BOUNDARY MODELING OF THE STELLARATOR WENDELSTEIN 7-X

To justify the design of the divertor plates in W7-X the magnetic fiel ds of finite-beta HELIAS equilibria for the so-called high-mirror case have been computed for various average beta-values up to [P] = 0.04 w ith the NMEC free-boundary equilibrium code [S.P. Hirshman, W.I. van R ij and W.I. Merkel, Comput. Phys. Commun. 43 (1986) 143] in combinatio n with the newly developed MFBE (magnetic field solver for finite-beta equilibria) code. In a second study the unloading of the target plate s by radiation was investigated. The B2 code [B.J. Braams, Ph.D. Thesi s, Rijksuniversiteit Utrecht (1986)] was applied for the first time to stellarators to provide of a self-consistent modelling of the SOL inc luding effects of neutrals and impurities.