학술논문
Photoelectron and fragmentation dynamics of the H$^{+}$ + H$^{+}$ dissociative channel in NH$_3$ following direct single-photon double ionization
Document Type
Working Paper
Author
Larsen, Kirk A.; Rescigno, Thomas N.; Severt, Travis; Streeter, Zachary L.; Iskandar, Wael; Heck, Saijoscha; Gatton, Averell; Champenois, Elio G.; Strom, Richard; Jochim, Bethany; Reedy, Dylan; Call, Demitri; Moshammer, Robert; Dörner, Reinhard; Landers, Allen L.; Williams, Joshua B.; McCurdy, C. William; Lucchese, Robert R.; Ben-Itzhak, Itzik; Slaughter, Daniel S.; Weber, Thorsten
Source
Phys. Rev. Research 2, 043056 (2020)
Subject
Language
Abstract
We report measurements on the H$^{+}$ + H$^{+}$ fragmentation channel following direct single-photon double ionization of neutral NH$_{3}$ at 61.5 eV, where the two photoelectrons and two protons are measured in coincidence using 3-D momentum imaging. We identify four dication electronic states that contribute to H$^{+}$ + H$^{+}$ dissociation, based on our multireference configuration-interaction calculations of the dication potential energy surfaces. The extracted branching ratios between these four dication electronic states are presented. Of the four dication electronic states, three dissociate in a concerted process, while the fourth undergoes a sequential fragmentation mechanism. We find evidence that the neutral NH fragment or intermediate NH$^+$ ion is markedly ro-vibrationally excited. We also identify differences in the relative emission angle between the two photoelectrons as a function of their energy sharing for the four different dication states, which bare some similarities to previous observations made on atomic targets.
Comment: 16 pages, 13 figures, 3 tables
Comment: 16 pages, 13 figures, 3 tables