Erosion of ITER-FEAT vertical targets during off-normal events

For calculation of target erosion, the plasma shield formation and its shielding efficiency in front of the target have to be known, For this purpose the 2-D multifluid radiation magnetohydrodynamics (R-MHD) code FOREV-2 was developed. FOREV-2 validation is completed with numerical simulation of plasma shield dynamics and erosion of vertical graphite targets and comparison with experimental results obtained at the TRINITI Troitsk MK-200 UG plasma gun facility. The observed drift of target plasma along the surface of a vertical target in these experiments can be described by use of the classical Spitzer diffusion coefficient in the solution of the multi-dimensional magnetic field equations. Therefore, plasma turbulence does not occur in the experimental plasma shields. The observed upstream shift of the erosion profiles can be explained by the reradiation from the expanding plasma shield. Finally results of a damage analysis for tungsten vertical targets are presented for off-normal events typical for ITER-FEAT. (C) 2001 Elsevier Science BN. All rights reserved.