K-shell excitation by K- to L-shell charge transfer in slow Kr^q+-Kr and Xe^q+-Xe collisions

Systematic study of impact parameter dependent K-vacancy probabilities in near symmetric gas- and solid-target collision systems

“…This could already be an indication for an overestimation of the 2p~-vacancy factor calculated by relation (1). Such a deviation was also found in [9] and [10] and will be discussed in the next part of this paper with a heavier collision system where the PK(b) obtained from K x-ray emission cannot be so strongly affected by the fluorescence yield correction as it is here. In a light collision system the fluorescence yield can have a strong dependence on the projectile charge state, because it is a large correction in PK and a.…”

“…A deviation of the same kind has been observed by other authors: e.g. Warczak et al [14] for Cu on Kr, Schmidt-B/Scking et al [9] for Ar on Ar, Schuch et al [10] for Kr on Kr and Xe on Xe.…”

“…The K-vacancy probability measured with gas target collision systems was found to be [5][6][7][8][9][10], in the region of the adiabatic peak, in good agreement with the shape of Prot(b). Exception to this being the results of Hagmann et al [11] who found strong deviations from Prot(b) for Cu+ Kr which are still not understood.…”

“…6 as a full line and does not agree with PK(b) at large b as noted above for Si-A1 and in some other collision systems before [19][20][21][22]. PK(b) measurements with gas targets in this Z-regime have been performed for 30MeV C1-Ar [7], 32MeV S -Ar [9], and 20 MeV Ar-Ar [10] and are in good agreement with the prediction of 2p~zx-2pc~ rotational coupling in the adiabatic peak region, therefore discarding the possibility that the disagreement found here might be somehow Z related. These results suggest, in contrast to the assumption made above, a strong influence of the L-vacancy production multiple collision process in solid targets on the shape of PK(b) at large b.…”

“…Contaminations of O 2 and N 2 in the Titarget are expected to be negligible as the Ti-targets were brought from the evaporation chamber to the target chamber without letting them to air. It can be seen again that although the absolute targets with low projectile charge states (see above and [8][9][10]) and could be also mainly due to direct 2p cr excitation. With increasing target thicknesses the probability for collisions where the projectile gets Lvacancies before a close collision with K-vacancy production increases considerably as one would suggest from the increasing P/~.…”