Fusion edge plasmas

Y. Hahn, Electron-ion recombination processes in plasmas, in R. Janev (Ed.), Atomic and Molecular Processes in Fusion Edge Plasmas, Plenum Publications Corp., New York, 1995, p. 91. 

Modeling of Fusion Edge Plasmas Atomic and Molecular Data Issues... 

Currently only Monte Carlo approaches can handle the wide range of surface geometries, reflection models and support complex atomic and molecular processes that occur in real fusion edge plasmas. Therefore the neutral particle transport (ionization, dissociation, etc.) as well as impurity ion transport in the edge region of fusion plasmas is often treated by Monte Carlo simulation on a kinetic level. 

From collisionality considerations in fusion edge plasmas one can conclude that a collisional transport model for the charged plasma components is adequate at least for transport along the field lines. By contrast, core plasma transport in the only relevant transport directions there, across the magnetic field, is often studied on the basis of the Vlasov-equation (see below), e.g., in the drift-wave theory of plasma transport. 

It is an experimental fact that cross field transport in fusion edge plasmas cannot be realistically described by the classical Coulomb collision effects. Strictly then a term — q,a/maV (((f (f/Q)) resulting from turbulent fluctuations in the electric field SE and in the phase space density Sfa must be included on the right-hand side of (2.1), see [3]. 

D. Reiter Modeling of Fusion Edge Plasmas. In this volume... 

In order to identify the location of the carbon sources, Zeeman spectroscopy has turned out to be a valuable tool. The principles of the influence of the magnetic field on carbon and oxygen ions in the fusion edge plasma (B = 1 to 10 T) have been outlined in [19,20]. The method works well when the Zee-man (Paschen-Back) effect plays an important, or dominant, role in relation to other broadening mechanisms. In general the line splitting is given by ... 

Hydrocarbon molecules are abundant constituents of planetary atmospheres and major compounds in combustible gas mixtures and in fusion edge plasmas [7-11]. Methane is the simplest of these hydrocarbon molecules. Acetylene, C2H2, is the simplest hydrocarbon molecule that contains 2 carbon atoms. Thus absolute total and partial photon [24-27] and electron [15,28-34] ionization cross-sections and nascent fragment ion energy distributions [19,20,28,36-40] have been studied extensively for these molecules. For the deuterated methane molecule electron impact ionization and dissociative ionization cross-sections were determined for the CD (x=l—4) molecule and radicals applying a fast neutral beam technique [41]. Electron impact total ionization cross-sections have been determined also theoretically applying the BEB (Binary-Encounter-Bethe) model [42], the DM (Deutsch-Mark) method [43] and the JK (Jain-Khare) method [44], Partial electron impact ionization cross-sections were calculated for methane [45,46] as well as total electron impact cross-sections for various CH radicals [47]. The dissocia-... 

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