Production of multiply charged Xeⁱ⁺ ions via photoionization and excitation in the L-edge region

Fractional charge distributions of multiply charge Xeⁱ⁺ ions produced under (4.1-8.0 keV) X-ray impact on Xe atoms have been measured and the corresponding cross sections for their production have been determined after normalizing the known total photoionization cross sections. Both of them show stepwise variations near the L edges, indicating that the inner-shell ionization followed by a series of vacancy cascades play a significant role in the production of these multiply charged ions. In addition, sharp enhancement of the production cross sections for ions with some charge states has been observed over very narrow energy regions just below the L edges, in particular the L₃ edge, and is qualitatively understood to be due to the photoexcitation of an inner-shell electron into the unfilled outer levels.