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TURE PUBLICATIONS

DOI: 10.1134/S1063778810080223

Experimental Investigations of Fast-Proton Production in Picosecond Laser Plasma V. S. Belyaev, A. P. Matafonov, S. M. Rybakov, V. P. Danilov, V. P. Krainov, V. S. Lisitsa, V. P. Andrianov, G. N. Ignat’ev, and A. S. Rusetsky

Results of experimental investigations of fast-proton production in a laser plasma are presented for the case where the intensity of laser radiation at the targets is 2 × 1018 W/cm2 . Three processes of fast-proton acceleration in a laser plasma are investigated: (1) the acceleration of protons from the forward surface toward the laser pulse, (ii) the acceleration of protons from the forward surface of the target toward its interior, and (iii) the acceleration of protons from the backward foil surface in the outward direction. The activation procedure and CR-39 tracker detectors featuring a set of various-thickness aluminum ﬁlters were used to record fast protons. It turned out that the proton-acceleration process is the most eﬃcient in the case of proton acceleration from the backward foil surface in the outward direction. Experimental results revealed that about Np = 107 protons of energy in the region Ep > 1.9 MeV that are accelerated from the target surface toward a laser ray, Np = 4 × 107 protons of energy in the region Ep > 1.9 MeV that are accelerated from the forward surface of the target toward its interior, and Np = 4 × 108 protons of energy in the region Ep > 1.9 MeV that are accelerated from the backward foil surface in the outward direction are generated at the laser-radiation intensity of 2 × 1018 W/cm2 at the surface of aluminum, copper, and titanium targets. Experimental investigations aimed at optimizing the process of proton acceleration from the backward surface of aluminum foils are performed by varying the foil thickness over the range between 1 and 100 μm. The results of these experiments showed that there is an optimum foil thickness equal to 10 μm, in which case protons of maximum energy 5 MeV are generated.

Description of Superheavy Nuclei on the Basis of the Modiﬁed Energy-Density Functional DF3 S. V. Tolokonnikov and E. E. Saperstein

The possibility of describing nuclei of the uranium and transuranium region within the generalized method of the energy-density functional proposed by Fayans and his coauthors is studied. It turned out that, in the functional DF3, it is necessary, for this purpose, to modify the spin–orbit terms whose parameters were chosen in such a way as to describe the binding energies and charge radii of spherical nuclei from calcium to lead. The modiﬁed functional (DF3-a) describes well the energy features and charged radii for isotopic chains of uranium and neighboring elements. For deformed nuclei, the deformation was taken into account approximately. The nucleon-drip-line position obtained for these chains proved to be close to the predictions of one of the most successful calculations by the Skyrme–Hartree–Fock method with the HFB-17 functional. It is veriﬁed that the use of the functional DF3-

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