A Study of Transfer Excitation in F8+ + He, Ne and Ar Collisions

High resolution x-ray spectroscopy has been used to measure F K x rays resulting from the decay of doubly excited two electron states formed during F8+ + He, Ne, or Ar collisions. The energy range spanned by the spectrometer includes the 2s2p(3P) ¿ 1s2s(3S), 2s2p(1P) ¿ 1s2s(lS), 2p2(1D) ¿ 1s2p(1P), 2p2(3P) ¿ 1s2p(3P) and the 2p2(1S) ¿ 1s2p(1P) transitions. These states may be formed by nonresonant transfer excitation, in which electron excitation is coupled with electron capture to an excited state, or by resonant transfer excitation, a process related to dielectronic recombination, in which the capture of a loosely bound target electron results in projectile electron excitation. Calculations have been performed to estimate the contribution of each process to the total measured cross section.