Effects of thick blanket modules on the resistive wall modes stability in ITER

Abstract

In this paper we analyse the effects of three-dimensional ITER conducting structures on resistive wall modes (RWMs) growth rates. In particular, a highly detailed description of the thick ITER blanket modules (BMs) is given, with a volumetric mesh including slits, holes, pockets and an anisotropic resistivity to take into account cooling channels. Also other important details of the vacuum vessel are included, such as the outer triangular support, copper cladding, port extensions. To deal with the resulting huge computational model, a fast/parallel implementation of the CarMa code has been successfully developed and used. Both n = 1 (kink-like instability) and n = 0 (axisymmetric vertical instability) RWM are considered. The computational model is validated, on 2D test cases, by the consistency of fits to the growth rate with no-wall and ideal-wall limits calculated with MARS-F. Considering the full 3D model, the detrimental effect of ports on n = 1 growth rates is essentially counteracted by the beneficial effect of BMs.