An excitonic mechanism of detonation initiation in explosives

A novel mechanism for detonation initiation in solid explosives is proposed . This is based on electronic excitations induced by an impact wave propaga ting through the crystal. We illustrate the model by using the RDX (C3H6N6O 6) crystal as an example. In our model, a key role belongs to lattice defec ts, in particular edge dislocations, which promote dramatic changes in the electronic structure, primarily a reduction of the optical gap due to the s plitting off of local electronic states from both valence and conduction ba nds. The pressure inside the impact wavefront further reduces the band gap, making it close to zero. This promotes highest occupied molecular orbital- lowest unoccupied molecular orbital HOMO-LUMO transitions resulting in N-NO 2 bond breaking and the creation of favorable conditions for the initiation of a chain reaction. Experimental facts supporting the suggested mechanism are discussed. (C) 2000 American Institute of Physics. [S0021-9606(00)7060 7-6].