Influence of the Density of PETN-Coal Composites on the Threshold Characteristics of Explosive Decomposition in Laser Initiation
B. P. Aduev, D. R. Nurmukhametov, G. M. Belokurov, Ya. V. Kraft, Z. R. Ismagilov
Institute of Coal Chemistry and Material Science, Siberian Branch, Russian Academy of Sciences, Kemerovo, 650000 Russia
Keywords: лазерное инициирование, тэн, бурый уголь, низкометаморфизованный уголь, лазер, оптоакустика, фотометрический шар, laser initiation, PETN, brown coal, low-metamorphosed coal, laser, optoacoustics, photometric ball
Abstract
This paper presents the results of measuring the thresholds of explosive decomposition of PETN-coal under the action of laser radiation pulses (λ= 1 064 nm and τ= 14 ns). Samples whose thickness is 1 mm and whose densities are 1.1 and 1.7 g/cm3 with inclusions of submicron particles of brown coal (750 nm) are investigated. A minimum explosive threshold of 1.8 J/cm2 is reached with a concentration of inclusions of 0.5 % (by weight). The explosion is adiabatic. Composites with a density of 1.1 g/cm3 have a scattering matrix. A minimum explosive threshold of 2.3 J/cm2 is obtained for a concentration of inclusions of 1 %. An extinction rate is estimated: kext = 135 cm-1. Radiation is absorbed at a depth of <0.1 mm. Explosive decomposition in an unirradiated section develops according to the shock-wave mechanism of explosive combustion.
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