Vibrational deactivation of F{sub 2}({nu}=1, j=0) by {sup 3}He at very low energy: A comparative study with the He-N{sub 2} collision

Journal Article · Mon Sep 01 00:00:00 EDT 2003 · Physical Review. A

DOI:https://doi.org/10.1103/PhysRevA.68.032716· OSTI ID:20640190

Stoecklin, T; Voronin, A; Rayez, J C ^[1]

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1. Laboratoire de Physico-Chimie Moleculaire, Universite de Bordeaux 1, 351 Cours de la Liberation, 33405 Talence Cedex, (France)

Following our previous study on He-N{sub 2}, we present close-coupling calculations of the vibrational quenching cross sections and rate constants for the F{sub 2}({nu}=1,j=0) molecule colliding with {sup 3}He atoms. High-level ab initio molecular electronic-structure calculations are carried out for the He-F{sub 2} van der Waals complex at the BCCD(T) level. A potential energy surface is obtained by fitting the ab initio points using the reproducing kernel Hilbert space method. This surface exhibits two minima, the linear minimum being deeper than the T-shaped one. Close-coupling calculations are performed in the collision energy 10{sup -6} to 2000-cm{sup -1} interval. A comparison is made with the previous investigations of the vibrational relaxation of O{sub 2} and N{sub 2} molecules with {sup 3}He atoms at very low energies. We find that these three systems exhibit the same general behavior due to scattering resonances. We also analyze the very low energy limit, using a recent semiclassical approach due to Dashevskaya and Nikitin [Phys. Rev. A 63, 012711 (2000)]. We find that the simple algebraic formulas they proposed provide good estimates of the relative quenching rates at ultra-low temperatures.

• OSTI ID: 20640190
• Journal Information: Physical Review. A, Vol. 68, Issue 3; Other Information: DOI: 10.1103/PhysRevA.68.032716; (c) 2003 The American Physical Society; Country of input: International Atomic Energy Agency (IAEA); ISSN 1050-2947
• Country of Publication: United States
• Language: English

Related Subjects

74 ATOMIC AND MOLECULAR PHYSICS
ATOM-MOLECULE COLLISIONS
ATOMS
COMPARATIVE EVALUATIONS
COUPLING
CROSS SECTIONS
DEACTIVATION
ELECTRONIC STRUCTURE
ENERGY TRANSFER
FLUORINE
HELIUM
HELIUM 3
HILBERT SPACE
MOLECULES
POTENTIAL ENERGY
QUENCHING
RELAXATION
RESONANCE
SCATTERING
SEMICLASSICAL APPROXIMATION
VAN DER WAALS FORCES