High vacuum sputter deposition of nuclear accelerator targets

Isotopically enriched accelerator targets were prepared with high reliability by Xe-beam induced sputter deposition in a cryopumped vacuum chamber. Due to the low residual gas pressure of 5x10-6 Pa in the system a number of self-supporting elemental targets, including problematic cases like B, Si, Cr, Zr, Os and W, could be made. These foils exhibit excellent mechanical stability. Target films in oxide form were generally deposited on thin carbon backings. The stoichiometry of an oxide film can be controlled via the O2 partial pressure during its condensation. (orig.)