and solid transmutant elements still need to be addressed. Initial calculations indicate that He concentrations on the order of 100 appm are produced in the beam dump after several weeks of continuous operation and He embrittlement should be a concern. Recommendations are made for further investigation of Cu irradiation effects RIA-relevant conditions.

• W.S. Lockman
  SCIPP, Santa Cruz, California
• D. Aston, G.R. Bower, M. Cristinziani, H. Fieguth, D. H. Wright
  SLAC, Menlo Park, California
• N.R. Barlow, C.L. Edgar
  Manchester University, Manchester
• N.L. Blount, D. Strom
  University of Oregon, Eugene, Oregon
• M. Bondioli
  INFN-Pisa, Pisa
• G. Calderini
  UNIPI, Pisa
• B. Campbell, S.H. Robertson
  CHEP, Montreal, Quebec
• W. Kozanecki
  CEA/DSM/DAPNIA, Gif-sur-Yvette
• B.A. Petersen
  Stanford University, Stanford, Califormia

• K. Nagarathnam
  UTRON Inc, Manassas, Virginia

We present an overview of the net shape and cost-effective manufacturing aspects of high density accelerator (normal and superconducting) components (e.g., NLC Copper disks) and materials behavior of copper, stainless steel, refractory materials (W, Mo and TZM), niobium and SiC by innovative high pressure Combustion Driven Compaction (CDC) technology. Some of the unique process advantages include high densities, net-shaping, improved surface finish/quality, suitability for simple/complex geometries, synthesis of single as well as multilayered materials, milliseconds of compaction process time, little or no post-machining, and process flexibility. Some of the key results of CDC fabricated sample geometries, process optimization, sintering responses and structure/property characteristics such as physical properties, surface roughness/quality, electrical conductivity, select microstructures and mechanical properties will be presented. Anticipated applications of CDC compaction include advanced x-ray targets, vacuum seals, accelerator/RF microwave components, high temperature nozzle liner parts/heat sinks, and advanced high density magnets.

• M.J. Barnes, G.D. Wait
  TRIUMF, Vancouver
• L. Ducimetière
  CERN, Geneva

Each of the two LHC injection kicker magnet systems must produce a kick of 1.3 T.m with a flattop duration variable up to 7.86 microseconds, and rise and fall times of less than 900 ns and 3 microseconds, respectively. A kicker magnet system consists of four 5 Ohm transmission line magnets with matching terminating resistors, four 5 Ohm Pulse Forming Networks (PFN) and two Resonant Charging Power Supplies (RCPS). Nine PFNs, together with associated switch tanks, and dump switch terminating resistors have been built at TRIUMF and all have been tested at high voltage (54 kV) to ensure that the performance is within specification. This paper describes the HV measurements, compares these results with low voltage measurements and analyses the pulse performance of the PFNs. The measurements are compared with results from PSpice simulations and small discrepancies between the predictions and measurements are explained.

• S.-H. Jeong, H.S. Han, Y.G. Jung, H.-S. Kang, H.-G. Lee, K.-H. Park, C. K. Ryu, H.S. Suh
  PAL, Pohang, Kyungbuk
• H.H. Lee
  UU, Gyeongju

The 100-MeV PEFP proton linac has two proton beam extraction lines for user’ experiment. Each extraction line has 5 beamlines and has 5 Hz operating frequency. An AC switching magnet is used to distribute the proton beam to the 5 beamlines, An AC switching magnet is powered by PWM-controlled bipolar switching-mode converters. This converter is designed to operate at ±350A, 5 Hz programmable step output. The power supply is employed IGBT module and has controlled by a DSP (Digital Signal Process). This paper describes the design and test results of the power supply.

• S.-C. Kim, J. Choi, K.M. Ha, J.Y. Huang
  PAL, Pohang, Kyungbuk

High accuracy and stability digital power supply for magnet is developed at PLS. This power supply has three sections. The first section is digital controller including DSP&FPGA and precision ADC, the second consists of IGBT driver and four quad IGBT switch, and the third is LC output section. AC input voltage of power supply is 3-phase 21V, output current is 0 ~ 150 A dc. Switching frequency of IGBT is 25 kHz. The output current of power supply has very high accuracy of 100 mA step resolution at full range and the stability of ± 1.5 ppm for short term and ± 5 ppm for long term. This paper describes characteristics of filter and output current performance improvement after LC output filter at four quad digital power supplies.

• Y.-S. Kim, J.-S. Chai
  KIRAMS, Seoul
• C.W. Chung, H.-G. Lee, W.W. Lee, K.-H. Park
  PAL, Pohang, Kyungbuk
• B.-K. Kang
  POSTECH, Pohang, Kyungbuk

• F. Bordry, J.-P. Burnet, F. Voelker
  CERN, Geneva

• M.A. Clarke-Gayther
  CCLRC/RAL/ASTeC, Chilton, Didcot, Oxon

A description is given of two "state of the art" high voltage pulse generator systems, designed to address the requirements of a fast beam chopping scheme for next generation high power proton drivers.[1] Measurements of output waveform and timing stability, for fast transition short duration, and slower transition long duration pulse generators, are presented.

[1]M. A. Clarke-Gayther, "A Fast Beam Chopper for Next Generation High Power Proton Drivers," Proc. of the ninth European Particle Accelerator Conference (EPAC), Lucerne, Switzerland, 5-9 July, 2004, p. 1449-145.

• T.L. Allison, H. Higgins, E. Martin, W. Merz, S. Philip
  Jefferson Lab, Newport News, Virginia

Jefferson Lab’s Continuous Electron Beam Accelerator Facility (CEBAF) uses Trim Card I power supplies to drive approximately 1900 correction magnets. These trim cards have had a long and illustrious service record. However, some of the employed technology is now obsolete, making it difficult to maintain the system and retain adequate spares. The Trim Card II is being developed to act as a transparent replacement for its aging predecessor. A modular approach has been taken in its development to facilitate the substitution of sections for future improvements and maintenance. The resulting design has been divided into a motherboard and 7 daughter cards which has also allowed for parallel development. The Trim Card II utilizes modern technologies such as a Field Programmable Gate Array (FPGA) and a microprocessor to embed trim card controls and diagnostics. These reprogrammable devices also provide the versatility to incorporate future requirements.

• A.C. de Lira, P. Bellomo, J.J. Lipari, F.S. Rafael
  SLAC, Menlo Park, California

At PEP-II, seven large power supplies (LGPS) are used to power quad magnets in the electron-positron collider region. The LGPS ratings range from 72kW to 270kW, and were installed in 1997. They are unipolar off-line switch mode supplies, with a 6 pulse bridge rectifying 480VAC, 3-phase input power to yield 650VDC unregulated. This unregulated 650VDC is then input into one (or two) IGBT H-bridges, which convert the DC into PWM 16 kHz square wave AC. This high frequency AC drives the primary side of a step-down transformer followed by rectifiers and low pass filters. Over the years, these LGPS have presented many problems mainly in their control circuits, making it difficult to troubleshoot and affecting the overall accelerator availability. A redesign/rebuilding program for these power supplies was established under the coordination of the Power Conversion Department at SLAC. During the 2004 accelerator summer shutdown all the control circuits in these supplies were redesigned and replaced. A new PWM control board, programmable logic controller, and touch panel were all installed to improve LGPS reliability, and to make troubleshooting easier. In this paper we present the details of this rebuilding program and results.

• B. Deriy, A.L. Hillman, G.S. Sprau, J. Wang
  ANL, Argonne, Illinois

The higher requirements for beam injection stability at the APS storage ring demand improvement of pulsed power supplies for the septum magnets. The upgrade will be performed in two stages. In the first stage we will implement a new power supply circuit with a new regulation timing sequence that will provide better voltage regulation performance. A common design was made for all of the septum magnet power supplies at the APS. The new regulation module has already been tested on both thin and thick septum magnet power supplies. This test showed that the new target for the current regulation stability, 1/2000 with less than 10-ns jitter, is achievable with this approach. In the second stage we will implement an embedded microprocessor system that will provide digitally controlled shot-to-shot current regulation of the power supply. The system comprises modules for communication with EPICS, data acquisition, and precise timing. A prototype has already been built and will also be discussed.

• A.L. Hillman, S.J. Pasky, N. Sereno, R. Soliday, J. Wang
  ANL, Argonne, Illinois

Operational goals for the APS facility include 97% availability and a mean time between unscheduled beam losses (faults) of 70 hours, with more than 5000 user hours of scheduled beam per year. To meet this objective, our focus has changed to maximizing the mean time between faults (MTBF). We have made various hardware and software improvements to better operate and monitor the injector power supply systems. These improvements have been challenging to design and implement in light of the facility operating requirements but are critical to maintaining maximum reliability and availability of beam for user operations. This paper presents actions taken as well as future plans to continue improving injector power supply hardware and software to meet APS user operation goals.

• S. Yamanaka
  NIRS, Chiba-shi
• K. Egawa, K. Endo, Z. Fang
  KEK, Ibaraki

• K.R. Rust, W.E. Barnett, R.I. Cutler, J. T. Weaver
  ORNL, Oak Ridge, Tennessee
• S. Dewan, R. Holmes, S. Wong
  IE Power Inc., Mississauga, Ontario
• R.F. Lambiase, J. Sandberg
  BNL, Upton, Long Island, New York
• J. Zeng
  Digital Predictive Systems Inc., Toronto

This paper describes the types and quantities of magnet power supplies required for the SNS Linear Accelerator, High-Energy Beam Transport (HEBT), Ring and the Ring-Target Beam Transport (RTBT). There are over 600 magnets and more than 550 magnet power supplies. These magnet power supplies range in size from the bipolar-corrector supplies rated at 35 volts, 20 amps to the main-ring dipole supply that is rated at 440 volts, 6000 amps. The Linac power supplies have a ripple/stability specification of 1000 parts per million while the ring supplies have a specification of 100 parts per million. There are also pulsed power supplies for beam injection and beam extraction. The paper will show acceptance test results from the manufacturers as well as test results performed by the SNS magnet power supply group.

• V. Popov, S.M. Hartman, S. Mikhailov, O. Oakeley, P.W. Wallace, Y.K. Wu
  DU/FEL, Durham, North Carolina

The next generation electromagnetic OK-5/Duke storage ring FEL wigglers require three 3kA/70V power supplies with current stability about 20 ppm and current ripples less than 20ppm in their full operating range. Duke FEL Laboratory acquired three out-of-service thyristor controllable power supplies (Transrex, 5kA/100V) which was built almost 30 years ago. The existing archaic firing circuit, lack of any output voltage filtering and outdated DCCT, would not be able to meet the above requirements.To deliver the desirable high performance with very limited funds, all three T-Rex power supplies have been completely rebuilt in house at DFELL. Modern high stability electronic components and a Danfysik DCCT with a high current stability have been used. New symmetrical firing circuit, efficient passive LC filter and reliable transformer-coupled active filter are used to reduce output current ripples to an appropriate level. At the present time, the first refurbished power supply in operation since August, 2004 with good overall performance. The power supply testing results of this unit will also be presented in this paper.

• V. Popov, S.M. Hartman, S. Mikhailov, O. Oakeley, P.W. Wallace, Y.K. Wu
  DU/FEL, Durham, North Carolina

The on-going Duke storage ring upgrades and the development of a new booster synchrotron injection require more than 100 units of high performance unipolar and bipolar trim power supplies in the current range of -15A to +15A. However, most of the trim power supplies on the market do not deliver two critical performance features simultaneously: a high current stability and a low current noise.An in-house trim power supply development program is then put in force to design, fabricate, and test low cost linear power supplies with current stability about 100 ppm and current ripples less than 100 ppm in a broad band. A set of unipolar power supplies (0-12A) have been designed, fabricated and successfully tested. Since August, 2004 they have been used in storage ring operation with excellent performance. The prototype of bipolar power supplies (± 15 A) has been designed and tested as well. The main design principles and their performance results of both unipolar and bipolar supplies will be presented in this paper.

• G. Li, Y.G. Zhou
  USTC/NSRL, Hefei, Anhui

• J. Olszewski, F.-J. Decker, R.H. Iverson, A. Kulikov, G.C. Pappas
  SLAC, Menlo Park, California

Originally the PEP-II injection kickers where powered by one power supply. Since the kicker magnets where not perfectly matched, the stored beam got excited by about 7% of the maximum kicker amplitude. This led to luminosity losses which were especially obvious for trickle injection when the detector is on for data taking. Therefore two independant power supplies with thyratrons in the tunnel next to the kicker magnet were installed. This also reduces the necessary power by about a factor of five since there are no long cables that have to be charged. The kickers are now independantly adjustable to eliminate any non-closure of the kicker system and therefore excitation of the stored beam. Setup, commissioning and fine tuning of this system are discussed.

• E. Trakhtenberg, J.T. Collins, P.K. Den Hartog, M. White
  ANL, Argonne, Illinois