Laser cutting of pressed explosives: Revision 1

摘要

We have used a femtosecond laser beam to make cuts through small pressed pellets of six common explosives. The laser system, which produces 100 fs pulses of 820 nm light at a repitition rate of 1 kHz, was intitially developed for cutting metal. The advantage of using a femtosecond laser for cutting is that the cutting process transfers virtually no heat to the material that is being cut and produces almost no waste. We used LX-16 explosive (96% PETN/4% FPC 461 binder) for out intial experiments because PETN is one of the most sensitve of the secondary explosives. In some of the experiments the beam first cut through the HE pellet and then through a stainless steel substrate and in other experiments the beam first cut through the stainless steel and then through the pellet. We also cut through pellets that were not backed by a substrate. No evidence of reaction was observed in any of the LX-16 pellets. In addition to LX-16 we cut pellets of LX-14 (95.5% HMX/4.5% Estane), LX-15 (95% HNS/5% Kel-F), LX-17 (92.5% TATB/7.5% Kel-F), PBX-9407 (94% RDX/6% Exon 461), and pressed TNT with no evidence of reaction. The HE was easily cut at low power levels with one or two sweeps at 0.5 W average power sufficing to cut most of the pellets. There is obvioulsy much more work to be done before laser machining of explosives becomes a reality, but the results of these intitial experiments indicate that laser machining of explosives may be an attractive option for explosives processing.