Cold collisions in an atomic beam

Journal Article · Thu Mar 01 04:00:00 EST 1990 · Physical Review, A (General Physics); (USA)

DOI:https://doi.org/10.1103/PhysRevA.41.2873· OSTI ID:7134806

Thorsheim, H R; Wang, Y; Weiner, J ^[1]

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1. Department of Chemistry Department of Biochemistry, University of Maryland, College Park, Maryland 20742 (USA)

We report a measurement of the rate constant for associative ionization (AI) between excited Na(3{ital p}) atoms colliding within a single beam at a velocity of 11.9 msec{sup {minus}1}, corresponding to a temperature of 65 mK. The collisions take place in a narrow velocity class of excited atoms produced by crossing the collimated Na beam with a monomode dye laser at an angle of 45{degree}. Light polarized linearly in the collision plane yields an AI rate constant greater than that for circular polarization by a factor of 2. We find {ital K}{sub 65mK}{sup lin} =(12.2{plus minus}4.3){times}10{sup {minus}13} cm{sup 3} sec{sup {minus}1} and {ital K}{sub 65mK}{sup cir} =(6.1{plus minus}1.8){times}10{sup {minus}13} cm{sup 3} sec{sup {minus}1}. The experimental arrangement also permits absolute calibration of earlier crossed-beam measurements of the excitation function (cross section versus velocity) at conventional thermal beam kinetic energies. Present results together with earlier work show that the cross-sectional temperature dependence is in qualitative accord with theory.

• OSTI ID: 7134806
• Journal Information: Physical Review, A (General Physics); (USA), Journal Name: Physical Review, A (General Physics); (USA) Vol. 41:5; ISSN PLRAA; ISSN 0556-2791
• Country of Publication: United States
• Language: English

Related Subjects

640304* -- Atomic
Molecular & Chemical Physics-- Collision Phenomena
74 ATOMIC AND MOLECULAR PHYSICS
ALKALI METALS
ATOM COLLISIONS
ATOM-ATOM COLLISIONS
BEAMS
CHARGED PARTICLES
CHEMICAL REACTIONS
COLLIDING BEAMS
COLLISIONS
DIMERIZATION
ELEMENTS
ENERGY RANGE
ENERGY-LEVEL TRANSITIONS
EV RANGE
EXCITATION
IONIZATION
IONS
KINETICS
LASERS
METALS
MILLI EV RANGE
MOLECULAR IONS
POLYMERIZATION
SODIUM