kicker

Paper	Title	Other Keywords	Page
TUPLT099	A Kicker Pulse Power Supply with Low Jitter	septum, sextupole, gun, booster	1387
	C.-S. Fann, J.-P. Chiou, S.Y. Hsu, K.-B. Liu NSRRC, Hsinchu
	The performance of kicker pulse power supplies is the main parameter to increase injection efficiency of storage ring that is an important issue for laboratory of synchrotron radiation research. The output current waveform of a kicker pulse power supply with low timing jitter is our goal for years that must satisfy the Top-Up mode injection requirement of NSRRC. In the past years kicker pulse power supplies of storage ring of NSRRC are immersed in isolation oil to sustain high voltage operational environment that led difficult to maintain, electronic component degrading and uneasy to tune parameters. Air-cooling and air-isolation is adopted in the new design structure for kicker pulse power supply system and an pre-trigger unit MA2709A is installed to trigger thyratron tube CX1536A, a kicker pulse power supply with low timing jitter 1~2ns(p-p) is obtained and could satisfy for Top-Up mode injection and maintenance is more easier than before.
TUPLT102	Field Study of the 4T Superconducting Magnet for Rapid Cycling Heavy Ion Synchrotrons	septum, gun, booster, optics	1390
	V.A. Mikhaylov, P.G. Akishin, A.V. Butenko, A.D. Kovalenko JINR, Dubna, Moscow Region
	The problem of the magnetic field optimization of a 4T dipole magnet with circular aperture of 100-110 mm for rapid cycling synchrotron is considered. A single layer low inductance coil made of hollow superconducting high current cable operating at 30 kA is used. The magnetic field ramp rate up to 4 T/s should be achievable. Mathematical method to minimize sextupole and higher order non-linearities to the tolerable values by variation of angular coil turn position is developed. The results of numerical simulation for 2D part magnetic field are presented. The further possibilities to improve the field quality for similar lattice magnets and their application for heavy ion synchrotrons and boosters are discussed.
TUPLT188	SNS Extraction Kicker Power Supply Manufacture Status	focusing, electron, bunching, extraction	1571
	J.-L. Mi, H. Hahn, R.F. Lambiase, Y.Y. Lee, C. Pai, J. Sandberg, Y. Tan, N. Tsoupas, D.S. Warburton, R. Zapasek, W. Zhang BNL, Upton, Long Island, New York
	There are fourteen PFN power supplies, which will be installed in the SNS Extraction Kicker System. The Pulse Forming Network (PFN) power supplies for the SNS Extraction kicker were designed by Brookhaven. The basic configuration of the PFN is a lumped element Blumlein pulse forming network (BPFN). The PFN and power supply are fabricated by an industrial company. The first article of. PFN and power supply has been manufactured and tested with a dummy load at the company and onsite with the prototype magnet. The PFN has been tested beyond its specification and has met all requirements including rise time, pulse flatness, amplitude and pulse repetition rate. Additional heat runs are scheduled. The transverse coupling impedance of the kicker system with attached PFN has been measured. This paper will report on the SNS Extraction Kicker Power Supply engineering status, and will include output waveforms, impedance measurements, and production projections.
TUPLT189	Dipole and Quaqdrupole Sorting for the SNS Ring	focusing, electron, bunching, extraction	1574
	D. Raparia, A.V. Fedotov, Y.Y. Lee, J. Wei BNL, Upton, Long Island, New York
	The Spallation Neutron Source (SNS) accumulator ring is a high intensity ring and must have low uncontrolled losses for hands on maintenance. To achieve these low losses one needs very tight tolerance. These tight tolerances have been achieved through shimming the magnets and sorting. Dipoles are solid core magnets and had very good field quality but magnet to magnet variation were sorted out according to ITF, since all the dipole are powered with one power supply. Typically, sorting is done to minimize linear effects in beam dynamics. Here, sorting of quadrupoles was done according to a scheme which allows to reduce unwanted strength of nonlinear resonances. As a result, the strength of sextupole resonances for our base line tune-box was strongly reduced which was confirmed by a subsequent beam dynamics simulation.
TUPLT190	Acceleration of Polarized Beams using Multiple Strong Partial Siberian Snakes	focusing, electron, bunching, beamloading	1577
	T. Roser, L. Ahrens, M. Bai, E.D. Courant, J. Glenn, R.C. Gupta, H. Huang, A.U. Luccio, W.W. MacKay, N. Tsoupas, E. Willen BNL, Upton, Long Island, New York M. Okamura, J. Takano RIKEN, Saitama
	Acceleration of polarized protons in the energy range of 5 to 25 GeV is particularly difficult since depolarizing spin resonances are strong enough to cause significant depolarization but full Siberian snakes cause intolerably large orbit excursions. Using a 20 - 30 % partial Siberian snake both imperfection and intrinsic resonances can be overcome. Such a strong partial Siberian snake was designed for the Brookhaven AGS using a dual pitch helical superconducting dipole. Multiple strong partial snakes are also discussed for spin matching at beam injection and extraction.
TUPLT191	Transverse Optics Improvements for RHIC Run 4	focusing, electron, bunching, beamloading	1580
	J. Van Zeijts BNL, Upton, Long Island, New York
	The magnetic settings in RHIC are driven by an online model, and the quality of the resulting lattice functions depend on the correctness of the settings, including knowledge of the magnet transfer-functions. Here we first present the different inputs into the online model, including dipole sextupole compenents, used to set tunes and chromaticities along the ramp. Next, based on an analysis of measured tunes and chromaticities along the fy03 polarized proton ramp, we present predictions for quadrupole transfer-function changes. The changes are implemented for the fy04 Au ramp, and we show the improved model agreement for tunes, and chromaticities along the ramp, and measured transverse phase-advance at store. We also describe model improvements for derived observables like the quality of transverse bump closure and observed luminosity ratios between individual interaction points.
TUPLT192	Transition Crossing for the BNL Super Neutrino Beam	focusing, electron, bunching, beamloading	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.
WEXCH01	Experience with LHC Magnets from Prototyping to Large-scale Industrial Production and Integration	focusing, electron, bunching, beamloading	118
	L. Rossi CERN, Geneva
	The construction of the LHC superconducting magnets is approaching one third of its completion. At the end of 2003, main dipoles cold masses for more than one octant were delivered; meanwhile the winding for the second octant was almost completed. The other big magnets, like the main quadrupoles and the insertion quadrupoles, have entered into series production as well. Providing more than 20 km of superconducting magnets, with the quality required for an accelerator like LHC, is an unprecedented challenge in term of complexity that has required several steps from the construction of 1 meter-long magnets in the laboratory to today production of more than one 15 meter-long magnet per day in Industry. The work and its organization is made even more complex by the fact that CERN supplies most of the critical components and part of the main tooling to the magnet manufacturers, both for cost reduction and for quality issues. In this paper the critical aspects of the construction and the time plan will be reviewed and the actual achievements in term of quality and construction time will be compared with the expectations.
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WEOACH01	High Field Gradient Cavity for J-PARC 3 GeV RCS	focusing, electron, bunching, beamloading	123
	C. Ohmori, S. Anami, E. Ezura, K. Hara, Y. Hashimoto, A. Takagi, M. Toda, M. Yoshii KEK, Ibaraki M. Nomura, A. Schnase, F. Tamura, M. Yamamoto JAERI/J-PARC, Tokai-Mura, Naka-Gun, Ibaraki-Ken
	A new type of rf cavity will be used for J-PARC project. To minimize the beam loading effects, the quality factor of the core stack is increased by a cut core configuration. High power test of the rf system has been performed. Temperature rise around the cut surface of the cores were observed. It is minimized by improving the cooling efficiency.
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WEOACH02	Gas Condensates onto a LHC Type Cryogenic Vacuum System Subjected to Electron Cloud	focusing, bunching, beamloading, antiproton	126
	V. Baglin, B.J. Jenninger CERN, Geneva
	In the Large Hadron Collider (LHC), the gas desorbed via photon stimulated molecular desorption or electron stimulated molecular desorption will be physisorbed onto the beam screen held between 5 and 20 K. Studies of the effects of the electron cloud onto a LHC type cryogenic vacuum chamber have been performed with the cold bore experiment (COLDEX) installed in the CERN Super Proton Synchrotron (SPS). Experiments performed with gas condensates such as H2, H2O, CO and CO2 are described. Implications to the LHC design and operation are discussed.
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WEOACH03	Achievement of 35 MV/m in the TESLA Superconducting Cavities Using Electropolishing as a Surface Treatment	focusing, bunching, beamloading, antiproton	129
	L. Lilje DESY, Hamburg
	The Tera Electronvolt Superconducting Linear Accelerator TESLA is the only linear electron-positron collider project based on superconductor technology for particle accelaration. In the first stage with 500 GeV center-of-mass energy an accelerating field of 23.4MV/m is needed in the superconducting niobium cavities which are operated at a temperature of 2 K and a quality factor Q0 of 1010. This performance has been reliably achieved in the cavities of the TESLA Test Facility (TTF) accelerator. The upgrade of TESLA to 800 GeV requires accelerating gradients of 35 MV/m. Using an improved cavity treatment by electrolytic polishing it has been possible to raise the gradient to 35 - 43 MV/m in single cell resonators. Here we report on the successful transfer of the electropolishing technique to multi-cell cavities. Presently four nine-cell cavities have achieved 35 MV/m at Q_0 = 5 × 109, and a fifth cavity could be excited to 39 MV/m. In two high-power tests it could be verified that EP-cavities preserve their excellent performance after welding into the helium cryostat and assembly of the high-power coupler. One cavity has been operated for 1100 hours at the TESLA-800 gradient of 35 MV/m and 57 hours at 36 MV/m without loss in performance.
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WEYCH01	Fast Pulsed SC Magnets	focusing, bunching, beamloading, antiproton	132
	G. Moritz GSI, Darmstadt
	The demand for high beam intensities leads to the requirement of fast pulsed magnets for synchrotrons. An example is the proposed 'International Facility for Beams of Ions and Antiprotons' at GSI, which will consist of two synchrotrons in one tunnel and several storage rings. The high field ramp rate and repetition frequency introduce many magnet design problems and constraints in the operation of the accelerator. Persistent currents in the superconductor and eddy currents in wire, cable, iron and vacuum chamber reduce the field quality and generate cryogenic losses. Due to the large number of magnet cycles during the lifetime of such a magnet, special attention has to be paid to magnet material fatigue problems. The large charging voltages put some constraints on the use of cold diodes for quench protection. R&D has started at GSI, in collaboration with many institutions, to comply with the constraints mentioned above. Model dipoles were built and tested. The results of the R&D are reported. The advantages of the use of low field, fast pulsed superconducting, compared to resistive, magnets will be discussed
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WEYCH02	Technical Issues for Large Accelerators based on High Gradient SC Cavities	focusing, bunching, beamloading, antiproton	137
	C. Pagani, C. Pagani DESY, Hamburg
	The perspective to build large accelerators based on high gradient superconducting cavities is posing a number of new problems that have been addressed in the preparation of the TESLA project. Starting from the experience gained with the past large installations, such as LEP2 at CERN and CEBAF at JLab, in this paper I discuss the new demands and the solution envisaged. Industrial production issues are focussed in terms of large scale production, reviewed quality control criteria and cost reduction. The impact on component design and engineering together with the expected improvements in term of performances and reliability are also outlined.
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WEYCH03	Low and Medium Beta Superconducting Cavities	focusing, bunching, beamloading, antiproton	142
	A. Facco INFN/LNL, Legnaro, Padova
	The use of low- and intermediate-beta superconducting cavities, once confined to low current heavy ion linacs, is steadily increasing in accelerators. The progress in this technology allowed a significant increase in cavity performance during the last 10 years; a large number of resonators, with different geometries, frequencies and gap numbers have been built for a large variety of applications and the development is still going on. The main boost is given by new projects of radioactive beam facilities and high power proton accelerators worldwide. While the advantages of SC resonators, compared with normal conducting structures, are rather well established in high-beta linacs, this is not always the case at low-beta. The choice of the optimum transition beam energy in a linac, where superconducting cavities should replace the room temperature ones, requires a careful evaluation that depends on the linac specifications.
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WEOBCH01	Performance Requirements for Monitoring Pulsed, Mixed Radiation Fields around High-energy Acclerators	radiation, focusing, bunching, beamloading	147
	D. Forkel-Wirth, S.M. Mayer, H.G. Menzel, A. Muller, T. Otto, M. Pangallo, D. Perrin, M. Rettig, S. Roesler, L. Scibile, H. Vincke CERN, Geneva C. Theis TUG/ITP, Graz
	Radiation protection survey around CERN's High Energy Accelerators represents a major technical and physical challenge due to the pulsed and complexity of the mixed radiation fields. The fields are composed of hadrons, leptons and photons ranging in energy from fractions of eV to several 10 GeV. In preparation of the implementation of a Radiation Monitoring System for the Environment and Safety (RAMSES) of the future Large Hadron Collider (LHC) and its injectors comprehensive studies were performed to evaluate the suitability of different existing monitors for this task. Different ionization chambers were exposed to short, high-intensity radiation pulses and their saturation levels for high dose rates determined. Limiting factors such as recombination effects and the capacity of the electronics to process a high number of charges within very short time were studied in detail. These results are being used to optimize the design of the read-out electronics. In additional studies, the response of two different types of ionization chambers to high-energy radiation was investigated by measurements in the mixed radiation fields of the CERN EU high-energy Reference Field (CERF) facility. The results of the experiments agreed well with calculations, clearly demonstrating that modern Monte-Carlo simulation techniques can be used to design radiation monitors and to optimize their performance.
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WEOBCH02	Design, Construction, and Initial Operation of the SNS MEBT Chopper System	radiation, focusing, bunching, beamloading	150
	R.A. Hardekopf, S.S. Kurennoy, J. Power LANL, Los Alamos, New Mexico A.V. Aleksandrov, D.E. Anderson ORNL/SNS, Oak Ridge, Tennessee
	The chopper system for the Spallation Neutron Source (SNS) provides a gap in the beam for clean extraction from the accumulator ring. It consists of a pre-chopper in the low-energy beam transport (LEBT) and a faster chopper in the medium-energy beam transport (MEBT). We report here on the final design, fabrication, installation, and first beam tests of the MEBT chopper. The traveling-wave deflector is a meander-line design that matches the propagation of the deflecting pulse with the velocity of the beam at 2.5 MeV, after the radio-frequency quadrupole (RFQ) acceleration stage. The pulser uses a series of fast-risetime MOSFET transistors to generate the deflecting pulses of ± 2.5 kV with rise and fall times of 10 ns. We describe the design and fabrication of the meander line and pulsers and report on the first operation during initial beam tests at SNS.
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WEOCCH01	A New 180 MeV H- Linac for Upgrades of ISIS	radiation, focusing, bunching, target	153
	F. Gerigk CCLRC/RAL/ASTeC, Chilton, Didcot, Oxon
	Several options have been studied to raise the beam power of the ISIS spallation neutron source to a level of 1 MW with the possibility of going to 4-5 MW in the longer term. All scenarios can operate in 2 modes, where the beam power is either delivered to a spallation target or, alternatively, to a target suitable to produce muons via pion decay for a neutrino factory. A more recent upgrade option takes an intermediate step and uses a 180 MeV H- linac, which is also foreseen for the 4-5 MW upgrade, as a replacement for the current 70 MeV injector. First estimates indicate that, due to the lower space charge forces, the ring would be able to carry twice as many particles, thus doubling the final beam power to 0.5 MW. This paper presents a first design for the 180 MeV linac, using a triple frequency jump from 234.8 to 704.4 MHz. The design profits from the development of 704.4 MHz cavities and RF equipment within the framework of the European HIPPI collaboration. The low frequency for the front-end was chosen to ease the DTL design as well as the development of a low energy beam chopper, which will be necessary to reduce beam losses at injection into the synchrotron.
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WEOCCH02	Construction Status and Issues of the Spallation Neutron Source Ring	radiation, focusing, bunching, target	156
	J. Wei BNL, Upton, Long Island, New York
	(For the Spallation Neutron Source collaboration) The Spallation Neutron Source (SNS) accelerator complex is now in its sixth year of a seven-year construction cycle. The design, fabrication, test, and assembly of the accumulator ring and its transport lines is approaching the final stage. In order to reach the design goal of this high-power ring to deliver 1.5 MW beam power (1.5$× 1014 protons of 1 GeV kinetic energy at a repetition rate of 60 Hz), stringent measures have been implemented to ensure the quality of the accelerator systems. This paper reviews the progress of the ring and transport systems with emphasis on the challenging technical issues and their solutions inccurred during the construction period.
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WEODCH01	1.5-GeV FFAG Accelerator as Injector to the BNL-AGS	radiation, focusing, acceleration, bunching	159
	A. Ruggiero, M. Blaskiewicz, T. Roser, D. Trbojevic, N. Tsoupas, W. Zhang BNL, Upton, Long Island, New York
	A 1.5-GeV Fixed-Field Alternating-Gradient (FFAG) Accelerator has been recently proposed as a new injector to the Alternating-Gradient Synchrotron (AGS) of Brookhaven National Laboratory (BNL). It is being considered as a replacement of the present 1.5-GeV AGS Booster. The substitution will enhance the performance of the AGS accelerator facility in a variety of ways. It would still allow acceleration of all hadronic particles: protons, and heavy-ions. The major benefit is that it would considerably shorten the typical combined AGS acceleration cycle, and, consequently, may yield to an improvement of beam stability, intensity and size. The AGS-FFAG will also facilitate the proposed upgrade of the AGS facility toward a 1-MW average proton beam power. The paper describes a compact FFAG design for acceleration of protons from 200 MeV to 1.5 GeV. The circumference is about 250 m. The lattice is a periodic sequence of FDF triplets of combined-function magnets. An adjusted field profile has been calculated to compensate the variation of the main lattice functions with momentum. At injection, a beam pulse 130 μs long of negative-ions (H?) is stacked with the charge-exchange method. Acceleration of one pulse with 2.5 x 1013 protons takes about 130 μs, if harmonic-jump scheme is used in conjunction with the choice of 201.25 MHz. Four of such beam pulses are required to fill entirely the AGS. The entire filling process thus takes less than one millisecond.
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WEODCH02	Interaction of Stored Ions with Electron Target in Low Energy Electrostatic Ring	electron, radiation, focusing, ion	162
	E. Syresin JINR, Dubna, Moscow Region K. Noda NIRS, Chiba-shi T. Tanabe KEK, Ibaraki
	The KEK electrostatic ring is used for investigations of molecular, bimolecular and DNA ions. The electron target installed in this ring has same construction as usual electron cooler. The interaction of stored ions with the electrons increases the ion lifetime at electron cooling caused by a suppression of the ion scattering on the residual gas atoms. The proton lifetime of 2 s was increased in the experiments by factor 2 at the electron cooling with the electron beam current of 0.2 mA, the proton energy of 20 keV and the residual gas pressure of 0.04 nTorr. However the electron-ion interaction can decrease the ion lifetime caused by an excitation of the transverse instability produced by an intensive electron beam. So in the KEK electrostatic ring the proton lifetime is reduced to 1.7 s at detuning of electron acceleration voltage from nominal cooler value on 0.4 V. The simulation of electron cooling and transverse instability of the light and DNA ions are discussed in this report.
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WEXLH01	Non-destructive Beam Measurements	electron, radiation, focusing, ion	165
	M. Bai BNL, Upton, Long Island, New York
	In high energy accelerators especially storage rings, non-destructive beam measurements are highly desirable to minimize the impact on the beam quality. In principle, the non-destructive tools can be either passive detectors like Schottky, or active devices which excite either longitudinal or transverse beam motions for the corresponding measurements. An example of such a device is ac dipole, a magnet with oscillating field, which can be used to achieve large coherent betatron oscillations. It has been demonstrated in the Brookhaven AGS that by adiabatically exciting the beam, the beam emittance growth due to the filamentation in the phase space can be avoided. This paper overviews both techniques in general. In particular, this paper also presents the beam tune measurement with Schottky detector, phase advance measurement as well as non-linear resonance measurements with the ac dipoles in the Brookhaven RHIC.
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WEOALH01	Particle-in-cell Beam Dynamics Simulations	electron, radiation, focusing, ion	170
	T. Lau, E. Gjonaj, T. Weiland TEMF, Darmstadt
	We describe the application of the Conformal Finite Integration Technique (CFIT) in the time-domain to beam dynamics simulations with the Particle-In-Cell (PIC) method. The conformal method results in a more accurate field solution for complicated geometries than the traditional FIT approach. For long-time simulations we investigate several methods for the suppression of the spurious noise, typically emerging in PIC simulations. The results are compared with the analytical solution for a bunch in a semi-infinite waveguide for each of the presented methods. As a realistic example simulations for the RF-Gun installed at Photo Injector Test Facility in DESY Zeuthen (PITZ) will be presented.
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WEOALH02	Multiturn Extraction Based on Trapping in Stable Islands at CERN PS: Recent Measurement Advances	electron, radiation, focusing, ion	173
	M. Giovannozzi, R. Cappi, S.G. Gilardoni, M. Martini, E. Métral, A. Sakumi, R.R. Steerenberg CERN, Geneva A.-S. Müller FZK-ISS-ANKA, Karlsruhe
	Recently a novel approach to perform multi-turn extraction was proposed based on beam splitting in the transverse phase space by means of trapping inside stable islands. During the year 2002 run, preliminary measurements at the CERN Proton Synchrotron with a low-intensity, single-bunch, proton beam, confirmed the possibility of generating various beamlets starting from a single Gaussian beam. The experimental campaign continued also in the year 2003 run to assess a number of key issues, such as feasibility of trapping with high-intensity beam, capture efficiency, and multi-turn extraction proper. The experimental results are presented and discussed in detail in this paper.
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WEOALH03	Installation Strategy for the LHC Main Dipoles	electron, radiation, focusing, ion	176
	S.D. Fartoukh CERN, Geneva
	All positions in the LHC machine are not equivalent in terms of beam requirements on the geometry and the field quality of the main dipoles. In the presence of slightly or strongly out-of tolerance magnets, a well-defined installation strategy will therefore contribute to preserve or even optimize the performance of the machine. In view of present state of the production, we have anticipated a list of potential issues (geometry, transfer function, field direction and random b3) which, combined by order of priority, have been taken into account to define a robust installation algorithm for the LHC main dipoles. Among the different possible strategies, the proposed one has been optimised in terms of simplicity and flexibility in order not to slow down and complicate the installation process. Its output is a prescription for installing the available dipoles in sequence while reducing to an absolute minimum the number of holes required by geometry or field quality issues.
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WEYLH01	Emittance Control for Very Short Bunches	electron, focusing, ion, bunching	179
	K.L.F. Bane SLAC, Menlo Park, California
	Many recent accelerator projects call for the production of high energy bunches of electrons or positrons that are simultaneously short, intense, and have small emittances. Two examples of such projects are linear colliders, such as the GLC/NLC, and Self-Amplified Spontaneous Emission (SASE) FEL's, such as the Linac Coherent Light Source (LCLS). A major challenge in such projects is keeping in check forces that increase short bunch emittances in accelerator components, such as: wakefields of accelerator structures, collimators, and surface roughness, and coherent synchrotron radiation (CSR). We describe such forces and their control.
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WEYLH02	Single Particle Linear and Non-linear Dynamics	electron, focusing, ion, bunching	184
	Y. Cai SLAC, Menlo Park, California
	I will give a comprehensive review of existing particle tracking tools to assess long-term particle stability for small and large accelerators in the presence of realistic magnetic imperfections and machine misalignments. The emphasis will be given to the tracking and analysis tools based upon the differential algebra, Lie operator, and "polymorphism". Using these tools, a uniform linear and non-linear analysis will be outlined as an application to the normal form. Finally I will compare simulation results with observations in existing circular accelerators. "Model independent analysis" will be treated as an example for measuring machine optics.
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WEYLH03	Collective Effects and Instabilities in Space Charge Dominated Beams	focusing, ion, bunching, beamloading	189
	J.A. Holmes ORNL/SNS, Oak Ridge, Tennessee
	Significant progress in the detailed computational study of collective beam dynamics is being driven by the spectacular increase in computer power. To take advantage of this, sophisticated physics models are being applied to ever more realistic and detailed situations, so that it is no longer necessary to restrict computer studies to highly idealized depictions of beam dynamics questions. This presentation will illustrate the application of a number of collective beam dynamics models to a range of accelerator physics problems in high intensity proton rings. In particular, we will consider the effects of space charge, transverse and longitudinal impedances, and electron cloud formation on beam parameters, stability, halo formation, collimation and losses, and possible equilibrium configurations. Examples will be taken from PSR, the CERN PS Ring, and SNS.
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WEILH00	Industrial Involvement in EC Supported Accelerator R&D in the 6th Framework Programme and in Preparing Large Scale Accelerator Projects	focusing, ion, bunching, beamloading	194
	D. Proch DESY, Hamburg
	The presentation will cover industrial involvement in EC supported accelerator R&D in the 6th framework programme and in preparing large scale accelerator projects (TESLA).
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WEILH01	Methods for Successful Technology Transfer in Physics	focusing, ion, bunching, beamloading	198
	K.N. Hill Qi3, Cambridge
	The development of accelerators for scientific research generates significant technologies of interest to industry. As physicists and technologists we also require strong partnerships with industry in order that it may supply us with the instrumentation and systems we require for new apparatus. We will discuss the methods developed for the UK Particle Physics and Astronomy Research Council (PPARC) and applied on behalf of CERN to encourage successful knowledge transfer into industry. Case studies will illustrate the hurdles that must be surmounted and effective methods to build successful partnerships, licensing opportunities and spinout companies. Factors considered will include assessment of the commercial potential of technologies, personal motivations for academic/industrial collaboration, sources of funding, and effects on the academic groups involved in knowledge transfer activity.
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WEILH03	Industrial Response to RF Power Requirements	focusing, ion, bunching, beamloading	202
	M. Wilcox e2v technologies, Chelmsford, Essex
	Today, high-energy physics machines are broadly speaking of two kinds. Some machines are dedicated to providing a service using particle acceleration as an intermediate step (light sources, neutron spallation sources, cancer therapy equipment etc.)and occasionally, particle colliders are built in which the particles are used directly to probe the nature and origin of matter. The latter machines have developed to a point where the technology needed is often at the extreme edge of what is understood, let alone of what is currently achievable. In addition the scope of supply and the level of equipment integration demanded of industry is increasing as RF skills become scarcer. This reduces the supplier base so placing greater demands on those remaining. To help offset this problem, companies should be brought 'inside' the project team at an early stage of the machine design so that better account can be taken of limitations, preferences and competing obligations that the companies may have. A more collaborative approach should result in projects being completed in a shorter time, to a lower cost, and with a more certain outcome.
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WEILH04	Industrial Involvement in the Construction of Synchrotron Light Sources	focusing, ion, bunching, beamloading	206
	M.S. de Jong CLS, Saskatoon, Saskatchewan
	The design, construction and commissioning of a modern third-generation synchrotron light source facility is a major project, costing hundreds of millions of dollars. The delivery of these new facilities, usually on a fixed budget and schedule, requires an effective working relationship with all suppliers providing equipment and services to the project. This talk will examine some of the key issues in developing and maintaining such a relationship with industry during the construction of a third-generation synchrotron light facility. These issues include project planning, the contract specification, the tendering process, communication techniques over the contract term, and other aspects of contract control. Examples, primarily from our experience constructing the Canadian Light Source but also from other new facilities planned or under construction, will be used to examine the effectiveness of various approaches to working with industry.
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WEPKF001	Diffusion Welding of Heterogeneous Materials in Accelerator Technique	focusing, ion, bunching, beamloading	1586
	V.S. Avagyan CANDLE, Yerevan A. Babayan, N.M. Dobrovolski, I.V. Tunyan YerPhI, Yerevan
	The results of the joining of heterogeneous materials, such as titanium with stainless steel (serviceable at 4.2 K), copper with aluminum, titanium with niobium (this work has been carried out for TESLA project), stainless steel with aluminum, copper with stainless steel are presented in this work.
WEPKF002	Magnets for the CANDLE Booster Synchrotron, Design and Prototyping	focusing, ion, bunching, beamloading	1588
	V.G. Khachatryan, Y.L. Martirosyan, A. Petrosyan CANDLE, Yerevan
	CANDLE booster synchrotron magnetic lattice contains 48 dipoles of H-shape. Detailed magnetic and mechanical design of those magnets is performed within the framework of the project. In this report, the design considerations of the dipole magnet, including the magnetic field simulation is presented. The main features of the fabricated first prototype dipole magnet are discussed.
WEPKF003	Design of the End Magnets for the IFUSP Main Microtron	focusing, ion, bunching, beamloading	1591
	M.L. Lopes, A.A. Malafronte, M.N. Martins, J. Takahashi USP/LAL, Bairro Butantan K.-H. Kaiser IKP, Mainz
	The Instituto de Física da Universidade de São Paulo (IFUSP) is building a two-stage 31 MeV continuous wave (cw) racetrack microtron. In this work we describe the characteristics of the end magnets for the IFUSP main microtron. The magnets are part of the main acceleration stage, which raises the energy from 4.9 to 31 MeV. We are studying the possibility of increasing the energy up to 38 MeV, so the magnets should have approximately 2x1 m2 region of useful field. The dipoles have a 0.1410 T magnetic field and 1 part in 1000 homogeneity without correcting devices. Using a 2D magnetic field code (FEMM), we illustrate the use of homogenizing gaps with different forms and non parallel pole faces to achieve the necessary homogeneity. The use of clamps to produce reverse fields to reduce the vertical defocusing strength on the beam is also described. In order to calculate the beam trajectories and to evaluate the magnetic field homogeneity within the useful region, a 3D magnetic field software (TOSCA) was used.
WEPKF004	Magnetic Quadrupole Lenses for the IFUSP Microtron	focusing, ion, bunching, quadrupole	1594
	T.F. Silva, M.L. Lopes, A.A. Malafronte, M.N. Martins, P.B. Rios, J. Takahashi USP/LAL, Bairro Butantan
	The Instituto de Física da Universidade de São Paulo (IFUSP) is building a two-stage 31 MeV continuous wave (cw) racetrack microtron. In this work, we describe the design of the magnetic quadrupole lenses for the IFUSP microtron. The design consists of a laminar structure divided in four equal pieces. Because each piece corresponds to an individual pole, it eases the assembling of the coils and the installation of the quadrupole on the beam transport line without breaking the vacuum. Due to the fact that the quadrupole is laminated along the longitudinal axis, it is possible to change the length of a given lens by adding or subtracting foils. We also present the magnetic field distribution calculated using the POISSON code. A prototype presented good mechanical rigidity and thermal performance, showing that a refrigeration system is not necessary. The magnetic measurements show that the field distribution within the region of interest agrees with the POISSON simulation.
WEPKF005	Pressure Field Distribution in a Cylindrical Geometry with Arbitrary Cross Section	focusing, ion, bunching, vacuum	1597
	F.T. Degasperi FATEC-SP, Sao Paulo, SP M.N. Martins, J. Takahashi USP/LAL, Bairro Butantan L.L. Verardi IBILCE - UNESP, Sao Jose do Rio Preto, SP
	This work presents analytical and numerical results for the pressure field distribution along the axis of tubular geometries with arbitrary axisymmetric cross sections with an arbitrary time- and position-dependent gas source. Several areas of applied physics deal with problems in high-vacuum and ultra high-vacuum technology that present tubular form. In many cases one finds tubes with non uniform cross sections, like parts of particle accelerators, colliders, storage rings, gravitational antennas, and electron devices, like klystrons, electron microscopes, and also parts of vacuum systems in general, for instance, bellows, conical pipes and others. In this work one can get the detailed pressure distribution is not determined. This work presents and describes in detail the pressure field in tubes with arbitrary axisymetric cross sections. Details of the mathematical and physical formulations and modeling are given; specific conductance and specific throughput are defined; and a detailed discussion about the boundary conditions is given. These concepts and approach are applied to usual realistic cases, like conical tubes and bellows, with typical laboratory dimensions.
WEPKF006	Field Quality and Hysteresis of LHC Superconducting Corrector Magnets	focusing, ion, bunching, vacuum	1600
	A. Santrich Badal, M. Allitt, C. Giloux, M. Karppinen, A.M. Lombardi, V. Remondino, W.  Venturini Delsolaro, R. Wolf CERN, Geneva M. Bagre, P. Khare, T. Maurya, A. Puntambekar CAT, Indore (M.P.)
	The Large Hadron Collider (LHC) will use some 6400 superconducting corrector magnets. There are 19 corrector types. These are assembled 14 different types of magnets of which 4 are nested. They are being manufactured by 4 firms in Europe and 3 in India. The magnetic field quality is measured at room temperature by 12 magnetic measurement benches employed by the corrector manufacturers. CERN performs magnetic measurement at 4.2K and at 1.9K on a small subset of corrector magnets. The paper discusses the correlation between the warm and cold field measurements. The field quality is compared to the magnet design expectations and to the target field quality for LHC. Many corrector circuits will be powered in a way which cannot be predicted before LHC will start operation and which even then may change between physics runs. The measured magnetic hysteresis and its influence on possible setting errors during operation is discussed, in particular for the orbit correctors and the tuning/trim quadrupole magnet circuits.
WEPKF007	Vacuum Characterisation of a Woven Carbon Fiber Cryosorber in Presence of H2	focusing, ion, bunching, vacuum	1603
	V. Baglin, H. Dupont, T. Garcin CERN, Geneva
	Some of the cryogenic components in the Large Hadron Collider (LHC) will operate at 4.5 K. The H2 desorption will rapidly increase to the saturated vapour pressure, 3 orders of magnitude larger than the design pressure. Therefore, the use of cryosorbers is mandatory to provide the required pumping capacity and pumping speed. The behaviour of a woven carbon fiber to be used as a cryosorber has been studied under H2 injection. The pumping speed and capacity measured in the range 6 to 30 K are described. Observations made with an electron microscope are shown. A proposed pumping mechanism and the implications to the LHC are discussed.
WEPKF008	A Strategy for Sampling of the Field Quality of the LHC Dipoles	focusing, ion, bunching, vacuum	1606
	L. Bottura, S.D. Fartoukh, V. Granata, E. Todesco CERN, Geneva
	We have measured the magnetic field of a considerable fraction of the superconducting LHC main dipoles, of the order of 300 in warm conditions and 100 in cold conditions. All LHC dipoles will be measured in warm conditions at the manufacturers to steer the production inside the acceptance limits imposed by beam dynamics. Using the available data we analysed the distributions of the main field and higher order field errors in warm and cold conditions, as well as the distribution of the warm-to-cold correlation. Based on this analysis we predict the minimum number of magnets that should be measured in cold conditions in order to guarantee that (1) the production is controlled within the specified limits (2) the field is known to a sufficient level for a sound installation and (3) the uncertainty on the knowledge of the magnetic field of the LHC dipoles is small enough for the commissioning of the accelerator and to insure operation of the machine in any condition, including higher energy. The main outcome of this analysis is that cold measurements on a fraction of the order of one third of the total production, i.e. approximately 400 dipoles, will be sufficient to achieve the above objectives.
WEPKF009	A Scaling Law for Predicting Snap-back in Superconducting Accelerator Magnets	focusing, ion, bunching, vacuum	1609
	T. Pieloni, L. Bottura, S. Sanfilippo CERN, Geneva G. Ambrosio, P. Bauer Fermilab, Batavia, Illinois M. Haverkamp METROLAB, Plan-les-Ouates
	The decay of the sextupole component in the bending dipoles during injection and the subsequent snap-back at particle acceleration are issues of common concern, albeit at different levels of criticality, for all superconducting colliders built (Tevatron, HERA, RHIC) or in construction (LHC) to date. The main difficulty is the correction of the relatively large and fast sextupole change during snap-back. Motivated by the above considerations, we have conducted an extended study of sextupole snap-back on two different magnet families, the Tevatron and the LHC bending dipoles, using the same measurement method. We show in this paper that it is possible to generalise all the results obtained by using a simple, exponential scaling law. Furthermore, we show that for magnets of the same family the parameters of the scaling law correlate linearly. This finding could be exploited during accelerator operation to produce accurate forecast of the snap-back correction based solely on beam-based measurements.
WEPKF010	Design of an Automatic System for the Electrical Quality Assurance during the Assembly of the Electrical Circuits of the LHC	focusing, ion, bunching, vacuum	1612
	D. Bozzini, V. Chareyre, A. Jacob, K.H. Mess, S. Russenschuck, R. Solaz Cerdan CERN, Geneva
	During the assembly of the LHC one of the challenges will be the correct wiring of the 1712 circuits powering the 10094 magnet units, for which all-together 70000 splices have to be done. Considering the complexity of the electrical scheme the risk of wrong wiring is high. Errors, if not detected during the assembly phase, will perturb the LHC operation. A method has been developed to verify automatically the cabling scheme. It first detects the continuity of a portion of circuit and then verifies the correct polarity and type of the magnets in the circuit. A 108-meter LHC cell is the shortest length that can be tested. The system is composed of a unit to be placed at the center of the cell and two de-multiplexers positioned at the extremities of the cell. The central unit contains a data acquisition system where in total 217 signals can be acquired and more than 3000 voltage combinations are possible. Pointing to different databases, a LabVIEW program automatically executes the test procedure, generates, and stores the reports. The hardware and software design, the data flow between databases, and the testing methodology applied to the different circuit types are described.
WEPKF011	Performance of the Superconducting Matching Quadrupoles for the LHC Insertions	focusing, ion, bunching, vacuum	1615
	N. Catalan-Lasheras, G. Kirby, R. Ostojic, J.C. Perez, H. Prin, W.  Venturini Delsolaro CERN, Geneva
	The optics flexibility of the LHC insertions is provided by the individually powered quadrupoles in the dispersion suppressors and matching sections. These units comprise special quadrupole magnets of the MQM and MQY type and range in length from 5.4 m to 11.4 m. In total, 82 insertion quadrupoles will be assembled at CERN. In this paper we present the advance in construction and report on the performance of the first series built quadrupoles. In particular, we present the quench performance of the individual magnets and alignment measurements of the cold masses, and discuss the field quality trends and possible implications.
WEPKF012	LHC Dipole Axis, Spool Piece Alignment and Field Angle in Warm and Cold Conditions	focusing, ion, bunching, vacuum	1618
	M. Coccoli, M. Buzio, J. Garcia Perez CERN, Geneva
	The installation and commissioning of the LHC dipoles requires the knowledge of the magnetic axis and of the spool piece corrector alignment at the operating conditions. The installation is based at present on the use of geometric information derived from mechanical measurements performed in warm conditions, with the assumption that the geometric and magnetic axis are coincident. Any discrepancies between mechanical and magnetic axis and unforeseen geometry variations from ambient to cold operating temperature can introuduce important uncertaintes in the prediction of the alignment at operational conditions. Such prediction is studied through correlations between measurements performed at room and liquid helium temperature. A statistic analysis of the measurement data available is presented showing uncertainties on the correctors alignment. They are compared with beam-based specifications of the positioning of the spool piece.
WEPKF014	Magnetic Field Tracking Experiments for LHC	focusing, ion, bunching, vacuum	1621
	V. Granata, J. Billan, F. Bordry, L. Bottura, P. Coutinho Ferreira, E. Effinger, G. Fernqvist, P. Galbraith, Q. King, J. Pett, A. Raimondo, A. Rijllart, H. Thiesen CERN, Geneva
	At the Large Hadron Collider (LHC) at CERN one of the fundamental requirements during the energy ramp is that the ratio between the field produced by the quadrupoles and the field in the dipoles remains constant in order to minimize the variation of the betatron tune that could induce particle loss. With a series of tracking experiments it has been demonstrated that this ratio can be maintained constant to better than 10-4 throughout the same current ramp as foreseen for the LHC. A technique has been developed to optimise the dipole and quadrupole current ramps to obtain the required ratio of B2/B1. Measurements performed by modulating the current with a harmonic function (so-called k-modulation) demonstrated that it is possible to modulate the strength of an individual quadrupole to determine the magnetic center through beam-based measurements.
WEPKF015	The Design of Cold to Warm Transitions of the LHC	focusing, ion, bunching, alignment	1624
	J. Knaster, B.J. Jenninger, D.R. Ramos, G. Ratcliffe, R. Veness CERN, Geneva
	The Large Hadron Collider (LHC) is the next accelerator being constructed on the CERN site to be operational in 2007. It will accelerate and collide 7 TeV protons and heavier ions up to lead. More than 2000 cryomagnets working at 1.9 or 4.5 k will form part of the magnetic lattice of the LHC. The transitions from cryogenic temperatures to room temperature zones will be achieved by 200 cold to warm transitions (CWTs). The CWTs will compensate for longitudinal and transversal displacements between beam screens and cold bores, ensuring vacuum continuity without limiting the aperture for the beam. The transverse impedance contribution is kept below the assigned total budget of 1 MΩ/m by means of a 5 μm thick Cu coating that also minimises the dynamic heat load through image currents. Tests have been performed that confirm that the static heat load per CWT to the cryomagnets remains below 2.5 W, hence validating the design.
WEPKF016	Instrumental Uncertainty in Measuring the Geometry of the LHC Main Dipoles.	focusing, ion, bunching, alignment	1627
	M. La China, G. Gubello, W. Scandale CERN, Geneva
	In the Large Hadron Collider 1232 superconducting dipoles will bend the two 7 TeV energy beams along a 27 km-circumference trajectory. The series production (assigned to three European firms) will require a well-defined procedure to check, in every magnet, the respect of the dimensional specifications. To verify the tolerances of few tenths of millimeter over the 15-meter length in each cold mass, a laser tracker is necessarily used. To access the two beam apertures and to increase the measurement accuracies, the laser tracker is placed in different stations around the dipole defining a 'multi-station measuring procedure'. The noise affecting all the data taken so far suggested a careful analysis of the procedure itself. Through the computer modeling (based on a Monte Carlo algorithm), the statistical error was quantified and compared to the experimental error. From this comparison the critical aspects of low accuracy rooted in the multi-station procedure were better understood, allowing the optimization of the procedure itself for the forthcoming series production.
WEPKF017	The 5 T Superconducting Undulator for the LHC Synchrotron Radiation Profile Monitor	focusing, undulator, bunching, alignment	1630
	R. Maccaferri, M. Facchini, R. Jung, D. Tommasini, W.  Venturini Delsolaro CERN, Geneva
	A Synchrotron Radiation Profile Monitor will be used in the LHC to measure the beam profiles from the injection energy of 450 GeV to the nominal energy of 7 TeV. The radiation will be provided by a sequence of two separate magnets: a two-periods 5 T superconducting undulator and the beam separation dipole D3. After a short description of the profile monitor layout, the paper reviews the electromagnetic and mechanical design of the undulator, and reports on the fabrication and cold test results of a first half period prototype.Finally, for the LHC operation with lead ion beams,a proposal for a monitor sensitivity upgrade by using a 12 T. superconducting undulator is presented and discussed.
WEPKF018	Beam-loss Induced Pressure Rise of LHC Collimator Materials Irradiated with 158 GeV/u In49+ Ions at the CERN SPS	focusing, ion, undulator, bunching	1633
	E. Mahner, I. Efthymiopoulos, J. Hansen, E. Page, H. Vincke CERN, Geneva
	During heavy ion operation, large pressure rises, up to a few orders of magnitude, were observed at CERN, GSI, and BNL. The dynamic pressure rises were triggered by lost beam ions that impacted onto the vacuum chamber walls and desorbed about 104 to 107 molecules per ion. The deterioration of the dynamic vacuum conditions can enhance charge-exchange beam losses and can lead to beam instabilities or even to beam abortion triggered by vacuum interlocks. Consequently, a dedicated measurement of heavy-ion induced molecular desorption in the GeV/u energy range is important for LHC ion operation. In 2003, a desorption experiment was installed at the SPS to measure the beam-loss induced pressure rise of potential LHC collimator materials. Samples of bare graphite, sputter coated (Cu, TiZrV) graphite, and 316 LN stainless steel, were irradiated under grazing angle with 158 GeV/u indium ions. After a description of the new experimental set-up, the results of the pressure rise measurements are presented, and the derived desorption yields are compared with data from other experiments.
WEPKF019	Magnetic Measurement Systems for the LHC Dipole Assembly Firms	focusing, ion, undulator, bunching	1636
	H. Reymond, J. Billan, J. Garcia Perez, D. Giloteaux, A. Raimondo, V. Remondino, A. Rijllart CERN, Geneva
	The LHC lattice superconducting dipole magnets are actually under construction in three European industries. Due to the extremely high magnet performance required for the LHC, these magnets have to be built with high accuracy during all the steps of their assembling. In order to detect defects in the earliest production phases and to ensure the quality of the magnetic field as specified by the CERN contracts, dedicated measurement benches have been built and installed in each industry to validate the magnetic field quality at two important production stages. This paper describes the initial requirements and the implementation of the magnetic measurement systems. Details on the technical solutions, the present status and measurement results are presented.
WEPKF020	The Design of the Special Magnets for PIMMS/TERA	focusing, undulator, bunching, vacuum	1639
	L. Sermeus, J. Borburgh, T. Fowler, M. Hourican, K.D. Metzmacher CERN, Geneva M. Crescenti TERA, Novara
	In the framework of a collaboration agreement with the TERA Foundation CERN provided the design, drawings and engineering specifications for 2 kickers, 1 chopper and 3 bumper magnets as well as 3 magnetic and 2 electrostatic septa, power supplies for the electrostatic septa, kickers and bumpers including control electronics for the PIMMS/TERA proton and carbon ion medical synchrotron. The first application will be in the Italian National Centre for Hadron Therapy, to be constructed in Pavia. The main features of the devices are described along with the strategic design choices, directed by the demand for very high reliability and minimum maintenance.
WEPKF021	Non-destructive Testing of Bus-bar Joints Powering LHC Superconducting Magnets, by Using Gamma Sources	focusing, undulator, bunching, vacuum	1642
	B. Skoczen CERN, Geneva J. Kulka AGH, Cracow
	The main LHC superconducting magnets (dipoles and quadrupoles) are powered by using Rutherford type cables, stabilized electrically and thermally with copper profiles. The portions of cables are connected to each other by a soft soldering technique (Sn96Ag4) with the overlapping length corresponding to one pitch of the superconducting strands. The splice constitutes a ?composite? structure with the interchanging layers of Sn96Ag4 and NbTi superconductor, located inside a Cu cage. In order to assure a high level of reliability (failure probability not exceeding 10-8) for some 10000 connections in the LHC, a non-destructive technique of checking the quantity of solder in the joint is planned to be implemented. The technique is based on a gamma ray source (241_Am) and the detection is position-sensitive in the transmission mode. 5 scintillating detectors of gamma rays are used and their accumulated length corresponds to the length of the radioactive source (120 mm). The method can be used in-situ, the equipment being optimized and portable, with implementation of direct on-line operation mode. The relevant criteria of acceptance of the splices have been defined. The first results of application of this technique will be shown.
WEPKF022	Electro-mechanical Aspects of the Interconnection of the LHC Superconducting Corrector Magnets	undulator, bunching, vacuum, alignment	1645
	J.-P.G. Tock, D. Bozzini, F. Laurent, S. Russenschuck, B. Skoczen CERN, Geneva
	In addition to the main 1232 bending dipoles and 474 focusing and defocusing quadrupoles, more than 6800 superconducting corrector magnets are included in the LHC machine. They are housed in the superfluid helium enclosures of the main cryomagnets. Among them, the closed orbit correctors (sextupole and octupole) are integrated in the main quadrupole helium vessel and they are powered via an externally routed cryogenic line (line N). During the assembly, these corrector magnets have to be connected according to a complex electrical scheme based on the optical requirements of the LHC machine. Along the 27-km long LHC machine, 440 interconnection boxes are installed and will allow the powering of the correctors by means of a 42-wires auxiliary bus-bar cable, of which the corresponding wires have to be routed to the SSS from the interconnection box. Stringent requirements in terms of volume, mechanical resistance, electrical conductance and insulation, reliability, and respect of the electrical schematics apply during the assembly and splicing of the junctions inside the line-N box. The activities and their sequence, aiming at ensuring the fulfilment of these requirements are presented. The planned activities (assembly, ultrasonic welding, general and electrical inspection, and electrical qualification) and the interactions between the various intervening teams are described.
WEPKF024	The Geometry of the LHC Main Dipole	undulator, bunching, vacuum, beamloading	1648
	E.Y. Wildner, J. Beauquis, G. Gubello, M. La China, W. Scandale CERN, Geneva
	The 15 m long main dipole of the Large Hadron Collider has a curvature following the beam trajectory with the aim to minimize the necessary coil aperture. To avoid feed-down effects and mechanical aperture restrictions strong constraints have to be imposed on the construction of the magnet in terms of tolerances and stability of the cold mass during transport, cryostating, cold tests and installation in the LHC tunnel. In this paper we show the behaviour of the shape of the magnet using available measurements taken at different stages of construction and assembly. In particular we discuss the evolution of the sagitta and the positioning of the corrector magnets that are used to compensate the multipole field errors. We propose alignment procedures to be used in case magnets are out of tolerance after transport and cold tests. The twist of the magnet and its relation to the field angle will also be discussed.
WEPKF025	Experience with the Hydrostatic Levelling System of the SLS	undulator, bunching, vacuum, beamloading	1651
	F.Q. Wei, L. Rivkin, A. Wrulich PSI, Villigen
	The Hydrostatic Levelling System (HLS) of the SLS was installed and commissioned in year 2000. It is a measurement system for monitoring the vertical positions of the SLS storage ring girders. It is integrated in the concept of dynamic alignment. The HLS was modified and re-calibrated in 2002. Since January 2003 the system has collected approximately 2 million measurements. The analysis of the data shows that displacement of the SLS storage ring foundation and the girder support was in the range of 0.15 mm in year 2003. The long term HLS stability was significantly improved. The short term precision of the HLS is in the micrometer range. The experience gained on the HLS is presented.
WEPKF026	Kicker Pulser with High Stability for the BESSY FEL	undulator, bunching, vacuum, beamloading	1654
	J. Feikes, O. Dressler, J. Kuszynski BESSY GmbH, Berlin
	In the BESSY FEL design a kicker system is forseen to extract electron bunches from the main LINAC into two FEL beam lines, beside the straigth main beamline. Sine half wave pulsers with a repetion rate of up to 1 kHz and modest pulse currents of 120A will be used. To receive the maximum FEL gain, it is crucial, that the extracted bunches enter well centered into the undulators. Hence, the extraction demands for very high short-term stability of the magnetic field (shot to shot). A kicker pulse amplitude with a relative amplitude jitter smaller than 5* 10-5 would be tolerable ?more than one order smaller than the jitter of conventional BESSY II kicker systems in use. A new highly stable semiconductor based kicker pulser prototype was designed, built and tested at BESSY. It was shown that the stability of the pulse current fulfills the FEL requirements. The pulser design, its layout and the corresponding pulse current jitter measurements are presented.
WEPKF027	R&D Vacuum Issues of the Future GSI Accelerator Facilities	ion, undulator, bunching, beamloading	1657
	H.R. Sprenger, M.C. Bellachioma, M. Bender, H. Kollmus, A. Krämer, J. Kurdal, P.J. Spiller GSI, Darmstadt
	The new GSI accelerator facilities are planned to deliver heavy ion beams of increased energy and highest intensity. Whereas the energy is planned to be increased roughly by a factor of 10, the ion beam intensities are planned to be enlarged by three orders of magnitude. To achieve highest beam intensities, medium charged heavy ions (e.g. U28+) are accelerated. Since the ionization cross sections for these ions are comparably high, a UHV-accelerator system with a base pressure in the low 10-12mbar regime is required, even under the influence of ion beam loss induced desorption processes. An intensive program was started to upgrade the UHV system of the existing synchrotron SIS18 (bakeable) and to design and lay out the UHV systems of the future synchrotron SIS100 and SIS300 (mainly cryogenic). The strategy of this program includes basic research on the physics of the ion induced desorption effects as well as technical developments, design and prototyping on bakeable UHV components (vacuum chambers, diagnostics, bakeout-control, pumping speed), collimator for controlled ion beam loss, NEG coating and cryogenic vacuum components.
WEPKF028	High Charge Transfer Operation of Light Trigged Thrystor Crowbars	ion, undulator, bunching, beamloading	1660
	W. Merz DESY, Hamburg
	High power klystrons are protected by the application of crowbar switches. The closing switch approach is most commonly used. It is characterized by establishing a short circuit path to bypass the klystron fault current. During short circuit operation the crowbar switch must be capable to carry both puls current of the filter capacitor and follow through current of the high voltage dc power supply. Depending on the main circuit parameters both the capacitor charge and the follow through charge can achieve significant amounts. The application of line controlled and uncontrolled hvdc power converters requires special attention regarding the follow through current charge transfer. This paper presents first practical results of series connected Light Triggered Thyristors (LTT) operating as closing crowbar switches. Measured data are discussed, which have been obtained from the DESY-II installation operating with thyristor controllers and the PETRA installation operating with uncontrolled rectifiers. Beside the puls operation the follow through current capability of the crowbar is pointed out.
WEPKF029	The Vacuum System of the Australian Synchrotron	vacuum, undulator, bunching, beamloading	1663
	E. Huttel FZK-ISS-ANKA, Karlsruhe B. Barg, A. Jackson, B. Mountford ASP, Melbourne
	A 3 GeV Synchrotron Radiation Source is being built in Melbourne, Australia. The storage ring has a circumference of 216 m and has a 14 fold DBA structure. The vacuum chambers of the storage ring will be made from stainless steel. They consist of a beam chamber (width 70, height 32mm ) connected to an ante chamber, where lumped absorbers and lumped ion pumps are installed. No distributed absorber and pumps are foreseen. The nominal pumping speed of the complete ring is 31 000 l/s. The vacuum chamber of an achromat will be baked ex situ and installed under vacuum. The design of the chamber, the pump configuration and the expected vacuum behaviour will be presented.
WEPKF030	The Storage Ring Magnets of the Australian Synchrotron	vacuum, undulator, bunching, beamloading	1666
	E. Huttel FZK-ISS-ANKA, Karlsruhe B. Barg, A. Jackson, G. LeBlanc ASP, Melbourne J. Tanabe SLAC, Menlo Park, California
	A 3 GeV Synchrotron Radiation Source is being built up in Melbourne, Australia. The storage ring has a circumference of 216 m and has a 14 fold DBA structure. For the storage ring the following magnets are required: 28 gradient dipoles, with B = 1.3 T, B’ = 3.35 T/m, 56 quadrupoles with a gradient of B’ = 18 T/m, 28 quadrupoles with a gradient of 9 T/m, 56 sextupoles with d2B/dr2 = 320 T/m2 and 42 with 150 T/m2. The design of pole faces was done by scaling the SPEAR III pole face to the required gap and bore of the ASP storage ring magnets. The sextupoles will be equipped with coils for horizontal and vertical correction and for a skew quadrupole. The design of the magnets and the calculated magnetic properties will be presented.
WEPKF031	Magnetic Field Correction of the Bending Magnets of the 1.5 GeV HDSM	vacuum, undulator, bunching, beamloading	1669
	F. Hagenbuck, P. Jennewein, K.-H. Kaiser IKP, Mainz
	Beam dynamics of the Harmonic Double Sided Microtron (HDSM), the fourth stage of MAMI, require a very precise magnetic field in the inhomogeneous bending magnets. By measuring the vertical field component By in and on both sides of the midplane, the complete set of field components Bx, By, Bz was determined in the whole gap. Starting from this the asymmetric pole surface current distribution necessary to correct both symmetric and antisymmetric field errors was calculated. However, tracking calculations showed that the influence of skewed field components on the beam deflection are negligible, so that symmetric field corrections are sufficient. Nevertheless, in order to demonstrate the functioning, a set of asymmetric correction coils was built and successfully tested. The symmetric coils are designed to reduce field errors below 2*10-4. Deflection errors in the fringe field region near the magnet corners, which cannot be corrected by surface currents, will be compensated by vertical iron shims in combination with small dipoles on each beam pipe.
WEPKF032	A General Method for 2d Magnet Pole Design	vacuum, undulator, bunching, beamloading	1672
	Z. Martí, J. Campmany, M. Traveria LLS, Bellaterra (Cerdanyola del Vallès)
	Accurate conventional combined magnets working in saturation are currently required to fulfil the increasing demands on low emittance accelerators with long straight sections required by the newest Synchrotron Light Sources. This fact yields stringent requirements on pole profile design, manufacture and characterization. The aim of this poster is to present a general method for designing two-dimensional pole profiles. To this end, we have set up a procedure with which to select an optimum pole profile in 2D without the constraint of relying on a set of initial assumptions, not only a particular set of initial parameters but even a particular pole profile model. Moreover, we have developed a group of codes that can be compiled and run on MS-DOS or UNIX which use POISSON or OPERA-2d codes. This procedure also includes the evaluation of the sensitivity of the final pole profile to geometrical and current intensity errors for tolerance estimation, a big requirement in this context. In order to test the feasibility of this method, we have applied it to the case of the 1.2 T combined magnet of the new synchrotron to be built nearby Barcelona.
WEPKF033	Application of Finite Volume Integral Approach to Computing of 3D Magnetic Fields Created by Distributed Iron-dominated Electromagnet Structures	vacuum, bunching, beamloading, antiproton	1675
	O.V. Chubar, C. Benabderrahmane, O. Marcouillé, F. Marteau SOLEIL, Gif-sur-Yvette J. Chavanne, P. Elleaume ESRF, Grenoble
	Iron-dominated electromagnet structures are traditionally considered as a domain of applications of the Finite-Element Method (FEM). FEM computer codes provide high accuracy for "close circuit" type geometries, however they are much less efficient for distributed geometries consisting of many spatially separated magnets interacting with each other. Examples of such geometries related to particle accelerators are insertion devices, quadrupole and sextupole magnets located close to each other, magnets with combined functions. Application of the finite volume integral approach implemented in the Radia 3D magnetostatics code to solving such geometries is described. In this approach, space around individual magnets does not require any meshing. An adaptive segmentation of iron parts, with the segmenting planes being roughly perpendicular or parallel to the expected directions of magnetic flux lines, minimizes dramatically the necessary CPU and memory resources. If a geometry is, nevertheless, too big for its complete interaction matrix to fit into memory, a special scheme of relaxation "by parts" can be applied. The results of calculations made for the SOLEIL electromagnet undulator HU256 will be presented.
WEPKF034	The Modified DAFNE Wigglers	vacuum, bunching, beamloading, antiproton	1678
	S. Guiducci, S. Bertolucci, M. Incurvati, M.A. Preger, P. Raimondi, C. Sanelli, F. Sgamma INFN/LNF, Frascati (Roma)
	Modifications to the pole shape of a spare wiggler have been tested to increase the width of the good field region, with the aim of reducing the effect of nonlinearities affecting the dynamic aperture and the beam-beam interaction. Additional plates realized with the same material of the pole have been machined in several shapes and glued on the poles. Accurate measurements of the vertical field component on the horizontal symmetry plane of the magnet have been performed to find the best profile. The particle motion inside the measured field has been simulated to minimize the field integral on the trajectory, to determine the wiggler transfer matrix and to estimate the amount of non linear contributions. All wigglers in the collider have been modified to the optimized pole shape. Measurements with beam performed with the modified wigglers show a significant reduction of nonlinearities.
WEPKF035	Analysis of the Cold Mass Displacements at the TTF	vacuum, bunching, beamloading, antiproton	1681
	A. Bosotti, C. Pagani, P. Pierini INFN/LASA, Segrate (MI) R. De Monte, M. Ferianis ELETTRA, Basovizza, Trieste R. Lange DESY, Hamburg
	Few of the TTF cryomodules have been equipped with wire position monitors (WPM) in order to monitor on line the displacements of the cold mass to verify alignment stability and reproducibility . Based on the operation experience of the first prototypical cryomodules, equipped with up to 36 WPMs distributed in two strings, on the last generation cryomodules a single string of 7 sensors has been installed. Here we review and analyze the data collected so far to prove that the the proposed cryomodule design is consistent with the TESLA alignment requirements.
WEPKF037	Structural Analysis of an Integrated Model of Short Straight Section, Service Module, Jumper Connection and Magnet Interconnects for the Large Hadron Collider	bunching, beamloading, antiproton, damping	1684
	S. Dutta, J. Dwivedi, A. Kumar, H.C. Soni CAT, Indore (M.P.) B. Skoczen CERN, Geneva
	The Short Straight Section (SSS) of the Large Hadron Collider (LHC) houses a twin quadrupole.The cryogens are fed to the SSS through a Jumper Connection between service modules of Cryogenic Distribution Line (QRL) and SSS.A Finite Element analysis has been performed in collaboration with CERN for the unified model of SSS of LHC,consisting of cold mass, cold supports,vacuum vessel and its bellows, interconnects, jumper connection and alignment jacks. The model has been developed to understand coupling between the quadrupole magnet and the service module due to ground motion and during the realignment or global smoothening of the LHC arc. The model incorporates experimental stiffness values for support posts, internal pipes and jacks and calculated stiffness for magnet-to-magnet interconnects. The computation space and time has been reduced by executing a two step linear static analycal approach with an initial trial analytical approach cycle in which the program estimates the behavior of the flexibles. A special routine is developed within ANSYS,using APDL which selects the correct secant stiffness of flexibles(by applying a user interactive logical algorithm)from their non-linear force displacement characteristics.
WEPKF038	The Alignment Jacks of the LHC Cryomagnets	alignment, bunching, beamloading, antiproton	1687
	J. Dwivedi, S.G. Goswami, A. Kumar, V. Madhumurthy, H.C. Soni CAT, Indore (M.P.) V. Parma CERN, Geneva
	The precise alignment of the some 1700 cryomagnets of the LHC collider, requires the use of some 7000 jacks. The specific requirements and the need for an cost-effective solution for this large production, justified the development and industrialisation of a dedicated mechanical jack which was developed, and is now being produced, in the framework of a collaboration between CERN and the Center for Advanced Technology in India. Three jacks support each of the 32-ton heavy, 15-meter long cryo-dipoles of LHC, and provide the required alignment features. The main requirements are a setting resolution of 0.05 mm, and a range of movement of 20 mm in the horizontal and 40 mm in the vertical direction. Each jack has two degrees of controlled movement in the horizontal and vertical direction, whereas the remaining horizontal movement is left free. By a suitable choice of the layout of the three jacks, the full range of alignment of a cryo-magnet can be obtained. The design of the jacks evolved from a preliminary value analysis between various concepts, towards the complete engineering of the retained concept, selection of the most appropriate and cost-effective industrial production processes and setting-up of an effective quality assurance policy. Building and testing of 36 prototype jacks allowed an extensive experimental validation of their performance at CERN, where they were operated in the String 2 facility, and yielded an improved understanding for cost-effective steering of the production processes before launching the series production. Presently, the mass production of the jacks is in progress with two Indian manufacturers, and some 1500 jacks have already been delivered to CERN. Considering the successful performance of the jacks, it is now envisaged to extend the use of the same type of jacks to provide the even higher-demanding alignment of the low-beta quadrupoles of LHC.
WEPKF039	The Vacuum System of Super SOR	alignment, bunching, beamloading, antiproton	1690
	H. Sakai, M. Fujisawa, A. Kakizaki, T. Kinishita, H. Kudo, N. Nakamura, O. Okuda, S. Shibuya, K. Shinoe, H. Takaki ISSP/SRL, Chiba K. Kobayashi KEK, Ibaraki T. Koseki RIKEN/RARF/BPEL, Saitama H. Ohkuma JASRI/SPring-8, Hyogo S. Suzuki LNS, Sendai
	The Super-SOR light source is a Japanese VUV and soft X-ray third-generation synchrotron radiation source, which consists of 1.8GeV storage ring and injector. The beam current is circulated up to 400mA. These accelerators are designed so as to fully meet requirements for top-up injection. In order to realize these operation modes, our vacuum system are required on following conditions. One is to obtain the long lifetime. The other is not to melt the vacuum chamber by irradiating the high flux synchrotron radiation. Finally beam instability is not occurred by large wake fields. We describe the design of the vaccum chamber of Super-SOR and present the recent R&D concerning this system.
WEPKF040	Magnetic Field Measurement of Quadrupole Magnets for S-LSR	alignment, bunching, beamloading, antiproton	1693
	T. Takeuchi, K. Noda, S. Shibuya NIRS, Chiba-shi H. Fadil, M. Ikegami, A. Noda, T. Shirai, H. Tongu Kyoto ICR, Uji, Kyoto
	S-LSR is a low energy ion storage/cooler ring. It has 12-quadrupole magnets (QM) with a bore radius of 70 mm and a maximum field gradient of 5 T/m. To suppress and control a magnetic flux in a fringing field of a bending magnet (BM), a field clamp with a thickness of 25 mm was installed in between BM and QM. The distance between the field clamp and QM is 80 mm. 3D calculation represented that the QM field is strongly influenced by the field clamp. Therefore, QMs were designed and optimized in considering the influence of the field clamp. Magnetic field measurements were performed by means of a Hall probe and a long search coil. A magnet field measurement by a Hall probe was carried out together with the field clamp and BM for S-LSR. For 12-quadrupole magnets, the measurement by the long search coil which moves in horizontal direction was carried out. The results for each measurements will be discussed.
WEPKF041	Permanent Magnet Generating High and Variable Septum Magnetic Field and its Deterioration by Radiation	alignment, bunching, radiation, septum	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.
WEPKF042	Installation and Operation of New Klystron Power Supply with Fast Solid-State Switch for Klystron Protection at the Photon Factory Storage Ring	alignment, bunching, radiation, septum	1699
	S. Sakanaka, M. Izawa, T. Takahashi, K. Umemori KEK, Ibaraki
	In the 2.5-GeV Photon Factory storage ring at KEK, there are four klystron power supplies which typically operate at an output voltage of -40 kV with 8 A. We replaced one of these power supplies during 2003 and the new power supply is in operation. This power supply is equipped with a solid-state high-voltage (HV) switch for klystron protection. This HV switch is made up of eighty insulated gate bipolar transistors (IGBT), and it can turn the high-voltage off within a few tens of microseconds in cases of any discharges in the klystrons. We report the performance of this new power supply.
WEPKF043	Measurement of the Vertical Quadrupolar Tune Shift in the Photon Factory Storage Ring	alignment, bunching, radiation, quadrupole	1702
	S. Sakanaka, T. Mitsuhashi, T. Obina KEK, Ibaraki
	We measured the frequencies of vertical quadrupole oscillations in the 2.5-GeV Photon Factory storage ring at KEK. The measured vertical quadrupole tunes showed remarkable dependence of about -7.5E-5/mA on the bunch current. This contrasts with our previous result of about +4.8E-5/mA (presented in PAC2003) for the horizontal quadrupole tune shift. These results will suggest that the transverse wake forces in a quadrupolar mode contribute significantly to the transverse motions of particles in the Photon Factory storage ring.
WEPKF046	Gradient Field Generation in a Uniform Gapped Magnet	alignment, bunching, radiation, quadrupole	1705
	Y. Iwashita Kyoto ICR, Uji, Kyoto Y. Arimoto, A. Sato Osaka University, Osaka
	Magnets with gradient field (indexed magnets) usually have different gap distances with the different entrance positions. This situation will break a uniformity of the effective length. Trim coils, which are usually used in Cyclotron, are not practical to modify a field distribution when a large gradient is required such as FFAG. In order to generate a gradient field in a constant gapped magnet, a novel method with use of inter-pole is devised. This magnet has not only constant gap but also smaller fringing field compared with a conventional one. This technique should widen the recipe to design a magnet with such a complex magnetic field.
WEPKF047	A Super Strong Adjustable Permanent Magnet for the Final Focus Quadrupole in a Linear Collider	alignment, bunching, radiation, quadrupole	1708
	T. Mihara, Y. Iwashita Kyoto ICR, Uji, Kyoto E. Antokhin, M. Kumada NIRS, Chiba-shi C.M. Spencer SLAC, Menlo Park, California E. Sugiyama NEOMAX Co., Ltd., Mishima-gun, Osaka
	A super strong magnet, which utilizes permanent magnet material and saturated iron, is considered as a candidate for the final focus quadrupole in a linear collider beamline. This modified Halbach magnet configuration can have a higher magnetic field gradient than a normal permanent magnet quadrupole (PMQ) or electromagnet. There are some issues to be solved if a PMQ is to be used as a final focus quadrupole: the variation of its strength with temperature and the need for the field strength to be deliberately changed. One can use special temperature compensation material to improve the temperature dependence with just a small decrease in field gradient compared to a magnet without temperature compensation. The required field variability can be obtained by slicing the magnet into pieces along the beamline direction and rotating these slices. Results of performance measurements on the PMQ with variable strength will be reported including the realization of the temperature compensation technique.
WEPKF048	Characteristics of Ground Motion at KEK and SPring-8	alignment, bunching, site, radiation	1711
	Y. Nakayama, T. Ito JPOWER, Kanagawa-ken S. Matsui, C. Zhang JASRI/SPring-8, Hyogo R. Sugahara, S. Takeda, H. Yamaoka, M. Yoshioka KEK, Ibaraki S. Yamashita University of Tokyo, Tokyo
	Authors Y. Nakayama, T. Ito, (JPOWER); R. Sugahara, S. Takeda, H.Yamaoka, M.Yoshioka (KEK); S.Matsui, C.Zhang (SPring-8); S. Yamashita (ICEPP): Abstract Stability of ground is preferable for accelerator beam operation. We have measured ground motion of ground at the KEKB and SPring-8 site, where the ground has quite different characteristics each other. In this paper, some of analysis results are shown, and the characteristics of the ground motion at the KEKB site and those at the Spring-8 site are compared.
WEPKF049	Stretched Wire Flip Coil System for Magnetic Field Measurements	alignment, bunching, site, radiation	1714
	D.E. Kim, C.W. Chung, H.S. Han, Y.G. Jung, H.G. Lee, W.W. Lee, K.-H. Park, H.S. Suh PAL, Pohang
	A flip-coil system using a stretched wire measuring the magnetic field properties of accelerator magnets is described. This system is similar to the conventional rotating coil system except that the stretched wires are used instead of wires wound on the machined surface. This system has advantage of simple fabrication and flexible operation so that different length and bore magnets can be easily measured using the same system. The system also has two loop coils to buck the dominant fundamental field so as to increase the measurement accuracy. This kind of system has issues related to the reproducibility, accuracy of the measured results. The system is evaluated to verify its performances and its results were discussed. The analyzing methods and various efforts to keep the system in high accuracy are presented. Measurement results with this loop coil system were compared with that of the other system.
WEPKF050	Measurement of Fast High Voltage Pulse and High Noisy DC Siganla for Modulator at the PLS Linac	alignment, bunching, site, radiation	1717
	S.-C. Kim, Y.J. Han, S.H. Kim, S.-H. Nam, S.S. Park PAL, Pohang
	The 2.5-GeV electron linac at Pohang accelerator laboratory (PAL) has been operated continuously as a full energy injector for the Pohang Light Source (PLS) since Dec. 1994. There have been continuous efforts to improve the klystron-modulator system more stable and reliable. At pulse operated modulator system, important pulse and DC signals are beam voltage, beam current, EOLC current HVDC voltage and HVDC current. Pulse signals are fast high voltage pulse 30 Hz, 5ms. These signals are adequate level down from modulator but including high level switching noisy. To amplitude measure of these signals for every trigger signal, we developed special module sampling hold, A/D, calculating and D/A. The output signals of these modules are 0 ~ 10 V DC signal and not include any noise signal. These output signals are connected interlock interface module of the modulator controller. Therefore computer system (PC) of the modulator controller is free to noise of these signals and can precise monitor pulse & noise DC signal. In these paper, we are described itself characteristics pulse and high noisy DC signals of the modulator, signal conditioning technique after noise elimination and operation status of the modulator controller.
WEPKF051	Operational Analysis of PLS 2-GeV Electron Linac Klystron-modulator System	klystron, alignment, bunching, site	1720
	S.S. Park, Y.J. Han, S.H. Kim, S.-C. Kim, S.-H. Nam PAL, Pohang
	The klystron-modulator(K&M) system of the Pohang Light Source(PLS) had been supplying high power microwaves for the acceleration of 2 GeV electron beams. There are 11 sets of K&M systems to accelerate electron beams to 2 GeV nominal beam energy without operating one klystron-modulator. One module of the K&M system consists of an 80 MW S-band (2856 MHZ) klystron tube and the matching 200 MW modulator. The total accumulated high-voltage run-time of the oldest unit among the 12 K&M systems has reached nearly 68,000 hours as of Dec. 2003 and the summation of all the units' high voltage run-time is approximately 820,000 hours. The overall system availability is well over 95%. There have been continuous efforts to improve the klystron-modulator system more stable and reliable. To improve self-diagnostic, operation, monitoring, and remote communication, we developed a new modulator controller based on an industrial PC platform in 2002. In this paper, we are able to review overall system performance of the high-power K&M system and the operational characteristics of the klystrons and thyratrons, and overall system's availability analysis from Jan. to Dec. 2003.
WEPKF053	Status and Development for the JAERI ERL-FEL for High-Power and Long-Pulse Operation	klystron, alignment, bunching, site	1723
	M. Sawamura, R. Hajima, N. Kikuzawa, E.J. Minehara, R. Nagai, N. Nishimori JAERI/FEL, Ibaraki-ken
	After the success of energy recovery linac (ERL) for the superconducting free-electron laser (FEL) in the Japan Atomic Energy Research Institute (JAERI), the JAERI ERL-FEL has been upgrading for high-power and long-pulse operation. The new grid pulser for the thermoionic cathode gun is under development and test to increase the beam current by increasing the repetition rate of 10MHz to 20MHz. The new RF sources of CW mode for higher power for non-energy-recovery parts have been installed and tested for long-pulse operation. The properties of the superconducting linac required for the long-pulse operation were also measured such as pressure in the cryomodule, vibration of frequency and piezo tuner response. The RF control systems have been also upgraded to reduce the fluctuation to less than 0.1% for amplitude and 0.1 deg for phase.
WEPKF054	Auto-filling Cryogenic System for Superconducting Wiggler	klystron, alignment, bunching, site	1726
	F.-Y. Lin, C.-H. Chang, H.-H. Chen, T.-C. Fan, M.-H. Huang, C.-S. Hwang NSRRC, Hsinchu
	A 3.2 Tesla superconducting wiggler with period length of 6.0 cm (SW6) was installed in January of 2004 at the National Synchrotron Radiation Research Center (NSRRC). A cryogenic plant for superconducting rf cavity will also provide liquid helium and liquid nitrogen for SW6 by using an independent automatic filling system. To facilitate a stable and precise auto-filling process, a PID controller, the kernel of the auto-filling system, will control the valves of liquid helium and liquid nitrogen, respectively. The authors shall present the control algorithm of different operation modes, namely the pre-cooling mode and normal auto-filling mode. The boil off rate of liquid helium and liquid nitrogen will be discussed.
WEPKF055	Design and Implementation of a Switching Mode Bipolar Power Stage of the Correction Power Supply	klystron, alignment, bunching, site	1729
	C.-Y. Liu, C.H. Kuo, K.-B. Liu NSRRC, Hsinchu
	In order to enhance efficiency of the correction power supply, the switching mode bipolar power stage was to implement and to substitute for the original power stage of the correction power supply. To ensure higher efficiency, the programming dc bus voltage of the power stage of the correction power supply must be working in accordance with the output current state and load. A new power conversion stage was constructed and employs power MOSFET operating at higher switching frequency then old 60 Hz energy conversion mode system. This will not only improve the efficiency but also decrease the weight of the correction power supply. The new switching mode power stage supply a bipolar power dc bus power and automatic turning working voltage by the feedback balance circuit. Results and working performance will be presented in this paper.
WEPKF056	Reducing Output Current Ripple of Power Supply with Component Replacement	klystron, alignment, bunching, site	1732
	K.-B. Liu, C.-S. Fann NSRRC, Hsinchu
	Correction magnets of synchrotron storage ring are served with linear power supplies (correction power supply) with 100 ppm output current ripple in National Synchrotron Radiation Research Center. Reducing output current ripple of correction power supply might reduce perturbation of beam position of storage ring. Replace correction power supplies with lower output current ripple ones is straightforward but costs lots of money. Without adding any other circuit and electronic component, some components of correction power supply are replaced by ones with more precious and lower output fluctuation; so that the same circuitry structure of correction power supply is kept without increasing its complexity and could reach 25 ppm output current ripple.
WEPKF057	Design and Study of a Superferric Model Dipole and Quadrupole Magnets for the GSI Fast-pulsed Synchrotron SIS100.	klystron, alignment, bunching, site	1735
	A.D. Kovalenko, N.N. Agapov, V. Bartenev, A. Donyagin, I. Eliseeva, H.G. Khodzhibagiyan, G.L. Kuznetsov, A. Smirnov, M.A. Voevodin JINR, Dubna, Moscow Region E. Fischer, G. Moritz GSI, Darmstadt
	New experimental results from the investigation of a model superferric Nuclotron-type dipole and quadrupole magnets are presented. The magnets operate at pulse repetition rate f = 1Hz, providing peak magnetic field B = 2 T and the field gradient G = 34 T/m in the dipoles and quadrupoles respectively. The superconducting coil is made from a hollow multi-filamentary NbTi cable cooled with two phase helium flow. Different possibilities were investigated to reduce AC power losses in the case of a cold iron yoke (T=4.5K). The achieved results are discussed. The value of 9W/m has been obtained for dipole magnet with the yoke at T=50K. The first 50 K yoke quadrupole was designed and tested. Other problems, connected with the magnetic field quality, mechanical and cryogenic stability of the magnets under SIS100 operating conditions are also discussed.
WEPKF060	Bending Magnets for the SAGA Storage Ring: Manufacturing and Magnetic Measurements	klystron, alignment, bunching, site	1738
	S.V. Sinyatkin, I.N. Churkin, O.B. Kiselev, V. Korchuganov, A.B. Ogurtsov, A.V. Philipchenko, L.M. Schegolev, K.K. Schreiner, A.G. Steshov, V. Ushakov BINP SB RAS, Novosibirsk M. Kuroda, Y. Tsuchida Saga Synchrotron Light Source, Industry Promotion Division, Saga City
	The paper describes the design, the manufacture and the magnetic measurement of the dipole bending magnets (BM) for SR Source storage ring (prefecture SAGA, Japan) carried out in BINP, Novosibirsk, Russia. The requirement was to create the laminated C-shape BMs with the 3.2 m radius and parallel edges. The magnetic field homogeneity must be not worth than ±2? 10-4 inside the working area: H = 30+40mm and V = ±20mm at 0.26T (250 MeV), and H = ± 28mm and V = ±20mm at 1.46 T (1.4GeV). The BMs were designed on the basis of the 2-D 3-D modeling taking into account the laminated core. The BMs yokes were produced with the help of the technology of the high temperature gluing. The computer simulations are in a good agreement with the magnetic measurements. The main parameters of the magnetic fields satisfy to the requirements and are presented. The features of the design, manufacturing and precise magnetic measurements of SAGA BMs are discussed.
WEPKF061	Study of Electrical Steel Magnetic Properties for Fast Cycling Magnets of SIS100 and SIS300 Rings	klystron, alignment, bunching, site	1741
	I. Bogdanov, S. Kozub, A. Shcherbakov, L. Tkachenko IHEP Protvino, Protvino, Moscow Region E. Fischer, F. Klos, G. Moritz, C. Muehle GSI, Darmstadt
	The operation conditions of yoke steels in superconducting magnets of the SIS100 and SIS300 are at 4.2 K and unipolar cycles with high magnetic induction. The results of measurements of different classes of electrical steels, both isotropic and anisotropic, in the operating conditions of superconducting dipoles are presented. The measurements are carried out on ring samples in quasistatic mode. Dependence of B(H) as well as values of Hc and hysteresis losses in bipolar and unipolar cycles are determined from hysteresis loops at different temperatures. The anisotropy of steels is measured at room temperature on the strip samples, cut along the rolling direction and across one. The comparison of results on ring and strip samples is carried out. The results of calculations of hysteresis and eddy current losses in iron yoke of fast-cycling dipole for the SIS300 are presented. The recommendations on choice of grade steels for fast cycle superconducting magnets are given.
WEPKF062	Study of the Quench Process in Fast-cycling Dipole for the SIS300 Ring	klystron, alignment, bunching, site	1744
	I. Bogdanov, S. Kozub, A. Shcherbakov, L. Tkachenko, S. Zintchenko, V. Zubko IHEP Protvino, Protvino, Moscow Region J. Kaugerts, G. Moritz GSI, Darmstadt
	The results of numerical quench process simulation in the coil of superconducting dipole with magnetic field of 6 T and 100-mm aperture for high-energy ion and proton synchrotron facility SIS300 are presented. The peculiarities of quench process developed in dipole are discussed for several variants of quench conditions. The coil quench behavior determines the features, scopes, and limitations in possible quench protection scheme. Main design characteristics of the preferable protection system are considered.
WEPKF063	Comparison of Three Designs of Wide Aperture Dipole for SIS300 Ring	klystron, alignment, bunching, site	1747
	L. Tkachenko, I. Bogdanov, S. Kozub, A. Shcherbakov, I. Slabodchikov, V. Sytnik, V. Zubko IHEP Protvino, Protvino, Moscow Region J. Kaugerts, G. Moritz GSI, Darmstadt
	The GSI Fast-Pulsed Synchrotron Project is found now under development. The last stage of this machine is the SIS300 ring, which will use superconducting dipoles with 100-mm aperture, 6-T magnetic field amplitude and 1-T/s field ramp rate. This dipole has to posses minimal heat losses both in the coil and in the iron yoke. This article considers three designs of such dipole. The main distinction of these designs is the different thickness of stainless steel collars, which are supported the coil. The collars in the first design hold all forces arisen in the magnet. The second design needs collars only for assembly of the coil and cooling down of the magnet. An iron yoke in this design will withstand ponderomotive forces. The third design has no collars and the iron yoke will hold all forces, including preload, forces originated during cooling down and ponderomotive forces. The different mechanical, magnetic and thermal characteristics are presented and comparative analysis of these designs is carried out.
WEPKF064	Methods for Reducing Cable Losses in Fast-Cycling Dipoles for the SIS300 Ring	klystron, alignment, bunching, site	1750
	L. Tkachenko, I. Bogdanov, S. Kozub, A. Shcherbakov, I. Slabodchikov, V. Zubko IHEP Protvino, Protvino, Moscow Region G. Moritz GSI, Darmstadt V. Sytnikov RCSRDI, Moscow
	A new synchrotron facility is being designed for the acceleration of high intensity and high-energy ion and proton beams at GSI, Darmstadt. The main magnetic elements of the second stage (SIS300) are superconducting dipoles with 100 mm aperture, 6-T magnetic field amplitude, and 1 T/s field ramp rate. The main requirements for these magnets, in addition to high field quality, are minimal heat losses, both in the coil and in the iron yoke, at an acceptable temperature margin. An increase of the temperature margin can be achieved by increasing the volume of superconductor in the cable. However, increasing the number of strands in the cable results in a growth of the cable width. Since coupling losses in the cable are proportional to the fourth power of cable width, these losses rise dramatically. This presentation considers and analyses different ways of reducing these cable heat losses. The calculated results of heat losses for different geometries, based on various cable designs, as well as the parameters of optimal cable designs, based on computer simulations, are presented.
WEPKF065	Study of Thermal Stability and Quench Process of HTS Dipole	klystron, alignment, bunching, site	1753
	V. Zubko, I. Bogdanov, S. Kozub, A. Shcherbakov, L. Tkachenko IHEP Protvino, Protvino, Moscow Region
	The dipole with a coil made from HTS composite on a Bi2223 basis and placed in the ferromagnetic yoke has been developed and produced in IHEP. A designed magnetic field of the dipole in 20-mm aperture is 1 T at temperature of liquid nitrogen. The numerical analysis of factors, having influence on thermal stability of the magnet, as well as the computer simulations of dipole heating during quench was carried out. An anisotropy of voltage-current characteristics of HTS tapes in a magnetic field is taken into account in calculations of quench process. The measured results of voltage-current characteristics during powering and quench of the coil are in a good agreement with the numerical calculations
WEPKF066	Stability of Fast-cycling Dipole for SIS300 Ring	klystron, alignment, bunching, site	1756
	V. Zubko, I. Bogdanov, S. Kozub, A. Shcherbakov, L. Tkachenko, S. Zintchenko IHEP Protvino, Protvino, Moscow Region M. Kauschke, G. Moritz GSI, Darmstadt
	Funding AgencyShould not exceed 200 charactersFootnotesFootnotes: Not exceeding 200 chaThe main requirement to the superconducting dipole with 100-mm aperture, 6-T magnetic field amplitude and 1-T/s field ramp rate for the SIS300 accelerator, developed in the GSI, Darmstadt, is a stability of the magnet influenced by various heat releases arising during operation mode. The computer simulation of the heating of superconducting dipoles and cooling helium during the SIS300 operating cycle was carried out. The analysis of stability is based on the numerical solution of the heat balance equation in the coil and in a single?phase helium flow. Temperature margin of the superconducting dipole during the SIS300 operating cycle was calculated. Possible ways to increase the temperature margin are discussed.