Analytic Solutions for Initiation of Plasma Absorption above Laser-Irradiated Surfaces; Laser Effects Calculations.

Abstract

A program to obtain analytic solutions for the effects of vapor and air absorption, and the subsequent onset of plasma shielding, on the radiation that impinges upon a laser-irradiated surface has been initiated. The problem addressed in this report is the determination of the time scale for ignition of a laser supported absorption wave as a function of laser intensity, material, spot size and wavelength. It is shown that over a range of intensities the vapor properties up to the time for ignition can be calculated by uncoupling the heating from the gas dynamics. The time history of the heating effects is obtained by doing a perturbation upon the flow field. The flow is either one-dimensional planar or two-dimensional axisymmetric depending upon the ratio of an appropriate absorption time scale to a characteristic flow time. (Modified author abstract)

Document Details

Document Type
Technical Report
Publication Date
May 31, 1974
Accession Number
AD0781738

Entities

People

  • Anthony N. Pirri

Organizations

  • Physical Sciences (United States)

Tags

DTIC Thesaurus Topics

  • Absorption
  • Abstracts
  • Axisymmetric
  • Dynamics
  • Flow
  • Flow Fields
  • Gas Dynamics
  • Ignition
  • Intensity
  • Materials
  • Perturbations
  • Radiation
  • Shielding
  • Two Dimensional

Fields of Study

  • Physics

Readers

  • Combustion and Flow Dynamics.
  • Molecular Photonics/Laser Physics
  • Plasma Physics / Magnetohydrodynamics

Technology Areas

  • Directed Energy
  • Directed Energy - Lasers