Vol 80, No 8 (2016)

The orthogonality condition model (OCM) is used to describe α+¹⁶O scattering at low energies. A double folding potential with density-dependent effective NN interactions is used as the local potential of the model. The energies and widths of α-cluster resonances and differential cross sections are calculated. The results are compared to one obtained using the standard potential approach, without the nonlocal interaction of the OCM.

The design and expected characteristics of an experimental setup for generating a beam of singly, doubly, and triply charged ions of ^229mTh isomer are considered. The scheme of ion transport, the preparation of the thin source, and the means of registering low-energy conversion electrons are described.

The transition of 910 eV in the ¹⁵⁴Eu nucleus is presented as a new object of study of the influence of a matrix on the probability of low-energy nuclear transitions. The variation of this transition probability causes variations in the γ-quantum yields of ^154mEu decay which are easily detected from a matrix with ^154mEu nuclei. Using this approach, the probability of the transition of 910 eV occurring for ^154mEu nuclei in a Sm–Sn alloy is found to be 33% lower than for ^154mEu nuclei in Sm chloride or metallic Sm.

The inclusive spectra of light charged particles formed upon interaction between 50.5 MeV ³Не ions and ²⁷Al nuclei are studied. The experimental results are analyzed using the exciton model of nucleus decay, with the PRECO-2006 code describing the transition of an excited system to equilibrium state. The contributions from composite, pre-equilibrium, and direct processes of integral cross section formation are calculated. Determination of these mechanisms is of interest to both fundamental nuclear physics and different areas of application, particularly the nuclear transmutation of long-lived radioactive contamination.

Pairing energies are calculated from empirical values of the masses of deformed nuclei in the 150 < A < 190 region using a new expression that includes the mass of only a single odd-neutron or odd-proton nucleus. This allows us to draw conclusions on variations in pairing energies along the chain of isotones or isotopes. The accuracy of the proposed expression is examined on the basis of the familiar Garvey–Kelson mass relation.

A modified hydrodynamic approach using a nonequilibrium equation of state is used to describe heavy-ion collisions at intermediate energies. The calculated energy spectra of protons produced in heavyion collisions are compared to experimental data and the results from calculations based on solving the Vlasov–Uehling–Uhlenbeck (VUU) kinetic equation.

A unified mechanism of the emergence of T-odd ROT- and TRI-asymmetries is proposed for describing experimental T-odd asymmetry coefficients D(θ) in the angular distributions of prescission alphaparticles that are emitted in true ternary and quaternary nuclear fission reactions induced by cold polarized neutrons. The mechanism is related to the different ways in which the Coriolis interaction of the total spin of a polarized compound fissile nucleus with the orbital moment of alpha-particles affects even (for ROT-asymmetries) and odd (for TRI-asymmetries) components of the amplitude of an undisturbed angular distribution of emitted alpha-particles. Coefficients D_ROT(θ) and D_TRI(θ) derived with this mechanism for T-odd ROT- and TRI-asymmetries successfully describe the dependences of corresponding experimental coefficients for ²³⁵U and ²³⁹Pu nuclei over the range of angles θ, and for the ²³³U nucleus in the angular range of 60° < θ < 110°. It is explained why only ROT-type T-odd asymmetries emerge for evaporated neutrons and γ-quanta emitted by fission fragments in similar reactions if we allows for the Coriolis interaction of the total spin of the compound fissile nucleus with the orbital moments of the fission fragments and the wriggling vibrations of the above nucleus near its scission point.

A dynamic model developed earlier is used to describe the last stage of nuclear fission: the postscission motion of fission fragments. In this process, Coulomb repulsive energy turns into the kinetic energy of fission fragments measured by experimenters. It is shown that the dissipated energy can be as high as 10% of the average experimental kinetic energy.

Irregularities in the cross section of electron scattering off hydrogen and hydrogen-like He⁺, Li⁺⁺, and Be⁺⁺⁺ ions are studied using an s-wave model. The resonance structure and irregularities in the scattering data are compared. A unified approach based on an exterior complex scaling method is used in performing calculations. The potential splitting approach is used for calculations of scattering in systems with asymptotic Coulomb interactions.

We present the results from testing Monolithic Active Pixel Sensors of the detector ALPIDE (ALICE Pixel Detector). The purpose of these tests was to measure the pixel threshold and noise distributions in each of the four sectors of the detector, as well as the analysis of the hit maps produced by different radioactive sources.

An extended version of the multi-pomeron exchange model for the description of pp collisions in a wide energy range (from ISR to LHC) is presented by accounting of strange particle yields. This model effectively includes the interaction of quark-gluon strings in the form of fusion. The yields of different types of particles are differentiated using the Schwinger mechanism of string hadronization. The results on the multiplicity of strange particles and their transverse momentum and correlations are presented and compared to the experimental data. The possible effect of higher resonances on the observed characteristics is discussed, along with the applicability of the Schwinger mechanism.

Processes of the diffraction scattering of protons on nuclei in the context of developing the HARDPING (Hard Probe Interaction Generator) Monte Carlo event generator are considered with allowance for nuclear effects in the initial and final states. Effects such as the length of formation, energy losses, and the multiple rescattering of incident and produced hadrons are studied.

A Clifford extension of the Grassmann algebra is considered in which operators are built from products of Grassmann variables and derivatives with respect to them. It is shown that a subalgebra of operators, isomorphic to the usual matrix algebra, can be separated in this algebra, while the algebra itself is a generalization of the matrix algebra, contains superalgebraic operators expanding the matrix algebra, and produces transformations of supersymmetry.

A comprehensive study of laser ablation in liquids is performed. The use of iron, gold, copper, and magnesium nanoparticles in medicine is shown. The results from studying gold and copper colloid systems synthesized using the second harmonic of a Nd:YAG laser are reported.

Original data on the formation of fractal structures via the pulsed laser deposition of titanium in a high vacuum without external electric or magnetic fields are presented. The obtained thread-like structures are thin-walled strained tubes with diameters of 1–3 μm and lengths of up to 500 μm. The composition and structure of the samples are investigated.

The layerwise laser cladding of powdered alloy based on intermetallic gamma Ni₃Al phase is studied. The effect deposition parameters have on the geometry of the deposited beads is shown. Microstructures are investigated and the cracking susceptibility of the deposited material is analyzed. The effective deposition parameters are determined within a range of specific laser energy inputs of (2–8) × 10⁶ J kg⁻¹ at beam scanning rates of (1.67–10) × 10⁻³ m/s and a powder feed of 6.3 × 10⁻⁵ kg/s⁻¹.

The manufacturing of biochips by heating a multicomponent layer of polymeric microparticles that contain sensitive elements is simulated. Heating is performed up to the stage of polymer shell melting without damage to the sensitive elements. The corresponding thresholds of laser parameters (radiation power density) are detected. The preservation of biological complex functionality under these parameters is experimentally shown.

Transmission electron microscopy and magnetic measurements are used to study the formation of the microstructure and magnetic properties of Fe₂NiAl (alni) alloy upon cooling at the critical rate (V ∼ 2°/min) from the region of single-phase solid solution (1240°C). Cooling is interrupted by water quenching caused by temperatures Т_quench. The periodical modulated structure formed during sample cooling at the critical rate guarantees the strongest possible coercive force (Н_с = 670 Oe). The decomposition of the solid solution below 900°C includes a stage of primary modulated structural failure upon continuous cooling to temperature Т_quench ∼ 850°C, which corresponds to the weakest coercive force on the Н_с(Т_quench) curve. The periodical modulated structure is recovered when the temperature falls further; this is accompanied by an increase in the coercive force (up to Н_с = 670 Oe) after cooling to 20°C.

Structural and thermodynamic parameters characterizing the process of dynamic relaxation in FeNi alloy are determined by means of XRD structural analysis and instant electromotive force fixation (IEFF) for different modes of megaplastic deformation (MPD) in a Bridgman chamber. The factors that determine the level of dynamic relaxation during MPD are established.