EXPANDING FLOW PLASMA SOURCE FOR HIGH BRIGHTNESS NEGATIVE DEUTERON BEAMS

THE TRANSPORT OF AN INTENSE BEAM OF PARTICLES FROM A SOURCE TO A DISTANT TARGET REQUIRES A HIGH QUALITY BEAM WITH A BRIGHTNESS GREATER THAN CURRENTLY AVAILABLE. A HIGH DENSITY NEGATIVE ION BEAM SOURCE FOR PRODUCING HIGH BRIGHTNESS NEUTRAL PARTICLE BEAMS IS BEING INVESTIGATEDTHAT UTILIZES A HIGH DENSITY PLASMA DISCHARGE FOR PRODUCING HIGH BRIGHTNESS NEGATIVE DEUTERON BEAMS. A SIGNIFICANT IMPROVEMENT IN BEAMBRIGHTNESS COULD BE ACHIEVED IF THE IONS WERE TO BE PRODUCED AT A MUCHHIGHER PLASMA DENSITY THAN CURRENTLY BEING INVESTIGATED. A NEGATIVE ION SOURCE IS BEING EXAMINED WHICH SEEKS TO ACHIEVE A HIGH BRIGHTNESS DEUTERIUM ION BEAM BY EXPLOITING THE ADVANTAGES INHERENT IN HIGH DENSITY ION PRODUCTION. A HIGH DENSITY, LOW TEMPERATURE PLASMA IS GENERATED IN A PLASMA SOURCE AND EXPANDS AWAY FROM THE EXIT APERTURE TOWARD THE EXTRACTION PLANE. BRIGHTNESS IS CONSERVED AS THE PLASMA EXPANDS, HENCE THE PERPENDICULAR ION TEMPERATURE DECREASES AS THE PLASMA EXPANDS TOWARD THE EXTRACTION PLANE. THE EXTRACTION PLANE IS LOCATED WHERE THE PLASMA DENSITY HAS DROPPED TO A SUFFICIENTLY LOW VALUE FOR OPTIMUM EXTRACTION CONDITIONS. THIS ION SOURCE CONFIGURATION OFFERS THE UNIQUE CAPABILITY OF OPTIMIZING THE SOURCE PERFORAMNCE FOR HIGH BRIGHTNESS WHILE SATISFYING THE NECESSARY CONDITION AT THE EXTRACTION PLANE. THE NEW ION SOURCE HAS THE POTENTIAL TO INCREASE NEGATIVE ION BEAM BRIGHTNESS BY A FACTOR GREATERTHAN 10.