Optical Studies of Chemical Energy Release During Shock Initiation of Granular Explosives

摘要

Achieving a predictive understanding of shock growth to detonation in granular explosives requires an accurate description of the temporal and spatial behavior or chemical energy release following shock compression. Direct experimental observations of the complex mechanisms involved are very difficult, and global reaction rates are typically inferred from pressure or particle velocity measurements. In the present study, visible emission from an explosive/window interface is examined using instrumentation that provides spectral, temporal, and spatial resolution. This instrumentation includes an image-converter streak camera to record histories of emission intensities dispersed by a 0.25-m specrometer, an image-converter framing camera to record multiple images of a highly magnified area of the explosive surface, and a channel intensifier tube to greatly enhance the sensitivity of either camera. Planar impact experiments were conducted on a compressed-gas gun facility using samples of the explosives hexanitrostilbene and PBX-9404. The streak emission records show a distinct structure within the earliest observable emission. (ERA citation 11:032404)