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Optical Diagnostics for Characterizing Explosive Performance
Published in Mark J. Mezger, Kay J. Tindle, Michelle Pantoya, Lori J. Groven, Dilhan M. Kalyon, Energetic Materials, 2017
Several other optical diagnostic techniques have become viable for explosive testing due to the development of high-speed data acquisition systems. These techniques make pointwise measurements from laser or direct illumination sources captured on photodetectors connected to oscilloscopes operating at gigahertz rates. Spectroscopic diagnostics rely on the ability to measure light output changes at near detonation-rate timescales to quantify product gas species and ultimately explosive fireball temperatures. Surface measurement interferometry techniques like Photon Doppler Velocimetry (PDV) require tens of gigahertz sampling frequencies to resolve variations in light wavelength changes due to accelerations of surfaces from which the measurement is made.
An Introduction to Materials
Published in Paul J. Hazell, Armour, 2023
Using gauges is one of several diagnostic techniques that can be used. However more commonly it is non-invasive laser-based techniques that are preferred as these directly record the free-surface velocities of the target material during shock. This allows for the direct measure of the particle velocity in the material, which is an important parameter for establishing the shock conditions in the target. Examples of systems that employ this approach are Velocity Interferometer System for Any Reflector (VISAR) developed by Barker and Hollenbach (1972), and Photon Doppler Velocimetry (PDV), see (Strand et al., 2006).
A New Era of Nuclear Criticality Experiments: The First 10 Years of Godiva IV Operations at NCERC
Published in Nuclear Science and Engineering, 2021
Joetta Goda, Caiser Bravo, Theresa Cutler, Travis Grove, David Hayes, Jesson Hutchinson, George McKenzie, Alexander McSpaden, William Myers, Rene Sanchez, Jessie Walker
The other was a Photon Doppler Velocimetry (PDV) system that used the reflection of laser light on the surface of the Godiva IV core. A visible laser signal was used to target the probes at the fuel rings as shown in Fig. 22. The Class IV laser used for the actual measurements did not operate at a visible wavelength and was not turned on when personnel were present.