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) : Holstein,Theodore D.

Report Date : SEP 1968

Pagination or Media Count : 18

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)

Descriptors :   (*ATMOSPHERES, *LIGHT TRANSMISSION), (*LASERS, LIGHT TRANSMISSION), WATER, MOLECULAR ENERGY LEVELS, ROTATION, PRESSURE, MATHEMATICAL MODELS, QUANTUM THEORY, PROBABILITY

Subject Categories : Lasers and Masers
      Optics

Distribution Statement : APPROVED FOR PUBLIC RELEASE