Results of experiments aimed at amplification of the pressure of laser-induced shock wave on the passage from low- to high-density target material via vacuum gap are presented. During the action of nanosecond laser pulse of terawatt power on plane composite targets comprising a layer of laser radiation absorber of low-density (0.01–0.025 g/cm3) spaced by vacuum gap from a layer of aluminum, the shock-wave velocity in aluminum reached 25–29 km/s and a pressure jump at the aluminum layer boundary was 1.2–1.5 times as large as that observed in experiments on the cumulative transition of laser-induced shock wave into a solid. The obtained experimental data are compared to results of the numerical calculations performed using hydrodynamic programs in which the shock-wave generation and propagation was modeled with allowance for the interaction of laser pulses with partly homogenized plasma of the porous material. Based on the results of experiments, numerical calculations, and their theoretical analysis, the efficiency of using low-density porous media in the targets intended for their equation of state investigations and inertial confinement fusion ignition is considered.

We present the results of our experiments at the Luch laser facility in which the processes of the destruction of iron asteroids and cometary nuclei in space by nuclear explosions on their surface are simulated based on the principle of physical similarity. We present the results of our numerical simulations of impacts on the surface of iron objects confirming the similarity of the key processes in the full-scale and model cases. The technologies of fabricating miniature mockups with parameters close to those of iron asteroids and cometary nuclei are described. For various mini-mockups 3–12 mm in size at a laser energy from 50 to 450 J we provide an experimental estimate of the energy threshold for the undeniable destruction of mockups and investigate the parameters of their fragmentation. Conclusions about the probable results of the impact of a nuclear explosion on hazardous cosmic objects have been drawn.

We report on the results of experiments performed on the Iskra-5 laser facility for studying the effect of the polydeuteroethylene (CD 2 ) n working layer thickness on the operation parameter of an inverted-corona target. In all experiments of this series, the neutron yield at a level of 10 7 –3 × 10 8 DD neutrons per shot was detected for the total laser radiation energy supplied to the target by 12 second-harmonic beams in the range of 1.6–2.2 kJ. Using the neutron time-of-flight technique, we have detected an increase in the ion temperature from approximately 6.4 to 14 keV upon a decrease in the (CD 2 ) n layer thickness from 1 to 0.1 μm.

We present the results of preliminary experiments at laser facilities in which the processes of the undeniable destruction of stony asteroids (chondrites) in space by nuclear explosions on the asteroid surface are simulated based on the principle of physical similarity. We present the results of comparative gasdynamic computations of a model nuclear explosion on the surface of a large asteroid and computations of the impact of a laser pulse on a miniature asteroid simulator confirming the similarity of the key processes in the fullscale and model cases. The technology of fabricating miniature mockups with mechanical properties close to those of stony asteroids is described. For mini-mockups 4–10 mm in size differing by the shape and impact conditions, we have made an experimental estimate of the energy threshold for the undeniable destruction of a mockup and investigated the parameters of its fragmentation at a laser energy up to 500 J. The results obtained confirm the possibility of an experimental determination of the criteria for the destruction of asteroids of various types by a nuclear explosion in laser experiments. We show that the undeniable destruction of a large asteroid is possible at attainable nuclear explosion energies on its surface.

Fuel-containing layers in targets used in laser fusion experiments at the Iskra-4 and Iskra-5 facilities, have been investigated. The layers are formed from the condensed deuterium or deuterium-tritium mixture, as well as of metal hydrides and polyethylene containing deuterium and tritium.

An investigation was made of fuel films in targets used in experiments on laser thermonuclear fusion in Iskra-4 and Iskra-5 systems. These films were formed from condensed deuterium and a deuterium—tritium mixture, and also from metal hydrides and polyethylene containing deuterium and tritium.

The first experiments have been carried out on the hot plasma produced during indirect illumination of microballoons containing a gaseous DT mixture at the Iskra-5 laser installation. The integrated yield of DT neutrons reached 6 X 10(9) per pulse.

In VNIIEF the first experiments with thermonuclear targets of the powerful 12-channel iodine laser set-up <<ISKRA-5>> are performed. The output emission energy in these experiments is about 12 kJ with the pulse duration of 0.25 ns and beam divergence of less than 10(-4) rad. The technique is developed and thermonuclear thin wall targets with the inner input of laser emission (inverted corona target) are fabricated. For the targets containing polydeuteroethylene as a working substance, the yield of 5.10(9) D-D neutrons is obtained. The magnitude of the measured temperature of the plasma ionic component reaches 7 keV. The results of experiments agree satisfactorily with calculation-theoretical estimates.