Electronic autoionization and vibrational-state distributions in resonant multiphoton ionization of H/sub 2/

Journal Article · Tue Aug 01 00:00:00 EDT 1989 · Phys. Rev. A; (United States)

DOI:https://doi.org/10.1103/PhysRevA.40.1700· OSTI ID:5939839

Dixit, S N; Lynch, D L; McKoy, B V; Hazi, A U

We investigate the effects of electronic autoionization on the vibrationalbranching ratios in resonant multiphoton ionization of H/sub 2/./ital Ab/ /ital initio/ calculations are performed to obtain the vibrational branchingratios for (3+1) resonant-enhanced multiphoton ionization (REMPI) ofH/sub 2/ via the /ital C/ /sup 1//Pi//sub u/ state. Our calculationsinclude the effects of the dissociative/sup 1//Pi//sub g/(1/sigma//sub u/1/pi//sub u/) autoionizing state andproperly account for the interference between the direct and the indirect(autoionization) channels. We find that the direct and indirect amplitudes arecomparable for excitation via the higher (/ital v//sub /ital i///ge/2) vibrationallevels of the /ital C/ state. Autoionization greatly enhances the branchingratios for /Delta//ital v//ne/0 transitions. These calculations underscore thenecessity for a proper treatment of both the direct and indirect contributionsin understanding the REMPI of molecules via autoionizing states.

• Research Organization: Theoretical Atomic and Molecular Physics Group, Lawrence Livermore National Laboratory, L-446 Livermore, California 94550(US); Los Alamos National Laboratory, Los Alamos, New Mexico 87545; Department of Chemistry, University of Nevada, Reno, Nevada 89557; Noyes Laboratory of Chemical Physics, California Institute of Technology, Pasadena, California 91125; Theoretical Atomic and Molecular Physics Group, Lawrence Livermore National Laboratory, L-446 Livermore, California 94550
• DOE Contract Number: W-7405-ENG-48; FG03-87ER60513
• OSTI ID: 5939839
• Journal Information: Phys. Rev. A; (United States), Journal Name: Phys. Rev. A; (United States) Vol. 40:3; ISSN PLRAA
• Country of Publication: United States
• Language: English

Related Subjects

640302* -- Atomic
Molecular & Chemical Physics-- Atomic & Molecular Properties & Theory
74 ATOMIC AND MOLECULAR PHYSICS
AUTOIONIZATION
BRANCHING RATIO
ELEMENTS
ENERGY LEVELS
EXCITED STATES
HYDROGEN
IONIZATION
MOLECULES
MULTI-PHOTON PROCESSES
NONMETALS
PHOTOIONIZATION
SCHWINGER VARIATIONAL METHOD
VARIATIONAL METHODS
VIBRATIONAL STATES