EPAC08 - Classification:04 Hadron Accelerators/A04 Circular Accelerators

04 Hadron Accelerators

A04 Circular Accelerators

Paper	Title	Page
MOYCGM01	FAIR: Challenges Overcome and Still to be Met	17
	H. Stöcker GSI, Darmstadt
	FAIR will be one of the leading accelerator facilities worldwide making use of a highly sophisticated and cost-effective accelerator concept. The intensity frontier will be pushed by several orders of magnitude for the primary and especially for the secondary beams. To reach the unprecedented beam parameters several technical challenges such as operation with high brightness, high current beams, control of the dynamic vacuum pressure or the design of rapidly cycling superconducting magnets have to be mastered. For most of those challenges solutions have been found and prototypes are being built. The remaining open questions are addressed in close collaborations with the partners of FAIR.
	Slides
MOPC100	Design Status of the FAIR Synchrotrons SIS100 and SIS300 and the High Energy Beam Transport System	298
	P. J. Spiller, U. B. Blell, O. Boine-Frankenheim, E. S. Fischer, G. Franchetti, F. Hagenbuck, I. Hofmann, J. E. Kaugerts, M. Kauschke, M. Kirk, H. Klingbeil, A. Kraemer, D. Krämer, G. Moritz, C. Omet, N. Pyka, H. Ramakers, S. Ratschow, A. Saa-Hernandez, M. Schwickert, J. Stadlmann, H. Welker GSI, Darmstadt A. D. Kovalenko JINR, Dubna, Moscow Region
	The present status of system- and technical design and R&D for the new heavy ion synchrotrons SIS100 and SIS300 and the HEBT system is summarized. The overall machine planning and the general layout has been completed and the detailed technical machine design has been started. Device and component specifications, technical parameter lists and technical design reports are in preparation with the goal to enable international partners or industry to finalize the component design to achieve production readiness. In the frame of international working groups the distribution and sharing of the work packages, especially of the cryomagnetic system is under discussion.
MOPC101	Design Considerations of Fast-cycling Synchrotrons Based on Superconducting Transmission Line Magnets	301
	H. Piekarz, S. Hays, Y. Huang, V. D. Shiltsev Fermilab, Batavia, Illinois
	Fast cycling synchrotrons have become necessary components of contemporary accelerator systems for advanced nuclear and high-energy physics programs. We explore a possibility of using super-ferric dipole magnets of up to 2 Tesla B-field powered by a superconducting transmission line conductor. We present both the LTS and the HTS conductor design options for these magnets and their impact on both static and dynamic power losses with operation cycles from o.5 Hz to 5 Hz, depending on the beam energy and the size of the accelerator ring. We also discuss expected B-field quality and the corrector magnets options. We outline magnet string inter-connections and creation of space for the corrector magnets and discuss option for a superconducting dump switch of the quench protection system.
MOPC103	Short Circuit Tests: First Step of LHC Hardware Commissioning Completion	304
	B. Bellesia, E. Barbero-Soto, F. Bordry, M. P. Casas Lino, G.-J. Coelingh, G. Cumer, K. Dahlerup-Petersen, J.-C. Guillaume, J. Inigo-Golfin, V. Montabonnet, D. Nisbet, M. Pojer, R. Principe, F. Rodriguez-Mateos, R. I. Saban, R. Schmidt, H. Thiesen, A. Vergara-Fernández, M. Zerlauth CERN, Geneva A. Castaneda, I. Romera Ramirez CIEMAT, Madrid
	The Large Hadron Collider operation relies on 1232 superconducting dipoles with a field of 8.33T and 400 superconducting quadrupoles with a strength of 220 T/m powered at 12kA, operating in superfluid He at 1.9K. For dipoles and quadrupoles as well as for many other magnets more than 1700 power converters are necessary to feed the superconducting circuits. Between October 2005 and September 2007 the so-called short circuit tests were carried-out in the 15 underground areas where the power converters of the superconducting circuits are located. The tests were aimed at the qualification of the normal conducting components of the circuits: the power converters, the normal conducting DC cables between the power converters and the LHC cryostat, the interlocks and energy extraction systems. In addition, the correct functioning of the infrastructure systems (AC distribution, water and air cooling, control system) were validated. The final validation test for each underground area was the powering of all converters at ultimate current during 24h. This approach highlighted a few problems that were solved long before the beginning of magnet commissioning and beam operation.
MOPC104	A New Method of Beam Stacking in Storage Rings	307
	C. M. Bhat Fermilab, Batavia, Illinois
	Use of barrier buckets at synchrotron storage rings has paved way for development of new techniques for beam stacking in storage rings. The Fermilab Recycler, anit-proton storage ring, has been augmented with multipurpose broad-band barrier rf systems. Recently we have developed a new beam accumulation scheme called "longitudinal phase-space coating" that can be used for stacking beam over already e-cooled high intensity low emittance antiproton beam and demonstrated with beam experiments. Multi-particle beam dynamics simulations convincingly validate the concepts and practicality of the method. Starting with a proof-of-principle beam experiment both protons and anti-protons have been stacked a number of times using this technique in the Recycler. We present the results from both simulations and experiments. The method presented here is the first of its kind.
MOPC105	Activities of Hitachi Relating to Construction of J-PARC Accelerator	310
	Y. Chida, S. Koseki Hitachi Ltd., Ibaraki-ken M. Abe Hitachi, Ltd., Power & Industrial Systems R&D Laboratory, Ibaraki-ken K. Nakamura, M. Watanabe, T. Watanabe, T. Watanuki Hitachi. Ltd., Hitachi Works, Hitachi-shi
	The Japan Proton Accelerator Research Complex (J-PARC) consists of a 330-m-long linac, a 3-GeV rapid cycle synchrotron with a circumference of 350 m, and a 50-GeV synchrotron with a circumference of 1,570 m. Owing to a collaboration between the Japan Atomic Energy Agency (JAEA) and the High Energy Accelerator Research Organization (KEK), the accelerators will be commencing operations at the site of JAEA Tokai Research and Development Center. The beam commissioning of the entire accelerator system is planned to take place before the end of 2008. Along with the JAEA and KEK, Hitachi has contributed to the construction of the system by manufacturing some major equipment with specifications that are of the highest level in the world.
MOPC106	Injection and Acceleration of Au³¹⁺ in the BNL AGS	313
	W. Fischer, L. Ahrens, K. A. Brown, C. J. Gardner, J. W. Glenn, H. Huang, M. Mapes, J. Morris, V. Schoefer, L. Smart, P. Thieberger, N. Tsoupas, K. L. Unger, K. Zeno, S. Y. Zhang BNL, Upton, Long Island, New York C. Omet, P. J. Spiller GSI, Darmstadt
	Injection and acceleration of ions in a lower charge state reduces space charge effects, and, if further electron stripping is needed, may allow elimination of a stripping stage and the associated beam losses. The former is of interest to the accelerators of the GSI FAIR complex, the latter for BNL RHIC collider operation at energies lower than the current injection energy. Lower charge state ions, however, have a higher likelihood of electron stripping which can lead to dynamic pressures rises and subsequent beam losses. We report on experiments in the AGS where Au³¹⁺ ions were injected and accelerated instead of the normally used Au⁷⁷⁺ ions. Beam intensities and the average pressure in the AGS ring are recorded, and compared with calculations for dynamic pressures and beam losses. The experimental results will be used to benchmark the STRAHLSIM dynamic vacuum code and will be incorporated in the GSI FAIR SIS100 design.
MOPC108	AGS Polarized Proton Operation in Run 8	316
	H. Huang, L. Ahrens, M. Bai, K. A. Brown, C. J. Gardner, J. W. Glenn, F. Lin, A. U. Luccio, W. W. MacKay, T. Roser, S. Tepikian, N. Tsoupas, K. Yip, A. Zelenski, K. Zeno BNL, Upton, Long Island, New York H. M. Spinka, D. G. Underwood ANL, Argonne, Illinois
	A dual partial snake scheme has been used for AGS polarized proton operation for several years. It has provided polarized proton beams with 1.5*10¹¹ protons per bunch and 65% polarization for the RHIC spin program. There is still residual polarization loss due to both snake resonances and horizontal resonances. Several schemes were tested in the AGS to mitigate the loss. This paper presents the experiment results and analysis.
MOPC110	Commissioning of the Heidelberg Cryogenic Trap for Fast Ion Beams (CTF)	319
	M. Lange, K. Blaum, M. Froese, M. Grieser, D. Kaiser, S. Menk, D. Orlov, A. Shornikov, T. Sieber, J. Varju, A. Wolf, R. von Hahn MPI-K, Heidelberg O. Heber, M. Rappaport, J. Toker, D. Zajfman Weizmann Institute of Science, Physics, Rehovot
	At the MPI für Kernphysik, a cryogenic electrostatic heavy-ion storage ring (CSR) is being developed. As a cryogenic test facility (CTF), an electrostatic ion beam trap is nearing completion. It will store ions between two electrostatic mirrors, confining them radially by two einzel lenses set apart by 30 cm. This linear, open design leaves room for testing beam diagnostic devices developed for the CSR, e.g. split ring electrodes and a residual gas monitor. As for the CSR, parts of the vacuum system will be brought in direct contact with superfluid helium, to achieve an operating temperature of 2-10 K. Under these conditions, we expect residual gas pressures in the 10^-15 mbar range, and storage times on the order of minutes for light molecular ions. We will present first results from the commissioning of the CTF, especially the temperatures and residual gas pressures reached in the trap, as well as experiences with the position stability of the mechanical suspension of the trap electrodes in cryogenic operation.
MOPC111	Lattice Studies for Spin-filtering Experiments at COSY and AD	322
	A. Garishvili, A. N. Nass, E. Steffens University of Erlangen-Nürnberg, Physikalisches Institut II, Erlangen A. Lehrach, B. Lorentz, R. Maier, F. Rathmann, R. Schleichert, H. Ströher FZJ, Jülich P. Lenisa, M. Statera INFN-Ferrara, Ferrara S. A. Martin UGS, Langenbernsdorf
	In the framework of the FAIR project, the PAX collaboration has proposed a research program based on polarized antiprotons. Polarized antiprotons are to be produced by spin-dependent attenuation on a polarized hydrogen target. For a better understanding of this mechanism it is planned to perform Spin-Filtering studies with protons at COSY (Jülich). In a second phase, it is envisioned to study Spin-Filtering with antiprotons at the AD (CERN). Which will allow for the determination of the total spin-dependent transverse and longitudinal cross sections. In order to achieve the required long storage times, a storage ring section has to be developed which minimizes the spin-independent losses due to Coulomb scattering. The Coulomb-loss cross section for single scattering losses at fixed energy is proportional to the acceptance angle. Therefore, at the target point the beta functions should be as small as possible. Fot the 'low-beta' section, superconducting quadrupole magnets are utilized. It is composed of two (COSY) and three (AD) SC quadrupoles on each side of the target. Results of the lattice studies and requirements for the superconducting quadrupole magnets will be discussed
MOPC112	HESR Linear Lattice Design	325
	B. Lorentz, A. Lehrach, R. Maier, D. Prasuhn, H. Stockhorst, R. Tölle FZJ, Jülich
	The High Energy Storage Ring (HESR) is a part of the future Facility for Antiproton and Ion Research (FAIR) at GSI in Darmstadt. The ring is used for hadron physics experiments with a pellet target and the PANDA detector, and will supply antiprotons of momenta from 1.5 GeV/c to 15 GeV/c. The ring will consist of two 180 degree bending sections (arcs) of 157 m length, each, and two 132 m long straight sections. In one of the straight sections the PANDA experiment will be installed, the other straight section will be equipped with a High Energy Electron Cooler. A longitudinal and transverse stochastic cooling system will be used in the momentum range from 3.8 GeV/c to 15 GeV/c. Adjustment of beta functions at target and electron cooler, to achieve highest beam lifetimes, most efficient cooling and highest luminosities are the main design requirements. The basic design consists of FODO cell structures in the arcs. The arc quadrupole magnets are grouped into four families, to allow a flexible adjustment of transition energy, horizontal and vertical tune, and dispersion. The details of the linear lattice and operation modes will be discussed in this presentation.
MOPC113	Head-on Beam-beam Compensation with Electron Lenses in the Relativistic Heavy Ion Collider	328
	Y. Luo, N. P. Abreu, E. N. Beebe, J. Beebe-Wang, C. Montag, M. Okamura, A. I. Pikin, G. Robert-Demolaize BNL, Upton, Long Island, New York
	The working points for polarized proton operation in the Relativistic Heavy Ion Collider (RHIC) are currently constrained between 2/3 and 7/10, and the beam and luminosity lifetimes are limited by head-on beam-beam effects. To further increase the bunch intensity, we propose a low energy Gaussian electron beam, or electron lens, to collide head-on with the proton beam in order to compensate the large tune shift and tune spread generated by the proton-proton collisions in 2 interaction points. In this article, outline of the RHIC head-on beam-beam compensation with e-lenses and parameters for both proton and electron beams are presented.
MOPC114	Status of the Electrostatic and Cryogenic Double Ring DESIREE	331
	P. Löfgren, G. Andler, L. Bagge, M. Björkhage, M. Blom, H. Danared, A. Källberg, S. Leontein, L. Liljeby, A. Paal, K.-G. Rensfelt, A. Simonsson MSL, Stockholm H. Cederquist, M. Larsson, S. Rosén, H. T. Schmidt Stockholm University, Department of Physics, Stockholm
	DESIREE is a double electrostatic storage ring being built at the Manne Siegbahn Laboratory and Stockholm University. The two rings in DESIREE have the same circumference, 8.7m, and a common straight section along which stored ions can interact. The ion optics for both rings will be housed in a single double walled vacuum chamber built like a cryostat with a radiation screen and several layers of super insulation in between the two chambers. The inner chamber, which holds all the optical elements, will be cooled by four cryogenerators attached to the bottom of this chamber. It is constructed in pure aluminum to ensure good thermal conductivity over the whole structure. The whole accelerator structure will be cooled below 20K. This low temperature in combination with the unique double ring structure will result in a powerful machine for studying interactions between cold molecular ions close to zero relative energy. The outer vacuum chamber is constructed in steel with a high magnetic permeability to provide an efficient screening of the earth magnetic field. DESIREE will be provided with two injectors which will be able to supply both positive and negative ions to both rings.
MOPC116	On the Possibility of Realizing Shortest Bunches in Low-energy Storage Rings	334
	A. I. Papash, K.-U. Kuehnel, C. P. Welsch MPI-K, Heidelberg A. A. Alzeanidi, M. O.A. El Ghazaly KACST, Riyadh A. I. Papash JINR, Dubna, Moscow Region
	For some very interesting experiments in future low-energy storage rings it is highly desirable to realize ultra-short bunches in the nanosecond regime. These bunches could then be used for collision studies with atomic or molecular gas jet targets where the time structure of the bunches would be used as a trigger for the experiment. Thus, the control of the longitudinal time structure of the stored beam is of central importance since it directly determines the resolution of the envisaged experiments. Since many years, it has been a significant challenge for the storage ring accelerator-physics community to develop techniques to reduce the duration of bunches. Up to now, all methods that have been developed go along with various difficulties, which can include reduced stored-beam lifetimes. Thus, novel and innovative concepts for the manipulation and control of the longitudinal beam structure have to be developed. In this paper, novel approaches to realize shortest bunches in storage rings are presented.
MOPC117	Hybrid Snake Spin Resonance in RHIC	337
	V. H. Ranjbar, D. T. Abell Tech-X, Boulder, Colorado M. Bai, A. U. Luccio BNL, Upton, Long Island, New York
	Simulations reveal a potential polarization loss during low beta squeeze. This depolarization appears to be driven by a spin tune modulation caused by spin precession through the strong low beta quads due to the vertical fields. The modulation of the spin tune introduces an additional snake resonance condition at ν_s0 ± n ν_x - ν_z l = integer which while the same numerology as the well known sextupole resonance, can operate in the absence of sextupole elements.
MOPC118	Coordination of the Commissioning of the LHC Technical Systems	340
	R. I. Saban, B. Bellesia, M. P. Casas Lino, C. Fernandez-Robles, M. Pojer, R. Schmidt, M. Solfaroli Camillocci, A. Vergara-Fernández CERN, Geneva
	The Large Hadron Collider operation relies on 1232 superconducting dipoles with a field of 8.33T and 400 superconducting quadrupoles with a strength of 220 T/m powered at 12kA, operating in superfluid He at 1.9K. For dipoles and quadrupoles as well as for many other magnets more than 1700 power converters are necessary to feed the superconducting circuits. A sophisticated magnet protection system is crucial to detect a quench and safely extract the energy stored in the circuits (about 1GJ only in one of the dipole circuits) after a resistive transition. Besides, in such complex architecture, many technical services (e.g. cooling and ventilation, technical network, electrical distribution, GSM network, controls system, etc.) have to be reliably available during commissioning. Consequently, the commissioning of the technical systems and the associated infrastructures has been carefully studied. Procedures, automatic control and analysis tools, repositories for test data, management structures for carrying out and following up the tests have been put in place. This paper briefly describes the management structure and the tools created to ensure safe, smooth and rapid commissioning.
MOPC120	J-PARC RCS Non-linear Frequency Sweep Analysis	346
	A. Schnase, K. Haga, K. Hasegawa, M. Nomura, F. Tamura, M. Yamamoto JAEA/J-PARC, Tokai-Mura, Naka-Gun, Ibaraki-Ken S. Anami, E. Ezura, K. Hara, C. Ohmori, A. Takagi, M. Toda, M. Yoshii KEK, Ibaraki
	A standard method to measure the S21-transfer function of a system of amplifier and cavity involves a network analyzer and a linear or logarithmic frequency sweep. However, to characterize the transfer function of the broadband (Q=2) RCS RF system, we measure and analyze several harmonics at the same time under high power ramping conditions. A pattern driven DDS system generates frequency and amplitude as in accelerator operation. During the 20ms acceleration part of the cycle, a large memory oscilloscope captures the RF-signals. The data are analyzed off-line with a down-conversion process like in a multi-harmonic LLRF-system, resulting in multi-harmonic amplitude and phase information. Using this setup in the cavity test phase we were able to find and cure resonances before installation into the tunnel. We show examples. RCS is in the commissioning phase and has reached the milestone of acceleration to final energy and beam extraction. 10 RF systems are in operation, and the low-level RF system controls the fundamental h(2) and the second harmonic h(4). Using a multi-harmonic analysis during beam operation allows checking the RF system behavior with and without beam-loading.
MOPC121	Progress on Dual Harmonic Acceleration on the ISIS Synchrotron	349
	A. Seville, D. Bayley, I. S.K. Gardner, J. W.G. Thomason, C. M. Warsop STFC/RAL/ISIS, Chilton, Didcot, Oxon D. J. Adams STFC/RAL/ASTeC, Chilton, Didcot, Oxon
	The ISIS synchrotron at the Rutherford Appleton Laboratory in the UK is currently undergoing an RF upgrade. Four, h=4 cavities have been installed in addition to the existing 6, h=2, cavities and should be capable of increasing the operating current from 200 to 300 μA. Two of the four cavities have been in operation for the last 2 user cycles improving trapping lossess and increasing operating currents beyond 200 μA. The remaining two cavities were commissioned in the spring of 2008. This paper reports on hardware commissioning, beam tests and beam simulation results.
MOPC122	Experiments with Fe-ion Beam Generation Acceleration and Accumulation in ITEP-TWAC Facility	352
	B. Y. Sharkov, P. N. Alekseev, N. N. Alexeev, A. Balabaev, V. I. Nikolaev, V. A. Schegolev, A. Shumshurov, V. P. Zavodov ITEP, Moscow Y. Satov SRC RF TRINITI, Moscow region
	The laser ion source (LIS) developed in collaboration ITEP-TRINITI-CERN with an upgraded version of powerful 100J CO2-laser has been used for Fe-ion beam generation at the input of the pre-injector U-3 delivering separated species of Fe¹⁶⁺ ions with energy of 1.1 MeV/u to booster synchrotron UK for acceleration up to the energy of 160 MeV/u and accumulation in the storage ring U-10 using multiple charge exchange injection technique. First results of Fe-ion beam treating from laser ion source to accumulator ring are presented.
MOPC123	Lattice Study for the Carbon Ion Synchrotron forTherapy with Electron Cooling	355
	S. V. Sinyatkin, V. A. Kiselev, E. B. Levichev, V. V. Parkhomchuk, V. B. Reva, V. A. Vostrikov BINP SB RAS, Novosibirsk
	In this paper the preliminary design of magnet lattice of the Carbon Ion Therapy Facility with electron cooling is described. The influence of misalignments of magnetic elements on ring parameters and the layout of orbit correction are estimated. The different methods of ion extractions from the synchrotron are considered, i.e., the pellet extraction, recombination extraction and the extraction on the sextupole resonance.
MOPC124	Ion Optical Design of SIS100 and SIS300	358
	J. Stadlmann, G. Franchetti, B. J. Franczak, M. Kirk, N. Pyka, A. Saa-Hernandez, P. J. Spiller GSI, Darmstadt
	The ion optical layout of the two synchrotrons SIS100/300 of the FAIR project is presented. SIS100 will provide high intensity ion beams of all species from H to U up to a magnetic rigidity of 100 Tm. To minimize the space charge effects and to reach the necessary ion intensities for the FAIR project SIS100 will be operated with intermediate charge state heavy ions (U²⁸⁺). The ion optical layout of SIS100 has been optimized for this purpose. The layout assures the separation of beam particles which are ionized by collisions with residual gas molecules from the circulating beam. Since SIS100 and SIS300 will be installed in the same tunnel, the lattice layout of SIS300 has to follow precisely the geometry of SIS100. SIS300 will provide beams of highly charged heavy ions with a maximum rigidity of 300 Tm. In addition, it will function as a stretcher ring for SIS100. The beam transfer system from SIS100 to SIS300 is designed to fit in a single straight section of the two machines. The effect of dynamic field errors in SIS300 has been considered and the maximum tolerable error levels for the operation of SIS100, such as tracking errors and power supply ripples have been investigated.
MOPC125	The HESR RF-system and Tests in COSY	361
	R. Stassen, K. Bongardt, F. J. Etzkorn, H. Stockhorst FZJ, Jülich A. Schnase JAEA/J-PARC, Tokai-Mura, Naka-Gun, Ibaraki-Ken
	Two RF cavities will be installed in the High-Energy Storage Ring (HESR) of the future International Facility for Antiproton and Ion Research (FAIR) at the GSI in Darmstadt, one “small” cavity for barrier-bucket operation and one “large” cavity to accelerate and decelerate the beam and for bunch rotation. Additionally a barrier bucket with h=1..5 will be formed by this cavity to separate the decelerated beam from the refilled beam in the high luminosity mode (HL). Both prototype cavities have been built and first RF measurements were carried out. The recent results will be presented.
MOPC126	Beam Acceleration with Full-digital LLRF Control System in the J-PARC RCS	364
	F. Tamura, K. Haga, K. Hasegawa, M. Nomura, A. Schnase, M. Yamamoto JAEA/J-PARC, Tokai-mura S. Anami, E. Ezura, K. Hara, C. Ohmori, A. Takagi, M. Toda, M. Yoshii KEK, Ibaraki
	In the J-PARC RCS (Rapid Cycling Synchrotron) we employ a full-digital LLRF control system to accelerate an ultra-high intensity proton beam. The key feature is the multi-harmonic RF signal generation by using direct digital synthesis (DDS) technology. By employing a full-digital system, highly accurate, stable and reproductive RF voltages are generated in the wide-band RF cavities loaded by magnetic alloy (MA) cores. The beam commissioning of the J-PARC RCS has been started in October 2007. The accelerators, the linac and the RCS, show good stability. The beam orbit and the longitudinal beam shape and phase are reproductive from cycle to cycle especially thanks to the stability of the linac energy, the RCS bending field and the frequency and voltage of the RCS RF. This reproductivity makes the beam commissioning efficient. We present the examples of the orbit signals and the longitudinal current signals. Also, we discuss the longitudinal beam control performance and future plans.
MOPC128	J-PARC Accelerator Scheme for Muon to Electron Conversion Search	367
	M. Tomizawa KEK, Ibaraki M. Aoki, I. Itahashi Osaka University, Osaka
	The searching for coherent neutrino-less conversion of a muon to an electron (COMET) at sensitivity of 10?16 has been proposed as an experiment using the J-PARC Nuclear and Particle Experimental (NP) Hall. The experiment is planned to utilize a 56 kW, 8 GeV-bunched proton beam slowly extracted from the J-PARC main ring. The 1 MHz beam pulsing with an extremely low bunch to bunch gap background is needed to eliminate beam-related background events and keep an experimental sensitivity as high as possible. The 8 GeV extraction energy is rather lower than an ordinary energy. The beam size must be less than apertures of the extracted orbit in the ring and the transport line to the NP Hall. Accelerator scheme to satisfy above requirements will be reported in this paper.
MOPC129	Lattice without Transition Energy for the Future PS2	370
	D. Trbojevic, S. Peggs BNL, Upton, Long Island, New York Y. Papaphilippou, R. de Maria CERN, Geneva
	The Large Hadron Collider (LHC) will be commissioned very soon. Improvements of the LHC injection complex are considered in the upgrade possibilities. In the injection complex it is considered that the aging Proton Synchrotron (PS) would be replaced with a new fast cycling synchrotron PS2. The energy range would be from 5-50 GeV with a repetition rate of 0.3 Hz. This is a report on the PS2 lattice design using the Flexible Momentum Compaction (FMC) method. The design is trying to fulfill many requirements: high compaction factor, racetrack shape with two long zero dispersion straight sections, circumference fixed to a value of 1346 meters (CPS2=15/77 CPS), using normal conducting magnets and avoiding the transition energy. D. Trbojevic et al. ”Design Method for High Energy Accelerator Without Transition Energy”, EPAC 90, Nice, June 12-16 (1990) pp. 1536-1538.
MOPC130	Space Charge Loss Mechanisms Associated with Half Integer Resonance on the ISIS Synchrotron	373
	C. M. Warsop, D. J. Adams, B. G. Pine STFC/RAL/ISIS, Chilton, Didcot, Oxon
	ISIS is the spallation neutron source at the Rutherford Appleton Laboratory in the UK. Operation centres on a 50 Hz proton synchrotron, which accelerates ~3·10¹³ ppp from 70 to 800 MeV, corresponding to mean beam powers of 0.2 MW. Beam loss limits operational intensity, and a main contributing mechanism is the action of half integer resonance under high space charge. Progress on studies using particle in cell simulations to explore the evolution of envelope motion, associated 2:1 parametric halo, growth of particles from the outer core, and effects of dispersion and longitudinal motion is presented. Comparisons are made with relevant theoretical models and progress on experimental studies summarised, presently emphasising the simplified 2D coasting beam case.
MOPC131	Ions for LHC: Towards Completion of the Injector Chain	376
	D. Manglunki, M. Albert, M.-E. Angoletta, G. Arduini, P. Baudrenghien, G. Bellodi, P. Belochitskii, E. Benedetto, T. Bohl, C. Carli, E. Carlier, M. Chanel, H. Damerau, S. S. Gilardoni, S. Hancock, D. Jacquet, J. M. Jowett, V. Kain, D. Kuchler, M. Martini, S. Maury, E. Métral, L. Normann, G. Papotti, S. Pasinelli, M. Schokker, R. Scrivens, G. Tranquille, J. L. Vallet, B. Vandorpe, U. Wehrle, J. Wenninger CERN, Geneva
	The CERN LHC experimental programme includes heavy ion physics with collisions between two counter-rotating Pb⁸²⁺ ion beams at a momentum of 2.76 TeV/c/nucleon per beam and luminosities as high as 1·10²⁷ cm^-2 s^-1. To achieve the beam parameters required for this operation the ion accelerator chain has undergone substantial modifications. Commissioning with beam of the various elements of this chain started in 2005 and in 2007 it was the turn of the final stage, the Super-Proton-Synchrotron (SPS) following extensive changes to the low-level RF hardware. The major limitations of this mode of operation of the SPS (space charge, intra-beam scattering) are presented, together with the performance reached so far. The status of the pre-injector performance will also be reviewed together with a description of the steps required to reach nominal performance.
MOPC132	Acceleration Voltage Pattern for J-PARC RCS	379
	M. Yamamoto, K. Hasegawa, M. Nomura, A. Schnase, F. Tamura JAEA/J-PARC, Tokai-Mura, Naka-Gun, Ibaraki-Ken S. Anami, E. Ezura, K. Hara, C. Ohmori, A. Takagi, M. Toda, M. Yoshii KEK, Ibaraki
	The beam commissioning has been started at the J-PARC RCS. Some acceleration voltage patterns are tested to prevent the beam losses. The calculation code for the acceleration voltage pattern is usually based on the differential equation of the longitudinal synchrotron motion. We have developed the code based on the forward-difference equation which satisfies the synchronization with the bending magnetic field ramping accurately. This is very useful especially at the rapid cycling synchrotron where the ramping rate is high. The results of the test are described.
MOPC133	Radiation Level in the J-PARC Rapid Cycling Synchrotron after First Study	382
	K. Yamamoto, N. Hayashi, S. Hiroki, R. Saeki JAEA/J-PARC, Tokai-Mura, Naka-Gun, Ibaraki-Ken K. Satoh, M. Tejima KEK, Ibaraki T. Toyama J-PARC, KEK & JAEA, Ibaraki-ken
	The 3GeV RCS (Rapid-Cycling Synchrotron) in J-PARC has been commissioned in October of 2007. The most important issue in the beam study is to reduce unnecessary beam loss and to keep the beam line clean for the sake of maintenance and upgrade of the machines. In order to achieve this purpose, we observed the beam loss monitors located around the RCS beam line and observed them for beam commissioning. We also investigated the residual dose of accelerator components during an interval of beam study. From these results, we found that beam loss points were the injection junction point, the branch of H0 dump and extraction line, transverse collimators, and dispersion maximum points in the arcs. Especially, the entrance of the primary collimator chamber and the current transformer of the H0 dump line were the most radio-activated points in the RCS. To make the best use of these results for beam commissioning, we managed to minimize the beam losses and succeeded in suppressing the residual dose to a level low enough to allows us to work close to those components.
MOPC134	The Status of the J-PARC RF Systems	385
	M. Yoshii, S. Anami, E. Ezura, K. Hara, C. Ohmori, A. Takagi, M. Toda KEK, Ibaraki K. Haga, K. Hasegawa, M. Nomura, A. Schnase, F. Tamura, M. Yamamoto JAEA/J-PARC, Tokai-Mura, Naka-Gun, Ibaraki-Ken
	The first acceleration of a proton beam at the J-PARC Rapid Cycling Synchrotron started in October 2007. The R&D for magnetic alloy (MA) loaded rf-systems to realize a high field gradient accelerating system for a rapid cycling machine has been initiated in 1996 with the aim of surpassing standard ferrite loaded cavities. The RCS RF system is broad-band and designed to cover both the RCS accelerating frequency range and the second harmonic for bunch shape manipulation. The optimum Q value of the RCS cavities is approximately 2. This is realized by combining a high-Q parallel inductor with an un-cut core configuration. The beam commissioning of the 50GeV Main Ring synchrotron will start in May 2008. Acceleration and slow-beam extraction are planned for December 2008. In case of the MR RF system, the accelerating frequency swing is small. The Q-value in the order of 20 has been selected to reduce transient beam loading due to the multiple-batch injection scheme. The MR RF cavities realize the Q-value by a cut-core configuration. The details of the RF systems and the results of beam accelerations are summarized.
MOPC135	Present Status and Future improvement of HIRFL-CSR	388
	Y. J. Yuan, J. W. Xia, W.-L. Zhan, H. W. Zhao IMP, Lanzhou
	The HIRFL-CSR project is a national mega project of China, which concentrates on heavy ion synchrotron and cooling storage ring. It is finished recently. The present commissioning results, testing experiments are introduced in this paper. The future improvement of the machine is also shown.
MOPC136	Beam Bunch Leakage and Control in the SNS Ring	391
	Y. Zhang, J. Galambos ORNL, Oak Ridge, Tennessee
	In recent neutron production operations at SNS, beams contaminated the longitudinal extraction gap of the accumulator ring due to the limitation of the beam choppers. It caused significant beam loss and activation in the ring and in the extraction beam line. From simulations with computer models and in experimental measurements, properly utilizing the ring RF systems with additional storage turns after the beam accumulations in the ring effectively reduced beam loss in the SNS accelerator systems. Simulations and beam measurement results will be discussed
MOPC137	The Cryogenic Storage Ring Project at Heidelberg	394
	R. von Hahn, K. Blaum, J. R. Crespo López-Urrutia, M. W. Froese, M. Grieser, M. Lange, F. Laux, S. Menk, D. Orlov, R. Repnow, C. D. Schroeter, D. Schwalm, T. Sieber, J. Ullrich, J. Varju, A. Wolf MPI-K, Heidelberg H. Quack TU Dresden, Dresden M. Rappaport, D. Zajfman Weizmann Institute of Science, Physics, Rehovot X. Urbain UCL CRC, Louvain-la-Neuve
	At the Max-Planck-Institut für Kernphysik in Heidelberg a next generation electrostatic storage ring at cryogenic temperatures is under development. The main perspective of this unique cryogenic storage ring (CSR) is the research on ions, molecules and clusters up to bio molecules in the energy range of 20 keV -300 keV at low temperatures down to 2 Kelvin. The achievement of this low temperature for all material walls seen by the ions in the storage ring not only causes a strong reduction of black body radiation incident onto the stored particles, but also acts as a large cryopump, expected to achieve a vacuum of better than 1·10^-15 mbar (corresponding to 1·10^-13 mbar room temperature äquivalent). The low temperature and the extreme low vacuum will allow novel experiments to be performed, such as rotational and vibrational state control of molecular ions and their interaction with ultra-low energy electrons and laser radiation. A 20 W at 2 K refrigerator was designed and successfully commissioned. A connection with the fully assembled cryogenic prototype ion trap is under way. In this paper the concept and the status of the cryogenic storage ring will be presented.
MOPP006	Machine Induced Backgrounds for FP420	559
	R. Appleby, K. M. Potter, F. Roncarolo, G. J. Sellers UMAN, Manchester I. Azhgirey, I. Baishev, I. L. Kurochkin, V. Talanov IHEP Protvino, Protvino, Moscow Region M. Ruspa INFN-Torino, Torino
	The LHC FP420 collaboration is assessing the feasibility of installing forward proton detectors at 420m from the ATLAS and/or CMS interaction points. Such detectors aim at measuring diffracted protons, which lost less than 2% of their longitudinal momentum. The success of this measurement requires a very good understanding of the charged and neutral particle environment in the detector region in order to avoid the signal being swamped as well as for detector survivability. This background receives contributions from beam-gas interactions, halo particles surviving from the Betatron and momentum cleaning systems and secondary showers produced by particles from the 14TeV collision region striking the beampipe upstream of the FP420 detectors. In this paper, such background sources are reviewed, and the expected background rates calculated.
TUOBM01	Advanced Design of the FAIR Storage Ring Complex	1004
	M. Steck, C. Dimopoulou, A. Dolinskii, O. E. Gorda, V. Gostishchev, K. Knie, S. A. Litvinov, I. Nesmiyan, F. Nolden, D. Obradors-Campos, C. Peschke GSI, Darmstadt
	The storage ring complex of the FAIR comprises three storage rings with a magnetic rigidity of 13 m. Each of the three rings, CR, RESR, and NESR, serves specific tasks in the preparation of secondary beams, rare isotopes and antiprotons, or for experiments with heavy ion beams. The CR is optimized for fast stochastic pre-cooling of secondary beams. The RESR design has been recently revised for optimum performance of antiproton accumulation. The concept for the installation of both rings in a common building is elaborated. The ion optical and engineering design of the NESR for experiments with heavy ions, the deceleration of ions or antiprotons for a subsequent low energy facility, and the accumulation of rare isotope beams is proceeding. A section for collision experiments with circulating ions and counter propagating electrons or antiprotons has been worked out. This report will give a summary of the various new concepts conceived in the process of the design of this new storage ring facility.
	Slides
THXG02	J-PARC Progress and Challenges of Proton Synchrotrons	2897
	M. Kinsho JAEA/J-PARC, Tokai-Mura, Naka-Gun, Ibaraki-Ken
	After briefly outlining the status of the J-PARC linac, the talk should concentrate on describing the outcome of the 3 GeV J-PARC synchrotron commissioning programme, and also include discussion of the challenges of successfully running high power proton synchrotrons.
	Slides