John Greene, Connor Mohs, Claus Mueller-Gatermann, Argonne National Laboratory, Argonne, IL
Physical Vapor Deposition (PVD) has been routinely employed over the past half century for the production of thin isotopically enriched metal targets at facilities producing accelerated beams for nuclear physics studies. The Center for Accelerator Target Science (CATS) at Argonne National Laboratory (ANL) is tasked with the preparation of such targets for the Low-Energy Nuclear Physics Community in the United States as well as demands world-wide using a variety of techniques. We concentrate our efforts primarily on thermal evaporation of the isotopic metals required using state-of-the-art vacuum deposition systems. Thin films of the desired target material are deposited onto glass substrates with thicknesses ranging from sub-micron to many kilo-angstroms. To obtain free-standing foils, the glass is first treated with a parting agent for release from the substrate. Occasionally these deposits are, by necessity, evaporated onto already mounted thin backings foils which act only as a spectator during the accelerator physics experiments. The separated isotopic target starting materials are obtained from the National Isotope Development Center at Oak Ridge National Laboratory (ORNL) usually as metal powder. In some instances, when the metallic form is not available, certain chemical and metallurgical processes become necessary before deposition. Current work on the production of these targets and some examples will be presented.