X-ray emission from inner shell (2p) excited sputtered Al-atoms/ions resulting from Ar + and Ne + impact on solid Al

Abstract

The X-ray emission of innershell (2p) excited sputtered AI atoms/ions in the photon energy region ≈ 60–80 eV is extracted from measurements of the soft X-ray emission spectra of solid Al under 40 keV Ar + and Ne + impact, using a procedure which includes extrapolation towards vanishing atomic line radiation. Thus the basis of the extraction procedure is not the subtraction of the Al L 23 band, as it is given by proton or electron impact on solid Al. The shape of the Al L 23 emission band turning out from this procedure is distinctly different from the H + induced band, presumably due to high temperatures in the region of the collision cascades produced by Ar + impact. The ratio of X-ray emission from innershell (2p) excited sputtered Al atoms to emission from solid Al changes drastically from ≈ 0.1 at nearly normal ion incidence on the Al surface to ≈ 4 at nearly grazing incidence. The 6 observed atomic lines show a strong dependence on the incidence angle of impinging Ar + ions which differs distinctly from the usual behavior of sputtered particles.