ECR AND CESIUM IONIZER SYSTEMS FOR THE TRIANGLE-UNIVERSITIES NUCLEAR-LABORATORY ATOMIC-BEAM POLARIZED ION-SOURCE

A plasma ionizer in which the electrons are heated via electron-cyclot ron resonance is used to produce beams of polarized H+ (or D+) ions fr om spin-polarized H-0 (or D-0) beams. The plasma is confined axially v ia a magnetic mirror field and radially by a sextupole field created b y permanent magnets. Plasma heating is accomplished via 75 to 100 W of rf power fed radially into the region between the mirror coils either from a variable frequency, 2.8 or 4.8 GHz traveling wave tube amplifi er or from a 2.45 GHz magnetron source. The operation of the system is simple, stable, and reproducible. The extracted positive polarized be am can be converted to negative by adding electrons in a cesium vapor charge-exchange canal; the effective conversion efficiency ranges betw een 15 and 20%. The extracted polarized beam has an energy spread < 15 eV.