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Published on: July 5, 2016
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In operando measurements of high explosives
Dhanalakshmi Sellan1, Xuan Zhou1, Lawrence Salvati1
1School of Chemical Sciences, University of Illinois at Urbana-Champaign, 600 S. Mathews Ave., Urbana, Illinois 61801, USA.
The Journal of Chemical Physics
|December 22, 2022
Summary
Researchers developed a tabletop shock compression microscope to safely study high explosives and dynamic extreme conditions. This high-throughput method allows detailed analysis of detonation buildup in materials like nitromethane and plastic-bonded explosives.
Area of Science:
- Materials Science
- Chemical Physics
- Shock Wave Phenomena
Background:
- Studying high explosives under dynamic extreme conditions is crucial for understanding detonation.
- Existing methods often lack the resolution or safety for detailed in operando analysis.
Purpose of the Study:
- To present a novel, safe, tabletop method for producing and studying detonations and extreme conditions.
- To enable high-throughput, high-resolution analysis of detonation initiation and propagation.
Main Methods:
- Utilized a shock compression microscope with a pulsed laser to launch hypervelocity flyers.
- Integrated velocimetry, optical pyrometry, and nanosecond imaging for high-fidelity measurements.
- Investigated detonation buildup in liquid nitromethane and plastic-bonded explosives (PBX) based on HMX.
Main Results:
- Demonstrated safe, high-throughput detonation studies on a tabletop scale.
- Achieved high spatial (2 µm) and temporal (2 ns) resolution measurements of pressure, density, and temperature.
- Observed detonation buildup mechanisms, including hotspot formation and deflagration growth in PBX.
Conclusions:
- The shock compression microscope provides a powerful tool for fundamental detonation science.
- Enabled study of detonation in minimal sample volumes and detailed analysis of microstructural ignition in PBX.
- Paved the way for identifying critical hot spots responsible for PBX ignition.
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