Astrophysics and Space Science

, Volume 235, Issue 2, pp 269–287 | Cite as

The yield of ionization in critical ionization velocity space experiments

  • Shu T. Lai
  • William J. Mcneil
  • Edmond Murad


We compare the conditions in laboratory and space critical ionization velocity (CIV) experiments. One significant difference that comes to light is the rapid expansion of the neutral cloud in space experiments, which does not take place in the laboratory. This has important ramifications for the ultimate ionization yield if there is a time delay in the ignition of the CIV discharge. We find that a simple kinetic model implies that the delay time of CIV ignition is a critical factor in determining the ultimate yield of the experiment. Although the delay time is difficult to calculate precisely, we provide some estimates that predict low CIV yield for typical space experimental geometries, densities and expansion rates. We examine the possibility of the variation of experimental conditions to maximize yield, but find that natural limitations in the design of space experiments may lead to low yields in the best of circumstances. This implies that experiments to date neither prove nor disprove the relevance of the CIV process to cosmology.


Delay Time Kinetic Model Critical Factor Velocity Space Rapid Expansion 
These keywords were added by machine and not by the authors. This process is experimental and the keywords may be updated as the learning algorithm improves.


Unable to display preview. Download preview PDF.

Unable to display preview. Download preview PDF.


  1. Alfvén, H.: 1954,On the Origin of the Solar System, Oxford University Press, Oxford.Google Scholar
  2. Alfvén, H. and Arrhenius, G.: 1975,Structure and Evolutionary History of the Solar System, Reidel Press, MA.Google Scholar
  3. Alfvén, H.: 1960, Collision between a non-ionized gas and a magnetized plasma,Rev. Mod. Phys. 32, 710–713.Google Scholar
  4. Alfvén, H.: 1972, in: K. Schindler (ed.),Cosmic Plasma Physics, Plenum Publishing Co., N. Y., pp. 179–187.Google Scholar
  5. Biasca, R., Hastings, D. and Cooke, D.: 1992, Simulation of the critical ionization velocity: effect of using physically correct mass ratios,J. Geophys. Res. 97, 6451.Google Scholar
  6. Biasca, R., Hastings, D. and Cooke, D.: 1993, Upper bound estimates of anomalous ion production in space-based critical ionization velocity experiments,J. Geophys. Res., 17569.Google Scholar
  7. Brenning, N.: 1981, Experiments on the critical ionization velocity interaction in weak magnetic fields,Plasma Phys. 23, 967.Google Scholar
  8. Brenning, N.: 1982, Comments on the Townsend Condition, in Proc. of Workshop on Alfvén's Critical Velocity Effect, Report, Max-Planck Inst. für Extraterr. Phys., Garching, Germany, pp. 313–320.Google Scholar
  9. Brenning, N., Fälthammar, C-G., Haerendel, G., Kelley, M., Marklund, G., Providakes, J., Stenbaek-Nielsen, H.C., Swensson, C., Torbert, R. and Wescott, E.M.: 1990, Electrodynamic interaction between the CRIT1 ionized barium streams and the ambient ionosphere,Adv. Space Res. 10, 763–766.Google Scholar
  10. Brenning, N.: 1992, Review of the CIV phenomenon,Space Sci. Rev. 59, 209–314.Google Scholar
  11. Brenning, N. and Axnäs, I.: 1988, Critical ionization velocity interaction: some unresolved problems,Astrophys. Space. Sci. 144, 15–30.Google Scholar
  12. Chen, S.T. and Gallagher, A.: 1976, Excitation of theBa andBa + resonance lines by electron impact onBa atoms,Phys. Rev. A. 14, 593–601.Google Scholar
  13. Danielsson, L. and Brenning, N.: 1975, Experiment on the interaction between a plasma and a neutral gas, II,Phys. Fluids 18, 661–671.Google Scholar
  14. Deehr, C.S., Wescott, E.M., Stenbeck-Nielsen, H., Romick, G.J., Hallinan, T.J. and Föppl, H.: 1982, A critical velocity interaction between fast barium and strontium atoms and terrestrial ionospheric plasma,Geophys. Res. Letters 9, 195.Google Scholar
  15. Goertz, C.K., Machida, S. and Lu, G.: 1990, On the theory of CIV,Adv. Space Res., 33–46.Google Scholar
  16. Haerendel, G.: 1983, The role of momentum transfer to the ambient plasma in critical velocity experiments, in:Active Experiments in Space, ESA Spec. Publ. SP-195, p. 245, European Space Agency, Neuilly, France.Google Scholar
  17. Haerendel, G.: 1982, Alfvén's critical velocity effect tested in space,Z. Naturforsch. 37A, 728.Google Scholar
  18. Hallinan, T.J.: 1988, Observed rate of ionization in shaped-charge releases of barium in the ionosphere,J. Geophys. Res. 93, 8705.Google Scholar
  19. Heppner, J.P., Miller, M.L., Pongratz, M.B., Smith, G.M., Smith, L.L., Mende, S.B. and Nath, N.R.: 1981, The Cameo barium releases:E fields over the polar cap,J. Geophys. Res. 86, 3519.Google Scholar
  20. Himmel, G., Möbius, E. and Piel, A.: 1976, Investigation of the structure and the plasma parameters in a ‘critical velocity’ rotating plasma,Z. Naturforsch. 31A, 934–941.Google Scholar
  21. Hunton, D.E.: 1993, Long-term expansion characteristics of CRRES barium release clouds,Geophys. Res. Letters 20, 563–566.Google Scholar
  22. Kelley, M.C., Pfaff, F. and Haerendel, G.: 1986, Electric field measurements during the CONDOR critical velocity epxeriment,J. Geophys. Res. A91, 9939.Google Scholar
  23. Lai, S.T., Denig, W.F., Murad, E. and McNeil, W.J.: 1988, The role of plasma processes in Space Shuttle environment,Planet. Space Sci. 36, 841–849.Google Scholar
  24. Lai, S.T., Murad, E. and McNeil, W.J.: 1989, An overview of atomic and molecular processes in critical velocity ionization,IEEE Trans. Plasma Sci. 17, No. 2, 124–134.Google Scholar
  25. Lai, S.T. and Murad, E.: 1989, Critical ionization velocity experiments in space,Planet. Space Sci. 37, No. 7, 865–872.Google Scholar
  26. Lai, S.T. and Murad, E.: 1992, Inequality conditions for critical velocity ionization space experiments,IEEE Trans. Plasma Sci. 20, 770–777.Google Scholar
  27. Lai, S.T., Murad, E. and McNeil, W.J.: 1992, Amplification of critical velocity ionization by associative ionization,J. Geophys. Res. 97, No. A4, 4099–4107.Google Scholar
  28. Machida, S. and Goertz, C.K.: 1986, A simulation study of the critical ionization velocity process,J. Geophys. Res. 91, 11965.Google Scholar
  29. McBride, J.B., Ott, E., Boris, J.P. and Orens, J.H.: 1972, Theory and simulation of turbulent heating by the modified two-stream instability,Phys. Fluids 15, 2367.Google Scholar
  30. McNeil, W.J., Lai, S.T. and Murad, E.: 1990, Interplay between collective and collisional processes in critical velocity ionization,J. Geophys. Res. 95, No. A7, 10345–10356.Google Scholar
  31. Möbius, E., Papadopoulos, K. and Piel, A.: 1987, On the turbulent heating and the threshold condition in the critical ionization velocity interaction,Planet. Space Sci. 35, 345.Google Scholar
  32. Möbius, E., Boswell, R.W., Piel, A. and Henry, P.: 1979, A spacelab experiment on the critical ionization velocity,Geophys. Res. Letters 6, 29.Google Scholar
  33. Newell, P.T.: 1985, Review of critical ionization velocity effect in space,Rev. Geophys. 23, 93–104.Google Scholar
  34. Newell, P.T. and Torbert, R.B.: 1985, Competing atomic processes in Ba and Sr injection critical velocity experiments,Geophys. Res. Letters 12, 835.Google Scholar
  35. Papadopoulos, K.: 1984, On the shuttle gow (The plasma alternative),Radio Sci. 19, 571.Google Scholar
  36. Piel, A.: 1990, Review of laboratory experiments on Alfvén's critical ionization velocity,Adv. Sp. Res. 10, No. 7, 7–16.Google Scholar
  37. Raadu, M.A.: 1978, The role of electrostatic instabilities in the critical ionization velocity mechanism,Astrophys. Space Sci. 55, 125.Google Scholar
  38. Stenbaek-Nielsen, H.C., Wescott, E.M., Haerendel, G. and Valenzuela, A.: 1990, Optical observations on the CRIT II critical ionization velocity experiment,Geophys. Res. Letters 17, No. 10, 1601–1604.Google Scholar
  39. Stenbaek-Nielsen, H.C., Wescott, E.M., Rees, D., Valenzuela, A. and Brenning, N.: 1990, Non-solar UV produced ions observed optically from the CRIT1 critical velocity ionization experiment,J. Geophys. Res. A95, 7749–7757.Google Scholar
  40. Swenson, G.R., Mende, S.B., Meyerott, R.E. and Rairden, R.L.: 1991, Charge exchange contamination of CRIT II barium CIV experiment,Geophys. Res. Letters 18, 401–403.Google Scholar
  41. Swenson, C.M.: 1992, In situ observation of an ionospheric critical velocity experiment, Ph.D. Thesis, Cornell University, Ithaca, NY.Google Scholar
  42. Tanaka, M. and Papadopoulos, K.: 1983, Creation of high energy tails by means of the modified two-stream instability,Phys. Fluids 26, 1697.Google Scholar
  43. Torbert, R.B.: 1988, Critical velocity experiments in space,Adv. Space Res. 8, 39.Google Scholar
  44. Torbert, R.B.: 1989, An overview of the CRIT II experiment (abstract),EOS 70, No. 43, 1277.Google Scholar
  45. Torbert, R.B.: 1990, Review of critical velocity experiments in the ionosphere,Adv. Space Res. 10, No. 7, 47–58.Google Scholar
  46. Torbert, R.B. and Newell, P.T.: 1986, A magnetospheric critical velocity experiment: particle results,J. Geophys. Res. A91, 9947.Google Scholar
  47. Wescott, E.M., Stenbaek-Nielsen, H.C., Hallinan, T.J., Deehr, C., Romick, J., Olson, J., Kelley, M.C., Pfaff, R., Torbert, R.B., Newell, P., Föppl, F., Fedder, J. and Mitchell, H.: 1985, Plasmadepleted holes, waves, and energized particles from high-altitude explosive plasma perturbation experiments,J. Geophys. Res. 90, 4281–4298.Google Scholar
  48. Wescott, E.M., Stenbaek-Nielsen, H. and Hampton, D.: 1990, Preliminary results from the CRRES critical velocity experiments, AGU Fall Mtg, San Francisco, CA, Dec.Google Scholar
  49. Wescott, E.M., Stenbaek-Nielsen, H.C., Hallinan, T., Föppl, H. and Valenzuela, A.: 1986a, Star of Lima: overview and optical diagnostics of a barium Alfvén critical velocity experiment,J. Geophys. Res. A91, 9923–9932.Google Scholar
  50. Wescott, E.M., Stenbaek-Nielsen, H.C., Hallinan, T., Föppl, H. and Valenzuela, A.: 1986b, Star of Condor: a strontium critical velocity experiment, Peru, 1983,J. Geophys. Res. A91, 9933.Google Scholar
  51. Wescott, E.M., Stenbaek-Nielsen, H.C., Hallinan, T.J., Deehr, C.S., Romick, G.J., Olson, J.V., Roederer, J.G. and Sydora, R.: 1980, A high-altitude barium radial injection experiment,Geophys. Res. Letters 7, 1037–1040.Google Scholar
  52. Wescott, E.M., Stenbaek-Nielsen, H.C. and Hampton, D.L.: 1992, Xenon critical velocity releases from the ACTIVNY satellite: discussion of attempted optical observations,Geophys. Res. Letters 19, 2079–2081.Google Scholar
  53. Wescott, E.M., Stenbaek-Nielsen, H.C., Hampton, D.L. and Delamere, P.A.: 1994, Results of critical velocity experiments with barium, strontium and calcium releases from CRRES satellite.J. Geophys. Res. 99, 2145–2158.Google Scholar

Copyright information

© Kluwer Academic Publishers 1996

Authors and Affiliations

  • Shu T. Lai
    • 1
  • William J. Mcneil
    • 2
  • Edmond Murad
    • 3
  1. 1.Phillips LaboratoryHanscom AFB
  2. 2.Radex, Inc.Bedford
  3. 3.Phillips LaboratoryHanscom AFB

Personalised recommendations