Experimental results obtained with “Kanal-2” facility under the study of powerful laser pulse interaction with the low density microstructure media are presented and discussed in this paper. Forward scattering, back scattering, and transmission of laser radiation by aerogel foil plasma have been investigated. The temporal, spectral, and energy characteristics of both the radiation scattering in the direction of heating radiation beam and the back scattering radiation were studied; the directional diagrams of forward and back scattering radiation were obtained for ω0 and 2ω0 frequencies. Analysis of intensity redistribution on the heating beam cross-section after passing through a polymer microstructure target was carried out.

New results obtained in experiments on laser irradiation (I = 5 × 1013 W/cm2, λ = 1.054 µm) of low-density (2–10 mg/cm3) porous materials (agar, triacetate cellulose, and foam polysterene) are presented and discussed from the standpoint of optimum porous material utilization in target designs for inertial confinement fusion. The influence of low-density material microstructure of irradiated samples on the absorption of laser radiation and the energy transfer processes was investigated using X-ray and optical diagnostic methods with high temporal and spatial resolution.

The experience of target fabrication with low-density and cluster heterogeneity is presented. Cluster plasma research is strongly dependent on target fabrication development and target structure characterization. Ten more target parameters should be measured for experiment interpreting in case of micro-heterogeneous plasma. Foam and foil targets, high-Z doped also, are produced and irradiated on the existing laser facilities. The density of 4.5 mg/cc cellulose triacetate in the form of regular three-dimensional polymer networks are achieved which is as low as plasma critical density for the third harmonic of iodine laser light. The possibilities of varying important target parameters, methods of their monitoring are discussed. Experiments with underdense foam targets with or without clusters irradiated on Prague Asterix Laser System (PALS) laser facility are analyzed preliminary for target optimization. Under-critical foams of varying structure (closed-cell foam or three-dimensional networks) and densities are reported for plasma experiments. Thermal and radiation transport in such targets are considered.

Popular target designs are reviewed. Possible methods of fusion target fabrication are discussed and the equipment and samples are demonstrated. The properties of the uniform and structured (cluster) materials are considered, showing the advantage of cluster material for energy conversion into soft X rays. The target materials with high content of hydrogen isotopes (BeD2, LiBeD3, or ND3BD3) prove to be more effective for high-power drivers in comparison with beryllium or polyimide.

Recently much attention has been paid to multilayer inertial confinement fusion (ICF) targets, among them the targets with low-density layers. This allows one to get a number of interesting results using the presently existing and future facilities. This concerns the volume absorption of the laser radiation in a porous matter of the density higher than the critical plasma density, and the formation of the radiation absorption region under condition of increasing geometric opacity of the low-density matter. We consider the low-density foams, 3D nets, free-standing “snow-like” layers, and pseudo low-density layers. We use artificial foam as a convenient model to allow easier comparison of the experimental laser shot data and the simulation. The requirements to such layers are also analyzed. The methods of precision control of the low-density targets are discussed.