Laser Instrumentation to Measure Energy Release Dynamics and Reaction Zone Structures From Shocked Energetic Materials

Abstract

This project seeks to understand the dynamics of detonations in energetic materials (EM) at a deep and fundamental level using advanced tabletop experimental methods. The proposal requests funding for a custom-build laser amplifier to boost the energy of our laser used to launch mini flyer plates from 2.5J to 8J. The higher energy flyer plates are needed to drive shocks with the needed power and duration into tiny charges of EM. The tiny EM charges are fabricated in an array with typically 100-200 identical targets loaded with plastic-bonded or nanoenergetics. The amplifier will increase the laser energy to the level needed to launch flyer plates that will produce states very close to actual detonations. They will not be true detonations since the charges are too small to support self-sustaining waves, but the molecules in the reaction zone behind the shock front will be in the same state as in a detonation. Experiments will also use shocks below and above the detonation velocity. The tabletop detonations will be probed using femtosecond infrared absorption to monitor chemical composition, optical pyrometry to monitor heat release and photon Doppler velocimeter (PDV) to monitor the work done and the time evolution of the shock profile. Composition, work and heat measurements will be made simultaneously. Variable-thickness flyer plates that generate shock durations ranging from 2 ns to 50 ns will be used to map out the structure of the reaction zone to reveal how chemical, thermal and mechanical processes vary in time and space behind the detonation front.

Document Details

Document Type
DoD Grant Award
Publication Date
Feb 14, 2019
Source ID
W911NF1810185

Entities

People

  • Dana D. Dlott

Organizations

  • Army Contracting Command
  • United States Army
  • University of Illinois Urbana–Champaign

Tags

Fields of Study

  • Physics

Readers

  • Combustion Dynamics and Shock Wave Physics.
  • Optical Physics and Photonics.
  • Rocket Propulsion.

Technology Areas

  • Directed Energy
  • Space
  • Space - Hall-Effect Thruster