Temperature measurements of expansion products from shock compressed materials using high-speed spectroscopy

Abstract

Results from spectral radiance measurements using optical multi-channel analyzer over the visible and near infrared regime provide estimates of temperature from expansion products resulting from shocked materials. Specifically, we have made spectral radiance measurements over the wavelength regime of 300–1500 nm. Experiments conducted on aluminum, cerium, and Composition-B high explosive span a wide regime of E/E_v, where E is the internal energy increase of the shocked material, and E_v, is the specific energy required to vaporize the material. For the materials investigated, the ratio is ~ 1, 3 and 5 for aluminum, cerium, and Composition-B, respectively. The basic assumption made to deduce these temperatures is that the debris cloud is radiating as a blackbody with emissivity of one and independent of the wavelength. We are also assuming that the probe is monitoring the debris, which is at a single temperature and that there is no spatial temperature gradient. Temperatures at or above the boiling point are confirmed for aluminum and cerium, while the results for Composition-B provide the time-dependent temperature expansion history for shocked Composition-B over the stress regime of 28–130 GPa. These are the first measurements of temperature obtained from the expansion products from materials that have been shocked to very high pressures.

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