Spectral-Kinetic Characteristics of Brown-Coal Flame and Plasma Glow After Exposure to High-Power-Density Laser Radiation

The spectral-kinetic characteristics of the glow of brown-coal samples exposed to laser pulses (1064 nm, 14 ns, 1 GW/cm 2 ) in air at atmospheric pressure and in vacuum at a pressure of 10 −2 Torr were studied. A vapor plasma torch was observed over the samples in a vacuum during the action of the laser pulses. Glow lines of ionized carbon and hydrogen atoms were identified. The CO flame glow dominated the spectra at atmospheric pressure. The rotational-vibrational glow of H 2 O and the thermal glow of carbon particles were distinguished in the spectra after exposure to the laser. The nonvolatile residue of coal particles combusted with escape of incandescent carbon particles at a temperature of ~2500 K in air at atmospheric pressure in the time interval 0.2–1.0 ms with exposure to laser pulses of W = 1 GW/cm 2 .