Recoil effects on molecular-orbital X-ray spectra in solid targets

Abstract

Using the work of Lindhard et al. (1963, 1968) on radiation effects of ions penetrating into solids the authors compute recoil effects on molecular-orbital (MO) spectra in solid targets. In symmetric collisions the dominant effect is due to scattered projectile and recoiling target atoms which carry an inner-shell vacancy into subsequent collisions where MO X-rays are emitted. In asymmetric collisions in which the target is the higher Z partner, the dominant effect is due to recoiling target atoms which emit MO X-rays in subsequent multiple-collision processes. The authors apply their expressions to MO X-rays emitted in Ni+Ni and Ne+Al collisions. In the presently available 12-92 MeV Ni+Ni MO spectra recoil effects are too small to be detectable. In 0.3-1.6 MeV Ne+Al MO spectra measured by Knaf and Presser (1974) recoil effects appear at the lower bombarding energies, which agree well with the authors' calculations.