Copper K-shell x-ray emission induced by the impact of ion beam from an electron cyclotron resonance ion source

The K-α and K-β x-ray emission (at 8.05 keV and 8.9 keV respectively) produced from a copper target by the impact of 25 keV hydrogen (H⁺) and nitrogen (N⁺) ion beams, and 200 keV for argon (Ar⁺⁸) beams from an electron cyclotron resonance ion source (ECRIS), has been studied experimentally. The K-α x-ray line intensity exhibited an increase with increasing ion beam energy with a scaling law I_K-α∝E^γ, where the scaling exponent γ was 4.0, 4.2, and 4.1 for hydrogen, nitrogen, and argon ion beam respectively. The results can be explained by considering the K-shell ionization cross-section for ion impact. The peak to background ratio of x-ray line intensity was observed to increase rapidly with the ion beam energy and highest ratio of 6×10⁵ was observed for hydrogen ions. The study is important for optimizing ECRIS for generating a low cost, long life x-ray source for applications in material science