A2B6 electric-discharge semiconductor focon laser

The working principle of the electric-discharge semiconductor focon laser is considered. CdS, Cd _x Zn_1?x Se, and CdS _x Se_1?x plates were used as active medium. In the case of CdS, lasing at λ = 525 nm was observed. The radiation power reached 3 kW, the pulse duration being 3 ns. The conditions of generation initiation in the streamer regime are considered. The spectral characteristics of discharge channel radiation in Cd _x Zn_1?x Se and CdS _x Se_1?x plates are investigated. The spectrum is shown to consist of discrete lines occurring upon discharge propagation and corresponding to the change in the composition of the ternary compound obtained in the course of single crystal growth. The application of ternary solid solutions A2B6 is supposed to help in obtaining a successive laser pulse generation within the range of 480 to 700 nm.     

Kinetic Parameters of the Dissolution of Gold in Thiourea Solutions

The temperature dependence of the rate constants for the dissolution of gold in thiourea solutions was determined. The activation energies calculated suggest that the rate of gold dissolution is diffusion-controlled at 5-22 °C but is kinetically-controlled at 25-60 °C (E _a = 42.83 kJ/mol). Auger spectroscopy was used to study the composition of the surface adsorption layers and a mechanism for the passivation of the reactive surface during the gold dissolution process was proposed.     

Electro-optical polarization mode dispersion in PbMg<Subscript>1/3</Subscript>Nb<Subscript>2/3</Subscript>O<Subscript>3</Subscript> single crystals

The polarization mode dispersion induced by an external ac electric field in PbMg_1/3Nb_2/3O₃ single crystals is studied experimentally at frequencies of 10⁴–10⁷ Hz. It is established that the discovered electro-optical polarization mode dispersion (EPMD) displays anomalous properties related to the orientation of the induced dipole moments in microregions of the crystal. Analytical expressions describing the peculiarities of the physical properties of relaxors giving rise to the EPMD are obtained.     

Small oscillations of a viscous incompressible fluid with a large number of small interacting particles in the case of their surface distribution

We study the asymptotic behavior of solutions of the problem that describes small motions of a viscous incompressible fluid filling a domain Ω with a large number of suspended small solid interacting particles concentrated in a small neighborhood of a certain smooth surface Γ ⊂ Ω. We prove that, under certain conditions, the limit of these solutions satisfies the original equations in the domain Ω\Γ and some averaged boundary conditions (conjugation conditions) on Γ.     

Collision of a comet with Jupiter: Determination of fragment penetration depths from the molecular spectra

After the fragments of comet Shoemaker-Levy 9 fell onto Jupiter, some molecules which were formed as a result of chemical reactions in the shock-compressed gas during the explosion of the comet fragments and ejected into the upper atmosphere by the shock wave were observed in the upper atmosphere. As the initially hot gas expanded, these molecules were quenched. Therefore they represent a kind of “memory” of the shock processes which occurred in the region of generation of the strong shock wave. The radiation from such molecules was registered by both ground-based observers and the Hubble space telescope. In the present paper we estimate the penetration depth and energy of the largest comet fragments on the basis of data on the content of shock-synthesized molecules in Jupiter’s upper atmosphere. Pis’ma Zh. éksp. Teor. Fiz. 63, No. 6, 387–391 (25 March 1996)     

Generator of picosecond laser pulses

The design of the generator of picosecond laser pulses and the results on semiconductor target (ZnSe, CdS, and others) excitation by electric field and electron beam pulses are presented. The maximum power of laser radiation reached 10 kW at pulse durations of 100–200 ps.