The near-threshold C-12(0 (2) (+) ) resonance provides unique possibility for fast helium burning in stars, as predicted by Hoyle to explain the observed abundance of elements in the Universe. Properties of this resonance are calculated within the framework of the alpha cluster model whose two-body and three-body effective potentials are tuned to describe the alpha-alpha scattering data, the energies of the 0 (1) (+) and 0 (2) (+) states, and the 0 (1) (+) -state rootmean-square radius. The extremely small width of the 0 (2) (+) state, the 0 (2) (+) -> 0 (1) (+) monopole transition matrix element, and transition radius are found in remarkable agreement with the experimental data. The 0 (2) (+) -state structure is described as a system of three alpha particles oscillating between the ground-state-like configuration and the elongated chain configuration whose probability exceeds 0.9.

The optical scheme and design of a four-frequency polarizing microscope intended for simultaneous recording of plasma images in the wavelength range 0.4–1.1 μm with the spatial resolution 12 μm in the entire spectral range are described. The effectiveness of such a microscope in studies of plasmas produced on interaction of laser radiation with a target is demonstrated. The plasma images are obtained at the frequencies ω0, (3/2)ω0, 2ω0, and (5/2)ω0, where ω0 corresponds to the frequency of heating radiation. The transformation coefficient that characterizes the efficiency of conversion of heating radiation into the 2ω0, (3/2)ω0, and (5/2)ω0 harmonics generated in the plasma is determined.

The excited 0_2^+ state of 12 C is of key importance for description of the triple- α reaction, which is the only way for helium burning in stars. Authors’ efforts to calculate the lowest 0 + states within the framework of the α -cluster model are summarized and discussed. In particular, the recently calculated 0_2^+ state’s width and 0_2^+ → 0_1^+ transition density are in good agreement with the experimental data.

The excited \({0_2^+}\) state of 12C is of key importance for description of the triple-α reaction, which is the only way for helium burning in stars. Authors’ efforts to calculate the lowest 0+ states within the framework of the α-cluster model are summarized and discussed. In particular, the recently calculated \({0_2^+}\) state’s width and \({0_2^+ \to 0_1^+ }\) transition density are in good agreement with the experimental data.

The excited 0(2)(+) state of C-12 is of key importance for description of the triple-alpha reaction, which is the only way for helium burning in stars. Authors' efforts to calculate the lowest 0(+) states within the framework of the alpha-cluster model are summarized and discussed. In particular, the recently calculated 0(2)(+) state's width and 0(2)(+) -> 0(1)(+) transition density are in good agreement with the experimental data.

A polarointerferometer designed for studying magnetic fields in high-temperature laser or electric-discharge plasma with the method of measuring the Faraday rotation of the plane of polarization of a probing laser beam is described. The instrument's optical system allows three - shadow, polarization, and interference - images of an object to be formed in a single diagnostic channel, thereby making it possible to record plasma images using only one digital camera.

A method for obtaining a broad (30–100 Å) emission line in neodymium-glass lasers is proposed. In this case, an active medium is a combination of two different glass matrices, silicate and phosphate, doped with Nd3+ ions. The structure and spectrum width of such lasers were experimentally studied depending on the active element properties, cavity type, and pump power. A radiation spectrum width more than twice larger in comparison with silicate-glass lasers was achieved.

A new approach to the problem of IFE laser driver based on generation and amplification of radiation with controllable coherence proposed and realized at P.N.Lebedev Physical Institute of the RAS had initiated the studies of an interaction efficiency of a partially coherent radiation with matter.Recent results of experiments carried out with the aim to study of the physical processes in targets under illumination by the laser with controllable coherence of radiation are presented and discussed, especially such important laser-matter interaction phenomena as absorption and scattering of laser radiation, the laser radiation harmonic generation, X-ray generation, crater formation and plasma expansion under laser pulse, conversion of laser radiation by means of nonlinear crystals, influence of coherence degree on the processes mentioned above.

New concept of creation of high power laser systems based on generation and amplification of radiation with controllable coherence is suggested. The performed studies demonstrate that the laser based on such a principle has a number of advantages as compared to conventional schemes of lasers (suppression of small-scaled self-focusing without application of spatial filtration, good matching of a laser-target system and control of the laser radiation intensity distribution). It was demonstrated that the laser radiation pulse may be amplified up to very high level of output laser energy density (up to 20 J/cm(2) at least) and transported to considerable distance without using of the traditional correcting elements (such as phase plates, spatial filters, adaptive optics, etc.). Combined with the compactness, decreasing of the requirements to precision of manufacturing of optical elements and to the room hygiene all these lead to significant reducing of the cost of the output laser energy unit.

Properties of the lowest 0+ states of 12C are calculated to study the role of three-body interactions in the α-cluster model. An additional short-range part of the local three-body potential is introduced to incorporate the effects beyond the α-cluster model. There is enough freedom in this potential to reproduce the experimental values of the ground-state and excited-state energies and the ground-state root-mean-square radius. The calculations reveal two principal choices of the two-body and three-body potentials. Firstly, one can adjust the potentials to obtain the width of the excited 02+ state and the monopole 02+↦01+ transition matrix element in good agreement with the experimental data. In this case, the three-body potential has strong short-range attraction supporting a narrow resonance above the 02+ state, the excited-state wave function contains a significant short-range component, and the excited-state root-mean-square radius is comparable to that of the ground state. Next, rejecting the solutions with an additional narrow resonance, one finds that the excited-state width and the monopole transition matrix element are insensitive to the choice of the potentials and both values exceed the experimental ones.

The formation of craters in targets of various materials under the action of a high-power neodymium-laser pulse at radiation intensities from 1010 to 1014 W/cm2 was studied experimentally and theoretically. The interaction between the laser beam and solid targets is investigated to determine the efficiency of the ablation loading of various materials and the transformation of the laser energy into the energy of a shock wave.

The ${0}^{+}$ states of $^{12}\mathrm{C}$ are considered within the framework of the microscopic three-$\ensuremath{\alpha}$-cluster model. The main attention is paid to accurate calculation of the width of the extremely narrow near-threshold ${0}_{2}^{+}$ state which plays a key role in stellar nucleosynthesis. It is shown that the ${0}_{2}^{+}$-state decays by means of the sequential mechanism $^{12}\mathrm{C}\ensuremath{\rightarrow}\ensuremath{\alpha}+^{8}\mathrm{Be}\ensuremath{\rightarrow}3\ensuremath{\alpha}$. Calculations are performed for a number of effective $\ensuremath{\alpha}\text{\penalty1000-\hskip0pt}\ensuremath{\alpha}$ potentials which are chosen to reproduce both energy and width of $^{8}\mathrm{Be}$. The parameters of the additional three-body potential are chosen to fix both the ground and excited state energies at the experimental values. The dependence of the width on the parameters of the effective $\ensuremath{\alpha}\text{\penalty1000-\hskip0pt}\ensuremath{\alpha}$ potential is studied in order to impose restrictions on the potentials.

The current status of laser thermonuclear fusion research in the leading world scientific centers is characterized by the development of superhigh-power multi-channel laser facilities of megajoule pulse-energy level. The development of such laser installations operating in the pulse-repetition mode with a large number of laser beams, which are necessary for high-symmetry irradiation of a spherical thermonuclear target, is an extremely difficult physical and engineering problem. The concept of a special laser with a controllable function of mutual coherence of radiation is proposed. The studies performed demonstrate that a laser based on such a principle has a number of advantages as compared to the conventional schemes of lasers. In particular, the optical scheme of the laser is significantly simplified, and the cost of the output-energy unit is reduced by several times. The influence of radiation coherence on the homogeneity of the thermonuclear target irradiation is analyzed. The feasibility of suppressing the small-scale self-focusing without application of spatial filtration is shown. A module of the laser facility has been triggered to check the validity of the principles proposed for constructing a laser driver for power stations, and the first experimental results are reported. The possibility of controlling the coherence of laser beams used in ICF experiments without violation of the laser--target system matching is demonstrated, as well as controlling the distribution of the laser radiation intensity in the lens focus.

Представлены результаты экспериментов и теоретических исследований по образованию кратеров в мишенях из различных материалов при воздействии мощного импульса неодимового лазера в диапазоне интенсивностей от 10 10 до 10 14 Вт/см 2. Исследования взаимодействия лазерного пучка с твердыми мишенями проводились с целью определения эффективности абляционного нагружения материалов и трансформации лазерной энергии в энергию ударной волны.

The effect of wave-function mixing in antiprotonic helium is discussed. This effect manifests itself in a considerable change of the Auger decay rate of long-lived states of 3,4He\(\bar {\mathcal{p}}\)e. Properties of short-lived states which influence the decay rate of long-lived ones are described. It is proposed to observe these short-lived states in a direct experiment.

Auger decay rates of the metastable antiprotonic helium 3,4He\({\bar p}\) e are calculated. The variational method and solution of coupled differential equations are combined to determine the initial metastable state wave function. Besides metastable states, the calculation reveals specific short-lived states of the antiprotonic helium with an essentially different structure of the wave function. An effect of mixture of the wave functions is taken into account to calculate the decay rate for a few metastable states, which are close in energy to the short-lived ones.