M-shell X-ray production induced by H¹⁺ and He²⁺ on Au

Abstract

<p indent="0mm">The X-ray emissions from H¹⁺ and He²⁺ beams impinging on Au surface are measured. The results show that the yields and production cross sections of M_ζ and M_α of target atom Au increased with the kinetic energy of H¹⁺ and He²⁺. The measured production cross sections are higher than the theoretical predictions based on the PWBA approximation, the BEA approximation and ECPSSR theory. The measured production cross sections increased trend with ionic kinetic energy close to the theoretical predictions based on the PWBA. The fluorescence yield is enhanced dramatically owing to multiple vacancies as the projectiles approach target atoms. In the low projectile-energy region (<italic>E</italic> <sc>&lt;1 MeV),</sc> because the projectiles velocities are nearly the M-shell electronic Bohr velocity of the high-Z target atom, and the bound of target atomic nucleus to electron decrease, so multiple ionization effects easily occur. One would have to conclude that these theories clearly fail at low velocities due to the electrons be assumed to be at rest in the early stage of these theories were constituted.</p>

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