• Yu.Korotaev, I.Meshkov, A.Sidorin, A.V.Smirnov
  JINR Russia

• J. Dietrich, V. Kamerdjiev, R. Maier, D. Prasuhn, H.J. Stein, H. Stockhorst,
  ForschungszentrumJuelich Germany

• A. Noda, T. Shirai,
  Institute for Chemical Research Kyoto University, Japan

Results of experimental studies of the electron cooling of a proton beam at COSY (Juelich, Germany) are presented. Intensity of the proton beam is limited by two general effects: particle loss directly after the injection and development of instability in a deep cooled ion beam. Results of the instability investigations performed at COSY during last years are presented in this report in comparison with previous results from HIMAC (Chiba, Japan) CELSIUS (Uppsala, Sweden) and LEAR (CERN). An influence of secondary ions stored in cooling electron beam was studied, the results are presented. The methods of the instability suppression, which allow increasing the cooled beam intensity, are described. Electron cooling at COSY was also investigated at extremely low proton current. Experimental results for the attempt to achieve of ordered state of proton beam is presented. This work is supported by RFBR grant # 05-02-16320 and INTAS grant #03-54-5584.

31

• V.F.Bykovsky, A.G.Kobets, Yu.V.Korotaev, V.I.Lohmatov, I.N.Meshkov, R.V.Pivin, A.Yu.Rudakov, I.A.Seleznev, A.O.Sidorin, A.V.Smirnov, G.V.Trubnikov, S.L.Yakovenko
  Joint Institute Nuclear Research, Dubna, Russia

General goal of the LEPTA (Low Energy Particle Toroidal Accumulator) project, which is under development in JINR now, is to create small positron storage ring equipped with an electron cooling system. Storage ring of LEPTA facility was commissioned in September, 2004. Results of testing the storage ring with electron beam are presented. Positron injector for the ring is based on ²²Na radioactive source. Positrons from the source are moderated in the solid neon and stored in electromagnetic trap. First experiments with the solid moderator have been performed. The positron trap is under test now with electron beam. This work is supported by RFBR grant 05-02-16320.

MOBP06

• I.Meshkov, R.Pivin, A.Sidorin, A.V.Smirnov, G.Trubnikov
  Joint Institute Nuclear Research, Dubna, Russia

BETACOOL program developed by JINR electron cooling group is a kit of algorithms based on common format of input and output files. The program is oriented to simulation of the ion beam dynamics in a storage ring in presence of cooling and heating effects. The version presented in this report includes three basic algorithms: simulation of r.m.s. parameters of the ion distribution function evolution in time, simulation of the distribution function evolution using Monte-Carlo method and tracking algorithm based on molecular dynamics technique. General processes to be investigated with the program are intrabeam scattering in the ion beam, electron cooling, interaction with residual gas and internal target.