Measurement of Quasi-Isentropic Compressibility of Gaseous Helium at a Pressure of ~10 TPa

A nonideal helium plasma has been compressed to a density of ~9 g/cm³ by a pressure of P ~ 10000 GPa produced by an explosive charge of 85 kg of TNT in a spherical two-cascade device. The experiment has been performed on an X ray setup using simultaneously three betatrons with a boundary energy of about 60 MeV and a multichannel optoelectronic system of recording X-ray images. The pressure of the compressed helium has been determined from the gas-dynamic calculation.

     

Experimental evidence of thermal vibrational convection in a nonuniformly heated fluid in a reduced gravity environment

We report experimental evidence of convection caused by translational vibration of nonuniformly heated fluid in low gravity. The theory of vibrational convection in weightlessness is well developed but direct experimental proof has been missing. An innovative point of the experiment is the observation of a temperature field in the front and side views of the cubic cell. In addition, particle tracing is employed. The evolution of this field is studied systematically in a wide range of frequencies and amplitudes. The flow structures reported in previous numerical studies are confirmed. The transition from four-vortex flow to the pattern with three vortices is observed in the transient state.     

Possibility of Anderson transition in liquid Se and As in the region of high temperatures and pressures

Conductivity of selenium and arsenic at high temperatures, 2000°C, and supercritical pressures has been measured. With the density decrease the conductivity was found to drop rapidly from the ～ 10² Ω^?1 cm^?1 level corresponding to the minimal conductivity estimated by Mott. This is accounted for by the Anderson localization of electrons and confirmed by the calculations presented.     

Lattice Relaxation Effect on the Electronic Structure of Helium Solutions in Calcium Fluoride Crystals

The discrete variation (DV) and molecular static methods are used to study the effects of atomic displacements near the anion vacancies and He impurity centers in the interstitial and vacancy positions on the electronic structure of CaF₂. Lattice ion displacements near the helium atom were estimated at 1% lattice constant in the former case and 4% in the latter. This leads to decreased splitting between the occupied and vacant impurity levels in the presence of isolated defects and to increased splitting for interacting defects. Effective charges are less sensitive to lattice relaxation than the electronic energy spectrum, except the case of high defect concentration.     

Invariant Solutions of the Thermal-Diffusion Equations for a Binary Mixture in the Case of Plane Motion

The group properties of the thermal-diffusion equations for a binary mixture in plane flow are studied. Optimal systems of first-and second-order subalgebras are constructed for the admissible Lie operator algebra, which is infinite-dimensional. Examples of the exact invariant solutions are given, which are found by solving ordinary differential equations. Exact solutions are found that describe thermal diffusion in an inclined layer with a free boundary and in a vertical layer in the presence of longitudinal temperature and concentration gradients. The effect of the thermal-diffusion parameter on the flow regime is studied. __________ Translated from Prikladnaya Mekhanika i Tekhnicheskaya Fizika, Vol. 47, No. 1, pp. 95–108, January–February, 2006.     

ELECTRONIC STRUCTURE OF DIOXIDE CfO2

Journal of Structural Chemistry - The electronic structure of CfO2 is calculated in the fully relativistic cluster approximation of the discrete variation method (RDV). Theoretical X-ray...     

Interference Transport in a Two-Dimensional Topological Insulator in a CdHgTe Quantum Well

JETP Letters - Interference transport in mesoscopic samples of a two-dimensional topological insulator in CdHgTe quantum wells is studied for the first time. It is established that quasi-ballistic...     

Quasi-Isentropic Compression of a Nonideal Plasma of Deuterium and its Mixture with Helium at Pressures up to 250 GPa

Journal of Experimental and Theoretical Physics - We present data on the quasi-isentropic compressibility of a strongly coupled (nonideal) plasma of a deuterium–helium mixture in the range of...     

Comparison of Collective Accelaration of Protons and Deuterons in Luce Diode with a Polyethylene Anode

Russian Physics Journal - Collective acceleration of protons and deuterons is compared in the same geometry of a Luce diode with a polyethylene anode at an accelerating diode voltage of 250 kV,...