Test results of HIRFL-CSR main ring electron cooling device

Electron cooling device for HIRFL-CSR main ring has been completed under the cooperation between BINP and IMP. It has three distinctive characters. Variable profile electron beam can be produced by the electron gun, the size and density distribution of electron beam can be changed. The parallelism of the magnetic field in the cooling section achieves less than 1 x 10-5, in this case, the r.m.s angle deviations of the magnetic field line in horizontal and vertical direction are 7.838 x 10-6 and 8.044 x 10-6 respectively. The electron beam loss is reduced, the vacuum condition is improved, and the instability of the electron beam is suppressed because of using of electrostatic bending plate in the toroid. The beam profile and density distribution were measured in the test bench. The characters of the gun and collector were investigated. The main test results are presented in this paper