[en] Although the energy of the radiation pulses generated by the world's largest laser facilities approach the MJ limit, it is still lower than that calculated on means of the Lawson criterion for thermonuclear fusion. The severe energy requirements can be weakened by efficient pre-compression of laser targets and by non-linear conversion of laser radiation to shorter wavelengths. The homogeneity of the laser target irradiation can be improved by using multi-beam or indirect-drive laser schemes. The neodymium laser facilities such as Nova Upgrade in Livermore or Gekko XII in Osaca are still the most promising fusion drivers, but the chances of powerful iodine lasers such as ISKRA 5 in Arzamas and Asterix in Munich are also high. The prospects of these and other laser fusion drivers are critically assessed and the role of smaller devices as the Prague iodine laser Perun is discussed. (J.U.) 6 figs., 7 refs

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No abstract available

[en] The one-dimensional dispersion equation of the electroacoustic instability of the low pressure positive column is numerically analyzed. The column steady state parameters were obtained from the plasma balance equations based on a Maxwell distribution. The computed curves are compared with the experimental dispersions measured for spontaneously existing anode-directed wave observed at the cathode end of the column. Although the agreement between the observed and computed dispersion curves is fairly good the current driven electroacoustic instability does not provide a universal explanation for all of these waves. (author)

[en] A numerical solution of the Boltzmann equation for the electron gas in the positive column of a DC discharge in nitrogen is presented. The Boltzmann equation was solved with the inclusion of the second-kind (superelastic) collisions proceeding from the first six excited vibrational levels of molecular nitrogen. The vibrational level population is supposed to follow the Boltzmann distribution for the given vibrational temperature Tsub(v), with a possible deviation of the ground level, which can be overpopulated in the given ratio γ. Apart from the electron distribution functions, which were gained for various values of E/p₀, Tsub(v) and γ, the values of some production frequencies and kinetic coefficients are presented in form of tables and plots. It is found that the electron distribution (and also the corresponding production rates) only above a certain energy limit depends on Tsub(v) and γ through the normalization constant. (author)

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No abstract available

[en] A theory explaining positive column constriction in terms of a thermal effect is presented. As a result of heating the neutral gas becomes more rarefied near the tube axis and a locally increased molecular ion production ensues. If this is balanced by the dissociative (volume) recombination a constriction occurs at higher currents and pressures. The density profiles and other physical quantities are computed and compared with available experimental data. All computations are performed for a non-Maxwellian plasma neglecting the electron Coulomb interaction. As against the theories based on an ionization mechanism the thermal theory also predicts a constriction of the density profile. (author)

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No abstract available