Ablation and Plasma Formation During Directed Energy Testing

Abstract

Continuous radio-wave telemetry is required during planned tests of directed-energy weapons systems in order to characterize in situ the effects of laser irradiation on different target materials. Unfortunately, the incident radiation can cause disruption of the radio signal during the directed-energy testing. Several phenomena associated with directed-energy impact can lead to communication path losses, such as ablation, charged particle emission, charring, and chemical changes in the target materials. Directed-energy impact on the target material leads to target heating and consequent ablation. A numerical model has been developed to describe the laser induced ablation of metal surfaces. The model describes the absorption of the laser energy by the metal and the resulting temperature rise in the surface. This temperature rise then induces ablation of the target material. Results for an aluminum target irradiated with a KrF laser were obtained. Temperature profiles in the target material and surface temperature changes are presented along with the ablation rate as a function of time as the aluminum target is irradiated. This report presents results for cases when laser energy absorption by the plasma plume created above the surface is not significant.

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Document Details

Document Type
Technical Report
Publication Date
Dec 31, 2008
Accession Number
ADA498298

Entities

People

  • Iain D. Boyd

Organizations

  • University of Michigan

Tags

Communities of Interest

  • Energy and Power Technologies

DTIC Thesaurus Topics

  • Ablation
  • Absorption
  • Absorption Coefficients
  • Aluminum
  • Chemical Reactions
  • Directed Energy Weapons
  • Equations
  • Evaporation
  • Heat Energy
  • Krypton Fluoride Lasers
  • Laser Beams
  • Lasers
  • Materials
  • Metals
  • Radiation
  • Surface Temperature
  • Temperature Gradients

Fields of Study

  • Physics

Readers

  • Optical Physics and Photonics.
  • Space/Atmospheric Physics.
  • Thermal Physics or Thermal Science.

Technology Areas

  • Directed Energy