(2+1 prime ) rotationally resolved resonance enhanced multiphoton ionization via the E sup 2. Sigma. sup + (4 s ,3 d ) and H sup 2. Sigma. sup + (3 d ,4 s ) Rydberg states of NO

Journal Article · Thu Nov 15 04:00:00 EST 1990 · Journal of Chemical Physics; (USA)

DOI:https://doi.org/10.1063/1.459428· OSTI ID:6162539

Rudolph, H; McKoy, V ^[1]

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1. Arthur Amos Noyes Laboratory of Chemical Physics, California Institute of Technology, Pasadena, CA (USA)

The results of studies of ionic rotational branching ratios and photoelectron angular distributions resulting from (2+1{prime}) resonance enhanced multiphoton ionization of NO via various high {ital J} ({approx}21.5) rotational branches of the {ital E}{sup 2}{Sigma}{sup +}(4{ital s},3{ital d}) and {ital H}{sup 2}{Sigma}{sup +}(3{ital d},4{ital s}) Rydberg states are presented. The rotational branching ratios show the expected {Delta}N=even rotational propensity rule with very small {Delta}N=odd signals. The branching ratios for the {ital E}{sup 2}{Sigma}{sup +} state are seen to be independent of photoelectron energy with the {Delta}N=+2 signals strongest and no appreciable higher rotational transfer peaks ({vert bar}{Delta}N{vert bar}{ge}3). The higher rotational transfer signal for ionization of the {ital H}{sup 2}{Sigma}{sup +} state are also negligible but the rotational branching ratios are strongly energy dependent due to a Cooper minimum in the {ital l}=3 partial wave of the {ital k}{sigma}- and {ital k}{pi}-continua at a photoelectron kinetic energy of 2.6 eV and 2.9 eV, respectively. This leads to a strong rotational selectivity that can be exploited to produce ions in a specific rotational level. These consequences of Cooper minima close to threshold are quite general and their influence on rotational distributions should be readily observable in other molecular systems. The photoelectron angular distributions via both states show a strong energy dependence with a rapid change in the angular distributions around the Cooper minimum associated with the {ital H}{sup 2}{Sigma}{sup +} state.

• DOE Contract Number: FG03-87ER60513
• OSTI ID: 6162539
• Journal Information: Journal of Chemical Physics; (USA), Journal Name: Journal of Chemical Physics; (USA) Vol. 93:10; ISSN JCPSA; ISSN 0021-9606
• Country of Publication: United States
• Language: English

Related Subjects

640302* -- Atomic
Molecular & Chemical Physics-- Atomic & Molecular Properties & Theory
74 ATOMIC AND MOLECULAR PHYSICS
ANGULAR DISTRIBUTION
BRANCHING RATIO
CHALCOGENIDES
DISTRIBUTION
ELECTRON SPECTROSCOPY
ENERGY DEPENDENCE
ENERGY LEVELS
EXCITED STATES
IONIZATION
MULTI-PHOTON PROCESSES
NITRIC OXIDE
NITROGEN COMPOUNDS
NITROGEN OXIDES
OXIDES
OXYGEN COMPOUNDS
PHOTOELECTRON SPECTROSCOPY
PHOTOIONIZATION
ROTATIONAL STATES
RYDBERG STATES
SPECTROSCOPY