POSSIBLE DEVELOPMENTS OF HIGH-POWER TARGETS FOR RADIOACTIVE BEAMS

The development of the RIST, tantalum foil target for the production o f radioactive nuclei by bombardment with energetic (similar to 1 GeV) proton beams of high intensity (100 mu A) has shown that targets capab le of dissipating 20-60 kW of thermal power can be constructed. Tantal um is a good material for high power dissipation because, as a metal, it has a relatively good thermal conduction and is able to stand very high temperatures. However, for a full range of unstable beams, it wil l be necessary to have targets made from many different materials. Dev elopments of high power target and ion source designs are discussed wi th particular emphasis on non-metallic, non-refractory powder and liqu id target materials. Also, the possibilities of combining targets and ion sources to reduce effusion times are considered, as well as method s to increase the surface-desorption rates of the radioactive particle s. (C) 1998 American Institute of Physics.