Deposition of planar waveguide structures with a fluorosilicate shell on silicon and quartz substrates in a local microwave discharge of reduced pressure.

An efficient method of gas-phase multilayer heterogeneous deposition of quartz and fluorosilicate glass in a non-isothermal plasma of a resonant local low pressure microwave discharge on quartz glass substrates and silicon wafers for the optical structures formation of waveguides and other waveguide elements based on them, is presented. It is shown that the nonisothermal plasma of a resonant local low pressure microwave discharge is an effective tool for the films formation on silicon and quartz substrates, both pure silicon dioxide and doped with fluorine. The cracks presence in films doped with fluorine is not observed even at their considerable thicknesses (20…60 µm). Deposition high rates and efficiency of silica glass doped with fluorine have been achieved (up to 7 wt.% of glass doping with fluorine at a film deposition rate of more than 3 μm/min). Planar and strip multimode and single-mode optical waveguides have been created. They are the basic structures of various fiber-optic components of local information transmission systems.

Large-amplitude solitary waves in a relativistic nonisothermal plasma with warm ions

Large amplitude solitary waves in a relativistic plasma with non-isothermal electrons and finite ion temperature are studied using Sagdeev's pseudopotential technique. It is found that there exists a critical value of beta, the ratio of the temperatures of the free and trapped electrons respectively, beyond which soliton solutions cease to exist. This critical value depends on other parameters. Also the relativistic effect and finite ion temperature restrict the region of existence of solitary waves. A small amplitude expansion of the pseudopotential is derived to find different kinds of solitary waves.PACS Nos.: 52.35 Fp, 52.35 Sb, 52.35 Tc

Transport of thermal plasma above the auroral ionosphere in the presence of electrostatic ion-cyclotron turbulence

The electron component of intensive electric currents flowing along the geomagnetic field lines excites turbulence in the thermal magnetospheric plasma. The protons are then scattered by the excited electromagnetic waves, and as a result the plasma is stable. As the electron and ion temperatures of the background plasma are approximately equal each other, here electrostatic ion-cyclotron (EIC) turbulence is considered. In the nonisothermal plasma the ion-acoustic turbulence may occur additionally. The anomalous resistivity of the plasma causes large-scale differences of the electrostatic potential along the magnetic field lines. The presence of these differences provides heating and acceleration of the thermal and energetic auroral plasma. The investigation of the energy and momentum balance of the plasma and waves in the turbulent region is performed numerically, taking the magnetospheric convection and thermal conductivity of the plasma into account. As shown for the quasi-steady state, EIC turbulence may provide differences of the electric potential of ΔV≈1–10 kV at altitudes of 500 < h < 10 000 km above the Earth's surface. In the turbulent region, the temperatures of the electrons and protons increase only a few times in comparison with the background values.Key words. Magnetospheric physics (electric fields; plasma waves and instabilities)