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Title: A geophysical shock and air blast simulator at the National Ignition Facility

The energy partitioning energy coupling experiments at the National Ignition Facility (NIF) have been designed to measure simultaneously the coupling of energy from a laser-driven target into both ground shock and air blast overpressure to nearby media. The source target for the experiment is positioned at a known height above the ground-surface simulant and is heated by four beams from the NIF. The resulting target energy density and specific energy are equal to those of a low-yield nuclear device. The ground-shock stress waves and atmospheric overpressure waveforms that result in our test system are hydrodynamically scaled analogs of full-scale seismic and air blast phenomena. This report summarizes the development of the platform, the simulations, and calculations that underpin the physics measurements that are being made, and finally the data that were measured. Agreement between the data and simulation of the order of a factor of two to three is seen for air blast quantities such as peak overpressure. Historical underground test data for seismic phenomena measured sensor displacements; we measure the stresses generated in our ground-surrogate medium. We find factors-of-a-few agreement between our measured peak stresses and predictions with modern geophysical computer codes.
Authors:
; ; ; ; ; ; ; ; ; ;  [1] ; ;  [2]
  1. Lawrence Livermore National Laboratory, P.O. Box 808, L-481, Livermore, California 94550 (United States)
  2. National Securities Technologies, Vasco Rd., Livermore, California 94551 (United States)
Publication Date:
OSTI Identifier:
22314287
Resource Type:
Journal Article
Resource Relation:
Journal Name: Review of Scientific Instruments; Journal Volume: 85; Journal Issue: 9; Other Information: (c) 2014 AIP Publishing LLC; Country of input: International Atomic Energy Agency (IAEA)
Country of Publication:
United States
Language:
English
Subject:
46 INSTRUMENTATION RELATED TO NUCLEAR SCIENCE AND TECHNOLOGY; 70 PLASMA PHYSICS AND FUSION TECHNOLOGY; AIR; ATMOSPHERIC PRESSURE; COMPUTER CODES; ENERGY DENSITY; EXPERIMENTAL DATA; EXPLOSIONS; LASER TARGETS; SEISMIC S WAVES; SENSORS; SHOCK WAVES; SIMULATORS; STRESSES; US NATIONAL IGNITION FACILITY; WAVE FORMS