Experiments on the start up of the JINR collective accelerator prototype

The experiment results at the JINR collective accelerator prototype under compression and extraction of electron rings are given. During the experiments a ring radius, transverse sizes of cross section, ring position and the number of ring particles were controlled. The experiments on ring capture into closed orbit showed the capture efficiency to be 50-70%. The value of the captures current is 200-300 A (1-1.5x1013 particles). Life time of the formed ring is 5 ms. In the acceleration process the electron ring radius varies from 3.7 to 4.5 cm. The electron ring velocity at the end of the acceleration space is 0.45+-0.05 s. The experiments on the electron ring compression, extraction and acceleration were carried out at 3.5x10-7-3.5x10-6 T residual gas pressure in the electron ring accelerator chamber. The number of ring fast ions (approximately 30 MeV) is 104 particles. The experiments showed that in the presence of close conducting walls the electron ring destruction does not result from overcompensation. Near the compensation the ions leave the ring cross section forming an ion cloud. The stability of the electron ring itself is completely maintained