A NEW MODIFICATION OF PIG-TYPE H- ION SOURCE FOR THE COMPACT CYCLOTRON.

A directly heated cathode ion source has been developed to produced negative ions for use in the MPC-10 cyclotron. In operation uith hydrogen, the ion beam current is 5.6mA, with energy 15kV and gas flow about lO&/min, at the tl- ion beam current density equal to 92mA/cm2. Using electrocondactive ceramics for cathode and reflector permits to increasing life-time of the ion source. The MO converter is installed in the discharged chamber for increasing tl- ion yield. It’s allows to vary the beam current in a wide range and to decrease a cyclotron gas load. In development of a small-size cyclotron intended for production of ultrashort-lived isotopes, wear problem studies and neutron radiography some specific requirements are imposed on the H- ion source. At high ion beam current the ion source must be very compact, perform at small working gas flow, have a sufficiently long life-time, and not contaminate the accelerating system of the cyclotron. 2. H- ION SOURCE WITH SELF-HEATED CATHODS For a compact cyclotron MPC-10 the internal PIG-type negative ion source was design [Il. Tests this source with self-heated cathodes made of different materials was provide on the control bench and it was shown that a beam of accelerated tl- ions with current I = ImA can be obtained at the following parameters