Search for resonant electron-transfer-double excitation in Kr34+ + H2 collisions

Abstract Resonant electron-transfer-double excitation (RT2E) is a three-electron correlation mechanism which is expected to occur in an ion-atom collision when electron transfer is accompanied by simultaneous excitation of two electrons to form an intermediate excited state. In the present work, RT2E was investigated for Kr 34+ + H 2 collisions by detecting coincidences between single-electron capture events and X-ray emission. As for the earlier work for this same collision system, no coincidences associated with Kr K X-rays were observed to a sensitivity of about 10 −25 cm 2 . However, events did occur at about twice the Kr K X-ray energy. The change in the X-ray energy of these latter events with beam energy indicates that radiative electron capture (REC) is the mechanism responsible, and the observed cross sections are in good agreement with theoretical calculations.