Measurements of XeF ground state dissociation and vibrational equilibration

Journal Article · Fri Jan 01 04:00:00 EST 1988 · Journal of Chemical Physics

DOI:https://doi.org/10.1063/1.454850· OSTI ID:6909825

Bott, J. F. ^[1]; Heidner, R. F. ^[1]; Holloway, J. S. ^[1]; Koffend, J. B. ^[1]; Kwok, M. A. ^[1]

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1. The Aerospace Corporation, Los Angeles, CA (United States). Aerophysics Laboratory, Laboratory Operations

The removal rates of the lower levels of the XeF(B → X) excimer laser transitions strongly affect the overall efficiency of the E-beam-pumped devices. We have deduced the removal rates of XeF(X,v) in argon, helium, and neon by measuring the populations of vibrational levels v = 0, 1, 3, and 4 formed by the photolysis of XeF₂. The time history of each vibrational population is monitored with a cw tunable dye laser tuned to an absorption feature of the selected vibrational/rotational level. The studies show a rapid vibrational relaxation followed by a common decay rate of the coupled vibrational levels. Helium and neon were found to remove these levels with the same rate coefficient of (2.0 +- 0.2) x 10⁴ (s Torr)^-1 at room temperature. The corresponding rate coefficients for argon were larger by about 25%. The removal rate coefficients increased with temperature in the range of T = 23-95 °C. The rate coefficient for the vibrational excitation of v = 0 by helium was measured to be (3.6 +- 0.7) x 10⁵ (s Torr)^-1 at room temperature. This is considerably larger than the value of (4.8 +- 1.5) x 10⁴ (s Torr)^-1 previously reported by Fulghum et al. Fast vibrational relaxation is required to empty the lower levels of the laser transitions so that vibrational ''bottlenecking'' does not terminate the laser prematurely.

• Research Organization: The Aerospace Corporation, Los Angeles, CA (United States). Aerophysics Laboratory, Laboratory Operations
• OSTI ID: 6909825
• Journal Information: Journal of Chemical Physics, Journal Name: Journal of Chemical Physics Journal Issue: 7 Vol. 89; ISSN JCPSA6; ISSN 0021-9606
• Publisher: American Institute of Physics (AIP)
• Country of Publication: United States
• Language: English

Related Subjects

42 ENGINEERING
420300* -- Engineering-- Lasers-- (-1989)
ELECTRICAL PUMPING
ELECTRON BEAM PUMPING
ENERGY LEVELS
EXCIMER LASERS
EXCITED STATES
FLUORIDES
FLUORINE COMPOUNDS
GAS LASERS
HALIDES
HALOGEN COMPOUNDS
KINETICS
LASERS
PERFORMANCE
PUMPING
RARE GAS COMPOUNDS
RELAXATION
VIBRATIONAL STATES
XENON COMPOUNDS
XENON FLUORIDES