|
ANALYTICAL STUDY OF BEAM EQUILIBRIUM IN HIGH ENERGY STORAGE RINGFOR NON-MAGNETIZED ELECTRON COOLING |
|
|
P. Zenkevichª¹, A. Lehrach² ¹Alikhanov Institute for Theoretical and Experimental Physics, Moscow, Russia ²Forschungszentrum Jülich GmbH, Jülich, Deutsch Abstract In high energy storage rings (for example, in proposed antiproton High Energy Storage Ring (HESR), which is part of the international accelerator complex FAIR), it is intended to use electron cooling for the compensation of beam heating due to beam interaction with the internal pellet target. For beams with high emittance (such emittance is necessary in order to get sufficient beam- target overlap) magnetized electron cooling does not work. Therefore we consider an analytical theory of beam equilibrium in presence of internal target using formulae derived in [1] for non-magnetized model of electron cooling. As a result we find the analytical expressions for momentum spread and the electron current as function of the beam emittance and beam energy. This theory is applied for estimation of HESR parameters. ª – corresponding author |
|
|
ELECTRON BEAM DYNAMICS IN LINAC OF KURCHATOV SOURCE OF SYNCHROTRON RADIATION WITH ENERGY DOUBLING |
|
|
A. Anoshin, E. Fominª, V. Korchuganov, S. Tomin Russian Research Centre Kurchatov Institute, Moscow, Russia Abstract According to new injection scheme projected for the Kurchatov synchrotron radiation source a full energy booster synchrotron is planed to be the injector of the main storage ring SIBERIA-2. An existing linear accelerator will simultaneously serve as 80 MeV injector for storage ring SIBERIA-1 and as injector for the booster synchrotron with the electron energy of 160 MeV. The energy doubling scheme will be realized by magnetic mirror at the end of linac structure and second passage of electrons through accelerator structure of the linac. This paper describes the possibility of electron energy doubling. The results of computer simulation of electron beam dynamics during the double passage linac structure are presented. ª – corresponding author |
|
|
INFLUENCE OF BEAM SPACE CHARGE ON DYNAMICAL APERTURE OF TWAC STORAGE RING |
|
|
V.V. Kapinª, A.Ye. Boshakov, P.R. Zenkevich Alikhanov Institute for Theoretical and Experimental Physics, Moscow, Russia Abstract High intensity ion beams are planned to store in Terra Watt Accumulator (TWAC) at ITEP (Moscow). A size of the phase-space domain where one can safely operate with the beam is related to the dynamic aperture (DA). The DA measured in units of Courant-Snyder invariant is studied numerically with account of the space charge forces (the "frozen core" model) and perturbations of the guiding magnetic field for particles with non-zero momentum deviations. An economical DA-algorithm used for SIS-100 studies with the "Micromap-code" developed at GSI (Darmstadt) has been implemented for MADX-code via its macro-scripts. The results have shown a significant dependence of DA on intensity, especially for particles with a non-zero momentum deviation. ª – corresponding author |
|
|
LHC TRANSVERSE FEEDBACK SYSTEM: FIRST RESULTS OF COMMISSIONING |
|
|
E.V. Gorbachev¹, N.I. Lebedev¹, A.A. Makarov¹, N.V. Pilyar¹, S.V. Rabtsun¹, R.A. Smolkov¹, V.M. Zhabitskyª¹, P. Baudrenghien², W. Hofle², F. Killing², I. Kojevnikov², G. Kotzian², R. Louwerse², E. Montesinos², V. Rossi², M. Schokker², E. Thepenier², D. Valuch² ¹Joint Institute for Nuclear Research, Dubna, Russia ²Organisation Européenne pour la Recherche Nucléaire, Genève, Switzerland Abstract A powerful transverse feedback system ("Damper") has been installed in LHC. It will stabilise the high intensity beam against coupled bunch transverse instabilities in a frequency range from 3 kHz to 20 MHz and at the same time damp injection oscillations originating from steering errors and injection kicker ripple. The LHC Damper can also be used as means of exciting transverse oscillations for the purposes of abort gap cleaning and tune measurement. The LHC Damper includes 4 feedback systems on 2 circulating beams (in other words one feedback system per beam and plane). Every feedback system consists of 4 electrostatic kickers, 4 push-pull wide band power amplifiers, 8 preamplifiers, one digital processing unit and 2 beam position monitors with low-level electronics. The power and low-level subsystem layout is described along with first results from the commissioning of 16 power amplifiers and 16 electrostatic kickers located in the LHC tunnel. The achieved performance is compared with earlier predictions and requirements for injection damping and instability control. Requirements and first measurements of the performance of the power and low-level subsystems are summarized. ª – corresponding author |
|
|
REVIEW OF STUDIES AND APPLICATION OF BENT CRYSTALS FOR BEAM STEERING AT U70 |
|
|
Yu.A. Chesnokovª, A.G. Afonin, V.T. Baranov, G.I. Britvich, V.N. Chepegin, V.I. Kotov, V.A. Maisheev, I.A. Yazynin Institute of High Energy Physics, Protvino, Russia Abstract This report overviews studies accomplished in the U70 proton synchrotron of IHEP-Protvino during the recent two decades. Major attention is paid to a routine application of bent crystals for beam extraction from the machine. It has been confirmed experimentally that efficiency of beam extraction with a crystal deflector of around 85% is well feasible for a proton beam with intensity up to 1012 protons per cycle. Another trend is to use bent crystals for halo collimation in a high energy collider. New promising options emerge for, say, LHC and ILC based on the "volume reflection" effect, which has been discovered recently in machine study runs at U70 of IHEP (50 GeV) and SPS of CERN (400 GeV). Perspectives to use bent crystals for extraction of light ions from the U70 accelerator are also disclosed. ª – corresponding author |
|
|
No paper Slides |
Contribution not received |
|
STATUS OF THE LEPTA PROJECT |
|
|
V. Bykovsky, E. Ahmanova, V.I. Kaplin, V.N. Karpinsky, A. Kobetsª, V. Lokhmatov, V. Malakhov, I. Meshkov, R. Pivin, A. Rudakov, G. Trubnikov, S. Yakovenko Joint Institute for Nuclear Research, Dubna, Russia Abstract The project of the Low Energy Positron Toroidal Accumulator (LEPTA) is under development at JINR. The LEPTA facility is a small positron storage ring equipped with the electron cooling system. The project positron energy is of 4÷10 keV. The main goal of the facility is to generate an intense flux of positronium atoms – the bound state of electron and positron. The focusing system of the LEPTA ring after solenoidal magnetic field remeasurement and correction has been tested with pulsed electron beam by elements. Some resonant effects of beam focusing have been observed. Storage ring of LEPTA facility was commissioned in September 2004. Since then the ring was equipped with additional beam diagnostics. The magnetic field quality in the ring was improved. Results of testing the storage ring with electron beam after the upgrade are presented. The experiments aiming to increase the life time of the circulating electron beam and test the electron cooling elector beam are in progress. ª – corresponding author |
|
|
STIMULATED RADIATION COOLING |
|
|
E.G. Bessonovª, P.M. Feshhenko Lebedev Physical Institute of Russian Academy of Sciences, Moscow, Russia Abstract In this paper the Stimulated radiation cooling (SRC) of ion beams and methods of formation of the broadband laser beams with given spectral distribution are discussed. ª – corresponding author |
|