Abstract: | The initiation threshold sensitivity of HNS versus explosive grain size has been measured, using an electric gun, with two flyer thicknesses. The initiation threshold, (kinetic energy of flyer plate), versus explosive grain size shows that the threshold curve increases dramatically at grain size over 5.4 m̈m (for flyer thickness 76.2 m̈m at explosive density 1.6 g/cm3). Minimum critical energies were calculated to be 12.15 ± 0.5 J/cm2 and less than 7.0 J/cm2, for flyer thicknesses 76.2 m̈m and 20.0 m̈m, respectively. |