Contribution of intrashell excitation to the 1 mixing of excited states of one-electron ions in solids

Abstract

Target thickness dependence measurements of Lyman X-ray emission cross sections in collisions of 33 MeV u-1 Kr36+ ions with C, Al and Cu targets have been performed. The results have been compared with the predictions of a rate-equation model including the nl-nl' process. The needed intrashell excitation cross sections have been calculated for 2<or=n<or=10 in the PWBA with screening and antiscreening effects accounted for. Using these cross sections, poor agreement with experiment is obtained. On the other hand, a set of fitted l-changing cross sections can be found to reproduce the data. These last cross sections are a factor 3-50 larger than the calculated ones. The authors believe this discrepancy to be an indication of a specific effect of free (or quasi-free) electrons in solid targets.