Cutting and Machining Energetic Materials with a Femtosecond Laser

Abstract

A femtosecond (fs) laser has been used as a tool for solving many problems involving access, machining, disassembly, inspection and avoidance of undesirable hazardous waste streams in systems containing energetic materials. Because of the unique properties of the interaction of ultrashort laser pulses with matter, the femtosecond laser can be used to safely cut these energetic materials in a precise manner without creating an unacceptable waste stream. Many types of secondary high explosives (HE) and propellants have been cut with the laser for a variety of applications ranging from disassembly of aging conventional weapons (demilitarization), inspection of energetic components of aging systems to creating unique shapes of HE for purposes of initiation and detonation physics studies. Hundreds of samples of energetic materials have been cut with the fs laser without ignition and, in most cases, without changing the surface morphology of the cut surfaces. The laser has also been useful in cutting nonenergetic components in close proximity to energetic materials.

Laser‐induced Deflagration for the Characterization of Energetic Materials

“…When focused on the surface of a solid material, the short pulse laser ablates the material into the air, rapidly ionizing and heating the ablated material to form a microplasma with very high peak temperatures (much greater than 10,000 K) [23][24][25][26][27] and pressures of up to 40 GPa [28], comparable to peak detonation temperatures and pressures. The laser-induced plasma has many uses for energetic material applications including machining [29], residue detection [30], and studying high temperature chemical reactions [31][32][33][34]. The laser-induced plasma also generates a shock wave that rapidly becomes spherical as it expands into the air above the sample surface [35].…”

Pulsed laser ignition of reactive multilayer films

“…It has been shown that femtosecond pulse lasers can be used for machining of explosive materials without ignition due to highly limited energy dissipation. 11 Similarly, femtosecond pulse length lasers can controllably machine reactive multilayers without ignition, first demonstrated for Ni/ Al ͑Ref. 12͒ and Co/ Al ͑Ref.…”

One Year Term Review as a Participating Guest in the Detonator and Detonation Physics Group

“…-Laser femtosecond safely machining of HE parts, and detonators [1] -Diameter effect experiments in initiating explosives [10] -Floret test, comparison between experiments and simulations of the dent, [11] -Small scale cylinder test with a groove, comparison between experiments and calculations [12] -Shock arrival time metrology using photo-diode, numerical simulations [13] -Corner turning test with initiating HE -Thermal analysis -Low impact velocity safety test -Isentropic compression up to 200 kbars for LX 04, Numerical simulations and Comparison with Z-accelerator experiment shot 1067 [14] -Isentropic compression for TATB based HE samples, numerical simulations and comparison with Z-accelerator experiment shot 1967 [15] -Isentropic compression with a rectangular configuration for Tungstene and Tantalum, computations and comparison with Z-accelerator experiments shots 1511 and 1555 [16] -Copper tube compression in Z-current geometry, numerical simulations and comparison with Cyclope experiments [17] -Isentropic compression in a strip line, numerical simulations and comparison with GEPI shot 268 [18] 1.4…”