Mass spectrometric investigation of explosive gas blast

The gas blast of secondary explosives detonating in high vacuum shows mean front velocities of the expanding gas cloud of up to 20 km/s. The measuring methods used, however, allowed neither identification of individual chemical components with the clouds nor measurement of inherent speeds. Therefore, a modified quadrupole mass spectrometer was coupled to a differentially pumped vacuum system, in which the detonation occurs, for dynamic sampling of the gaseous species. Work started with the simple primary explosives lead azide Pb(N3)2, the decomposition products of which are lead and nitrogen. With the main component N2 of the gas blast, a systematic experimental study resulted in time resolved signal curves as the basis for calculating velocity distributions of the molecules.