Scaling relations in the rotational excitation of NH(X /sup 3/summation/sup -/) N = 0 by argon

Journal Article · Thu Jun 01 04:00:00 EDT 1989 · J. Chem. Phys.; (United States)

OSTI ID:6168056

Dagdigian, P J

Integral cross sections for rotational transitions out of the lowest rotational level of NH(/sup 3/summation/sup -/)v = 0, namely N = 0, J = 1 F/sub 1/, induced by collisions with argon have been measured in a crossed beam experiment. A pulsed beam of rotationally cold NH(/sup 3/summation/sup -/) was produced by 193 nm photolysis of a dilute mixture of ammonia in nitrogen seed gas at the tip of a nozzle, the argon beam was also prepared in a pulsed source. The final rotational and spin--state populations were interrogated in the collision zone by laser fluorescence excitation in the A /sup 3/Pileft-arrowX /sup 3/summation/sup -/(1,0) band of NH. Within a given N' manifold, the F/sub 1/ spin level had the largest values for the cross sections out of N = 0. The spin--state distributions are, in fact, well described by the general formulas for inelastic collisions of a case (b) /sup 3/summation molecule. The derived spin--free tensor opacities show a rapid decrease as a function of increasing N'.

• Research Organization: Department of Chemistry, The Johns Hopkins University, Baltimore, Maryland 21218
• OSTI ID: 6168056
• Journal Information: J. Chem. Phys.; (United States), Journal Name: J. Chem. Phys.; (United States) Vol. 90:11; ISSN JCPSA
• Country of Publication: United States
• Language: English

Related Subjects

640304* -- Atomic
Molecular & Chemical Physics-- Collision Phenomena
74 ATOMIC AND MOLECULAR PHYSICS
ARGON
ATOM COLLISIONS
ATOM-MOLECULE COLLISIONS
ATOMIC BEAMS
BEAMS
COLLISIONS
CROSS SECTIONS
ELEMENTS
ENERGY LEVELS
ENERGY-LEVEL TRANSITIONS
EXCITATION
EXCITED STATES
FLUIDS
GASES
HYDRIDES
HYDROGEN COMPOUNDS
INTEGRAL CROSS SECTIONS
MOLECULAR BEAMS
MOLECULE COLLISIONS
NITROGEN COMPOUNDS
NITROGEN HYDRIDES
NONMETALS
RADICALS
RARE GASES
ROTATIONAL STATES
SCALING LAWS