Optimized analysis of deuterium depth profiles in beryllium

Abstract

Various accelerator-based ion beam analysis techniques are reviewed in simulations as well as experimentally with emphasis on their depth resolution and sensitivity for detecting deuterium in beryllium. The depth information contained in the α particles that originate from the nuclear reaction analysis (NRA) with 3He is compared to elastic recoil detection analysis (ERDA) with various projectiles. The best depth resolution for D implanted up to approximately 150 nm below the Be surface is obtained with medium-heavy ion ERDA: for ERDA with 10 MeV 28Si ions a resolution of 47 nm (2σ) is experimentally attained. ERDA with 4He and 28Si as well as NRA are applied to analyse a Be sample implanted with 3×1022 D m−2 at an energy of 3 keV per atom. The resulting depth profile can only be resolved with medium-heavy ion ERDA. The depth profile of the D concentration features a plateau close to the sample surface with a constant D atomic fraction of 0.1. It drops to zero around a depth of 150 nm, corresponding to the calculated ion range.