Development of a highly reproducible mixed ion beam sputtering method for long-lived carbon stripper foils

Abstract

Heavy ion beam sputtering may be used to prepare carbon stripper foils with long lifetimes, but the breakage rate during foil preparation is very high. Carbon stripper foils have hence been prepared by a heavy ion beam sputtering method with mixed noble gas ions and tested with 3.2 MeV Ne + ions. The mechanical stress and shrinkage under high intensity beam irradiation has been partially overcome by this method, and the lifetime was extended by a factor of about 60 compared with commercially available foils. The average lifetime was 174 mC and the longest lifetime was 252 mC. These foils further showed a low breakage rate during preparation, and were very stable and reproducible.