Energy loss straggling of energetic 3He and 6Li ions into polymer foils

Energy loss straggling of 1.1–4.5 MeV 3He ions and 1.2–4.8 MeV 6Li ions into three widely-used polymer foils (polycarbonate, polyethylene terephthalate and polypropylene) was measured by means of a transmission technique. An improved self-supporting method using a surface barrier detector was used to determine the corresponding energy straggling. The experimental results are in satisfactory agreement with those yielded with Bohr theoretical calculations as well as an empirical formula except at lower energies. The measured data also confirm the validity of Bragg’s rule when applied to lighter ions bombarded into polymer foils.