Formation mechanisms of multi-charged Kr ions through 2p shell photoionization using a coincidence technique

Multiply charged Kr ions have been measured using monochromatized undulator radiation combined with a coincidence technique. Above the L 3 ionization threshold, photoionization has yielded multi-charged ions in a variety of charge states, which range mainly 3+ through 7+. The charge state distribution obtained using a pulse field technique is close to the spectra previously measured with different techniques, and is slightly different from that obtained by calculation. The coincidence measurements between multi-charged ions and energy-selected Auger electrons have disentangled complex decay processes. The Auger final states formed through L 3 M 45 M 45 decays turn significantly into Kr 4+ and those through L 3 M 23 M 45 decays generate Kr 5+ mainly. The Auger decays of L 3 M 23 M 23 types yield Kr 6+ dominantly. These findings are consistent with the consideration of energy levels of Kr ions; higher energy states turn into more highly-charged ions.