Molecular orbital x-ray emission from primary exciting collisions

Abstract

The theory of molecular-orbital x-ray emission occurring during the primary vacancy-producing collision (the "one-collision spectrum") is developed. Calculations are presented for an illustrative excitation process (direct impact ionization in a symmetric collision system). It is shown that because of coherence of the excitation and radiative processes the resulting emission profile is very different from that expected if the events were incoherent (quasistatic model). In particular, the profile undergoes a strong red shift relative to the incoherent component and is relatively velocity independent in shape.