Technical Physics

, Volume 44, Issue 10, pp 1150–1158 | Cite as

Nonadiabatic excitation of iodine molecules in the translational disequilibrium zone of a shock wave

  • V. Yu. Velikodnyi
  • A. V. Emel’yanov
  • A. V. Eremin
Gases and Fluids


Short-lived peaks of nonequilibrium emission are detected at 320–350 nm in shock-wave fronts in He, Ne, Ar, and H2 containing from 0.1 to 3% iodine molecules. The effect is observed in the range of Mach numbers from 3.2 to 6.3 for initial pressures of the mixtures ranging from 133 to 2660 Pa. The emission observed is assigned to the electronic I2(D3Σ→B3Π) band, which is located at excitation energies 5.45→1.8 eV, i.e., significantly above the dissociation threshold of iodine molecules (1.54 eV). An analysis of the results shows that the leading role in the excitation of iodine molecules is played by high-energy collisions in the translational disequilibrium zone of the shock wave. The best description of the experimental data is achieved for the value of the effective collision energy in the front calculated on the basis of a numerical solution of the Boltzmann equation by a modified Tamm-Mott-Smith method. The absolute values of this energy under the conditions of the experiments performed are roughly 10 times greater than the mean collision energy in the equilibrium zone behind the shock wave. The probability of nonadiabatic supercollisions of the type I2+I2→I2(D3Σ)+I2−6.4eV exceeds the adiabatic values by a factor of 1015–1020.


Experimental Data Iodine Shock Wave Mach Number Excitation Energy 
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  1. 1.
    Ya. B. Zel’dovich, A. P. Genich, and G. B. Manelis, Dokl. Akad. Nauk SSSR, 248, 349 (1979) [Sov. Phys. Dokl. 24, 756 (1979)].ADSGoogle Scholar
  2. 2.
    H. Mott-Smith, Phys. Rev. 82, 885 (1951).CrossRefADSzbMATHMathSciNetGoogle Scholar
  3. 3.
    G. A. Bird, Phys. Fluids 13, 1172 (1970).Google Scholar
  4. 4.
    C. Cercignani, Theory and Application of the Boltzmann Equation [American Elsevier, New York (1975); Mir, Moscow (1978)].Google Scholar
  5. 5.
    V. V. Struminskii and V. Yu. Velikodnyi, Dokl. Akad. Nauk SSSR 266, 28 (1982) [Sov. Phys. Dokl. 27, 659 (1982)].ADSGoogle Scholar
  6. 6.
    G. A. Bird, Rarefied Gas Dynamics: Proceedings of the 14th International Symposium, Univ. of Tokyo Press (1984), Vol. 1, pp. 175–182.Google Scholar
  7. 7.
    A. P. Genich, S. V. Kulikov, G. V. Manelis, and S. L. Chereshnev, Preprint of the Institute of Chemical Physics, Academy of Sciences of the USSR, Chernogolovka (1991).Google Scholar
  8. 8.
    V. Yu. Velikodnyi and V. A. Bityurin, Pis’ma Zh. Tekh. Fiz. 22(4), 39 (1996) [Tech. Phys. Lett. 22(2), 150 (1996)].Google Scholar
  9. 9.
    S. V. Kulikov, Shock Waves 7, 25 (1997).CrossRefADSzbMATHGoogle Scholar
  10. 10.
    J. Troe, Fast Reactions in Energetic Systems, edited by C. Cepellos and R. F. Walker, Reidel, Dordrecht-Boston (1981), pp. 125–139.Google Scholar
  11. 11.
    A. V. Eremin, I. S. Zaslonko, and V. V. Shumova, Kinet. Katal. 37, 485 (1996) [Kinet. Katal. 37, 455 (1996)].Google Scholar
  12. 12.
    E. E. Nikitin, Theory of Elementary Atomic and Molecular Processes in Gases [Clarendon Press, Oxford (1974); Nauka, Moscow (1970), 456 pp.].Google Scholar
  13. 13.
    T. Lenzer, K. Luther, I. Troe et al., J. Chem. Phys. 103, 626 (1995).CrossRefADSGoogle Scholar
  14. 14.
    V. Bernshtein, I. Oref, and G. Lendvay, J. Phys. Chem. 100, 9738 (1996).CrossRefGoogle Scholar
  15. 15.
    A. S. Mullin, C. A. Michaels, and G. W. Flynn, J. Phys. Chem. 102, 6032 (1995).Google Scholar
  16. 16.
    P. V. Kozlov, S. A. Losev, Yu. V. Romanenko, and O. P. Shatalov, Preprint No. 27–29 of the Institute of Mechanics, Moscow State University, Moscow (1997).Google Scholar
  17. 17.
    D. L. Baulch, J. Duxbury, S. J. Grant, and D. C. Montague, J. Phys. Chem. Ref. Data Suppl. 10,Suppl. 1, 1–1 (1981).Google Scholar
  18. 18.
    M. McCusker, in Excimer Lasers, edited by C. K. Rhodes, Springer-Verlag, Berlin-Heidelberg (1979), pp. 69–117.Google Scholar
  19. 19.
    M. Sauer, W. Mulac, R. Cooper, and F. Grieser, J. Chem. Phys. 64, 4587 (1976).CrossRefADSGoogle Scholar
  20. 20.
    E. I. Dashevskaya, E. E. Nikitin, and I. Oref, J. Chem. Phys. 97, 9397 (1993)Google Scholar

Copyright information

© American Institute of Physics 1999

Authors and Affiliations

  • V. Yu. Velikodnyi
    • 1
  • A. V. Emel’yanov
    • 1
  • A. V. Eremin
    • 1
  1. 1.Scientific-Research Center for the Thermal Physics of Pulsed Effects, Joint Institute of High TemperaturesRussian Academy of SciencesMoscowRussia

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