COOL 2007 - List of Keywords (target)

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

target

Paper	Title	Other Keywords	Page
MOM2I04	Cooling Simulations with the BETACOOL Code	simulation, ion, electron, 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.
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MOA1C02	Stochastic Cooling for the HESR at FAIR	antiproton, emittance, proton, pick-up	30
	H. Stockhorst, R. Maier, D. Prasuhn, R. Stassen FZJ, Jülich T. Katayama CNS, Saitama L. Thorndahl CERN, Geneva
	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 combination 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 resolution 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. A detailed numerical and analytical approach to the Fokker- Planck equation for momentum cooling including an internal target has been carried out to demonstrate the stochastic cooling capability. Cooling model predictions are compared with the stochastic cooling performance of the operational cooling system in the cooler synchrotron COSY.
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MOA2C05	Calculations on High-energy Electron Cooling in the HESR	electron, antiproton, emittance, luminosity	44
	D. Reistad, B. Gålnander, K. Rathsman TSL, Uppsala A. O. Sidorin JINR, Dubna, Moscow Region
	Funding: This work is supported by Uppsala University through The Svedberg Laboratory and by the European Community under Contract Number 515873, DIRACsecondary-Beams The HESR will work in a high-resolution mode with 1·10¹⁰ stored antiprotons and a high-luminosity mode with 1·10¹¹ stored antiprotons. It will be equipped with both stochastic cooling and electron cooling systems. The main purpose of the electron-cooling system is to provide relative momentum spread in the antiproton beam of a few 1·10^-5 (90 %) during experiments with an internal hydrogen pellet target and with luminosity 2·10³¹ – 2·10³² cm^-2s^-1. The hydrogen pellet target is expected to produce a stream of frozen hydrogen pellets with diameter 30 μm, which move with 60 m/s and at a rate of 20,000 s^-1. The pellet stream is expected to have a diameter of 2–3 mm. Therefore, in order to avoid excessive fluctuations in the count rate, the antiproton beam size at the target must not be too small. This is solved by slightly tilting the electron beam with respect to the antiproton beam, thus making use of a so-called Hopf bifurcation. In order to get a high duty factor on another time scale, while not sacrificing momentum acceptance, a barrier-bucket rf. system will be employed. The electron-cooling system will initially be built for an antiproton energy range from 800 MeV to 9 GeV, but will be built so that its energy can be extended to the full energy of the HESR (14 GeV) at a later stage. The paper discusses the choice of parameters for the electron cooling system and presents simulations.
	Slides

TUM2I05	MICE: The International Muon Ionization Cooling Experiment	electron, coupling, emittance, factory	73
	A. P. Blondel, J. S. Graulich DPNC, Genève
	An international experiment to demonstrate muon ionization cooling is scheduled for beam at Rutherford Appleton Laboratory (RAL) in 2008. The experiment comprises one cell of the neutrino factory cooling channel, along with upstream and downstream detectors to identify individual muons and measure their initial and final 6D emittance to a precision of 0.1%. Magnetic design of the beam line and cooling channel are complete and portions are under construction. The experiment will be described, including cooling channel hardware designs, fabrication status, and running plans. Phase 1 of the experiment will prepare the beam line and provide detector systems, including time-of-flight, Cherenkov, scintillating-fiber trackers and their spectrometer solenoids, and an electromagnetic calorimeter. The Phase 2 system will add the cooling channel components, including liquid-hydrogen absorbers embedded in superconducting Focus Coil solenoids, 201-MHz normalconducting RF cavities, and their surrounding Coupling Coil solenoids. The MICE Collaboration goal is to complete the experiment by 2010.
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THAP02	Implementation of Synchrotron Motion in Barrier Buckets in the BETACOOL Program	ion, synchrotron, simulation, electron	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.

THAP20	Internal Target Effects in the ESR Storage Ring with Cooling	simulation, electron, storage-ring, ion	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.

FRM1C03	Electron Cooling with Photocathode Electron Beams Applied to Slow Ions at TSR and CSR	electron, ion, 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)
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