Production of Multiply Charged Kr Ions by Synchrotron Radiation

Branching ratios of krypton ions were measured around the 2s edge using synchrotron radiation. The present results are compared with existing theoretical and experimental values. Collective effects of electrons in the 2s orbital might have a significant action. It is shown that one-electron photoionization is enhanced just below this inner-shell threshold. This is due to the fact that the transition of an inner shell electron changes the self-consistent field acting upon the outer electrons, allowing one or several of them to be ejected. This effect is very pronounced in krypton around the 2s edge, where a strong maximum in the seven-fold charged-ion yield occurs near the Kr 2s threshold.