TARGET SELECTION FOR THE HRIBF PROJECT

Experiments are in progress at the Oak Ridge National Laboratory (ORNL ) which are designed to select the most appropriate target materials f or generating particular radioactive ion beams for the Holifield Radio active Ion Beam Facility (HRIBF). The 25-MV tandem accelerator is used to implant stable complements of interesting radioactive elements int o refractory targets mounted in a high-temperature FEBIAD ion source w hich is on-line at the UNISOR facility. These experiments permit selec tion of the target material most appropriate for the rapid release of the element of interest, as well as realistic estimates of the efficie ncy of the FEBIAD source. From diffusion release data information on t he release times and diffusion coefficients can be derived. Diffusion coefficients for Cl implanted into and diffused from CeS and Zr5Si3 an d As, Br, and Se implanted into and diffused from Zr5Ge3 have been der ived from the resulting intensity versus time profiles.