Study of the thermal initiation of ammonium dinitramide (ADN) crystals and prills

Abstract The thermal initiation by electron beam heating (and calibrated hot stage), of single crystals and prills of ADN, has been filmed / recorded in an Environmental Scanning Electron Microscope, from the formation of microscopic “reaction sites” (0.01 μm in diameter) to full crystal consumption. The transformations of the ADN prills and crystals were compared and recorded in real time at various magnifications (x10,000-100) and under different atmospheres (pure nitrogen and nitrogen/water vapour mixtures). The initiation characteristics of the prills and crystals were found to differ and are related to the microstructural characteristics produced by different prill manufacturing techniques namely, the “prilling tower” technique (Thiokol) and the “melt-stir” technique (CSD).