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Multiphoton ionization and ion-pair formation in molecular hydrogen

Conference ·
DOI:https://doi.org/10.2172/10169172· OSTI ID:7183036

We have investigated both photoionization and ion-pair formation in molecular hydrogen by using double-resonance excitation via the E,F ¹Σg⁺, v=6 level. The energetic threshold for ion-pair formation occurs just below the H₂⁺ X ²Σg⁺, v⁺=9 ionization. threshold. The spectrum in this region was studied by using both conventional and constant-ionic-state photoelectron spectroscopy, as well as by monitoring the H⁻ production. The decay dynamics in this region are extremely rich, because excited levels may decay by rotational and vibrational autoionization, by predissociation to neutral H + H* (n=2,3,4), by predissociation to the ion pair H⁺ + H⁻, and by fluorescence. In addition, the dissociative potential curve of the 2pσu3sσg ¹Σu⁺ doubly excited electronic state crosses the H₂⁺ X ²Σu⁺ potential curve in the same energy region, and the electronic autoionization of this state is found to significantly influence these decay processes.

Research Organization:
Argonne National Lab., IL (United States)
Sponsoring Organization:
USDOE, Office of Health and Environmental Research
DOE Contract Number:
W-31109-ENG-38
OSTI ID:
7183036
Report Number(s):
ANL/CP--76280; CONF-920735--2; ON: DE92019026
Country of Publication:
United States
Language:
English