On the distributions of photoelectrons over the illuminated part of the moon

The existing view of the photoemission properties of lunar regolith does not provide the unambiguous treatment of the parameters and distributions of photoelectrons over the illuminated part of the Moon. This is indicated by the present calculations of the density, temperature, and distribution function of photoelectrons. It has been demonstrated that the quantum yield of lunar regolith is the main parameter determining the generation of photoelectrons near the surface of the Moon. At present, this parameter is determined with significant uncertainty. The measurement of the quantum yield of regolith directly on the surface of the Moon has been proposed as a variant of the solution of the indicated problem. Such measurements can be performed in the framework of future lunar missions.     

Dusty plasma structures in He-Kr DC glow discharge

Ion drift in gas mixtures has certain properties that can be used to generate ion flows with desired characteristics. For example, when the field is strong, ion heating is significant, and there is a large difference in atomic weight between ions and atoms, the ion velocity distribution can be highly anisotropic. Ion distribution anisotropy, in turn, can cause a substantial change in properties of dust structures in plasmas. Experiments on dusty plasma structures in glow discharge in mixtures of light and heavy gases (helium and krypton) are performed, and results of numerical simulations of ion and electron drift in the mixture are presented.     

Cr-Ni-Mo-Co surface alloying layer formed by plasma surface alloying in pure iron

Using double glow plasma alloying technique, a multi-elements alloyed layer containing elements of Cr, Ni, Mo and Co was formed on the surface of pure iron. After undergoing suitable aging treatment followed solid solution treatment, the formed alloying layer keeps a good combination of corrosion resistance and wear resistance. The relationship between the process parameters of heat treatments and the properties of the formed Cr-Ni-Mo-Co alloying layer, such as the chemical composition, hardness, corrosion resistance and wear resistance, was investigated in this study. It was revealed that the formed alloying layer exhibits a better behavior than that of 304 stainless steel and pure iron by employing a suitable heat treatment system. The temperature employed in solid solution treatment is 1453 K (1180 °C) followed by water quenching and the aging temperature is 813 K (540 °C) followed by water cooling.     

Dusty plasma in the stratified glow discharge in moderate magnetic field

This article presents the experimental study of dust structures formed in striations of glow discharge in an external magnetic field of up to 10⁴ G, which was created using a cryomagnet. A magnetic field classification based on probe theory is described. In moderate magnetic field, we obtained stable dust structures. The corresponding experimental setup and the experiment itself are described in detail. Special attention was paid to the influence of magnetic field on the change of the diameter and inter‐particle distance of dusty cloud. And, we also determined the dependence of angular velocity of dust rotation on magnetic induction.     

Dusty plasma structures in magnetic fields in a dc discharge

The formation of dusty plasma structures has been experimentally investigated in a cylindrical dc discharge in axial magnetic fields up to 2500 G. The rotation of the dusty plasma structures about the discharge symmetry axis with a frequency depending on the magnetic field has been observed. When the field increases to 700 G, the displacement of dust particles from the axial region of the discharge to the periphery, along with the continuation of the rotation, has been observed. The kinetic temperatures of the dust particles, the diffusion coefficients, and the effective nonideality parameter have been determined for various magnetic fields. The explanation of the features in the behavior of the dust particles in the discharge in the magnetic field has been proposed on the basis of the analysis of ambipolar diffusion in the magnetized plasma. The maximum magnetic field at which the levitation of the dust particles in the discharge is possible has been estimated.     

Statistical properties of the illuminated parts of a random surface

We consider the modifications in statistical characteristics caused by shadings in the case of oblique illumination of a random surface. It is shown that shadings and height ruptures in the illuminated part of the surface result in distortions of its height distribution function and peaking of the autocorrelation function for the visible part of the surface. At the limit, this function tends to an exponential one for an arbitrary autocorrelation function of the initial actual surface. Institute of Radio, Moscow, Russia. Translated from Izvestiya Vysshikh Uchebnykh Zavedenii, Radiofizika, Vol. 43, No. 5, pp. 413–425, May 2000.     

Parametric interaction of surface waves guided by a plasma layer

We study the linear stage of the parametric instability of high-frequency surface waves guided by a homogeneous plasma layer on a metallic substrate when a TM-polarized plane electromagnetic wave is incident on the layer. The instability growth rate and the threshold value of the pumping wave amplitude are determined. It is shown that the instability can be thresholdless in a certain range of permittivities and thicknesses of the layer. Radiophysical Research Institute, Nizhny Novgorod, Russia. Translated from Izvestiya Vysshikh Uchebnykh Zavedenii, Radiofizika, Vol. 40, No. 7, pp. 870–876, July, 1997.     

Quasi-static surface modes of plasma layer with anisotropic electron temperature

Quasi-static surface wave propagation in a plasma layer with anisotropic electron temperature is considered. The case is analyzed where the electron temperature in the direction normal to the plasma boundary is considered to be zero, while in the direction along the boundary, electrons are described by the Maxwellian velocity distribution. It is shown that the modes of such a layer are described by equations for bulk plasma waves with renormalization of the electron density affecting the surface wave dispersion and damping.     

Transverse waves in a two-dimensional screened-coulomb crystal (Dusty plasma)

Transverse shear waves were observed experimentally in a two-dimensional screened Coulomb crystal. They were excited by applying a chopped laser beam to a 2D dusty plasma, i.e., a monolayer of charged microspheres levitated in a plasma. Measurements of the dispersion relation reveal an acoustic, i.e., nondispersive, character over the entire range of wave numbers measured, 0.2相似文献   

Thermal neutrons from the earth’s surface during the upper and lower transits of the moon and the sun on new moon and full moon days

The times of increases in the thermal neutron flux from the earth are compared with the passages of the moon and the sun at the longitudes of the observation sites on July 26, 1991, July 27, 1991, July 12, 1995, July 29, 1996, and July 21, 1997 (the upper and lower transits of the moon and the sun). The results confirm the role of tidal forces in the generation of thermal neutron fluxes from the earth’s surface. The study uses the astronomical annuals of the Russian Academy of Sciences for the corresponding years.     

Analytical treatment of plasma injected into an illuminated photoconductor

An analytical treatment of optically generated carriers in a double injection structure is given. The quasineutrality approximation is used, and both recombination through traps (constant lifetime) and bimolecular recombination are considered.     

Homogeneous model for surface roughness in identical double layer system

In this paper a homogeneous model for surface roughness in the identical double layer system has been presented. It has been shown that the reflectance change in non-absorbing layers is directly proportional to the square of the total thickness of the layers. In an absorbing layer, it has been shown that the thickness of each layer is equal to the surface roughness of the identical double layer system. The extinction coefficients of both layers are directly proportional to the thickness of that layer.     

Radiation model of the system scattering layer + rough surface in the microwave range

Institute of Radio Engineering and Electronics, Academy of Sciences of the USSR. Translated from Izvestiya Vysshykh Uchebnykh Zavedenii, Radiofizika, Vol. 34, No. 4, pp. 472–476, April, 1991.     

CEMS,CXMS and X-ray investigation of the microstructure of the surface layer in plasma nitrocarburized steel

The microstructure of the compound layer formed by plasma nitrocarburizing of steels has been investigated by means of conversion electron, conversion X-ray Mössbauer spectroscopy (CEMS, CXMS) and X-ray diffraction. A carbon steel C35 was plasma nitrocarburized using a gas mixture of nitrogen, hydrogen and methane. The compound layer was mechanically removed in steps, followed by Mössbauer and X-ray investigations. It was found that this layer consists of different nitrides and carbides. Their concentrations vary with the depth below the surface.     

Boundary graphene layer effect on surface plasmon oscillations in a quantum plasma half-space

The effect of graphene on unique features of surface plasmon-polariton excitations near the interface of vacuum and quantum plasma half-space is explored using a quantum hydrodynamic model including the Fermi electron temperature and the quantum Bohm potential together with the full set of Maxwell equations.It is found that graphene as a conductive layer significantly modifies the propagation properties of surface waves by making a change on the corresponding wave dispersion relation.It is shown that the presence of graphene layer on the interface of vacuum and plasma leads to a blue-shift in the surface Plasmon frequency.The results of present study must be contributed to the modern electronic investigations.