Diagnostics of Optical Characteristics and Parameters of Gas-Discharge Plasma Based on Mercury Diiodide and Helium Mixture

The results of diagnostics of spectral, temporal and energy characteristics of the radiation of gas-discharge plasma in a mixture of mercury diiodide vapor with helium in the spectral range of 350 - 900 nm, and the plasma parameters in the range of reduced electric field E/N = 1 - 100 Td are presented. The plasma is created in the barrier discharge device with a cylindrical aperture. The electrodes are placed 0.2 m in length at a distance of 0.015 m. The amplitude of the pump pulse, the duration and frequency were 20 - 30 kV, 150 ns and 1 - 20 kHz, respectively. Radiation in the visible region of the spectrum of mercury monoiodide exciplex molecule is revealed. Regu larities in the optical characteristics of the plasma, depending on the partial pressures of the components of the mixture, the electron energy distribution function, mean electron energy, specific losses of discharge power on the process of dissociative excitation of mercury monoiodide (state B2Σ+1/2) molecules as well as the rate constant of dissociative excitation of mercury monoiodide molecules in working mixture depending on the given reduced electric field are established.

Discovery of gas-discharged pits(gas pit)in the plains of the Yellow River delta

A kind of special sedimentary structures are developed in the overwater plains of the Yellow River delta. They look like funnels: round or nearly round, concave of pit-like, with a diameter ranging from several centimeters to 20 or 30 cm, and depth from several millimeters to over 20 cm. There is a vertical pipe (called gas discharging conduit) in the center, with a diameter of several millimeters to 1 cm, depth of several centimeters to more than 10 cm. There may be a lip-like relief (called 'lip-like relief') on the periphery or some parts of the periphery, with ring structures showing horizontal stratification on the inner margin. Plant debris carbonized, plant fragments or dark-colored minerals may sometimes be found in the center of the pits. Such structures are usually developed in silt (with minor clay laminations), often underlain by one or more thin layers of mud matter. Our studies find that they are genetically related with gas discharging of organic matter during biological degradation.

Non-Uniform Axial Electric Field in Argon Glow Discharge Plasma

The non-uniform argon dc glow discharge plasma system has been constructed in a very special design to investigate the effects of variable tube radius on plasma parameters. By using isolated computer controlled three couples of a double probe （TCDP） system, the electron temperature, electron density, the reduced electric field, and electron drift velocity are measured at low and intermediate pressures. It is shown that the electron temperature and reduced electric field （density） decreases （increases） as the radius decreases, at low discharge current and pressures. For large radius regions, at high discharge currents and pressures, the behaviour of the plasma parameters of specially reduced electric field change similarly to those in a uniform discharge system.