STUDY OF SPACE CHARGE COMPENSATION IN LEBT

A 20 MeV, 30 mA CW proton accelerator is being built in BARC which consists of 50 keV ECR ion-source, LEBT, 3 MeV RFQ, MEBT and 20 MeV DTL. In designing low energy beam transport (LEBT) line, which matches the beam from ion-source to RFQ, the expansion of the proton beam is a severe problem. As the energy of the beam is 50 keV, Coulomb repulsion is enormous and for minimization of this repulsion, space charge compensation is done. To simulate the beam dynamics part, a PIC code is written, which allows beam of different distributions like KV, Parabolic and Waterbag. This is an electrostatic code, which can also take care of external magnetic fields. A Monte Carlo collision scheme is being implemented for the ionization of the background gas. In this paper, we are presenting the simulation of space charge compensation of the 30 mA proton beam at 50 keV.