Abstract
The system of equations of hydrodynamics, which describes the process of escape of the mixtures CO2 + N2 + He, H2O from a nozzle, is solved numerically in conjunction with the equations of the kinetics of the excitation of the vibrational degrees of freedom of the molecules. It is found that an inverted population of the CO2 molecules with respect to the transition [00 °1] − [10 °0], is produced under certain conditions at the exit from the nozzle. The magnitude of the inversion depends both on the nozzle configuration and on the initial values of the gas temperature and pressure. It is shown that for a specified nozzle configuration there exist optimal values of these parameters, at which the inverted population of the CO2 molecules reaches approximately 1015 cm−3.
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N. G. Basov and A. N. Oraevskli, “Obtaining negative temperatures by the method of heating and cooling a system,” Zh. Éksperim. i Teor. Fiz.,44, No. 5 (1963).
V. K. Konyukhov and A. M. Prokhorov, “Inverted population in adiabatic expansion of a gas mixture,” Pis, Zh. Éksperim. i Teor. Fiz.,3, No. 11 (1966).
N. G. Basov, V. G. Mikhailov, A. N. Oraevskii, and V. A. Shcheglov, “Obtaining inverted population of molecules in a supersonic stream of binary gas in a Laval nozzle,” Zh. Tekh. Fiz.,38, No. 12 (1968).
A. S. Biryukov, B. F. Gordiets, and L. A. Shelepin, “Vibrational relaxation and inverted population of CO2 levels under nonstationary conditions,” Zh. Éksperim. i Teor. Fiz.,57, No. 12 (1968).
N. I. Yushchenkova and Yu. A. Kalenov, “Chemical and vibrational relaxation in supersonic streams of carbon dioxide,” Zh. Prikl. Spektr.,9, No. 3 (1969).
J. O. Anderson, “Time-dependent analysis of population inversions in an expanding gas,” Phys. Fluids,13, No. 8 (1970).
B. F. Gordiets, N. N. Sobolev, and L. A. Shelepin, “Kinetics of physical processes in CO2 lasers,” Zh. Éksperim. i Teor. Fiz.,53, No. 11 (1967).
K. F. Herzfeld and T. A. Litovitz, Absorption and Dispersion of Ultrasonic Waves, Academic Press, London (1959).
K. H. Shin, “Effect of molecular orientations on vibrational-translational energy transfer,” J. Chem. Phys.,47, No. 9 (1967).
R. D. Sharma and C. A. Brau, “Energy-transfer in near-resonant molecular collisions due to long-range forces with application to transfer of vibrational energy fromv 3 mode of CO2 to N2,” J. Chem. Phys.,50, No. 2 (1969).
E. V. Stupochenko, C. A. Losev, and A. I. Osipov, Relaxation Processes in Shock Waves [in Russian], Nauka, Moscow (1965).
R. L. Taylor and S. Bitterman, “Survey of vibrational relaxation data for processes important in the CO2-N2 laser system,” Rev. Mod. Phys.,41, No. 1 (1969).
M. H. Wallman, “Die einstelldauer der Schwingungswärme in CO2 in abhängigkeit von fremdgaszusätzen und vom druck,” Ann. Phys.,21, No. 7 (1935).
J. F. Roach and W. R. Smith, “Shock-tube study of vibration-vibration energy exchange in N2-N2O mixtures,” J. Chem. Phys.,50, No. 9 (1969).
C. K. Rhodes, M. J. Kelly, and A. Javan, “Collisional relaxation of the 10 °0 state in pure CO2,” J. Chem. Phys.,48, No. 12 (1968).
W. A. Rosser and E. T. Gerry, “De-excitation of vibrationally excited CO2 * (v 3) by collisions with He, O2, and H2O,” J. Chem. Phys.,51, No. 5 (1969).
D. J. Eckstrom and D. Bershader, “Vibrational relaxation studies of the 10 °0 and 02 °0 states of shock-heated CO2,” J. Chem. Phys.,53, No. 7 (1970).
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Translated from Zhumal Prikladnoi Mekhaniki i Tekhnicheskoi Fiziki, No. 5, pp. 24–34, September–October, 1971.
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Generalov, N.A., Kozlov, G.I. & Selezneva, I.K. Inverted population of Co2 molecules in expanding gas streams. J Appl Mech Tech Phys 12, 652–660 (1971). https://doi.org/10.1007/BF00851117
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DOI: https://doi.org/10.1007/BF00851117