POLARIZED ELECTRON GUN BEAM TESTS IN mA RANGE

Abstract

The high intensity polarized electron gun at MIT-Bates was designed as an injector for the linac-ring version of ERHIC.. The design implements a separate preparation chamber, load lock, large area cathode, ring-shaped beam and active cathode cooling. Very good vacuum conditions have been achieved in both the gun chamber and the preparation chamber. Reliable cathode transfer between the load lock, the preparation chamber and the gun chamber has been demonstrated. Beam tests have been conducted with a current from 50 nA to 5 mA. The results of these tests are discussed.