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Using multidimensional particle-in-cell simulations, we show that an electron beam with a huge space charge can be accelerated to high energies by irradiating the edge of a solid density target with an intense femtosecond laser pulse at parallel incidence. The process of energy gain of each electron is divided into two parts: the transverse laser field and the longitudinal field of the excited surface plasma wave (SPW). It is shown that the longitudinal field of the SPW dominates the acceleration of the major part of electrons. This process leads to generation of a highly collimated electron beam with a huge space charge.

The results of the operation of a wavefront correction system based on a deformable bimorph mirror of the PEARL subpetawatt laser facility are presented. An improvement in the quality of focusing of laser radiation, which led to an increase in the Strehl ratio from 0.3 to 0.6, is demonstrated. The features of the compensation for phase distortions of the wavefront in the case of a low pulse repetition rate, as well as the correct allowance for the noise of the CCD camera when calculating the Strehl ratio are investigated.

We present the results of studying experimentally the expansion of laser plasma in a strong external magnetic field (with a magnetic flux density of 13.5 T) at various sizes of the region of plasma formation on the surface of a solid-state target. It is shown that when the size of the plasma formation region is smaller than the classical plasma braking radius, a nearly identical topology of plasma flows is observed, which is characterized by the formation of a thin plasma sheet directed along the external magnetic field. If the width of the plasma formation region is comparable with the classical plasma braking radius, an additional plasma sheet starts to be formed.

The design of ellipsoidal plasma mirrors (EPMs) for the PEARL laser facility is presented. The EPMs achieve a magnification of 0.32 in focal spot size, and the corresponding increase in focused intensity is expected to be about 8. Designing and implementing such focusing optics for short-pulse (

The review of literature data related to the preparation, properties, and application of carbon nanotubes for sorption recovery of elements is given. Experimental data on the application of Taunit carbon nanofor radionuclide preconcentration from different solutions, as well as of Taunit-based solid-phase extractants for recovery of actinides and rare-earth elements from nitric acid solutions are presented.

Sorption of Pu from weakly acidic and weakly alkaline solutions on Taunit carbon nanomaterial was studied. Under these conditions, both polymeric Pu(IV) and ionic Pu(V, VI) species are recovered from freshly prepared solutions. Also, Pu is efficiently sorbed from simulated groundwater after more than 10 months of storage. The Pu sorption in all the forms by carbon nanotubes is rapid and almost quantitative (95 ± 5%) at the sorbent-to-solution ratio of 1 : 80 g ml−1. Plutonium preliminarily sorbed on Taunit can be efficiently immobilized in a magnesium potassium phosphate ceramic whose physicochemical properties meet the requirements of prolonged environmentally safe storage of long-lived radionuclides.

The sorption of Pu(IV), polymeric Pu(IV), Pu(V) and Pu(VI) from the 0.1 M NaClO4 solution onto multiwalled carbon nanotubes was investigated. The kinetic study of the sorption process have shown that the polymeric Pu(IV) has the highest sorption rate, while decrease of sorption rate for plutonium aqua-ions in the order Pu(VI) > Pu(IV) > Pu(V) was found. Strong dependence of sorption kinetics of ionic plutonium species on pH was shown, in contrast to polymeric species, that were shown to quantitatively sorb (99%) in the wide pH range (pH 2–10). Two different sorption mechanisms for ionic and polymeric plutonium species were proposed: on the bases of sorption isotherms chemisorptions of plutonium aqua-ions onto carbon nanotubes and through intermolecular interaction for the polymeric plutonium species was defined. Distribution coefficients of plutonium in various oxidation states were found to increase with pH, showing the highest values for polymeric plutonium sorption (K d = 2.4 × 105 mL g−1 at pH = 6).

Solubility of UO2, NpO2, and PuO2 powders in simulated groundwater (SGW) was studied by attainment of the equilibrium from below. The solubility was determined in AnO2-SGW heterogeneous systems at different solid: liquid weight ratios and different pH values of the examined solutions both under ambient conditions and in an inert atmosphere. The solubility of UO2, NpO2, and PuO2 depends on the solid: liquid ratio but is independent of pH of the solutions in the range from 6 to 11. The solubilities of UO2 and NpO2 in SGW under ambient conditions are higher that those in an inert atmosphere. The solubility of freshly calcined PuO2 is virtually independent of the atmosphere. Formation of amorphous hydroxides by oxidation of the dioxide surface, whose area is proportional to the weight of the dioxides, increases their solubility.