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AbstractAbstract

[en] The electrical conductivity of partially ionized sodium-plasmas is calculated starting from the electron kinetic equation taking into account the electron-electron, electron-ion and the elastic electron-atom scattering. The transport cross sections follow from the scattering phase shifts solving the corresponding Schroedinger's equation with effective interaction potentials. In order to calculate the plasma composition a coupled law of mass action is used. The electrical conductivity of the plasma mixture is then discussed for densities 10

^{16}-10^{21}cm^{-3}and for temperatures 3000 K-10000 K. (author)Primary Subject

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5. international workshop on non-ideal plasmas; Wustrow (German Democratic Republic); 26-30 Sep 1988

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[en] The subject is covered under following headings: 1. introduction; 2. the statistical description, the Gibbs ensemble; 3. smoothing of microscopic quantities over physically infinitesimal scales, the Gibbs ensemble in the kinetic theory; 4. the constructive role of the dynamical instabilities of motion in the kinetic theory; 5. the Liouville and the Vlasov equations; 6. the kinetic equations for the smoothed distribution function

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5. international workshop on non-ideal plasmas; Wustrow (German Democratic Republic); 26-30 Sep 1988

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[en] One dimensional electrostatic potentials in plasmas have been studied using the Bohm equation. The derivation of the equation has been discussed from a viewpoint of the characteristics theory for partial differential equations. With specifying Cauchy data related to real characteristics, the original system of partial differential equations reduces to an eigenvalue problem associated with the Bohm equation. Wavy solutions related to the ion acoustic solitons bifurcate from the monotone asymptotic Bohm sheath solutions through structural instabilities with fluctuations. (author)

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[en] A nonlinear collisional-radiative model for determination of production of electrons, positive and negative ions, excited atoms, and spectral and continuum line intensities in stationary partially ionized atomic hydrogen is presented (11 000 K≤T

_{e}≤15 000 K, 10^{10}cm^{-3}≤N_{t}≤10^{18}cm^{-3}). Transport of radiation is included by coupling the rate equations for production of the electrons, ions, and excited atoms with the radiation escape factors, which are not constant but depend on plasma conditions. It is found that the contribution of the negative ion emission to the total continuum emission can be important. Comparison of the calculated total continuum emission coefficient, including the negative ion emission, is in good agreement with experimental resultsPrimary Subject

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[en] Marfes are toroidally symmetric bands of radiating plasma that form at the smaller major radius side of tokamaks. A model of marfes and density limit is studied. Though very simple, the model provides alternative explanation of the marfe onset beyond the density limit, explains the marfe poloidal location and states that a marfe can onset only when a particular criterion is is satisfied, involving the central temperature and the temperature of intensive impurity radiation. Density fluctuations observed in marfe experiments are explained as the manifestation of sound waves which are intermediate between the isothermal and adiabatic. (author)

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17. EPS conference on controlled fusion and plasma heating; Amsterdam (Netherlands); 25-29 Jun 1990

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[en] In JFT-2M, impurity behaviors during the H-mode were studied by the spectroscopic method. During the H-mode without Edge-Localized Modes(ELMs), emissions of highly ionized ion lines increased with time, although emissions of less ionized ion lines decreased just after the H-mode transition and kept constant with time. It was found from time behavior of emissions of impurity ion lines and the iron-ion density profiles that not only metal impurity but also light impurity accumulated near the plasma center during the ELM-free H-mode. During the H-mode with ELMs, the impurity accumulation was relaxed by the onset of this instability compared with the ELM-free H-mode. (author)

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[en] Single and two particle porperties in dense plasma are discussed in connection with their role in the mass action law for a partially ionized plasma. The two particle bound states are nearly density independent, while the continuum is essentially shifted. The single particle states are damped, and their energy has a negative shift and a parabolic behaviour for small momenta. (orig.)

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[en] Explaining anomalous plasma transport in magnetic confinement devices requires a deeper understanding of the underlying turbulent processes than presently exists. In this work, Markovian closures are built by imposing the constraints of realizability, conservation of quadratic invariants, and covariance to arbitrary linear transformations. One such closure is solved numerically. The results compare favorably to the data available from numerical simulations

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[en] The article presents results of probe measurements of the electron and ion densities in an argon rf discharge. The electron density is determined from the electron probe current at the space potential which is estimated by extrapolation of the linear part of the probe electron current dependence to the plasma potential. The plasma potential is calculated from the floating potential. The positive ion density is determined from the probe ion saturated current according to collisional Kopiczynski and Zakrewski model. The agreement between the electron and ion densities is better than in the work of Hopkins and Graham, where the collisionless Laframboise theory is used under similar conditions. (orig.)

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[en] A method for obtaining a medium pressure (p∝1 torr), how power (< 100 W), RF-generated plasma jet, suitable for chemical kinetics studies and technological applications is described. Though various supply gases can be used to create the plasma jet, only results on the properties of a nitrogen jet are given in this paper with an emphasis on some spectral and electrical characteristics. The emission spectra of the nitrogen jet are discussed and spatial distributions of the NH(A

^{0}Π_{g}, υ'=0) in the bulk of the postdischarge plasma are calculated from the intensity of their vibrational bands. Electrical space resolved double probe measurements and the spatial distributions of the electron density and temperature in the plasma jet are also presented. Possible applications are shortly discussed. (orig.)Primary Subject

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