Ignition and growth modeling of short pulse shock initiation experiments on fine particle Hexanitrostilbene (HNS)

Hexanitrostilbene (HNS) is a booster explosive that is usually initiated using short pulse duration shock waves produced by high velocity impacts with thin flyer plates. HNS is generally used at a density of 1.60 g/cm(3), which implies a porosity of 8%. It has been produced in several forms (I -IV, ultrafine, etc.) with various particle surface areas. The threshold flyer velocities for shock induced detonation versus failure to detonate for these different surface area materials vary slightly, but, in this paper, an average Ignition and Growth reactive flow model parameter set was determined using all of the experimental data from several aluminium and Kapton (TM) flyer plate studies. This data ranged from shock pressures of 4 GPa to above the Chapman-Jouguet (C-J) detonation pressure (similar to 20 GPa) and from 1 to 120 nanoseconds in time duration. Good agreement was obtained for the available short pulse duration detonation verses failure to threshold flyer velocity data using the Ignition and Growth model,