In review, general results obtained by Institute of Physics and Power Engineering (IPPE) during 1981–1992 are presented in the field of physics of nuclear-induced plasmas in the following directions: processes of primary ionization of different media by nuclear reaction products; function of electron distribution in nuclear-induced plasmas; processes of excitation and relaxation; track structure of nuclear-induced plasmas. Prospects of study progress are discussed with a view to improve the current concepts of physics of elementary processes occurring in nuclear-induced plasmas and obtain experimental and theoretical data on process constants needed to calculate the nuclear-pumped lasers.

An overview of nuclear-pumped laser programs conducted on various pulsed reactor types has been presented. The independent research undertaken in Russia and the United States have confirmed the concept of energy conversion from nuclear exothermal reactions to coherent optical radiation as feasible.

We suggest several cascade lasing schemes: (1) cascade of laser transitions between atom (ion) excited levels when the lower laser level of one laser transition is simultaneously the upper laser level of another transition located below; (2) successive lasing, first, on ion transitions, then after ion recombination on atom transitions; (3) while using multicomponent mixtures, successive lasing on atoms (ions) of separate components. These possibilities are discussed in terms of specific lasers, some of which have been studied experimentally.

Numerical simulation of active media nuclear-pumped lasers on noble gases and their mixtures with metal vapors are presented. Prospects of creation of high-power short-wavelength nuclear-pumped excimer lasers are discussed.

This article describes the design of a laser setup excited by 3He(n, p)3H reaction products and intended for investigations of the laser characteristics of 3He mixtures with metal vapors or other gases at temperatures up to 800˚C. This setup could also be used to study the effect of the medium heating on the characteristics of nuclear-pumped gas lasers.

It is shown that there is a principal possibility of effective burning with gain G > 200 of ecologically clean DHe3 fuel in reactor-type targets without increase of driver energy. The proper target consists of DHe3 fuel and a D-T ignitor with a central hot spark. Under proper conditions, the D-T burning wave reaches the DHe3 range with the temperature sufficient for ignition of DHe3 plasma. The simulation was carried out by means of TERA code based upon self-consistent solution of a kinetic equations system for products of primary and secondary thermonuclear reactions by the Monte Carlo method and a hydrodynamic equations system.

In this article, we derived new formulas for approximate representation of components of a plane electromagnetic wave in heterogeneous medium that has parameters changing along some fixed direction in an arbitrary manner. The formulas differ from ordinary WKB approximation by factors regarding relative rate of medium characteristics change and give solutions remaining continuous at turning points. Conditions of full opaque and of no reflectionbased on the solution are obtained.

Suggested by numerical simulations, recent experiments have shown that a significant guiding force is exerted by a reduced-density channel on electron beams propagating through initially un-ionized air. A theoretical analysis of this guiding force had been given that assumed uniform beam and channel and small beam-channel offset. From a 2-D model, relative to a beam slice, the guiding force is calculated in this article for arbitrary beamchannel offset and for various smooth beam and channel profiles. This calculation confirms the above-quoted experimental evidence of a guiding force significant with respect to the deflection force exerted by the earth's magnetic field. It also confirms the crucial role played by the secondary electron temperature distribution. Finally, it suggests optimal values for the ratio between channel and beam rms radii.

To predict the gain in a lasing transition in ions of a laser-produced plasma, it is essential to calculate the amount of the reabsorption of radiation emitted in the transition from the lower laser level to the ground state. An important quantity influencing the reabsorption is the plasma geometry as resulting from the design of the laser and target system. Modeling a nonaxially symmetrical geometry of the plasma arising from a target irradiated by line-focused laser beams, we consider the plasma in the form of a longitudinally cut-out circular cylinder, with central angle ø, and the length of the plasma much larger than its transversal extension. Accounting for the effect of resonance line trapping via the escape probability approach, and taking the absorption profile in the line center approximation, an explicit formula for the photon escape probability depending on the radial and angular coordinates of an interior point in the plasma is derived. This function is averaged over the angular variable to obtain an only radially varying mean escape probability.

Industrial applications of high-power ion beams, basically in the field of material engineering, are presented. The results of experimental investigations of some kinds of applications, such as ion implantation, metal modification, and compounds production of thin films, are considered.

The results of 1-D numerical study are reported for a class of simple D-T targets driven by the beams of heavy ions. A simple target is defined as a uniform spherical metallic shell with the frozen D-T deposited on its inner surface and the D-T gas in the central cavity. Optimum target parameters have been found for several combinations of the three relevant driver parameters—the input energy Ein, the beam pulse duration tin, and the beam ion energy Eb. A simple box pulse profile was assumed. As a central set of driver parameters around which most of the calculations have been done, the values Ein = 6.12 MJ, tin = 17 ns, and Eb = 20 GeV have been adopted. It was found that all the targets from the class under consideration ignite uniformly over the entire fuel mass. Maximum energy gains amount to Gopt = 80–100. The physical picture of the target performance is analyzed in detail.

The conditions for an experiment are being discussed in which the hydrodynamic efficiency could be measured and an optimum thermonuclear target design worked out that could be performed on a single-channel accelerator facility producing a 209Bi ion beam of ∼100 GeV per nucleus. As numerical simulations show, the expected values of the hydrodynamic efficiency are 5–10%, while the optimization of the target-beam system could be performed by compressing D-T gas in a conical cavity and registering some 109-1011 neutrons per shot.

The radiation transport effect on pellet implosion and the Rayleigh-Taylor (R-T) instability are studied in a light-ion beam (LIB) inertial confinement fusion (ICF) by numerical simulation and analytic work. First, we present the nonuniformity-smoothing effect of the radiation transport on implosion symmetry in an LIB ICF fuel pellet. The 2-D implosion simulation shows that the initial nonuniformity can be smoothed out well in an LIB ICF pellet; for example, the initial nonuniformity of 6% is smoothed to 0.07% during the implosion phase. In addition, linear analyses for the R-T instability under nonuniform acceleration in space and under radiation are also performed: The nonuniform acceleration field in space does not change the growth rate (γ) of the R-T instability. However, this nonuniformity may suppress the growth itself of the R-T instability. Radiation may reduc the growth rate (γ).