Experimental determination of Na--noble-gas velocity-changing and fine-structure-changing collision kernels

Journal Article · Tue Dec 01 04:00:00 EST 1987 · Phys. Rev. A; (United States)

DOI:https://doi.org/10.1103/PhysRevA.36.5251· OSTI ID:5646940

Haverkort, J E.M.; Woerdman, J P; Berman, P R

We report on an experimental investigation of the collision kernels governing the effects of velocity-changing collisions, fine-structure-changing collisions, and their interplay, for Na--noble-gas pairs. The velocity distributions in the two Na excited-state fine-structure levels and in the Na ground-state hyperfine levels have been measured in the presence of a pump laser which produces velocity-selective excitation. For interpretation of these experiments we use a rate-equation model developed in the context of light-induced drift: the velocity-changing collisions are accounted for by a composite Keilson-Storer kernel describing large-angle and small-angle collisions and the fine-structure-changing collisions are treated in the sudden limit. The model is valid for arbitrarily high pump laser intensities and uses only a single adjustable parameter characterizing the small-angle scattering. It is found that the theory describes the experimental velocity distributions in all four Na levels over a wide range of experimental parameters for each Na--noble-gas pair. The relevance of the collision kernels deduced in the present work is discussed in the context of light-induced drift.

• Research Organization: Molecular Physics Department, Huygens Laboratory, University of Leiden, P.O. Box 9504, 2300 RA Leiden, The Netherlands
• OSTI ID: 5646940
• Journal Information: Phys. Rev. A; (United States), Journal Name: Phys. Rev. A; (United States) Vol. 36:11; 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
ALKALI METALS
ATOM COLLISIONS
ATOM-ATOM COLLISIONS
COLLISIONS
DATA
ELECTROMAGNETIC RADIATION
ELEMENTS
ENERGY-LEVEL TRANSITIONS
EXCITATION
EXPERIMENTAL DATA
FINE STRUCTURE
FLUIDS
GASES
HYPERFINE STRUCTURE
INFORMATION
KERNELS
LASER RADIATION
LINEAR MOMENTUM TRANSFER
METALS
MOMENTUM TRANSFER
NONMETALS
NUMERICAL DATA
OPTICAL PUMPING
PUMPING
RADIATIONS
RARE GASES
SODIUM
VELOCITY