Temperature Plasma (temperature + plasma)

Distribution by Scientific Domains

Kinds of Temperature Plasma

  • low temperature plasma


  • Selected Abstracts


    Sheath in Front of a Negatively Biased Collector that Emits Electrons and is Immersed in a Two Electron Temperature Plasma

    CONTRIBUTIONS TO PLASMA PHYSICS, Issue 8 2005
    T. Gyergyek
    Abstract An extension of a recently published [Gyergyek T., ,er,ek M. Contrib. Plasma Phys., 45, (2005), 89] one dimensional fluid model of the sheath formation in front of a floating electrode (collector) that emits secondary electrons and is immersed in a two-electron temperature nonmagnetized, collisionless plasma is presented. The electron velocity distribution function is assumed to be a two-temperature maxwellian, while the singly charged positive ions and the emitted electrons are assumed to be monoenergetic. It is assumed that the electrons in the pre-sheath potential drop obey the Boltzmann relation, so that a larger fraction of the hot than of the cool electrons can penetrate to the sheath edge. Our model predicts that the collector can in some cases have 3 and in some cases, when the emission of electrons from the collector is critical, even 5 different floating potentials at the same hot to cool electron temperature and density ratios very far away from the collector. ( 2005 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim) [source]


    Comparative Study of the Carbonisation of CoTMPP by Low Temperature Plasma and Heat Treatment

    PLASMA PROCESSES AND POLYMERS, Issue 6 2010
    Iris Herrmann
    Abstract Low temperature plasma (LTP) treatment of cobalt-tetramethoxyphenylporphyrin (CoTMPP) has been applied as a promising alternative method to the conventional heat treatment in order to attain highly active catalysts for the electroreduction of oxygen. In this contribution it is shown that CoTMPP can be completely transformed into a carbon matrix by adjusting adequate LTP parameters. The carbonisation process of CoTMPP is investigated at different operation conditions by Raman and IR spectroscopy and compared with the structural features of the heat-treated samples. As a result it appears that the LTP occurs via a different carbonisation process, which yields in a more homogeneously defined molecular carbon structure. [source]


    Ion-Conducting Probes for Low Temperature Plasmas

    CONTRIBUTIONS TO PLASMA PHYSICS, Issue 5-7 2008
    S. A. Meiss
    Abstract Probes interacting with a low temperature plasma are typically built of electron conducting materials, mostly metals. We apply yttria-stabilized zirconia (YSZ) which is oxygen ion conducting at elevated temperatures and which is a typical solid electrolyte with high ionic and negligible electronic conductivity. The processes at the plasma|YSZ interface are discussed and first results of measurements with ion-conducting single- and double-probes in oxygen containing radio frequency plasmas are presented. ( 2008 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim) [source]


    New Developments of Self-emitting Electrostatic Probes for use in High Temperature Plasmas

    CONTRIBUTIONS TO PLASMA PHYSICS, Issue 7-8 2004
    M. A. Fink
    Abstract Emissive electrostatic probes for the use in fusion experiments must be able to sustain significantly higher thermal loads than in low-temperature plasma experiments. Several types of probe design are discussed, the results from the use of such probes in the edge plasma of the Wendelstein 7-AS stellarator are presented and compared with the predictions of emissive and non-emissive probe models. ( 2004 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim) [source]


    Ion-Conducting Probes for Low Temperature Plasmas

    CONTRIBUTIONS TO PLASMA PHYSICS, Issue 5-7 2008
    S. A. Meiss
    Abstract Probes interacting with a low temperature plasma are typically built of electron conducting materials, mostly metals. We apply yttria-stabilized zirconia (YSZ) which is oxygen ion conducting at elevated temperatures and which is a typical solid electrolyte with high ionic and negligible electronic conductivity. The processes at the plasma|YSZ interface are discussed and first results of measurements with ion-conducting single- and double-probes in oxygen containing radio frequency plasmas are presented. ( 2008 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim) [source]


    High Density Cascaded Arc Produced Plasma Expanding in a Low Pressure Region

    CONTRIBUTIONS TO PLASMA PHYSICS, Issue 5-6 2004
    R. P. Dahiya
    Abstract Experimental measurements made in thermal expanding argon, nitrogen and hydrogen plasmas with particular reference to molecular kinetics, surface nitriding and intense flux in magnetic field are discussed. The plasma is generated in a cascaded arc source. In the presence of molecular species (H2 / N2) dissociative recombination reactions involving rovibrationally excited molecules contribute to a rapid decay of the plasma species, especially for hydrogen system. A combination of nitrogen and hydrogen plasma gives an efficient plasma nitriding process, which has been applied for case hardening of machinery components. In another setup a strong axial magnetic field (0.4 - 1.6 T) contains and substantially prolongs the plasma beam in the chamber. In the presence of the magnetic field, an additional current drawn through the plasma beam using a biased substrate and a ring creates dense low temperature plasma giving a new unexplored plasma regime. The plasma kinetics are modified in this regime from the recombining to the ionising mode. When the additional current in the argon plasma beam exceeds 30 A, its light emission is predominantly in the blue region. With the additional current and magnetic field, the emission intensity of H, and other lines arising from higher energy levels in the hydrogen Balmer series is enhanced. ( 2004 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim) [source]


    Polysiloxane Softener Coatings on Plasma-Treated Wool: Study of the Surface Interactions

    MACROMOLECULAR MATERIALS & ENGINEERING, Issue 7 2007
    Cristina Canal
    Abstract Low temperature plasma (LTP) improves the shrink-resistance of wool fabrics but impairs their softness, so different polysiloxane coatings were applied. Modifications in surface hydrophilicity and topography of fabrics and fibres have been recorded through drop test, contact angle and SEM, respectively. LTP improves the deposition of the polysiloxanes which, depending on their functionalities alter the original hydrophilicity of the wool surface. Softness and shrink-resist results of the fabrics point out to a possible relationship between hydrophilicity of the wool fibre surface and the shrinkage behaviour of the fabrics. A possible mechanism of interaction between the different polysiloxane groups and the surface of untreated (UT) and LTP-treated wool is proposed. [source]


    Comparative Study of the Carbonisation of CoTMPP by Low Temperature Plasma and Heat Treatment

    PLASMA PROCESSES AND POLYMERS, Issue 6 2010
    Iris Herrmann
    Abstract Low temperature plasma (LTP) treatment of cobalt-tetramethoxyphenylporphyrin (CoTMPP) has been applied as a promising alternative method to the conventional heat treatment in order to attain highly active catalysts for the electroreduction of oxygen. In this contribution it is shown that CoTMPP can be completely transformed into a carbon matrix by adjusting adequate LTP parameters. The carbonisation process of CoTMPP is investigated at different operation conditions by Raman and IR spectroscopy and compared with the structural features of the heat-treated samples. As a result it appears that the LTP occurs via a different carbonisation process, which yields in a more homogeneously defined molecular carbon structure. [source]


    HI , the window to the early universe in X-rays

    ASTRONOMISCHE NACHRICHTEN, Issue 1-2 2003
    J. Kerp
    Abstract A detailed understanding of the soft X-ray background (SXRB) is of high importance for the next generation of X-ray telescopes, which will focus on early universe objects. Because of their high redshift the characteristic X-ray emission of the early universe objects will be observable in the soft X-ray energy domain below E = 1 keV. In this energy regime the photoelectric absorption of the galactic interstellar medium attenuates the X-ray emission most strongly. The confusion with the spatially highly variable galactic soft X-ray emission might be an additional severe problem to disentangle the emission of the early universe object and the SXRB. We present the cross correlation of the Leiden/Dwingeloo HI 21-cm line survey with the ROSAT all-sky survey. The analyses disclose the existence of a single temperature plasma within the Milky Way halo. The strength of the photoelectric absorption is quantitatively traced by the distribution of the HI emission across the whole sky. Both findings in combination open the window to the highly redshift early universe objects. [source]


    Modulated Induction Thermal Plasmas , Fundamentals and Applications ,

    IEEJ TRANSACTIONS ON ELECTRICAL AND ELECTRONIC ENGINEERING, Issue 4 2009
    Yasunori Tanaka Member
    Abstract This paper reviews fundamentals and applications of modulated induction thermal plasmas that have been developed. The coil-current modulation of the order of several hundreds amperes allows one to make a large disturbance in high-pressure and high temperature plasmas, and also to control the temperature and radical density in thermal plasmas in time domain. Examples will be introduced on application of the modulated induction thermal plasma to surface modification, in which thermally and chemically nonequilibrium effects are essential in temperature and radical density fields. Finally, dynamic behaviors of an arbitrary-waveform modulated induction thermal plasma that has recently been developed were also introduced as a new type of modulated induction thermal plasmas. 2009 Institute of Electrical Engineers of Japan. Published by John Wiley & Sons, Inc. [source]