S Yu Pichugin

Formation and quenching mechanisms of excited particles in an oxygen-iodine laser medium

New values of a number of kinetic constants of processes proceeding in oxygen-iodine laser media are presented. The total probabilities of formation of I2(X, 15 ≤ v ≤ 24) and I2(X, 25 ≤ v ≤ 47) molecules in the course of quenching of I* atoms by I2(X) are found to be 0.9 and 0.1, respectively. The quantum yield of singlet oxygen in the reaction O(1D) + N2O → N2 + O2(a1Δ) is close to 100%. The quenching rate constants of I2(A’) by O2, H2O, CO2, I2, and Ar and of I(2P1/2) by O(3P), O3, NO2, N2O4, and N2O are presented.

Attenuation of pulsed CO2 laser radiation in an argon medium containing fine aluminum particles

The attenuation of 10.6-μm radiation by aluminum aerosol particles dispersed in argon is studied experimentally. An optimal method of forming the initiating beam is found. The size and concentration of fine Al particles in the medium are estimated.

Condensation mode instability in a heat-releasing weakly ionized gas in a magnetic field

Linear equations and dispersion relations describing the condensation mode in weakly ionized plasma with heat release, being in an external magnetic field, are derived. The conditions of the instability onset of the condensation mode of the ion component are found.

Probabilities of the production of vibrationally excited iodine molecules in the reaction I({sup 2}P{sub 1/2}) + I{sub 2}(X) {yields} I({sup 2}P{sub 3/2}) + I{sub 2}(X, v > 10)

Vibrational distributions of I{sub 2}(X, v) (0 { 10) reaction the probability of the production of I{sub 2}(X, v > 23) molecules is 0.1 and the total probability of the direct excitation of iodine molecules at the vibrational levels from 15 to 23 is 0.9. Based on the data obtained, the dissociation mechanisms of iodine molecules in the active medium of the oxygen-iodine laser are analysed. (active media)Vibrational distributions of I2(X, v) (0 ≤ v ≤ 45) molecules are calculated and analysed in the active medium of an oxygen—iodine laser. It is found by comparing the calculated values with the experimental data that during the I(2P1/2) + I2(X) → I(2P3/2) + I2(X, v > 10) reaction the probability of the production of I2(X, v > 23) molecules is 0.1 and the total probability of the direct excitation of iodine molecules at the vibrational levels from 15 to 23 is 0.9. Based on the data obtained, the dissociation mechanisms of iodine molecules in the active medium of the oxygen—iodine laser are analysed.

Effect of vibrationally excited I{sub 2}(a{sup 1{Delta}}{sub g}) molecules on the parameters of the active medium of an oxygen - iodine laser

A comparison of the experimental and theoretical results shows that quenching of one singlet oxygen molecule leads to the formation of 4.5 vibrational quanta of the I2 molecule on the average in the active medium of an oxygen—iodine laser. The dependence of threshold yield of singlet oxygen and of the gain on the relative concentration of vibrationally excited I2(a1Δg) molecules are studied. The threshold yield of singlet oxygen increases with the relative concentration of vibrationally excited I2 molecules and may be several percent higher than the value assumed earlier. The gain depends weakly on the relative concentration of vibrationally excited oxygen molecules.

HF Laser Based on Thermal- and Photon-Branched Chain Reactions Initiated by IR Laser Radiation

A chemical H2–F2 laser (oscillator and amplifier) initiated by means of IR radiative excitation of vibrational levels of HF molecules is studied under the conditions of development of a thermal-branched chain reaction caused by thermal dissociation of gaseous additions to the laser mixture. It is shown that, using F2SO3 addition at a partial pressure of 40 Torr, an H2–F2 laser with a mixture pressure of 1~bar initiated by a pulsed hydrogen fluorine laser can provide an output exceeding 120–200 J/liter in 20–50 ns laser pulses.