Commission of HIRFL-CSRe Electron Cooling Device

Key words: 
• hollow electron beam /
• magnetic parallelism /
• high voltage generator

Abstract: ： In CSRe electron cooling device， a special electron gun which can produce variable profile electron beam with different size and density distribution was adopted for decreasing ion losses. Electrostatic bending device was used for reducing electron beam losses and improving vacuum condition. The instability of the electron beam is suppressed because the secondary electrons from collector would come back to the collector in the same orbit finally. Longitudinal magnetic field with parallelism better than 10^-4 was achieved by adopting of independent high precise solenoid coils at cooling section. In this case， the r.m.s deviations of the transverse magnetic field at cooling section in horizontal and vertical direction are 3.298×10^-5 and 2.458×10^-5 respectively. The characters of the gun and collector were investigated. The results were presented and indicate that it achieves the design purpose very well.