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In modern conditions of power consumption growing in Russia, apparently, it is difficult to find alternative to further development of nuclear power engineering. The negative party of nuclear power engineering is the spent fuel of nuclear reactors (radioactive waste). The gaseous and fluid radioactive waste furbished of highly active impurity, dumps in atmosphere or pools. The highly active fluid radioactive waste stores by the way of saline concentrates in special tanks in surface layers of ground, above the level of groundwaters. A firm radioactive waste bury in pods from a stainless steel in underground workings, salt deposits, at the bottom of oceans. However this problem can be esteemed in a positive direction, as irradiation is a hard radiation, which one can be used as a power source in nuclear - optical converters with further conversion of optical radiation into the electric power with the help of photoelectric converters. Thus waste at all do not demand special processing and exposure in temporary storehouses. And the electricity can be worked out in a constant mode within many years practically without gang of a stimulus source, if a level of a residual radioactivity and the half-lives of component are high enough. The nuclear-optical converter (NOC) esteem usually as a way of the ascent of energy from a nuclear reactor [1], a path of direct conversion of a nuclear energy into light.

Reciprocity inequalities (uncertainty relations) are studied for a finite light pulse with complex spatio-temporal structure and for statistical ensemble of such pulses. A possibility to create partially coherent pulses (and ensembles) with parameters close to minima of these inequalities both in temporal and spatial domains are discussed. The structure of optimal beams is analyzed from point of view of modal treatment of coherence (biorthogonal Karhunen-Loeve expansion).© (2002) COPYRIGHT SPIE--The International Society for Optical Engineering. Downloading of the abstract is permitted for personal use only.

The data on optimization of output parameters (output energy and laser efficiency) and distribution of laser radiation energy on the output window cross-section of the wide- aperture Xe-laser pumped by a radially-convergent e-beam with pulse duration of approximately 0,5 microsecond(s) at the FWHM were obtained. It is shown experimentally, that the requirement of homogeneity of output laser radiation across the aperture limits the energy deposition value from below, and the requirement of maximal laser efficiency restricts the energy deposition value from above. In the experiment the maximal laser efficiency as 1,5 - 2% was obtained at the specific energy deposition of 12 - 14 mJ./cm3atm. The calculations show that with cleaning of the operating mixture from molecular gases impurities the laser efficiency and energy output can be increased in 1.5 - 2 times. The negative influence of impurity gases at optimum range of pumping power is decreasing of electron temperature and as a consequence decreasing of the upper laser level pumping.

photoionization frequency of hydrogen atoms by pumping is sufficiently less of thatfor atom and ions of nitrogen. Energy deposition in electrons at ionization of atomof hydrogen by pumping also less, than average energy deposition in electrons ationization of atom of nitrogen.Despite of listed advantages, charge exchange reactions of ions with nitrogen

A great number o recent papers were devoted to the investigation or a Penning plasma laser under the conditions or electron-beam and nuclear puinpin,g and to the experimental and theoretical investigations or plasmochemical and radiation processes in the active medium (see , tor example , [1 1 ) . But the question about maximal erriciency o the laser is opened yet and this is the main purpose or the paper.

The exciplex lasers are now the most powerful among plasma lasers from visible to VUV range. The lasers on the exciplex molecules KrF ((lambda) equals 249 nm), ArF ((lambda) equals 193 nm), XeF ((lambda) equals 351, 353 nm) are most advanced. The operating transition of this laser is B yields X. The lower (ground) operating term X is the repulsive or weak-coupled one. The highest efficiency (10%) have KrF-laser and may be ArF-laser. The XeF-laser efficiency is not so high (approximately 3%), but this laser is of interest because it has the lowest threshold of pumping among exciplex lasers. Therefore, the opportunity of nuclear pumping of XeF-laser is under discussion. The X term have in XeF molecule a rather deep well. This peculiarity leads to more strong gas temperature dependence and not high efficiency. It must be mentioned that in the models of the XeF-laser developed up to today, the temperature dependence of plasma-chemical reaction rates, and its influence on laser output is not considered in details. Besides, the only effective operating transition, not the lasing on two separate transitions ((lambda) equals 351 and 353 nm) was considered in most papers.