Contrib. Plasma Phys. 46, No. 1-2, 3 – 191 (2006) / DOI 10.1002/ctpp.200610001 Plasma Edge Physics with B2-Eirene R. Schneider ∗1 , X. Bonnin 2 , K. Borrass 3 , D. P. Coster 3 , H. Kastelewicz 4 , D. Reiter 5 , V. A. Rozhansky 6 , and B. J. Braams 7 1 Max-Planck-Institut f ¨ ur Plasmaphysik, EURATOM Association, Teilinstitut Greifswald, Wendelsteinstr.1, D- 17491 Greifswald, Germany 2 LIMHP, CNRS-UPR 1311, Universit´ e Paris XIII, 99, avenue JB Cl´ ement, F-93430 Villetaneuse, France 3 Max-Planck-Institut f ¨ ur Plasmaphysik, EURATOM Association, Boltzmannstraße 2, D-85748 Garching, Ger- many 4 Max-Planck-Institut f ¨ ur Plasmaphysik, EURATOM Association, Mohrenstraße 41, D-10117 Berlin, Germany 5 Institut f ¨ ur Plasmaphysik, Forschungszentrum J ¨ ulich, Trilateral Euregio Cluster, D-52425 J¨ ulich, Germany 6 Saint-Petersburg State Polytechnical University, Polytechnicheskaya 29, 195251 St. Petersburg, Russia 7 Emory University, Mathematics and Science Center, 400 Dowman Drive, Atlanta, Georgia 30322, USA Received 8 March 2005, accepted 18 September 2005 Published online 25 Januar 2006 Key words Plasma edge, plasma modelling, plasma codes, plasma transport boundary layer. PACS 52.27.Lw, 52.65.Rr, 52.50.Qt 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 compe- tition 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. c  2006 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim ∗ Corresponding author: e-mail: Ralf.Schneider@ipp.mpg.de, Phone: +49 3834 882400, Fax: +90 3834 882409 c  2006 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim