Theory of Time Dependent Response of RDX Crystal to Shock
Abstract
Molecular dynamics is used to model a flyer plate of variable velocity and fixed mass impacting a RDX crystal. The response of the RDX crystal is computed and is found at the molecular level to have two components: one due to the initial impact, the other the natural response of the crystal. The time-dependent response due to the impact is a function of the velocity of impact whereas the time response of the crystal is a property of the crystal. The impulse is seen to move through the crystal at approximately 5 km/s with a risetime of approximately 10-13s. The result as seen by a given molecule is a disturbance caused by the passing shock of short duration, 1 ns. This disturbance forms a time dependent perturbation on the electronic structure of the molecule. We have investigated this perturbation and find that it is sufficient to cause a reasonable probability (0.01 or so) that an electron is excited by the passage of the shock. With a typical densities of 10^23molecule/cc, a significant number are excited. Some of these electrons will recombine radiatively indicating the probability of light emission in the time preceding detonation. Additionally some of these excited states may decay non-radiatively making it likely that some will produce electromagnetic radiation at lower frequencies. This is consistent with data from Chambers, Lee, et al.
- Publication:
-
APS Shock Compression of Condensed Matter Meeting Abstracts
- Pub Date:
- June 2001
- Bibcode:
- 2001APS..SHK.J1004O