Contributions To Plasma Physics 

About: Contributions To Plasma Physics is an academic journal published by Wiley. The journal publishes majorly in the area(s): Plasma & Electron. It has an ISSN identifier of 0863-1042. Over the lifetime, 3953 publications have been published receiving 36164 citations. The journal is also known as: Contributions to plasma physics (1985. Print).

Plasma edge physics with B2-eirene

Abstract: The B2-Eirene code package was developed to give better insight into the physics in the scrape-off layer (SOL), which is defined as the region of open field-lines intersecting walls. The SOL is characterised by the competition of parallel and perpendicular transport defining by this a 2D system. The description of the plasma-wall interaction due to the existence of walls and atomic processes are necessary ingredients for an understanding of the scrape-off layer. This paper concentrates on understanding the basic physics by combining the results of the code with experiments and analytical models or estimates. This work will mainly focus on divertor tokamaks, but most of the arguments and principles can be easily adapted also to other concepts like island divertors in stellarators or limiter devices. The paper presents the basic equations for the plasma transport and the basic models for the neutral transport. This defines the basic ingredients for the SOLPS (Scrape-Off Layer Plasma Simulator) code package. A first level of understanding is approached for pure hydrogenic plasmas based both on simple models and simulations with B2-Eirene neglecting drifts and currents. The influence of neutral transport on the different operation regimes is here the main topic. This will finish with time-dependent phenomena for the pure plasma, so-called Edge Localised Modes (ELMs). Then, the influence of impurities on the SOL plasma is discussed. For the understanding of impurity physics in the SOL one needs a rather complex combination of different aspects. The impurity production process has to be understood, then the effects of impurities in terms of radiation losses have to be included and finally impurity transport is necessary. This will be introduced with rising complexity starting with simple estimates, analysing then the detailed parallel force balance and the flow pattern of impurities. Using this, impurity compression and radiation instabilities will be studied. This part ends, combining all the elements introduced before, with specific, detailed results from different machines. Then, the effect of drifts and currents is introduced and their consequences presented. Finally, some work on deriving scaling laws for the anomalous turbulent transport based on automatic edge transport code fitting procedures will be described. (© 2006 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim)

Atmospheric Pressure Plasma Jet for Medical Therapy: Plasma Parameters and Risk Estimation

Abstract: A set of minimum standards which have to be adjusted if a plasma source is intended for therapeutic applications has been defined. The main performance parameters of an optimized low-temperature atmospheric pressure plasma source were investigated and controlled. This has been done to discuss global risk factors that have to be avoided during application. By using this minimum standard set of parameters it should become possible to directly compare different atmospheric plasma sources for special biomedical applications and to derive optimum treatment parameters found on different sources and locations. Up to now a strict comparison is mainly done indirectly by investigating the effect of the plasma treatment on the surface. Temperature, thermal load, UV radiation, production of radicals and toxic gases and the resulting biological effects have been investigated to minimize risk factors and to indicate first meaningful parameter ranges (dosages) for therapeutic applications. The mix of these parameters (like mixing a cocktail) has to be adapted individually for each application. For practical use constant energetic conditions at the visible tip of the investigated jet could be observed, therefore it could be recommended to adjust the visible tip of the pen in such a way that it just touches the surface.

Cross-Sections, Rate Constants and Transport Coefficients in Silane Plasma Chemistry

Abstract: This paper presents a critical review of the basic data concerning the physics and chemistry of low pressure SiH 4 glow discharges used to deposit hydrogenated amorphous silicon films (a-Si:H). Starting with an updated table of thermochemical data, we analyze the gas-phase elementary processes consisting of i) electron-molecule collisions, ii) ion-molecule collisions, iii) neutral-neutral collisions, iv) other electron and ion collisions involving electron-ion and ion-ion recombination, electron attachment on radicals and detachment of anions, and v) cluster growth kinetics in dusty plasmas. Experimental data or theoretical estimates are given and discussed in terms of cross-sections. collision and reaction rate constants, and transport coefficients. We also analyze the surface processes and reaction probabilities of ions, radicals and molecules.

Practical Improvements to the Lee‐More Conductivity Near the Metal‐Insulator Transition

Abstract: The wide-range conductivity model of Lee and More [1] is modified to allow better agreement with recent experimental data and theories for dense plasmas in the metal-insulator transition regime. Modifications primarily include a new ionization equilibrium model, consisting of a smooth blend between single ionization Saha (with a pressure ionization correction) and the generic Thomas-Fermi ionization equilibrium, a more accurate treatment of electron-neutral collisions using a polarization potential, and an empirical modification to the minimum allowed collision time. These simple modifications to the Lee-More algorithm permit a more accurate modeling of the physics near the metal-insulator transition, while preserving the generic Lee-More results elsewhere.

Models and Numerics in the Multi-Fluid 2-D Edge Plasma Code EDGE2D/U

Abstract: The JET edge plasma code EDGE2D/U is designed to simulate divertor configurations. We describe here the physical model and the numerical techniques used.