Investigating shock initiation thresholds using the James Curve framework

The full description of the safety profile of energetic materials is essential to the work of the fields in which they are used. The James Curve framework can be used to describe the full initiation space for impact induced initiation. This is particularly useful when investigating the effect of accidents on an energetic material. Accidents can result in rapid impacts from fragment attack through to vehicle collisions or slower impact conditions such as drops while handling. James Curves are commonly presented as an energy fluence and specific kinetic energy. They can be recast in terms of the more experimentally useful parameters, impact velocity and flyer thickness, for impact flyer experiments. Previous impact studies have used laser flyer plates, gap tests and electric guns to initiate samples. However, each of these methods suffer from the fact that they don't represent true one-dimensional shock initiation, making them difficult to model. In this work we investigate the use of a small gas gun set up for the long duration shock regime (the critical kinetic energy regime). We will then discuss how using the small gas gun technique combined with James Curve framework can be used to investigate the safety profile of energetic materials.