Surface Specularity as an Indicator of Shock-induced Solid-liquid Phase Transitions in Tin
When highly polished metal surfaces melt upon release after shock loading, they exhibit features that suggest significant surface changes accompany the phase transition. The reflection of light from such surfaces changes from specular (pre-shock) to diffuse upon melting. Typical of this phenomenon is the loss of signal light in velocity interferometer system for any reflector (VISAR) measurements, which usually occurs at pressures high enough to melt the free surface. Unlike many other potential material phase-sensitive diagnostics (e.g., reflectometry, conductivity), that show relatively small (1%-10%) changes, the specularity of reflection provides a more sensitive and definitive (>10x) indication of the solid-liquid phase transition. Data will be presented that support the hypothesis that specularity changes indicate melt in a way that can be measured easily and unambiguously.
- Research Organization:
- National Security Technologies, LLC (NSTec), Mercury, NV (United States)
- Sponsoring Organization:
- USDOE - National Nuclear Security Administration (NNSA)
- DOE Contract Number:
- DE-AC52-06NA25946
- OSTI ID:
- 926661
- Report Number(s):
- DOE/NV/25946-239; TRN: US200815%%335
- Journal Information:
- Shock Compression of Condensed Matter - 2007: Proceedings of the Conference of the American Physical Society Topical Group on Shock Compression of Condensed Matter. AIP Conference Proceedings, Vol. 955; Conference: 15th Topical Conference on Shock Compression of Condensed Matter
- Publisher:
- American Institute of Physics
- Country of Publication:
- United States
- Language:
- English
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