Radiation-induced shocks in oxygen

Abstract

The formation of pressure waves, induced by the absorption of radiation in the Schumann–Runge continuum of oxygen, was studied experimentally and theoretically. The 10-μs radiation pulse, produced by a capillary discharge at a color temperature of 6 × 104 °K, passed through an LiF window into a test chamber containing oxygen. Surprisingly, the propagation velocity of the pressure waves was found to be independent of the initial filling pressure p0 (v = 364 ± 8 m/s); however, as expected, their point of formation behind the LiF window varied inversely as p0. The evolution of the pressure waves was computed numerically on the basis of a simplified model and the method of characteristics modified to include the radiant-energy input. It appears that the wave is driven for some time after the decay of the radiation pulse by release of frozen dissociation energy.