Unexpected product fine-structure distributions in (3+1)-photon ionization of xenon

Journal Article · Mon May 01 04:00:00 EDT 1995 · Physical Review A

DOI:https://doi.org/10.1103/PhysRevA.51.3726· OSTI ID:44647

Bordas, C; Dyer, M J; Fairfield, T; Helm, H ^[1]; Kulander, K C ^[2]

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1. Molecular Physics Laboratory, SRI International, Menlo Park, California 94025 (United States)
2. Joint Institute for Laboratory Astrophysics, University of Colorado at Boulder, Boulder, Colorado 80309 (United States)

Three-photon resonance enhanced four-photon ionization of xenon shows preferential formation of Xe{sup +}({sup 2}{ital P}{sub 1/2}) when intermediate {ital ns}[3/2]{sub 1} Rydberg states are excited in the three-photon step. Here, the {ital nl}[{ital K}]{sub {ital J}} notation refers to {ital j}{sub {ital c}}{ital l} coupling, in which the angular momentum of the ion core, {ital j}{sub {ital c}}, is coupled to the orbital angular momentum of the Rydberg electron {ital l} to give {ital K}, which is then coupled to the Rydberg electron`s spin to give {ital J}. The primes following {ital l} denote states belonging to the {sup 2}{ital P}{sub 1/2} core. Multichannel-quantum-defect theory identifies these intermediates as nearly pure Rydberg states belonging to the Xe{sup +}({sup 2}{ital P}{sub 3/2}) core. An equivalent behavior is found for the 7{ital s}{prime}[1/2]{sub 1} intermediate state which preferentially produces Xe{sup +}({sup 2}{ital P}{sub 3/2}). On the other hand, for {ital nd} and {ital nd}{prime} resonances we observe final-state distributions which closely mirror the core character of the intermediate state. The suppression of the parent core channel for {ital s}-type Rydberg states is shown to be due to a Cooper minimum in the {ital ns}{r_arrow}{var_epsilon}{ital p} transitio n amplitudes. As a consequence, minor components of the resonance state wave functions play a major role in the selection of the final ionization channel, in particular via the much larger amplitudes of {ital nd}{prime}{r_arrow}{var_epsilon}{ital f}{prime} transitions.

• OSTI ID: 44647
• Journal Information: Physical Review A, Journal Name: Physical Review A Journal Issue: 5 Vol. 51; ISSN 1050-2947; ISSN PLRAAN
• Country of Publication: United States
• Language: English

Related Subjects

66 PHYSICS
AUGMENTATION
CONFIGURATION MIXING
FINE STRUCTURE
MULTI-PHOTON PROCESSES
PHOTOIONIZATION
PRECURSOR
RESONANCE
RYDBERG STATES
XENON
XENON IONS
YIELDS