Accession Number : AD0757517

Title :   The Interaction of Suspended Atmospheric Particles with Laser Radiation.

Descriptive Note : Technical rept. 1 Jun 71-31 Jul 72,

Corporate Author : SYSTEMS SCIENCE AND SOFTWARE LA JOLLA CALIF

Personal Author(s) : Triplett,J. R. ; Boni,A. A.

Report Date : NOV 1972

Pagination or Media Count : 218

Abstract : SUSPENDED PARTICLES. Initial breakdown in either the vaporized particle or in the shock-heated adjacent gas may result in a laser-supported detonation or in a subsonic ionization wave. The nonlinear, nonequilibrium kinetic equations describing the energy distribution of free electrons, the vibrational excitation of molecules, the dominant electronic excitation, attachment, and ionization reactions and their inverses, electron heating by the laser, and electron diffusion, are solved numerically. The dominant eigenvalue of the Jacobian of these equations is investigated as a criterion for breakdown. Calculations for vaporized silica and air at temperatures from 300K to 6000K under irradiation by a CO2 laser show expected lowering of breakdown threshold for preheated material. Heating of particle vapor and subsequent formation of a shock wave are calculated with a Lagrangian gasdynamic method. Preliminary theoretical predictions for the effects of particles on lowering of the air breakdown threshold are then obtained. (Abstract Modified Abstract)

Descriptors :   (*GAS DISCHARGES, COHERENT RADIATION), (*AEROSOLS, GAS DISCHARGES), (*ATMOSPHERES, LIGHT TRANSMISSION), VAPORIZATION, GAS IONIZATION, ELECTRON DENSITY, EXCITATION, NUMERICAL ANALYSIS, AIR, SILICON DIOXIDE, SHOCK WAVES, ATTENUATION

Subject Categories : Atmospheric Physics
      Physical Chemistry
      Lasers and Masers

Distribution Statement : APPROVED FOR PUBLIC RELEASE