antiproton

Paper	Title	Other Keywords	Page
MOPLT109	Longitudinal Schottky Spectra of Bunched Beams	synchrotron, storage-ring, proton, diagnostics	791
	V. Balbekov, S. Nagaitsev Fermilab, Batavia, Illinois
	In this paper we derive an expression for longitudinal Schottky spectrum of a bunched beam in a stationary bucket. The expression is then used to calculate longitudinal emittance of the antiproton beam in the Fermilab Recycler ring. The Recycler beam is bunched longitudinally by a barrier-bucket rf waveform. Under certain bucket conditions, dependence of synchrotron frequency on particle energy becomes non-monotonic. It complicates the Schottky spectrum derivation and interpretation; we address these difficulties in our paper.
MOPLT110	Stochastic Cooling in Barrier Buckets at the Fermilab Recycler	pick-up, betatron, electron, emittance	794
	D.R. Broemmelsiek, M. Hu, S. Nagaitsev Fermilab, Batavia, Illinois
	The Fermilab Recycler is a fixed 8-GeV kinetic energy storage ring located in the Fermilab Main Injector tunnel near the ceiling. The role of stochastic cooling in the Recycler is to pre-cool the transverse phase-space of injected antiprotons for efficient electron cooling. This requires a gated stochastic cooling system working on beam confined in a barrier bucket. The performance of this system is reviewed. In addition, a study of the cooling rates and asymmptotic emittances as a function of beam intensity is presented.
TUXCH02	FAIR - An International Accelerator Facility for Research with Ions and Antiprotons	ion, heavy-ion, synchrotron, plasma	50
	W.F. Henning GSI, Darmstadt
	This presentation describes the conceptual design for the accelerator facility and the physics research program, and discusses the status and the new challenges in accelerator physics and technology.
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TUPKF013	Studies on Maximum RF Voltages in Ferrite-tuned Accelerating Cavities	synchrotron, proton, ion, acceleration	985
	K. Kaspar, H.G. Koenig, T. Winnefeld GSI, Darmstadt
	The GSI SIS100 project requires very high accelerating voltages. With ferrite-tuned synchrotron cavities the gap voltage is often strongly limited by the Q-loss effect appearing at medium dc bias fields. At low bias fields, considerably higher voltages can be reached, however. The maximum usable amplitudes over the bias region have been studied. At zero bias, the ferrites could be driven to more than a factor 3 above the Q-loss limit. Except overheating, no other problems appeared. With increasing bias, the maximum amplitudes decrease continuously to the Q-loss level. In this fall-off region there is still a tuning factor up to 2.5 available, with rf flux densities by at least a factor 2 above the Q-loss level. Measurements on small samples of the ferrite material used in the GSI cavities could be verified very well in a full-size cavity, for the most part. The tests were mainly limited by the available anode voltage and the fear of damaging the cavity. It seems possible, to generalize the main results for other ferrite materials, also. Based on the results, a possible scenario for the SIS100 rf system is given. Additionally, the results lead to an alternative cavity design for higher voltages, which is described as well.
TUPLT007	The CERN-SPL Chopper Concept and Final Layout	vacuum, quadrupole, linac, proton	1141
	F. Caspers, Y. Cuvet, J. Genest, M. Haase, M. Paoluzzi, A. Teixeira CERN, Geneva
	The fast chopper for the CERN SPL (Superconducting Proton Linac) consists of a double meander structure with a beta (v/c) value of 8 % printed on an alumina substrate for the deflecting plates. Each chopper unit is 50 cm long and housed in a quadrupole magnet surrounding the vacuum chamber. The deflecting plates are operated simultaneously in a dual mode, namely traveling wave mode for frequencies above about 10 MHz and as quasi electro-static deflectors below. The deflecting structures are water-cooled to handle heating from beam losses as well as from the deflecting signal. A detailed mechanical layout is presented including the tri-axial feeding and termination technique as well as a discussion of the drive amplifier
TUPLT018	Layout of the Storage Ring Complex of the International Accelerator Facility for Research with Ions and Antiprotons at GSI	storage-ring, ion, electron, target	1174
	P. Beller, K. Beckert, A. Dolinskii, B.  Franzke, F. Nolden, C. Peschke, M. Steck GSI, Darmstadt
	The storage ring complex of the new international accelerator facility consists of three different rings: the Collector Ring CR, the accumulator/decelerator ring RESR and the New Experimental Storage Ring NESR. The CR will serve for fast stochastic precooling of antiproton and rare isotope (RI) beams. Cooling time constants of about 100 ms for RI beams are envisaged. For experiments with RI beams the RESR serves as a decelerator ring. Precooled RI beams will be injected at 740 MeV/u and then decelerated to variable energies down to 100 MeV/u within about 1 s. The NESR will be the main instrument for nuclear and atomic physics. Besides experiments using an internal gas target, the NESR offers the possibility to collide circulating bunches of ions with electron bunches counter-propagating in a small 500 MeV electron storage ring. The physics program with antiprotons requires the accumulation of high intensity antiproton beams. The accumulation of 7×1010 antiprotons at 3 GeV per hour is foreseen. This will be accomplished by operating the RESR as an accumulator ring equipped with a stochastic cooling system. The NESR could then be used to decelerate antiprotons to 30 MeV.
TUPLT041	Ultra-low Energy Antiprotons at FLAIR	storage-ring, electron, ion, injection	1240
	C.P. Welsch, M. Grieser, D. Orlov, J. Ullrich, A. Wolf, R. von Hahn MPI-K, Heidelberg
	The Future Accelerator Facility for Beams of Ions and Antiprotons at Darmstadt will produce the highest flux of antiprotons in the world. So far it is foreseen to accelerate the antiprotons to high energies (3-15 GeV) for meson spectroscopy and other nuclear and particle physics experiments in the HESR (High Energy Storage Ring). Within the planned complex of storage rings, it is possible to decelerate the antiprotons to about 30 MeV kinetic energy, opening up the possibility to create low energy antiprotons. In the proposed FLAIR facility the antiprotons shall be slowed down in a last step from 300 keV to 20 keV in an electrostatic storage ring (USR) for various in-ring experiments as well as for their efficient injection into traps. In this energy range - especially if one thinks about realizing a real multi-purpose facility with not only antiprotons, but also various highly-charged radioactive ions to be stored and investigated - electrostatic storage rings have clear advantages compared to their magnetic counterparts. In case one envisions to even approach the eV range, electrostatic machines are the only possible choice. This contribution presents the layout and design parameters of the USR.
TUPLT149	Beam Manipulation and Compression Using Broadband RF Systems in the Fermilab Main Injector and Recycler	emittance, proton, booster, target	1479
	G.W. Foster, C.M. Bhat, B. Chase, J.A. Mac Lachlan, K. Seiya, P. Varghese, D. Wildman Fermilab, Batavia, Illinois
	Successful tests of new method for beam manipulation, compression, and stacking using the broadband RF systems in the Fermilab Recycler and Main Injector are described. Under usual conditions an unbunched beam can be confined to a fraction of the azimuth of the ring by a set of "Barrier Pulses" which repel particles trying to escape from the ends of the segment of beam. One way to compress or expand the azimuthal extent of the segment of beam is to slowly change the distance between barrier pulses. However when it is desired to rapidly compress or expand the length of the segment, a linear ramp can be superimposed on the waveform between barrier pulses. This causes particles at the front and back of the beam segment to be accelerated or decelerated by differing amounts, and the velocity correlation along the length of the beam segment causes it to expand or contract. When the expansion or contraction is halfway completed, the ramp voltage is reversed so the all particles will come relatively to rest at the end of the process. With the Barrier pulses following appropriately, no particles leak out the ends of the beam segment and the emittance is preserved.
TUPLT151	Status of the Fermilab Electron Cooling Project	electron, recirculation, vacuum, acceleration	1485
	J.R. Leibfritz, D.R. Broemmelsiek, A.V. Burov, K. Carlson, B. Kramper, T. Kroc, M. McGee, S. Nagaitsev, L. Nobrega, G. Saewert, C.W. Schmidt, A.V. Shemyakin, M. Sutherland, V. Tupikov, A. Warner Fermilab, Batavia, Illinois G. Kazakevich BINP SB RAS, Novosibirsk S. Seletsky Rochester University, Rochester, New York
	Fermilab has constructed and commissioned a full-scale prototype of a multi-MV electron cooling system to be installed in the 8.9 GeV/c Fermilab Recycler ring. This prototype was used to test all of the electron beam properties needed for cooling. However, because the prototype is not located within proximity of the Recycler ring, the actual electron cooling of antiprotons can not be demonstrated until it is relocated. The Fermilab electron cooling R&D project is scheduled to be completed in May, 2004 at which time it will be disassembled and relocated to a newly constructed facility where it will be installed in the Recycler. This paper describes the experimental results obtained with the prototype cooler system, gives an overview of the new electron cooling facility, and discusses the overall status of the project.
TUPLT154	Aperture Studies for the Fermilab AP2 Anti-proton Line	lattice, kicker, injection, chromatic-effects	1491
	I. Reichel, M. Placidi, M.S. Zisman LBNL, Berkeley, California K. Gollwitzer, S. Werkema Fermilab, Batavia, Illinois
	The AP2 beamline transports anti-protons from the production target to the Debuncher ring. In the past the observed aperture has been smaller than that estimated from linear, on-energy optics. We have investigated possible reasons for the aperture limitation and have identified possible sources, including residual vertical dispersion from alignment errors and chromatic effects due to very large chromatic lattice functions. Some experiments have already been performed to study these effects. We present results of the experimental and theoretical studies and possible remedies.
WEYCH01	Fast Pulsed SC Magnets	dipole, synchrotron, ion, storage-ring	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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WEPKF072	Clearing Electrodes for Vacuum Monitoring at the Fermilab Recycler	ion, vacuum, electron, monitoring	1771
	D.R. Broemmelsiek, S. Nagaitsev Fermilab, Batavia, Illinois
	The Fermilab Recycler is a fixed 3.3-km 8-GeV kinetic energy storage ring located in the Fermilab Main Injector tunnel. Each split-plate beam position monitor in the Recycler is also used to generated an ion clearing field for ions trapped by the antiproton beam. Approximately 100 locations have been instrumented with pico-amp meters to measure the electron current, generated by the beam-ionized residual gas in the vacuum chamber. This electron current is found to be proportional to the beam current and to the residual gas pressure in the Recycler and may be used to monitor the Recycler vacuum.
WEPLT056	An Electron Cooling System for the Proposed HESR Antiproton Storage Ring	electron, target, storage-ring, acceleration	1969
	M. Steck, K. Beckert, P. Beller, A. Dolinskii, B.  Franzke, F. Nolden GSI, Darmstadt V.V. Parkhomchuk, V.B. Reva, A.N. Skrinsky, V.A. Vostrikov BINP SB RAS, Novosibirsk
	The HESR storage ring in the proposed new international accelerator facility will provide high quality antiproton beams for experiments with an internal target. In order to achieve the design luminosity for collisions with a hydrogen target powerful beam cooling is required. For dedicated experiments ultimate resolution is demanded. Therefore it is foreseen to provide cooled antiproton beams in the energy range 0.8-14 GeV with an energy spread of 100 keV or better. According to computer simulations the required cooling rates can be achieved by electron cooling with an electron current of 1 A. The conceptual design of an electron beam device which is based on electrostatic acceleration of the electrons and their transport in longitudinal magnetic fields into a cooling section with a strong magnetic field of up to 0.5 T will be presented. This design will allow cooling in the magnetized regime in order to reach the required high cooling rates. Some novel features for the generation and regulation of the accelerating voltage and for the beam transport are proposed.
WEPLT057	Simulation Results on Cooling Times and Equilibrium Parameters for Antiproton Beams at the HESR	electron, target, ion, simulation	1972
	A. Dolinskii, O. Boine-Frankenheim, B.  Franzke, M. Steck GSI, Darmstadt A. Bolshakov, P. Zenkevich ITEP, Moscow A.O. Sidorin, G.V. Troubnikov JINR, Dubna, Moscow Region
	The High Energy Storage Ring HESR is part of the "International Accelerator Facility for Ion and Antiproton Beams" proposed at GSI. For internal target experiments with antiproton beams in the energy range 0.8 GeV to 14.5 GeV a maximum luminosity of 5 inverse nbarn per second and a momentum resolution on the order of 10 ppm have to be attained. Electron cooling is assumed to be the most effective way to counteract beam heating due to target effects and intra-beam scattering. Cooling times and equilibrium parameters have been determined by means of three different computer codes: BETACOOL, MOCAC, and PTARGET. The results reveal that the development of fast, "magnetized" electron cooling with beam currents of up to 1 A and variable electron energies of up to 8 MeV in an extremely homogeneous longitudinal magnetic field of up to 0.5 T is crucial to achieve the required equilibrium beam parameters over the envisaged range of antiproton energies.
WEPLT126	Beam Dynamics Simulation in High Energy Electron Cooler	electron, simulation, target, vacuum	2146
	A.V. Ivanov, V.M. Panasyuk, V.V. Parkhomchuk, V.B. Reva BINP SB RAS, Novosibirsk
	The article deals with electron beam dynamics in projected high energy electron cooler. Classical electrostatic scheme with several MeV electron energy is considered. The increase of transversal energy of electrons in an accelerating section, in bends and at the matching point of magnetic fields is calculated. In order to calculate beam behavior in bends with electrostatic compensation of centripetal drift new ELEC3D electro- and magnitostatic 3D code is developed. BEAM code is used for simulation of dynamics in an accelerating section. The methods of keeping low transversal energy are estimated.
WEPLT143	Simulation Calculations of Stochastic Cooling for Existing and Planned GSI Facilities	ion, pick-up, simulation, kicker	2170
	I. Nesmiyan National Taras Shevchenko University of Kyiv, Radiophysical Faculty, Kiev F. Nolden GSI, Darmstadt
	The process of longitudinal stochastic cooling is simulated using a Fokker-Planck model. The model includes the sensitivities of pick-up and kicker electrodes as calculated from field theoretical models. The effect of feedback through the beam is taken into account. Intra beam scattering is treated as an additional diffusive effect. The calculations cover the existing system of the ESR storage ring at GSI as well as the cooling system for secondary heavy ion and antiproton beams at the proposed new accelerator facility. The paper discusses the resulting cooling times. Requirements on the system layout as amplification factors and electrical power can be derived from the simulations.
THOBCH03	Barrier RF Systems in Synchrotrons	synchrotron, emittance, hadron, proton	236
	C.M. Bhat Fermilab, Batavia, Illinois
	Recently, the barrier bucket techniques have been used in many interesting applications in proton synchrotrons around the world. Specially designed broad-band rf cavities are used to generate barrier buckets. At Fermilab we have barrier RF systems in four different rings and have used them for various beam gymnastics. Particularly, in the case of Fermilab Recycler Ring, all rf manipulations required during beam cooling, beam stacking and unstacking are carried out using barrier buckets. Also, we have explored new methods for increasing the beam intensities in the Main Injector. Here, I review various uses of barrier rf system in particle accelerators and possible new applications.
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THZCH01	Status of Tevatron Collider Run II and Novel Technologies for the Tevatron Luminosity Upgrades	electron, luminosity, proton, emittance	239
	V.D. Shiltsev Fermilab, Batavia, Illinois
	In the Tevatron Run-II, 36 antiproton bunches collide with 36 proton bunches at the CDF and D0 interaction regions at 980 GeV per beam. We present current status and performance of the collider complex. The plan for Run-II luminosity upgrades will be presented and novel technologies for the upgrade will be discussed.
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THZCH02	Electron Cooling: Remembering and Reflecting	electron, ion, proton, storage-ring	244
	I.N. Meshkov JINR, Dubna, Moscow Region
	The report contains a brief review of developments in electron cooling methods. The influence of electron cooling concepts on progress in particle beam physics is considered, particularly: development of alternative and complementary cooling methods - stochastic, laser, muon cooling; physics of cooled and intense particle beams; ordering effects in cooled ion beams and the idea of crystalline beams; intrabeam scattering in cooled beams, etc. Creation of new accelerator technology, based on electron cooling and its application to different fields of experimental physics, particle, nuclear and atomic physics, is described. Modern trends and new concepts of electron cooling applications are discussed.
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THPLT007	New Beam Profile Monitor Based on GEM Detector for the AD Transfer and Experimental Lines	hadron, cathode, electron, extraction	2472
	J. Bosser, K. Gnanvo, J. Spanggaard, G. Tranquille CERN, Geneva
	Many multi-wire proportional chambers, (MWPC's), are installed on the CERN Antiproton Decelerator (AD) transfer and experimental lines. They are used for the steering and profile measurement of the low energy antiproton beam that is extracted at the energy of 5.3 MeV from the AD machine. At this very low energy, the standard MWPC's are not only destructive for the beam but also perturb strongly the 2D profile measurement. These chambers are also based on technology that is outdated and in recent years have shown to be fragile and expensive to repair. For these reasons a new, low cost profile monitor, based on a Gas Electron Multiplier (GEM) detector is under development as a possible replacement of the MWPC's. This new profile monitor will enable high precision, true 2D profile measurements of the low energy antiproton beam. In this paper, we present the modification of the standard GEM detector required by our specific application and the first results of the profile monitor with antiproton beams.
THPLT031	Comparison of Rate Equation Models for Equilibrium Beam Parameters	scattering, electron, target, storage-ring	2544
	R.W. Hasse, O. Boine-Frankenheim GSI, Darmstadt
	We calculate equilibrium beam parameters from the counteraction of intrabeam scattering (IBS), electron cooling (EC) and target interaction for typical beams in the GSI cooler storge ring ESR and in the proposed HESR. This work is complementary to kinetic modeling efforts at GSI. We developed an easy to use simulation tool that includes various models for the EC rates and the IBS rates, averaged of the detailed ring lattices. The obtained scaling of the equilibrium parameters with beam current and energy are compared with existing experimental data from the ESR and with kinetic simulation results for the HESR.
THPLT135	Experience with the 1.7 GHz Schottky Pick-ups in the Tevatron	proton, pick-up, emittance, betatron	2777
	A. Jansson, P. Lebrun, R. Pasquinelli Fermilab, Batavia, Illinois
	During a 2003 shutdown, new high-frequency Schottky pick-ups were installed in the Tevatron. These devices operate at 1.7 GHz (harmonic ~36000 of the revolution frequency) and can in principle be used to measure tunes, chromaticities, momentum spread and transverse emittances of individual bunches. Only the transverse signal is used, as the longitudinal is dominated by coherent signal. The default mode of operation during a store is to sequentially acquire and analyze frequency data from different sets of bunches in the machine. This function is performed by an open access client written in Java/C++, running in the background. The resulting fit parameters are datalogged and can also be plotted in "real time" during the store. With an alternative setup, data from select bunches can be acquired continuously during the entire ramp (and squeeze), for analysis off-line. This paper describes the evolution, current status and performance of the acquisition and analysis software, and presents measurements with comparison to predictions and other measurement techniques. One example of such a measurement is the variation of beam-beam tune shift as a function of intensity and bunch position within a train.