Rear Surface Light Emission Measurements from Laser-produced Shock Waves in Clear and Al-coated Polystyrene Targets

Abstract

The Nike KrF laser, with its very uniform focal distributions, has been used at intensities near 10(exp.14) W/cm2 to launch shock waves in polystyrene targets. The rear surface visible light emission differed between clear CH targets and targets with a thin (125 nm) Al coating on the rear side. The uncoated CH targets showed a relatively slowly rising emission followed by a sudden fall when the shock emerges, while the Al-coated targets showed a rapid rise in emission when the shock emerges followed by a slower fall -- allowing an unambiguous determination of the time the shock arrived at the rear surface. A half-aluminized target allowed us to observe this difference in a single shot. The brightness temperature of both the aluminized targets and the non-aluminized targets were slightly below but close to rear surface temperature predictions of a hydrodynamic code. A discussion of preheat effects is given.

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Document Details

Document Type
Technical Report
Publication Date
Aug 01, 1999
Accession Number
ADA483119

Entities

People

  • A. N. Mostovych
  • A. V. Deniz
  • Andrew J. Schmitt
  • Edgar A. McLean
  • J. Seely
  • John A. Stamper
  • Stephen P.P. Obenschain
  • T. Lehecka

Organizations

  • United States Naval Research Laboratory

Tags

Communities of Interest

  • Air Platforms

DTIC Thesaurus Topics

  • Aluminum Coatings
  • Cameras
  • Dielectric Polymers
  • Emission
  • Hydrocodes
  • Intensity
  • Krypton Fluoride Lasers
  • Laser Beams
  • Lasers
  • Light Sources
  • Materials
  • Measurement
  • Shock Waves
  • Streak Cameras
  • Surface Temperature
  • Visible Spectra
  • X Rays

Fields of Study

  • Physics

Readers

  • Combustion Dynamics and Shock Wave Physics.
  • Pulsed Power and Plasma Physics.
  • Rocket Propulsion.

Technology Areas

  • Directed Energy
  • Directed Energy - Pulsed-Laser Deposition