EPAC 2006 - Classification:04 Hadron Accelerators/A04 Circular Accelerators

04 Hadron Accelerators

A04 Circular Accelerators

Paper	Title	Page
MOZAPA01	Approaches to High Intensities for FAIR	24
	P.J. Spiller, W. Barth, L.A. Dahl, H. Eickhoff, R. Hollinger, P.S. Spaedtke GSI, Darmstadt
	A new accelerator complex is planned to generate highest intensities of heavy ion and proton beams for the Facility for Antiproton and Ion Research (FAIR) at GSI. The two new synchrotrons, SIS100 and SIS300 which deliver the primary beams to the FAIR target stations, will make use of the existing GSI accelerators UNILAC and SIS18 as injectors. In order to reach the desired intensities close to 1012 uranium ions and 2.5 x 1013 protons per pulse, a substantial upgrade program of the existing facility is being prepared. The well defined technical subprojects of these upgrade programs and the concepts for approaching the intensity goals of SIS100/300 will be described.
	Transparencies
MOPCH074	Layout of an Accumulator and Decelerator Ring for FAIR	199
	P. Beller, K. Beckert, C. Dimopoulou, A. Dolinskii, F. Nolden, M. Steck, J. Yang GSI, Darmstadt
	Antiproton physics and experiments with rare isotope beams are major research fields at FAIR. Antiproton physics requires the accumulation of high intensity antiproton beams. The accumulation of up to 10¹¹ antiprotons at 3 GeV is foreseen. This will be accomplished by the combination of the collector ring CR for stochastic precooling and the specialized accumulator ring RESR. The accumulation scheme in the RESR is based on the usage of a stochastic cooling system. The requirements of this cooling system strongly affect the magnetic structure of the RESR. For experiments with short-lived rare isotope beams the RESR serves the task of fast deceleration. Precooled rare isotope beams will be injected at 740 MeV/u and then decelerated to energies between 100 and 400 MeV/u in less than 1 s. This contribution presents the ring design and lattice studies relevant for both tasks of the ring as well as a description of the antiproton accumulation scheme.
MOPCH075	Internal Target Effects in the ESR Storage Ring with Cooling	202
	V. Gostishchev, K. Beckert, P. Beller, C. Dimopoulou, A. Dolinskii, F. Nolden, M. Steck GSI, Darmstadt I.N. Meshkov, A.O. Sidorin, A.V. Smirnov, G.V. Trubnikov JINR, Dubna, Moscow Region
	The accurate description of beam-target effects is important for the prediction of operation conditions in terms of high luminosity and beam quality in the FAIR facility at GSI. Numerical models have been developed to evaluate beam dynamics in ion storage rings, where strong cooling in combination with a dense target is applied. First systematic benchmarking experiments were carried out at the existing ESR storage ring at GSI. The influence of the internal target on the beam parameters is demonstrated. Comparison of experimental results with simple models describing the energy loss of the beam particles in the target as well as with more sophisticated simulations with the BETACOOL code will be given.
MOPCH076	Baseline Design for the Facility for Antiproton and Ion Research (FAIR) Finalized	205
	D. Krämer GSI, Darmstadt
	The baseline design for the future international facility FAIR has been worked out. The unique accelerator complex will provide high intensity ion beams ranging from antiprotons to uranium for nuclear matter and hadron physics studies. Radioactive beams are generated for nuclear structure and astrophysics experiments. Phase space compression utilizing stochastic and electron cooling allow for fundamental tests at highest precision. Centered around two fast ramping superconducting synchrotrons, ions are accelerated to a beam rigidity of up to 100 Tm and 300 Tm, respectively. Two dedicated storage rings serve for beam accumulation and cooling, providing unprecedented beam quality for experiments in the NESR and HESR storage rings. An overview of the layout of the accelerator complex and beam delivery systems is given. Ongoing R&D activities are reported; project status and international participation will be presented.
MOPCH077	The Collector Ring CR of the FAIR Project	208
	F. Nolden, K. Beckert, P. Beller, U. Blell, C. Dimopoulou, A. Dolinskii, U. Laier, G. Moritz, C. Muehle, I. Nesmiyan, C. Peschke, M. Steck GSI, Darmstadt
	The Collector Ring is a storage ring in the framework of the FAIR project. It has the purpose of stochastic precooling of both rare isotope and antiproton beams and of measurung nuclear masses in an isochronous setting. The paper discusses progress in the development of magnet systems, rf systems, injection/extraction strategies and stochastic cooling systems. Finally it is discussed how to confirm the predicted performance of the slotline electrodes developed recently for stochastic cooling.
MOPCH078	Simulation of Dynamic Vacuum Induced Beam Loss	211
	C. Omet, P.J. Spiller, J. Stadlmann GSI, Darmstadt
	In synchrotrons, operated with intermediate charge state, heavy ion beams, intensity dependent beam losses have been observed. The origin of these losses is the change in charge state of the beam ions at collisions with residual gas atoms or molecules. The resulting A/Z deviation from the reference beam ion leads to modified trajectories in dispersive elements, which finally results in beam loss. At the impact positions, secondary particles are produced by ion stimulated desorption and increase the vacuum pressure locally. In turn, this pressure rise will enhance the charge change^- and particle loss process and finally cause significant beam loss within a very short time (a few turns). A program package has been developed, which links the described beam loss mechanisms to the residual gas status and determines the vacuum dynamics. Core of the program is an ion optics tracking routine, in which the atomic physics and vacuum effects are embedded.
MOPCH079	Ion Optical Design of the Heavy Ion Synchrotron SIS100	214
	J. Stadlmann, K. Blasche, B. Franczak, C. Omet, N. Pyka, P.J. Spiller GSI, Darmstadt A.D. Kovalenko JINR, Dubna, Moscow Region
	We present the ion optical design of SIS100, which is the main synchrotron of the FAIR project. The purpose of SIS100 is the acceleration of high intensity heavy ion and proton beams and the generation of short compressed single bunches for the production of secondary beams. Since ionization in the residual gas is the main loss mechanism, a new lattice design concept had to be developed, especially for the operation with intermediate charge state heavy ions. The lattice was optimized to generate a peaked loss distribution in charge separator like lattice cells. Thereby it enables the control of generated desorption gases in special catchers. For bunch compression, the lattice provides dispersion free straight sections and a low dispersion in the arcs. A special difficulty is the optical design for fast and slow extraction, and the emergency dumping of the high rigidity ions within the same short straight section.
MOPCH080	Design of the NESR Storage Ring for Operation with Ions and Antiprotons	217
	M. Steck, K. Beckert, P. Beller, C. Dimopoulou, A. Dolinskii, F. Nolden, J. Yang GSI, Darmstadt
	The New Experimental Storage Ring (NESR) of the FAIR project has two major modes of operation. These are storage of heavy ion beams for internal experiments and deceleration of highly charged ions and antiprotons before transfer into a low energy experimental area. The heavy ion beams can be either stable highly charged ions or rare isotope beams at an energy of 740 MeV/u selected in a magnetic separator. The antiprotons come with an energy of 3 GeV from the production target, they are pre-cooled and accumulated in a storage ring complex. The magnetic structure of the NESR has been optimized for large transverse and longitudinal acceptance by detailed dynamic aperture calculations. This will allow storage of multi-component beams with a large spread of charge to mass ratio, corresponding to a large spread in magnetic rigidity. Highest phase space density of the stored beams is provided by an electron cooling system, which for ions covers the full energy range and for antiprotons allows intermediate cooling during the deceleration process. For experiments with short-lived isotopes the cooling time and the time of deceleration will be optimized to a few seconds.
MOPCH081	FLAIR: a Facility for Low-energy Antiproton and Ion Research	220
	C.P. Welsch, C.P. Welsch CERN, Geneva H. Danared MSL, Stockholm
	To exploit the unique possibilities that will become available at the Facility for Antiproton and Ion Research (FAIR), a collaboration of about 50 institutes from 15 countries was formed to efficiently enable an innovative research program towards low-energy antimatter-physics. In the Facility for Low-energy Antiproton and Ion Research (FLAIR) antiprotons and heavy ions are slowed down from 30 MeV to energies as low as 20 keV by a magnetic and an electrostatic storage ring. In this contribution, the facility and the research program covered are described with an emphasis on the accelerator chain and the expected particle numbers. An overview of the novel beam handling, cooling and imaging techniques as they will be required across the facility is given.
MOPCH083	Design Study for an Antiproton Polarizer Ring (APR)	223
	A. Garishvili, A. Lehrach, B. Lorentz, S.A. Martin, F. Rathmann FZJ, Jülich P. Lenisa INFN-Ferrara, Ferrara E. Steffens Erlangen University, Erlangen
	In the framework of the FAIR* project, the PAX collaboration has suggested a new experiments using polarized antiprotons*, in particular the study of the transverse spin structure of the proton. To polarize antiprotons the spin filtering method is proposed. The PAX collaboration is going to design the Antiproton Polarizer Ring (APR). In this contribution the design of this storage ring is described. The basic parameters of the APR are antiproton beam energy of 250 MeV and emittance in both planes of 250 pi mm mrad. The APR consists of two 180 degree arcs and two straight sections. One straight section houses the injection/extraction and the polarized internal target cell, in the other straight section, the electron cooler and a Siberian snake are located. Different optical conditions have to be fulfilled in the straight sections: (1) The target cell requires a beta function of less than 0.3 m. (2) The beam has to be circular and upright in the phase space ellipse at the target, the electron cooler, and the snake. (3) The antiproton beam should have a size of 10 mm for an emittance of 250 pi mm mrad. (4) The momentum dispersion has to be zero in both straight sections. Conceptual Design Report for an International Accelerator Facility for Research with Ions and Antiprotons, available from www.gsi.de/GSI-Future/cdr.**PAX Technical Proposal, available from www.fz-juelich.de/IKP/pax.
MOPCH084	From COSY to HESR	226
	D. Prasuhn, J. Dietrich, A. Lehrach, B. Lorentz, R. Maier, H. Stockhorst FZJ, Jülich
	The High Energy Storage Ring (HESR) at the proposed Facility for Antiproton and Ion Research (FAIR) puts strong demands on quality and intensity of the stored antiproton beam in the presence of thick internal targets. The existing synchrotron and storage ring COSY in Juelich can be seen as a smaller model of the HESR. In this paper we will discuss possible benchmarking experiments at COSY, involving effects like beam cooling, target heating, intra-beam scattering, etc. The aim of these experiments is to support the design work for the HESR and ensure that the specified beam conditions can be achieved.
MOPCH085	Pickup Structures for the HESR Stochastic Cooling System	228
	R. Stassen, P.B. Brittner, G. Schug, H.S. Singer FZJ, Jülich
	The design of the High-Energy Storage Ring (HESR) of the future International Facility for Antiproton and Ion Research (FAIR) at the GSI in Darmstadt includes electron and stochastic cooling. Simulations have shown that the bandwidth of a 2-4 GHz stochastic cooling system is sufficient to achieve the requested beam parameter at the internal target. New 2-4 GHz pickup structures have been developed and tested. First results of the low impedance, printed loop structures will be presented.
MOPCH086	Stochastic Cooling for the HESR at the GSI-FAIR Complex	231
	H. Stockhorst, B. Lorentz, R. Maier, D. Prasuhn FZJ, Jülich T. Katayama CNS, Saitama
	The High-Energy Storage Ring (HESR) of the future International Facility for Antiproton and Ion Research (FAIR) at the GSI in Darmstadt is planned as an anti-proton cooler ring in the momentum range from 1.5 to 15 GeV/c. An important and challenging feature of the new facility is the combi-nation of phase space cooled beams with internal targets. The required beam parameters and intensities are prepared in two operation modes: the high luminosity mode with beam intensities up to 10¹¹ and the high reso-lution mode with 10¹⁰ anti-protons cooled down to a relative momentum spread of only a few 10-5. In addition to electron cooling, transverse and longitudinal stochastic cooling are envisaged to accomplish these goals. It is shown how the great benefit of the stochastic cooling system to adjust the cooling force in all phase planes independently is utilized to achieve the requested beam spot and the high momentum resolution at the internal target within reasonable cooling down times for both HESR modes even in the presence of intra-beam scattering. A numerical and analytical approach to the Fokker-Planck equation for longitudinal filter cooling has been carried out.
MOPCH087	Quasi-adiabatic Transition Crossing in the Hybrid Synchrotron	234
	Y. Shimosaki, K. Takayama, K. Torikai KEK, Ibaraki
	Non-adiabatic features around the transition energy are well-known to be one of most important beam physics issues in most of circular hadron accelerators. A novel technique to avoid them by the adiabatic motion, a quasi-adiabatic focusing-free transition crossing (QAFFTC), was proposed. In a longitudinally separated function-type accelerator, in which particles are confined by an rf voltage or burrier voltages and accelerated by a step voltage, the confinement voltage can be arbitrarily manipulated as long as the particles do not diffuse, while a strict acceleration voltage is necessary for the orbit of a charged particle to be balanced in the radial direction. The introduction of QAFFTC is most suitable for the longitudinally separated function-type accelerator. This new method was examined in this type of accelerator, both theoretically and experimentally. This was a first and significant application of the hybrid synchrotron. The results will be presented. K. Takayama and J. Kishiro, Nucl. Inst. Meth. A 451, 304 (2000).**K. Takayama et al. Phys. Rev. Lett. 94, 144801 (2005).
MOPCH088	Ion Cooler Storage Ring, S-LSR	237
	A. Noda, S. Fujimoto, M. Ikegami, T. Shirai, H. Souda, M. Tanabe, H. Tongu Kyoto ICR, Uji, Kyoto H. Fadil, M. Grieser MPI-K, Heidelberg T. Fujimoto, S.I. Iwata, S. Shibuya AEC, Chiba I.N. Meshkov, I.A. Seleznev, A.V. Smirnov, E. Syresin JINR, Dubna, Moscow Region K. Noda NIRS, Chiba-shi
	Ion cooler and storage ring, S-LSR has been constructed. Its beam commissioning has been successfully performed since October, 2005 and electron beam cooling for 7 MeV proton beam has been performed with both flat and hollow spatial distributions. Effect of relative velocity sweep between electron and ion beams on the cooling time* has been confirmed. Based on the success to create the peaks in the energy spectrum of laser-produced ions, injection of laser-produced ions into S-LSR after rotation in the longitudinal phase space by an RF cavity synchronized to the pulse laser is under planning in order to apply electron cooling for such real laser produced hot ions. Three dimensional laser cooling satisfying the condition of 'tapered cooling' is also under investigation. 24Mg+ ions are to be laser-cooled only in the 'Wien Filter' in order to be cooled down to the appropriate energy according to their horizontal positions*. In parallel with the computer simulation, construction of the laser cooling system with use of ring dye laser accompanied with the second harmonics generator is now underway. H. Fadil et al. Nucl. Instr. & Meth. in Phys. Res. A517, 1-8 (2004).**A. Noda and M. Grieser, Beam Science and Technology, 9, 12-15 (2005).
MOPCH089	Basic Aspects of the SIS100 Correction System Design	240
	V.A. Mikhaylov, A.V. Alfeev, A.V. Butenko, A.V. Eliseev, H.G. Khodzhibagiyan, A.D. Kovalenko, O.S. Kozlov, V.V. Seleznev, A.Y. Starikov, V. Volkov JINR, Dubna, Moscow Region E. Fischer, P.J. Spiller, J. Stadlmann GSI, Darmstadt
	The basic concept and the main design features of the superconducting SIS100 correction system are presented. The system comprises 84 steerer magnets consisting of two orthogonal dipole windings each for correction of the beam close orbit in vertical and horizontal planes, 48 normal sextupole windings connected in two families with opposite polarities for chromaticity correction and 12 units containing skew quadrupoles, normal and skew sextupoles and octupoles as well. The correction system should operate in a pulse mode corresponding to the accelerator cycle, i.e., up to 1 Hz. The main magnetic, geometrical and electrical parameters of the corrector magnets were specified. They are based on the beam dynamic analysis within the frames of the DF-type SIS100 lattice at different betatron tune numbers and tolerable alignment and manufacturing errors of the main lattice dipole and quadrupole magnets. The problem of reasonable unification of the corrector modules is discussed also, including their geometrical sizes, maximum supply current and cooling at 4.5 K. The concept of the SIS100 corrector magnets is based on the pulsed correctors designed for the Nuclotron.
MOPCH090	ITEP-TWAC Status Report	243
	N.N. Alexeev, D.G. Koshkarev, B.Y. Sharkov ITEP, Moscow
	Three years of successful operation the ITEP-TWAC facility delivers proton and ion beams in several modes of acceleration and accumulation of by using the multiple charge exchange injection technique. Substantial progress is achieved in output ion beam current intensity of the linear injector I3, in intensity of the buster synchrotron UK, in efficiency increasing of ion beam stacking and longitudinal compression in the storage ring U10. The machine status analysis and current results of activities aiming at subsequent improvement of beam parameters for extending beam technology applications are presented. N. Alexeev et al. Laser and Particle Beams (2002) V 20, N3, 385-392.
MOPCH091	An Alternative Nonlinear Collimation System for the LHC	246
	J. Resta-López, R.W. Assmann, S. Redaelli, J. Resta-López, G. Robert-Demolaize, D. Schulte, F. Zimmermann CERN, Geneva A. Faus-Golfe IFIC, Valencia
	The optics design of an alternative nonlinear collimation system for the LHC is presented. We discuss an optics scheme based on a single spoiler located in between a pair of skew sextupoles for betatron collimation. The nonlinear system allows opening up the collimator gaps and, thereby reduces the collimator impedance, which presently limits the LHC beam intensity. After placing secondary absorbers at optimum locations behind the spoiler, we analyze the beam losses and calculate the cleaning efficiency from tracking studies. The results are compared with those of the conventional linear collimation system.
MOPCH092	CRYRING Machine Studies for FLAIR	249
	H. Danared, A. Källberg, A. Simonsson MSL, Stockholm
	At the FLAIR facility (Facility for Low-energy Antiproton and Ion Research) at FAIR, antiprotons and heavy ions will be decelerated to very low energies and ultimately to rest. One step in this deceleration is made in the magnetic storage ring LSR (Low-Energy Storage Ring). CRYRING at the Manne Siegbahn Laboratory in Stockholm will be closed down within the next few years, and since CRYRING has an energy range quite similar to the proposed LSR, is equipped with beam cooling, and has several other features required for a deceleration ring, plans are being made for the transfer of CRYRING to FAIR and for its use as the LSR ring. This paper describes some of the characteristics of CRYRING relevant for its new role, modifications that need to be made, and test that have been performed at CRYRING with, e.g., deceleration of protons from 30 MeV to 300 keV kinetic energy, which is the proposed energy range for antiprotons at LSR.
MOPCH093	Design of the Double Electrostatic Storage Ring DESIREE	252
	P. Löfgren, G. Andler, L. Bagge, 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, K. Schmidt FYSIKUM, AlbaNova, Stockholm University, Stockholm
	A double electrostatic storage ring named DESIREE is under construction at the Manne Siegbahn Laboratory and Stockholm University. The two rings will have the same circumference, 9.2 m, and a common straight section where merged beam experiments with ions of opposite signs will be performed. The whole structure will be contained in a single vacuum vessel resulting in a very compact design. In addition to its unique double ring structure it will be possible to cool DESIREE down to 10-20K using cryogenerators. This will reduce the internal vibrational and rotational excitations of stored molecules. A cold system will also result in excellent vacuum conditions where longer lifetimes of the stored beams can be expected. While the ion optical calculations have entered a final phase much of the work is now devoted to solve many of the mechanical and cryogenic challenges of DESIREE. In order to test the mechanical and cryogenic properties of for example insulators, vacuum seals, and laser viewports a small test system has been built. The test system is expected to provide valuable information for the final design of DESIREE.
MOPCH094	Low-intensity Beams for LHC Commissioning from the CERN PS-booster	255
	M. Benedikt, J. Tan CERN, Geneva
	A variety of low-intensity beams will be required for LHC commissioning. In contrast to the nominal LHC physics beam, these single-bunch beams are produced without longitudinal bunch splitting in the injector chain. Consequently, not only the transverse but also the longitudinal beam characteristics have already to be established in the CERN PS-Booster. The required intensities extend down to four orders of magnitude below the typical PS-Booster working range and the transverse emittances must be adjustable to vary the beam brightness over a large range. The different beam variants are briefly summarized and the specific techniques developed for their production, like low-voltage rf capture, and transverse and longitudinal shaving, are described. In particular, the choice of harmonic number and its consequences for operation and beam reproducibility are discussed. Finally, the performance achieved for the different beams is summarized.
MOPCH095	Performance of Nominal and Ultimate LHC Beams in the CERN PS-booster	258
	M. Benedikt, M. Chanel, K. Hanke CERN, Geneva
	The requirements for nominal and ultimate LHC beams in the CERN PS-Booster were specified in 1993 and served as input for the definition of the "PS conversion for LHC" project. Already during the upgrade project and also after its completion in 2000, the beam intensities to be provided from the PS Booster were increased in order to compensate for changes on the LHC machine, the beam production scheme in the PS and for non-anticipated beam losses along the injector chain. In order to improve the beam brightness, to be compatible with the increased requirements, extensive machine studies have taken place on the PS-Booster. The working point was changed to reduce the influence of systematic resonances and the injection line optics was re-matched to improve the injection efficiency. The paper summarizes briefly the evolution of the performance requirements. The various measures undertaken to improve the LHC beam quality are outlined and the present performance achieved in the PS-Booster is presented.
MOPCH096	LEIR Lattice	261
	J. Pasternak, P. Beloshitsky, C. Carli, M. Chanel CERN, Geneva
	The Low Energy Ion Ring (LEIR) is a low energy ion cooling and accumulation ring and serves to compress long ion pulses from Linac 3 into high density bunches suitable for LHC ion operation. Issues of the LEIR lattice are to fulfil all constraints with a small number of quadrupoles and compensations of perturbations due to an electron cooler and gradients seen by the beam in the bending magnets during the ramp. Furthermore, experimental investigations via orbit reponse measurements will be reported.
MOPCH097	CERN Proton Synchrotron Working Point Control Using an Improved Version of the Pole-face-windings and Figure-of-eight Loop Powering	264
	R.R. Steerenberg, J.-P. Burnet, M. Giovannozzi, O. Michels, E. Métral, B. Vandorpe CERN, Geneva
	The working point of the CERN Proton Synchrotron, which is equipped with combined function magnets, is controlled using pole-face-windings. Each main magnet consists of one focusing and one de-focusing half-unit on which four pole-face-winding plates are mounted containing two separate coils each, called narrow and wide. At present they are connected in series, but can be powered independently. In addition, a winding called the figure-of-eight loop, contours the pole faces and crosses between the two half units, generating opposite fields in each half-unit. The four optical parameters, horizontal and vertical tune and chromaticity, are adjusted by acting on the pole-face-winding currents in both half units and in the figure-of-eight loop, leaving one physical quantity free. The power supply consolidation project opened the opportunity to use five independent power supplies, to adjust the four parameters plus an additional degree of freedom. This paper presents the results of the measurements that have been made in the five-current mode together with the influence of the magnetic nonlinearities, due to the unbalance in the narrow and wide winding currents, on the beam dynamics.
MOPCH098	LHC@FNAL: A Remote Access Center for the LHC at Fermilab	267
	E.S. McCrory, K.B. Biery, E.G. Gottschalk, S.G. Gysin, E.R. Harms, S.K. Kunori, M.J. Lamm, K.M. Maeshima, P.M. McBride, A.J. Slaughter, A.D. Thomas Fermilab, Batavia, Illinois M. Lamont CERN, Geneva
	A facility is being designed at Fermilab to help people contribute to the Large Hadron Collider (LHC) effort at CERN. This facility is called LHC@FNAL. The purpose of LHC@FNAL is to permit members of the LHC community in North America contribute their expertise to LHC activities at CERN, and to assist CERN with the commissioning and operation of the LHC accelerator and CMS experiment. As a facility, LHC@FNAL has three primary functions: 1) To provide access to information in a manner that is similar to what is available in control rooms at CERN, and to enable members of the LHC community to participate remotely in LHC and CMS activities. 2) To serve as a (bidirectional) communications conduit between CERN and members of the LHC community located in North America. 3. To allow visitors to Fermilab to see firsthand how research is progressing at the LHC. Visitors will be able to see current LHC activities, and will be able to see how future international projects in particle physics can benefit from active participation in projects at remote locations. LHC@FNAL is expected to contribute to a wide range of activities for the CMS experiment and for the LHC accelerator.
MOPCH099	Performance and Capabilities of the NASA Space Radiation Laboratory at BNL	270
	K.A. Brown, L. Ahrens, I.-H. Chiang, C.J. Gardner, D.M. Gassner, L. Hammons, M. Harvey, J. Morris, A. Rusek, P. Sampson, M. Sivertz, N. Tsoupas, K. Zeno BNL, Upton, Long Island, New York
	The NASA Space Radiation Laboratory (NSRL) at BNL has been in operation since 2003. The first commissioning of the facility took place beginning in October 2002 and the facility became operational in July 2003. The facility was constructed in collaboration with NASA for the purpose of performing radiation effect studies for the NASA space program. The NSRL is capable of making use of protons and heavy ions in the range of 0.05 to 3 GeV/n slow extracted from BNL's AGS Booster. It is also capable of making use of protons and heavy ions fast extracted from the AGS Booster. Many different beam conditions have been produced for experiments at NSRL, including very low intensity In this report we will describe the facility and its' performance over the eight experimental run periods that have taken place since it became operational. We will also describe the current and future capabilities of the NSRL.
MOPCH100	Polarized Proton Acceleration in the AGS with Two Helical Partial Snakes	273
	H. Huang, L. Ahrens, M. Bai, A. Bravar, K.A. Brown, E.D. Courant, C.J. Gardner, J. Glenn, A.U. Luccio, W.W. MacKay, V. Ptitsyn, T. Roser, S. Tepikian, N. Tsoupas, J. Wood, K. Yip, A. Zelenski, K. Zeno BNL, Upton, Long Island, New York F. Lin IUCF, Bloomington, Indiana M. Okamura, J. Takano RIKEN, Saitama
	Acceleration of polarized protons in the energy range of 5 to 25 GeV is particularly difficult: the depolarizing resonances are strong enough to cause significant depolarization but full Siberian snakes cause intolerably large orbit excursions and it is not feasible in the AGS since straight sections are too short. Recently, two helical partial snakes with double pitch design have been built and installed in the AGS. With careful setup of optics at injection and along the ramp, this combination can eliminate intrinsic and imperfection depolarizing resonances encountered during acceleration. This paper presents the accelerator setup and preliminary results. The effect of horizontal intrinsic resonances in the presence of two partial snakes are also discussed.
MOPCH101	On the Feasibility of a Spin Decoherence Measurement	276
	W.W. MacKay BNL, Upton, Long Island, New York
	In this paper, we study the feasibility of making a turn-by-turn spin measurement to extract the spin tune of a synchrotron from a polarized beam injected perpendicular to the stable spin direction. For the ideal case of a zero-emittance beam with no spin-tune spread, there would be no spin decoherence and a measurement of the spin tune could easily be made by collecting turn-indexed polarization data of several million turns. However, in a real beam there is a momentum spread which provides a tune spread. With a coasting beam the tune spread will cause decoherence of the spins resulting in a fast depolarization of the beam in a thousand turns. With synchrotron oscillations the decoherence time can be greatly increased, so that a measurement becomes feasible with summation of the turn-by-turn data from a reasonable number of bunches (100 or fewer). Both the cases of a single Siberian snake and a pair of Siberian snakes are considered.
MOPCH102	A Straight Section Design in RHIC to Allow Heavy Ion Electron Cooling	279
	D. Trbojevic, J. Kewisch, W.W. MacKay, T. Roser, S. Tepikian BNL, Upton, Long Island, New York
	The Relativistic Heavy Ion Collider (RHIC) has been continuously producing exciting results. One of the major luminosity limitations of the present collider is the intra beam scattering. A path towards the higher luminosities requires cooling of the heavy ion beams. Two projects in parallel electron and stochastic cooling are progressing very well. To allow interaction between electrons and the RHIC beams it is necessary to redesign one of the existing interaction regions in RHIC to allow for the longer straight section with fixed and large values of the betatron functions. We present a new design of the interaction region for the electron cooling in RHIC.
WEOBPA01	First Results of the CRFQ Proof of Principle	1873
	D. Davino Universita' degli Studi del Sannio, Benevento L. Campajola Naples University Federico II, Mathematical, Physical and Natural Sciences Faculty, Napoli V. Lo Destro, A.G. Ruggiero BNL, Upton, Long Island, New York M.R. Masullo INFN-Napoli, Napoli V.G. Vaccaro Naples University Federico II and INFN, Napoli
	The Circular Radiofrequency Quadrupole is a new concept of a storage and accelerator ring for intense beams of light and heavy ions, protons and electrons. It is basically a Linear Radiofrequency Quadrupole completely bent on a circle. The advantages, which are expected to be the same performance features of a linear RFQ, would be smaller overall dimension with respect to accelerators with comparable beam intensity and emittance. A collaboration between BNL and Italian research institute and universities was set up at the end of 2002 with the aim of the proof of the bending principle. The prototype design is based on a 4-rods scheme and have a linear sector followed by a 45-degree curved sector. The 1mA proton beam, produced by a reconditioned RF source, go through a beam gap diameter of 10mm with circular 10mm diameters rods. Each sector is 700mm long and is placed in a 150mm diameter pipe*. The RF power at 202.56MHz is fed by a CERN "Frank James" 50kW amplifier. In this paper the first power and beam tests of the linear sector are presented. A.G. Ruggiero, C-A/AP/65 note, Brookhaven National Laboratory, October 2001. A.G. Ruggiero et al., Proceedings of the EPAC 2004 conference.*D. Davino et al., Proceedings of the EPAC 2004 conference.
	Transparencies
WEOBPA02	LEIR Commissioning	1876
	C. Carli, P. Beloshitsky, L. Bojtar, M. Chanel, K. Cornelis, B. Dupuy, J. Duran-Lopez, T. Eriksson, S.S. Gilardoni, D. Manglunki, E. Matli, S. Maury, C. Oliveira, S. Pasinelli, J. Pasternak, F. Roncarolo, G. Tranquille CERN, Geneva
	The Low Energy Ion Ring (LEIR) is a central piece of the injector chain for LHC ion operation, transforming long Linac 3 pulses into high density bunches needed for LHC. LEIR commissioning is scheduled to be completed at the time of the conference. A review of LEIR commissioning highlighting expected and unexpected problems and actions to tackle them will be given.
	Transparencies