Bremsstrahlung induced by proton and He3-ion bombardments in the 1-4-MeV/amu energy range

Continuous x rays from a thin aluminum target produced by proton and He3-ion bombardments have been measured with a Si(Li) detector over the impact-energy ranges 1-4 MeV and 3-9 MeV, respectively. The experimental results obtained were compared with theoretical predictions based on the binary-encounter approximation. Agreements are obtained both in the shape of spectra and absolute cross sections without any adjustable parameter over the entire energy range measured, but generally the theoretical calculation predicts smaller cross sections than the experimental results as the photon energy becomes higher and the bombarding energy gets lower. Energy-dependent directional anisotropy of the bremsstrahlung was theoretically estimated and compared with the experimental results measured at directions 45°, 90°, and 135° with respect to the incident beam, showing qualitative agreement.