Accession Number:

AD0678422

Title:

HIGH INTENSITY LASER PROPAGATION IN THE ATMOSPHERE. IV. FAR WING PRESSURE BROADENING.

Descriptive Note:

Supplemental rept.,

Corporate Author:

TRW SYSTEMS REDONDO BEACH CALIF QUANTUM PHYSICS LAB

Personal Author(s):

Report Date:

1968-09-01

Pagination or Media Count:

18.0

Abstract:

The residual absorption in the 10 micrometers window is considered to be due in large measure to the very far wings of the pure-rotational lines of H2O. Experimental data indicate the broadening is mainly self-broadening arising from binary collision between H2O molecules. In order to explain the relatively large absorption observed at 10 micrometers, studies were carried out based upon a model of hindered rotational motion libration in which the ordinary rotational motion is suppressed by the strong dipole-dipole force during close collisions. Present results give a cross section which is one-half the experimental value multiplied by a Boltzmann factor describing the probability of achieving a frequency-matching configuration. It was found that for the particular model studied that this factor is too small. However, our studies indicate a variety of possible modifications which are capable of obtaining agreement with experiment. Author

Subject Categories:

  • Lasers and Masers
  • Optics

Distribution Statement:

APPROVED FOR PUBLIC RELEASE