MEVVA ION-SOURCE FOR THE APPLICATION OF MATERIAL SURFACE MODIFICATION

Several versions of Mevva ion sources have been developed in our insti tute since 1988. It operates in a pulsed mode with a pulse length of 1 .2 ms and a repetition rate of up to 50 pps. A time-averaged beam curr ent of 10 or 50 mA has been extracted at 30-80 kV from Mevva IIA-H and Mevva IIB, respectively. In order to develop surface modification of materials by ion implantation we have constructed three kinds of Mevva ion source implantation systems. High dose (3-5 X 10(17) cm-2) implan tation with Ti, Ce, Y, and Ti+C, etc. has been carried out for improvi ng the lifetime of metal cutting tools, relay contacts, dies, and some sophisticated components.