Mechanisms and dynamics of the NH2+ + H+ and NH+ + H+ + H fragmentation channels upon single-photon double ionization of NH3 Academic Article

Abstract We present state-selective measurements on the N H 2 + + H+ and NH+ + H+ + H dissociation channels following single-photon double ionization at 61.5 eV of neutral NH3, where the two photoelectrons and two cations are measured in coincidence using 3D momentum imaging. Three dication electronic states are identified to contribute to the N H 2 + + H+ dissociation channel, where the excitation in one of the three states undergoes intersystem crossing prior to dissociation, producing a cold N H 2 + fragment. In contrast, the other two states directly dissociate, producing a ro-vibrationally excited N H 2 + fragment with roughly 1 eV of internal energy. The NH+ + H+ + H channel is fed by direct dissociation from three intermediate dication states, one of which is shared with the N H 2 + + H+ channel. We find evidence of autoionization contributing to each of the d

Larsen, K. A., Rescigno, T. N., Streeter, Z. L., Iskandar, W., Heck, S., Gatton, A., ... Weber, T.

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