Use of thermal barriers in conceptual studies of high-temperature, high-intensity targets for producing radioactive ion beams

Thermal analyses are presented of a cylindrical target concept for the production of radioactive beams by intense, high-energy proton production beams. The basic principle is to extract heat generated internally by the production beam interactions with the target material through appropriate thermal barriers. This approach allows the target material to be operated at an elevated temperature to enhance the release of radioactivities produced by the production beam bombardment, yet remove the heat generated initially. Three classes of targets are considered: high temperature and moderate heat generation; moderate temperature and low heat generation; and low temperature and high heat generation. Various thermal barriers approaches appropriate to the combined temperature and heat removal constraints are included, such as contact thermal resistance, refractory material interfaces, and porous metal interfaces. It is shown that suitable thermal barrier approaches exist to encompass the range of target conditions expected for the production of intense beams of radioactive ions. (C) 1997 American Institute of Physics.