Heating of Energetic Materials by Continuous-Wave Near-IR Laser Radiation
L.V. Bachurin1, V. I. Kolesov2, A. N. Konovalov1, V. A. Ul'yanov1, N. V. Yudin2
1Crystallography and Photonics Federal Researcher Centre, Russian Academy of Sciences, Moscow, 119333 Russia
2Mendeleev Russian Chemical and Technological University, Moscow, 125480 Russia
Keywords: энергетические материалы, лазерное инициирование, лазерный нагрев, energetic materials, laser initiation, laser irradiation
Abstract
The heating of energetic materials by the radiation of fiber-coupled continuously-pumped lasers at near IR-wavelengths of 0.98, 1.56, and 1.94 μm was studied. Samples of pressed secondary explosives and loose gunpowder were used. The length of the linear portion of the temperature rise and the rate of its rise immediately after exposure to laser radiation were measured. It is established that the rate of temperature rise at the initial time is proportional to the laser radiation power aP. For a 600 μm diameter of the laser beam emerging from the fiber, the coefficient of proportionality a for secondary explosives was 6-250 K/(s × W) at a wavelength of 0.98 μm and 40-2000 K/(s × W) at wave lengths of 1.56 and 1.94 μm. For gunpowder, a = 7000-15000 K/(s × W), which is an order of magnitude or more higher than for most of the secondary explosives we studied. The possibility of increasing the efficiency of laser heating of secondary explosives by applying an absorbing thin film on the surface of the samples was studied. The heating dynamics and the initial stage of ignition of energetic materials by laser radiation were investigated.
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