COOL 2007 - List of Keywords (ion)

A B C D E F G H I K L O P Q R S T U V

ion

Paper	Title	Other Keywords	Page
MOM2I03	Progress of High-energy Electron Cooling for RHIC	electron, luminosity, emittance, simulation	11
	A. V. Fedotov BNL, Upton, Long Island, New York
	Funding: Work supported by the U. S. Department of Energy. The fundamental questions about QCD which can be directly answered at Relativistic Heavy Ion Collider (RHIC) call for large integrated luminosities. The major goal of RHIC-II upgrade is to achieve 10 fold increase in luminosity of Au ions at the top energy of 100 GeV/n. A significant increase in luminosity for polarized protons is also expected, as well as for other ion species and for various collision energies. Such a boost in luminosity for RHIC-II is achievable with implementation of high-energy electron cooling. The design of the higher-energy cooler for RHIC recently adopted a non-magnetized approach which requires a low temperature electron beam. Such high-intensity high-brightness electron beams will be produced with superconducting Energy Recovery Linac (ERL). Detailed simulations of the electron cooling process and numerical simulations of the electron beam transport including the cooling section were performed. An intensive R&D of various elements of the design is presently underway. Here, we summarize progress in these electron cooling efforts.
	Slides

MOM2I04	Cooling Simulations with the BETACOOL Code	simulation, electron, target, emittance	16
	A. O. Sidorin JINR, Dubna, Moscow Region
	BETACOOL program developed by JINR electron cooling group is a kit of algorithms based on common format of input and output files. General goal of the program is to simulate long term processes (in comparison with the ion revolution period) leading to variation of the ion distribution function in 6 dimensional phase space. The BETACOOL program includes three algorithms for beam dynamics simulation and takes into account the following processes: electron cooling, intrabeam scattering, ion scattering on residual gas atoms, interaction of the ion beam with internal target and some others.
	Slides

MOM2C05	Longitudinal Accumulation of Ion Beams in the ESR Supported by Electron Cooling	electron, injection, pick-up, accumulation	21
	C. Dimopoulou, B. Franzke, T. Katayama, G. Schreiber, M. Steck GSI, Darmstadt D. Möhl CERN, Geneva
	Recently,two longitudinal beam compression schemes have been successfully tested in the Experimental Storage Ring (ESR) at GSI with a beam of bare Ar ions at 65 MeV/u injected from the synchrotron SIS18. The first employs Barrier Bucket pulses, the second makes use of multiple injections around the unstable fixed point of a sinusoidal RF bucket at h=1. In both cases continuous application of electron cooling maintains the stack and merges it with the freshly injected beam. These experiments provide the proof of principle for the planned fast stacking of Rare Isotope Beams in the New Experimental Storage Ring (NESR) of the FAIR project.
	Slides

MOA1I01	Bunched Beam Stochastic Cooling at RHIC	proton, kicker, pick-up, beam-losses	25
	J. M. Brennan, M. Blaskiewicz BNL, Upton, Long Island, New York
	Stochastic cooling of ions in RHIC has been implemtneted to counteract Intra-Beam Scattering and prevent debunching during stores for luminosity production. The two main challenges in cooling bunched beam at 100 GeV/n are the coherent components in the Schottky spectra and producing the high voltage for the kicker in the 5 - 8 GHz band required for optimal cooling. The technical solutions to these challenges are described. Results of cooling proton beam in a test run and cooling gold ions in the FY07 production run are presented.
	Slides

TUM1I01	Cooling Results from LEIR	electron, injection, gun, controls	55
	G. Tranquille CERN, Geneva
	The LEIR electron cooler has been successfully commissioned for the cooling and stacking of Pb⁵⁴⁺ ions in LEIR during 2006. The emphasis of the three short commissioning runs was to produce the so-called “early” beam needed for the first LHC ion run. In addition some time was spent investigating the difficulties that one might encounter in producing the nominal LHC ion beam. Cooling studies were also made whenever the machine operational mode made it possible, and we report on the preliminary results of the different measurements (cooling-down time, lifetime etc.) performed on the LEIR cooler. Our investigations also included a study of the influence of variable electron density distributions on the cooling performance.
	Slides

TUM1I02	Commissioning of Electron Cooling in CSRm	electron, accumulation, injection, acceleration	59
	X. D. Yang, D. Q. Gao, Y. He, G. H. Li, J. Li, Y. Liu, L. J. Mao, R. S. Mao, M. T. Song, J. W. Xia, G. Q. Xiao, J. C. Yang, X. T. Yang, Y. J. Yuan, W.-L. Zhan, W. Zhang, H. W. Zhao, T. C. Zhao, J. H. Zheng, Z. Z. Zhou IMP, Lanzhou V. V. Parkhomchuk BINP SB RAS, Novosibirsk
	A new generation cooler was commissioned in CSRm, ¹²C⁶⁺ beam with energy 7MeV/u was delivered by a small cyclotron SFC, then injected into CSRm by stripping mode, the average pulse particle number is about 6.8×10⁸ in one injection, with the help of electron cooling of partial hollow electron beam, 3×10⁹ particle were accumulated in the ring after 10 times injection in 10 seconds, and 2×10⁹ particle were accelerated to final energy 1GeV/u, the momentum spread and the lifetime of ion beam were measured roughly. The work point of ring was monitored during the process of acceleration. The close-orbit correction was done initially. The momentum cooling time was about 0.3sec. About 1.6×10¹⁰ particle was stored in the ring after longer time accumulation.
	Slides

TUM1I03	Comparison of Hollow Electron Devices and Electron Heating	electron, accumulation, emittance, antiproton	64
	V. V. Parkhomchuk BINP SB RAS, Novosibirsk
	The first results of the electron cooling with hollow electron beam are present. The electron coolers with varable electron beam profiles was commissioned at CERN and IMP (China). Accumulation of the ion beam was demonstrated.
	Slides

TUA1C03	Necessary Condition for Beam Ordering	proton, electron, scattering, simulation	87
	A. V. Smirnov, I. N. Meshkov, A. O. Sidorin JINR, Dubna, Moscow Region J. Dietrich FZJ, Jülich A. Noda, T. Shirai, H. Souda, H. Tongu Kyoto ICR, Uji, Kyoto K. Noda NIRS, Chiba-shi
	The very low momentum spread for small number of particle was reached on different storage rings. When the sudden reduction of the momentum spread ("phase transition") was observed during decreasing of the particle number it was interpreted as ordered state of ion beams. The most extensive study of ordered ion beams was done on storage rings ESR (GSI, Darmstadt) and CRYRING (MSL, Stockholm). Recently, for the first time, the ordered proton beam has been observed on S-LSR (Kyoto University). From analysis of the ESR experimental results we assumed that the ordered state can be observed if the dependence of momentum spread on the particle number can be approximated as ∆P/P ~ N^k for k < 0.3. In pioneering experiments at NAP-M (INP, Novosibirsk) and, in recent years, at COSY (FZJ, Juelich) the phase transition was not observed and the coefficient was found equal k > 0.5. This report presents the experimental investigations of low intensity proton beams on COSY and S-LSR which have the aim to formulate the necessary conditions for the achievement of the ordered state. The experimental studies on S-LSR and numerical simulations with the BETACOOL code were done for the dependence of the momentum spread and transverse emittances on particle number with different misalignments of the magnetic field at the cooler section. As result of both experimental and numerical studies one can conclude that the necessary condition for the phase transition appearance is k < 0.3.
	Slides

TUA1I04	High-Energy Colliding Crystals – A Theoretical Study	lattice, collider, luminosity, simulation	91
	J. Wei BNL, Upton, Long Island, New York H. Okamoto Hiroshima University, Higashi-Hiroshima A. Sessler LBNL, Berkeley, California H. Sugimoto, Y. Yuri HU/AdSM, Higashi-Hiroshima
	*Funding: Work performed under the auspices of the U. S. Department of Energy. Recent theoretical investigations of beam crystallization mainly use computer modeling based on the method of molecular dynamics (MD) and analytical study based on phonon theory [1]. Topics of investigation include crystal stability in various accelerator lattices under different beam conditions, colliding crystalline beams [2], and crystalline beam formation in shear-free ring lattices with both magnets and electrodes [3]. In this paper, we review the above mentioned theoretical studies and, in particular, discuss the development of the phonon theory in a time-dependent Hamiltonian system representing a storage ring of AG focusing. Analytical study of crystalline beam stability in an AG-focusing ring was previously limited to the smooth approximation. In a typical ring, analytical results obtained under such approximation largely agrees with the results obtained with the molecular dynamics (MD) simulation method. However, as we explore ring lattices appropriate for beam crystallization at high energies (Lorentz factor gamma much higher than the betatron tunes) [2,4], this approximation fails. Here, we present a newly developed formalism to exactly predict the stability of a 1-dimensional crystalline beam in an AG focusing ring lattice. [1] X.-P. Li, et al, PR ST-AB, 9, 034201 (2006). [2] J. Wei, A. M. Sessler, EPAC, 862 (1998)[3] M. Ikegami, et al, PR ST-AB 7, 120101 (2004).[4] J. Wei, H. Okamoto, et al, EPAC 2006.**
	Slides

WEM2I05	Bunched Beam Stochastic Cooling Simulations and Comparison with Data	simulation, pick-up, emittance, kicker	125
	M. Blaskiewicz, J. M. Brennan BNL, Upton, Long Island, New York
	Funding: Work performed under the auspices of the United States Department of Energy. With the experimental success of longitudinal, bunched beam stochastic cooling in RHIC it is natural to ask whether the system works as well as it might and whether upgrades or new systems are warranted. A computer code, very similar to those used for multi-particle coherent instability simulations, has been written and is being used to address these questions.

WEM2C06	Simulation of Cooling Mechanisms of Highly-charged Ions in the HITRAP Cooler Trap	electron, simulation, space-charge, synchrotron	130
	G. Maero, F. Herfurth, O. K. Kester, H. J. Kluge, S. Koszudowski, W. Quint GSI, Darmstadt S. Schwarz NSCL, East Lansing, Michigan
	The use of heavy and highly-charged ions gives access to unprecedented investigations in the field of atomic physics. The HITRAP facility at GSI will be able to slow down and cool ion species up to bare uranium to the temperature of 4 K. The Cooler Trap, a confinement device for large numbers of particles, is designed to store and cool bunches of 10⁵ highly-charged ions. Electron cooling with 10¹⁰ simultaneously trapped electrons and successive resistive cooling lead to extraction in both pulsed and quasi-continuous mode with a duty cycle of 10 s. After an introduction to HITRAP and overview of the setup, the dynamics of the processes investigated via a Particle-In-Cell (PIC) code are shown, with emphasis on the peculiarities of our case, namely the space charge effects and the modelling of the cooling techniques.
	Slides

THM1I01	Commissioning and Performance of LEIR	injection, linac, vacuum, lattice	134
	C. Carli CERN, Geneva
	The Low Energy Ion Ring (LEIR) is a key element of the LHC ion injector chain. Under fast electron cooling, several long pulses from the ion Linac 3 are accumulated and cooled, and transformed into short bunches with a density sufficient for the needs of the LHC. Experience from LEIR commissioning and the first runs in autumn 2006 and summer 2007 to provide the so-called "early LHC ion beam" for setting-up in the PS and the SPS will be reported. Studies in view of the beam needed for nominal LHC ion operation are carried out in parallel to operation with lower priority.
	Slides

THM1I02	Electron Cooling Experiments at S-LSR	electron, proton, heavy-ion, simulation	139
	T. Shirai, S. Fujimoto, M. Ikegami, A. Noda, 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, A. V. Smirnov, E. Syresin JINR, Dubna, Moscow Region K. Noda NIRS, Chiba-shi
	Funding: The present work has been supported from Advanced Compact Accelerator Development Project by MEXT of Japan and 21 COE at Kyoto University-Center for Diversity and Universality in Physics. The ion storage ring, S-LSR in Kyoto University has an electron beam cooler and a laser cooling system. The electron cooler for S-LSR was designed to maximize the cooling length in the limited drift space of the ring. The effective cooling length is 0.44 m, while the total length of the cooler is 1.8 m. The commissioning of the electron cooling was started from October 2005. The 7 MeV proton beam from the linac was used and the first cooling was observed on October 31. The momentum spread became 2×10^-4 and the beam diameter was 1.2 mm with the particle number of 2×10⁸ and the electron current of 60 mA. The various experiments have been carried out using the electron cooling at S-LSR. The one-dimensional ordering of protons is one of the important subjects. The momentum spread and the beam size were observed while reducing the particle number. They were measured by the Schottky noise spectrum and the scraper. The particle number was measured by the ionization residual gas monitor. Abrupt jumps in the momentum spread and the Schottky noise power were observed for protons at a particle number of around 2000. The beam temperature was 0.17 meV and 1 meV in the longitudinal and transverse directions at the transition particle number, respectively. The normalized transition temperature of protons is close to those of heavy ions at ESR. The lowest momentum spread below the transition was 1.4×10^-6, which corresponded to the longitudinal beam temperature of 0.026 meV (0.3 K). It is close to the longitudinal electron temperature. The transverse temperature of the proton beam was much below that of electrons (34 meV). It is the effect of the magnetized electron.

THM2I05	Use of an Electron Beam for Stochastic Cooling*	electron, plasma, hadron, collider	149
	Y. S. Derbenev Jefferson Lab, Newport News, Virginia
	*Funding: Authored by Jefferson Science Associate under U. S. DoE Contract No. DE-AC05-06OR23177 Microwave instability of an electron beam can be used for a multiple increase in the collective response for the perturbation caused by a particle of a co-moving ion beam, i.e. for enhancement of friction force in electron cooling method. The low scale (hundreds GHz and larger frequency range) space charge or FEL type instabilities can be produced (depending on conditions) by introducing an alternating magnetic fields along the electron beam path. Beams’ optics and noise conditioning for obtaining a maximal cooling effect and related limitations will be discussed. The method promises to increase by a few orders of magnitude the cooling rate for heavy particle beams with a large emittance for a wide energy range with respect to either electron and conventional stochastic cooling [1,2]. [1] Ya. S.Derbenev, Coherent Electron Cooling, UM HE 91-28, August 7, 1991[2] Ya. S.Derbenev, AIP Conf. Proc., No 253, p. 103. AIP 1992**
	Slides

THM2I06	Electron Beams as Stochastic 3D Kickers	electron, kicker, space-charge, gun	154
	V. B. Reva, A. V. Ivanov, V. V. Parkhomchuk BINP SB RAS, Novosibirsk
	This article describes an idea combining electron and stochastic cooling in one device. The amplified signal about displacements of the ion from pick-up electrode applied to the control electrode of an electron gun. Thus, a wave of the space charge in the electron beam is induced. This wave propagates with the electron beam to the cooling section. The space charge of the electron beam acts on the ion beam producing a kick. The effectiveness of the amplification can be improved with using a structure similar to a traveling-wave tube.

THAP01	Electron Cooling Simulation for Arbitrary Distribution of Electrons	electron, simulation, emittance, acceleration	159
	A. O. Sidorin, A. V. Smirnov JINR, Dubna, Moscow Region I. Ben-Zvi, A. V. Fedotov, D. Kayran BNL, Upton, Long Island, New York
	Typically, several approximations are being used in simulation of electron cooling process, for example, density distribution of electrons is calculated using an analytical expression and distribution in the velocity space is assumed to be Maxwellian in all degrees of freedom. However, in many applications, accurate description of the cooling process based on realistic distribution of electrons is very useful. This is especially true for a high-energy electron cooling system which requires bunched electron beam produced by an Energy Recovery Linac (ERL). Such systems are proposed, for instance, for RHIC and electron – ion collider. To address unique features of the RHIC-II cooler, new algorithms were introduced in BETACOOL code which allow us to take into account local properties of electron distribution as well as calculate friction force for an arbitrary velocity distribution. Here, we describe these new numerical models. Results based on these numerical models are compared with typical approximations using electron distribution produced by simulations of electron bunch through ERL of RHIC-II cooler.

THAP02	Implementation of Synchrotron Motion in Barrier Buckets in the BETACOOL Program	synchrotron, simulation, electron, target	163
	A. V. Smirnov, A. O. Sidorin, G. V. Trubnikov JINR, Dubna, Moscow Region O. Boine-Frankenheim GSI, Darmstadt
	In the case of the internal pellet target the electron cooling and the stochastic cooling systems cannot compensate the mean energy losses of the ion beam. In bunched ion beams the space charge limit is reduced and the influence of intrabeam scattering is enhanced, which causes a decrease of the luminosity in comparison with a coasting beam. To resolve these problems barrier buckets are proposed for experiments with the pellet target. In the barrier bucket the long ion bunch fills nearly the whole circumference of the storage ring and a rf pulse is applied at the head and at the tail of the bunch. The general goal of the BETACOOL program is to simulate long term processes (in comparison with the ion revolution period) leading to the variation of the ion distribution function in six dimensional phase space. The investigation of the beam dynamics for arbitrary distribution functions is performed using multi particle simulation in the frame of the Model Beam algorithm. In this algorithm the ion beam is represented by an array of macro particles. The heating and cooling processes involved in the simulations lead to a change of the particle momentum components and particle number, which are calculated each time step. The barrier bucket model was developed in the Model Beam algorithm of the BETACOOL program. The trajectory of each model particle is solved analytically for a given barrier bucket voltage amplitude. An invariant of motion is calculated from the current position of the model particle and from the barrier bucket voltage amplitude. Then the phase of the invariant is calculated in accordance with the integration step and the particle gets a new coordinates. The heating and cooling effects are applied in usual procedure of the Model Beam algorithm. First simulation results for the FAIR storage rings are presented.

THAP04	Optimization of the Magnet System for Low Energy Coolers	electron, dipole, gun, alignment	167
	A. V. Bubley, V. M. Panasyuk, V. V. Parkhomchuk, V. B. Reva BINP SB RAS, Novosibirsk
	Aspects of magnet design and field measurements are discussed in the view of low energy coolers construction. The paper describes some engineering solutions for the magnetic field improvement which provides appropriate conditions for the cooling process as well as electron and ion beams motion.

THAP12	Electron Cooling Design for ELIC - a High Luminosity Electron-Ion Collider *	electron, emittance, collider, kicker	187
	Y. S. Derbenev Jefferson Lab, Newport News, Virginia
	*Funding: Authored by Jefferson Science Associate under U. S. DoE Contract No. DE-AC05-06OR23177** An electron-ion collider (EIC) of center mass energy 90 GeV (9 GeV of electron beam x 225 GeV of proton beam) at luminosity level up to 10³⁵/cm²s is envisioned by high energy Nuclear Physics community as a facility adequate for studying of the fundamental properties of quark-gluon structure of nucleons and strong interactions. In response to this quest, a high luminosity ring-ring EIC design (ELIC) is developed at Jefferson Laboratory utilizing 12 GeV upgrade CEBAF accelerator as a full energy injector for electron storage ring . An inevitable component of EIC is high energy electron cooling (EC) for ion beam. The EC facility concept for ELIC is based on use of 30 mA, 125 MeV energy recovery linac (ERL) and 3A circulator-cooler ring (CCR) operated at 15 and 1500 MHz bunch repetition rate, respectively. To switch electron bunches between ERL and CCR, fast kickers of a frequency bandwidth above 2 GHz are designed. The design parameters of EC facility and preliminary results of study of electron beam transports, stability and emittance maintenance in ERL and CCR, together with scenario of forming and cooling of ion beam will be presented.

THAP19	Influences of Space Charge Effect during Ion Accumulation Using Moving Barrier Bucket Cooperated with Beam Cooling	space-charge, injection, electron, accumulation	206
	T. Kikuchi, S. Kawata Utsunomiya University, Utsunomiya T. Katayama GSI, Darmstadt
	Space charge effect is important role for stacking of antiprotons and ions in an accumulation ring. The Coulomb force displaces the beam orbits from the designed correct motion. The beam particles kicked out from the ring acceptance by the space charge force are lost. The space charge effect interfere the beam stacking, and the number of the accumulated beam decreases and the emittance is increased. The longitudinal ion storage method by using a moving barrier bucket system with a beam cooling can accumulate the large number of secondary generated beams. After the multicycle injections of the beam bunch, the stored particles are kicked by the space charge effect of the accumulated beam. Using numerical simulations, we employ the longitudinal particle tracking, which takes into account the barrier bucket voltage, the beam cooling and the space charge effect, for the study of the beam dynamics during the accumulation operations. T. Katayama, P. Beller, B. Franzke, I. Nesmiyan, F. Nolden, M. Steck, D. Mohl and T. Kikuchi, AIP Conference Proc. 821 (2005) 196.

THAP20	Internal Target Effects in the ESR Storage Ring with Cooling	target, simulation, electron, storage-ring	210
	V. Gostishchev, C. Dimopoulou, A. Dolinskii, F. Nolden, M. Steck GSI, Darmstadt
	The accurate description of the internal target effects is important for the prediction of operation conditions which are required for the performance of experiments in the storage rings of the FAIR facility at GSI. A number of codes such as PTARGET, MOCAC, PETAG01 and BETACOOL have been developed to evaluate the beam dynamics in the storage ring, where an internal target in the combination with an electron cooling is applied. The systematic benchmarking experiments were carried out at the ESR storage ring at GSI. The ‘zero’ dispersion mode (dispersion at target position is about 0 m) was applied to evaluate the influence of the dispersion function on the beam parameters when the internal target is ON. The influence of the internal target on the beam parameters is demonstrated. Comparison of the experimental results with the Bethe-Bloch formula describing the energy loss of the beam particles in the target as well as with simulations with the BETACOOL code will be given.

THAP21	Longitudinal Schottky Signals of Cold Systems with Low Number of Particles	storage-ring, pick-up, simulation, electron	213
	R. W. Hasse GSI, Darmstadt
	Very cold systems of ions with sufficiently low number of particles arrange in an ordered string-like fashion. The determination of the longitudinal momentum spread and of the transverse temperature then is no longer possible by normal Schottky diagnosis. In this paper we simulate such systems in an infinitely long beam pipe with periodic boundary conditions under the influence of all long-range Coulomb interactions by Ewald summation. Then we derive the behaviour of the longitudinal Schottky signals for cold string-like systems as well as for the transition to warmer systems when the strings break, up to hot gas-like systems. Here effects from the finite number of particles, of higher harmonics and of temperature agree with those derived analytically in the limits of very low and very high temperatures.
	Poster

THAP22	Limitations of the Observation of Beam Ordering	electron, scattering, proton, emittance	217
	M. Steck, K. Beckert, P. Beller, C. Dimopoulou, F. Nolden GSI, Darmstadt
	One dimensional beam ordering of electron cooled low intensity heavy ion beams has been evidenced at the ESR storage ring as a discontinuous reduction of the momentum spread. Depending on the beam parameters, technical imperfections or any sources of heating can hamper or even prevent the observation of the momentum spread reduction. Limitations for the detection of the ordered beam will be described and illustrated by experimental results.

FRM1I01	Present Status and Recent Activity on Laser Cooling at S-LSR	laser, proton, induction, storage-ring	221
	A. Noda, M. Ikegami, T. Ishikawa, M. Nakao, T. Shirai, H. Souda, M. Tanabe, H. Tongu Kyoto ICR, Uji, Kyoto M. Grieser MPI-K, Heidelberg I. N. Meshkov, A. V. Smirnov JINR, Dubna, Moscow Region K. Noda NIRS, Chiba-shi
	Funding: The present work has been supported from Advanced Compact Accelerator Development Project by MEXT of Japan and 21 COE at Kyoto University-Center for Diversity and Universality in Physics. Ion storage and cooler ring, S-LSR, has been designed to enable the investigation of coldest possible ion beams with use of various beam cooling schemes such as an electron beam cooling and the laser cooling. Electron beam cooling of 7 MeV protons and laser cooling of 40 keV Mg ions have been applied up to now.　The first laser cooling applied to ~10⁸ Mg ions with the induction accelerator voltage of ~6 mV reduced the momentum spread (1 σ) from 1.7×10^-3 to 2.9×10^-4, which is considered to be saturated by the momentum transfer from transverse degree of freedom to the longitudinal one due to intra-beam scattering. The laser cooling force has been improved from the above one more than one order of magnitude owing to the precise alignment between the laser and Mg ion beam. Recent measurement with frequency shift of the laser showed the enhancement of the coherent signals in odd harmonics of the revolution frequency picked up with an electrostatic beam monitor and detailed measurements of various harmonics have been performed with changing the resolution bandwidth of the spectrum analyzer, although the origin of such coherency is not yet identified up to now. For the purpose of measurement of lowest possible temperature attainable by the laser cooling, measurement with reducing the ion numbers of Mg is needed, which has been blocked by the difficulty of observing the Schotty signal of such a low intensity beam. So as to cope with this situation, development of observing system of emitted light by the transition from the upper level to the ground state with the use of photomultiplier has been performed, which recently succeeded in detection of clear signals coming from the oriented process. Activities above mentioned will be presented together with the forth coming experimental results on laser cooling.
	Slides

FRM1C02	Schottky Noise Signal and Momentum Spread for Laser-Cooled Beams at Relativistic Energies	laser, bunching, electron, storage-ring	226
	M. H. Bussmann, D. Habs LMU, München K. Beckert, P. Beller, B. Franzke, C. Kozhuharov, T. Kuehl, W. Noertershaeuser, F. Nolden, M. Steck GSI, Darmstadt Ch. Geppert, S. Karpuk Johannes Gutenberg University Mainz, Mainz C. Novotny Johannes Gutenberg University Mainz, Institut für Physik, Mainz S. Reinhardt MPI-K, Heidelberg G. Saathoff MPQ, Garching, Munich U. Schramm FZD, Dresden
	We report on the first laser cooling of a bunched beam of C³⁺ ions at the ESR (GSI) at a beam energy of E = 1.47 GeV. Combining laser cooling of the 2S1/2-2P3/2 transition with moderate bunching of the beam lead to a reduction of the longitudinal momentum spread by one order of magnitude if compared to pure electron cooling. If additional electron cooling was applied, thus increasing the coupling between the longitudinal and transverse degree of freedom, three-dimensional cold beams with a plasma parameter of unity could be attained. In a second measurement campaign, a combination of a sweeping-frequency and a fixed-frequency laser beam was succesfully implemented to increase the momentum acceptance of the narrow band laser force. This cooling scheme improved the match of acceptance of the laser force to the momentum spread of the beam and reduced heating due to intra beam scattering. In addition to the interesting beam dynamics observed at low momentum spreads of ∆p / p < 10^-6 precision spectroscopy of 2S1/2-2P1/2 and 2S1/2-2P3/2 transition was performed, both absolute and relative, at a precision challenging the best theoretical models available. The laser cooling schemes used at the ESR can be directly extended to the regime of ultra-relativistic ion energies at the new FAIR facility. There, it becomes possible to cool a large number of ion species using a single laser beam source, exploiting the relativistic Doppler shift of the laser frequency. Finally, the fluorescence photons emitted by these ultra-relativistic laser cooled ion beams can be directly used for precision X-ray spectroscopy of the cooling transitions. The resolution of such measurements would essentially be only limited by the resolution of the X-ray spectrometers available.
	Slides

FRM1C03	Electron Cooling with Photocathode Electron Beams Applied to Slow Ions at TSR and CSR	electron, target, cryogenics, cathode	230
	D. Orlov, H. Fadil, M. Grieser, J. Hoffmann, C. Krantz, O. Novotny, S. Novotny, A. Wolf MPI-K, Heidelberg
	We report electron cooling experiments using a cold electron beam of 55 eV produced by a cryogenic GaAs photocathode. With this device the beam of singly charged ions with a mass of 31 amu, specifically the CF⁺ ion, was cooled at an energy of 3 MeV (about 90 keV/u). Transverse cooling within 2-3 seconds to a very small equilibrium beam size was observed with an electron current of 0.3 mA (electron density of 3×10⁶ cm^-3, magnetic guiding field of 0.04 T). A beam size of about 0.1 mm was deduced from imaging of recombination products. The short cooling times are mostly due to the low electron temperatures of 1 meV in transverse and 0.03 meV in longitudinal direction. An electrostatic Cryogenic Storage Ring (CSR) for slow ion beams, including protons, highly charged ions, and polyatomic molecules is under construction at the MPI-K. It will apply electron cooling at electron beam energies from 165 eV for 300 keV protons down to a few eV for polyatomic singly charged ions. Photoelectrons from the GaAs photocathode with laboratory energy spreads of about 10 meV [1] will be applied for generating such electron beams. In a storage ring of this type, even low electron-ion merging magnetic fields of toroids cause a strong coupling between the horizontal and vertical motions of the stored ions, reducing the ring acceptance to an intolerably low level. We present a new merging scheme of eV-electrons with stored ions, based on the idea of bringing electrons to the ion axis in a uniform dipole magnetic field superimposed to a straight solenoid field. The new magnetic field arrangement strongly improves the ring acceptance and allows to use guiding magnetic fields as high as required to provide high-quality electron beams of eV-energies for the cooling of ions and for merged beam studies in storage rings. [1] D. A. Orlov et al., Appl. Phys. Letters 78, 2721 (2001)
	Slides

FRM2C04	Studies of Cooling and Deceleration at CRYRING for FLAIR	antiproton, proton, electron, space-charge	234
	H. Danared, A. Källberg, A. Simonsson MSL, Stockholm
	It is planned that the CRYRING synchrotron and storage ring will be moved to the future FAIR facility at GSI. There it will be used as the Low-energy Storage Ring LSR at FLAIR (Facility for Low-energy Antiproton and Ion Research). LSR will mainly be used for deceleration of antiprotons from 30 MeV down to minimum 300 keV and for deceleration of highly charged ions in the same range of magnetic rigidities. As a preparation for the transfer of CRYRING to FAIR, studies have been made in order to evaluate the performance of CRYRING for deceleration of particles relevant to FLAIR and to set specifications for beams in and out of LSR. Deceleration of protons have been studied by first accelerating the particles to 30 MeV, then decelerating back to 300 keV again. Up to 3·10⁸ protons have been decelerated in 1.8 s without intermediate cooling, and requirements on longitudinal and transverse emittances at 30 MeV for successful deceleration have been estimated. Other studies have included investigations of the space-charge limit for protons at 300 keV and measurements of transverse cooling times for H^- ions, simulating antiprotons. Also an attempt to compare longitudinal cooling forces between protons and H^- ions has been made.
	Slides

FRM2C05	Simulation Study of Beam Accumulation with Moving Barrier Buckets and Electron Cooling	electron, injection, emittance, simulation	238
	T. Katayama, C. Dimopoulou, B. Franzke, M. Steck GSI, Darmstadt T. Kikuchi Utsunomiya University, Utsunomiya D. Möhl CERN, Geneva
	An effective ion beam accumulation method in NESR at FAIR project, is investigated with numerical way. The princile of accumulation method is as follows: Ion beam bunch from the collector ring or synchrotron is injected in the longitudinal gap space prepared by moving barrier voltage in NESR. Injected beam becomes instantly coasting beam after switching off the barrier voltage and is migrated with the previously stacked beam. After the momentum spread is well cooled by electron cooling, the barrier voltage is switched on and moved to prepare the empty gap space for the next injection. This process is repeated say 20 times to attain the required intensity. We have investigated this stacking process numerically, including the Intra Beam Scattering effect which might limit the stacking current in the ring. Detailed simulated results will be presented for the NESR case as well as the ESR experimental parameters.
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FRM2C06	Electron Cooling Simulations for Low-energy RHIC Operation	electron, simulation, emittance, luminosity	243
	A. V. Fedotov, I. Ben-Zvi, X. Chang, D. Kayran, T. Satogata BNL, Upton, Long Island, New York
	Funding: Work supported by the U. S. Department of Energy Recently, a strong interest emerged in running RHIC at low energies in the range of 2.5-25 GeV/n total energy of a single beam. Providing collisions in this energy range, which in RHIC case is termed “low-energy” operation, will help to answer one of the key questions in the field of QCD about existence and location of critical point on the QCD phase diagram. Applying electron cooling directly at these low energies in RHIC would result in dramatic luminosity increase, small vertex distribution and long stores. On the other hand, even without direct cooling in RHIC at these energies, significant luminosity gain can be achieved by decreasing the longitudinal emittance of the ion beam before its injection into RHIC from the AGS. This will provide good RF capture efficiency in RHIC. Such an improvement in longitudinal emittance of the ion beam can be provided at by a simple electron cooling system at injection energy of AGS. Simulations of electron cooling both for direct cooling at low-energies in RHIC and for pre-cooling in AGS were performed, and are summarized in this report.
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