Rotational Relaxation Studies of Hydrogen Fluoride

Rotational Relaxation Studies of Hydrogen Fluoride
Author: J. J. Hinchen
Publisher:
Total Pages: 28
Release: 1985
Genre:
ISBN:

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Two double laser resonance experiments of collisional hole filling and vibration to rotation transfer have been used to determine rotational relaxation rates for hydrogen fluoride. The rates for rotational levels J2 through J14 range from 55,000,000/sec/torr to 2,000,000 sec/torr and these results are described by kinetic rate models. the rates increase with temperature by about 20 percent 300 K and 1000 K. The effect of several added gases on the rates has been measured. Vibration to rotation transfer proceeds by the accepted vibrational relaxation rate. A significant fraction of V=1 population is transferred with about 35 percent passing through the levels J10 - J14 of V=0. Originator-supplied keywords include: Relaxation rates, V-R transfer, Hydrogen fluoride, Rotational population transfer, and Chemical lasers.

Rotational Relaxation Measurements and Resonant Phenomena in Laser-Excited Hydrogen Fluoride

Rotational Relaxation Measurements and Resonant Phenomena in Laser-Excited Hydrogen Fluoride
Author: G. H. Lindquist
Publisher:
Total Pages: 55
Release: 1974
Genre:
ISBN:

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Rates for the transfer of rotational energy (R-R) in vibrationally excited HF gas were measured using a single laser pump-probe technique. The relaxation time was found to be inversely proportional to HF pressure in the mTorr range and the self-relaxation rate constant was determined. Rotational relaxation of HF gas due to the presence of additive gases was observed. The relaxation rate for H2 was measured. The temporal evolution of HF laser pulses was examined and compared with the vibrational fluorescence of the laser discharge and the temporal gain of the discharge. The importance of hydrogen in the discharge is discussed. Reported observations of several resonant processes include bleaching, self-induced transparency, optical nutations, and an anomalous increase of 40 in the refractive index. (Modified author abstract).

Rotational Energy Transfer in Highly Vibrationally Excited Hydrogen Fluoride and Deuterium Fluoride

Rotational Energy Transfer in Highly Vibrationally Excited Hydrogen Fluoride and Deuterium Fluoride
Author: F. Fleming Crim
Publisher:
Total Pages: 7
Release: 1983
Genre:
ISBN:

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Overtone vibration-laser double resonance measurements have provided new data on vibrational and rotational relaxation in HF(v = 2). These experiments determine the magnitudes of the total vibrational relaxation rate constants for HF(v = 1 and 2) as well as their temperature dependences. Rotational relaxation data come from these measurements as well. The temporal evolution of individual rotational states observed in the double resonance studies provides level-to-level energy transfer rate constants when analyzed using an iterative fitting scheme which incorporates scaling relations among the rate constants.

Vibrational and Rotational Energy Transfer in Highly Vibrationally Excited Hydrogen Fluoride and Deuterium Fluoride

Vibrational and Rotational Energy Transfer in Highly Vibrationally Excited Hydrogen Fluoride and Deuterium Fluoride
Author: F. Fleming Crim
Publisher:
Total Pages: 6
Release: 1982
Genre:
ISBN:

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Combining the techniques of direct excitation of overtone vibrations and time resolved spectroscopic detection permits detailed measurements of the vibrational and rotational relaxation of highly vibrationally excited molecules. Using this technique, we have measured vibrational and rotational relaxation in HF(v = 3,4,5) between 300 K and 650 K and have compared these results to various theoretical calculations. Using laser double resonance to probe individual rotational states, we find phenomenological rotational relaxation rate constants which decrease montonically with rotational energy change in the vibrationally excited molecule, and we have directly measured the vibrational relaxation rate constants for v = 1 and v = 2 as well as made a preliminary estimate of the (surprisingly small) fraction of the relaxation which goes by vibration-to-vibration energy transfer.

AFOSR Chemical & Atmospheric Sciences Program Review

AFOSR Chemical & Atmospheric Sciences Program Review
Author: United States. Air Force. Directorate of Chemical and Atmospheric Sciences
Publisher:
Total Pages: 700
Release:
Genre: Atmospheric chemistry
ISBN:

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