Lifetime improvement of nitrided carbon stripper foils by ion-beam sputtering with a binary gas mixture

The lifetimes of our carbon stripper foils (10-25 mug/cm(2)) prepared by reactive nitrogen ion-beam sputtering were distributed in a wide range. Expressed in units of integrated beam current received, lifetimes of 750+/-400 mC/cm(2) were usual for a 3.2MeV Ne+ beam. This wide distribution of lifetimes have been improved by applying a binary gas mixture (N-2 + Ne) for sputtering of carbon. With high reproducibility, lifetimes of 475+/-80 mC/cm(2), approximately 15 times those of the best standard commercially available foils, have been achieved. We have also investigated the influence light-element admixtures had on the lifetimes of carbon stripper foils. (C) 2003 Elsevier B.V. All rights reserved.