L- and M-electron populations of fast xenon ions traveling in gases

Spectra of L x rays emitted by 5.2- to 14.4-MeV/nucleon Xe ions traveling in gaseous targets of He, Ne, and Ar have been measured with a curved crystal spectrometer. Detailed spectral analysis provided estimates of the average projectile charges and the average L- and M-electron populations inside the gases. In comparisons of the present results for gases with those obtained previously for solids, it was found that Xe ions emitting L x rays in solids have, on average, many more L vacancies than those that emit L x rays in gases. Average charges deduced for Xe ions traveling in Ar gas were 2.3 units lower than the average charges of Xe ions traveling in solid KCl.