The 12-beam, photodisssociative iodine laser system ISKRA V has been built for laser fusion research. In this article we describe the optical scheme, elements and parameters of the output radiation. Pulse power of 100 TW was achieved in the preliminary experiments.

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Review of some research into laser thermonuclear fusion carried out in Russian Federal Nuclear Center (RFNC-VNIIEF) within the last several years is presented. The review begins with a brief survey into ICF development in RFNC-VNIIEF starting from A.D. Sakharov and S.B. Kormer's pioneer proposals of the 1960s. The review concludes with the exposition of historical background of the 10 TW ISKRA-4 and 100 TW ISKRA-5 laser facilities creation and with the prospects of the 300 kJ ISKRA-6 (λ= 0.35 μm) laser development. The results of survey carried out at the ISKRA-5 facility are presented in the review. The high degree of symmetry (nonuniformity < 3%) of irradiation of a DT-shell by the X-ray emission made it possible to successfully conduct experiments with the asymmetrical shells. The asymmetry was effected through the asymmetrical Mg layers deposition on a spherically uniform glass shell surface. The asymmetry impact on neutron yield and the moment of neutron generation was investigated. The line X-ray emission characteristics of the H-like and He-like Ar, Fe, and Al ions were studied in another set of experiments. Ar was doped into DT-gas, while Fe and Al were deposited on the CH spherical hohlraums' inner surface. Development of the Cherenkov radiation generator in which the electron motion is actuated by the faster-than-light X-ray pulse motion on the surface of a plane sample, being under voltage, is reported. And in fine a brief description of experiments carried out at the ISKRA-4 facility under the program of turbulent mixing in plane multi layer targets is presented.

Possibilities of manipulating the Rabi frequency and luminescence rate from degenerate-level systems as well as the velocity of self-induced transparency of multi-level media are studied using a unitary transformation. The Rabi frequency and luminescence rate of an electronic system whose ground level is degenerate and coupled to a resonant mode are found to depend on the level of the degeneracy. The velocity of multi-mode optical solitons in a multi-level medium is found to be influenced by the number of propagating resonant pulses. Physical realizations of relevant systems are proposed.

The operation of laser system based on explosively pumped photodissociation lasers and designed to control the distribution of space debris not observed nowadays is described and the possibility of its breaking using laser radiation effect and its subsequent evaporation in the Earth's atmosphere is discussed.At present, the problem of safety of spacecraft flights is rather urgent since space is filled by particles ofnatural and artificial origin (further called space debris).Fragments of more than 50 mm diameter can be observed by present-day radar and optical facilities, at that the use of astronomic facilities for observation of space debris is possible only at night and at twilight. Currently there are no similar facilities for observation of fragments with diameter of smaller than 50mm. Therefore there is no reliable model of spatial distribution of similar fragments dangerous for spacecrafts. Thus, effect from collision of spacecraft with fragment of 1 0mm diameter is equivalent to effect of explosion of lOOg of trinitrotoluene (highly explosive substance). Therefore it is necessary to observe and as far as possible to catalog fragments and in the future to remove them from dangerous orbits. Fig. 1 shows the schemes of two variants of laser system proposed for observation and removal of fragments. The system includes laser locator, targetilluminating laser based on the explosively pumped photodissociation laser (EPPL) [11, high-power laser based on EPPL with phase conjugation (PC) [2]. For proper work ofthe system it is necessary to arrange an angle reflector (AR) on the spacecraft.The system operates in the following manner. When the spacecraft appears in the field of view of laser radar, the latter begins to track it making measurements of its coordinates and range. These coordinates are used for correction of tracking by rotators of illuminating EPPL and EPPL with PC in such manner that the spacecraft would not go from the field ofview ofthese laser devices.At the favorable moment (the moment of weak influence of Doppler frequency shift of radiation reflected from the moving spacecraft) target-illuminating EPPL begins to operate and its radiation irradiates the spacecraft, and then laser radiation reflected from AR gets to input of EPPL with PC. The latter starts and sends input radiation precisely in the opposite direction with simultaneous amplification. As a result, focused and self-pointed high-power radiation of EPPL with PC reaches spacecraft orbit in that point where the angle reflector was before.In the first variant of laser system realization the spacecraft to that moment moved away from this point on the distance R= EL/c, where V -tangential component of spacecraft velocity, L -mean distance between the spacecraft and the system, c -velocity of light, for example, R= 16m, if = 8km/s , L=300km. SPIE Vol. 3574 . 0277-786X/98/$1O.OO 437 Downloaded From: http://proceedings.spiedigitallibrary.org/ on 05/27/2015 Terms of Use: http://spiedl.org/terms