1. T. B. Lucatorto and T. J. McIlrath, Phys. Rev. Lett. 7, 280 (1976).
2. R. M. Measures and P. G. Cardinal, Phys Rev. A 23, 804 (1981).
3. V. A. Kas’yanov and A. N. Starostin, in Plasma Chemistry [in Russian], Énergoatomizdat, Moscow 1990, p. 67.
4. K. V. Bieg, G. C. Tisone, T. R. Lokner et al., Proceedings of the Eighth International Conference on High-Power Particle Beams, Novosibirsk, 1990, Vol. 2 (World Scientific), p. 933.
5. D. V. Gaidarenko and A. G. Leonov, Laser Phys. 2, 901 (1992).