Spectrally‐ and Temporally‐Resolved Optical Depth Measurements in High Explosive Post‐Detonation Fireballs.

Temporally‐and‐spectrally‐resolved‐optical‐depth‐measurements were made in fireballs from five common high explosives. Chambered explosive detonations were probed with 405 nm, 532 nm, 650 nm, 1310 nm, and 9600 nm laser light to quantify optical attenuation during the first 5 ms after initiation. Attenuation lengths are reported for each wavelength and high explosive as a function of time. Two charge sizes were studied to show optical depth scaling for charge mass. Trends in optical depth between type of explosive and probe wavelength are presented and discussed. The spectral dependence of attenuation departed strongly from the λ4 prediction from Rayleigh scattering, indicating significant absorption in addition to scattering. Beam steering effects were determined to be of minimal influence for the scale of explosives tested. Blast scaling is considered in attempt to generalize the results presented. [ABSTRACT FROM AUTHOR]