Thermal-Mechanical Analysis for In-Vessel Diagnostic Components in W7-X

For long pulse plasma operation of the W7-X stellarator, the most serious challenge for the design of in-vessel diagnostic systems is the thereto-mechanical problem. Thermal load from convective losses and from plasma radiation can be as high as 500 kW/m(2) at some locations close to plasma. The typical thermal load from plasma radiation alone ranges from several 10 to 100 kW/m2 as derived from 3-D Monte-Carlo simulations. A finite element analysis (FEA-ANSYS) is conducted for a better understanding of thermo-mechanical effects on in-vessel diagnostic components and to guide the design of the diagnostic system for steady state operation. All in-vessel diagnostic components require active cooling. Besides for long-pulse plasma operation optical components must be optimized to minimize thermal deformations. In this paper, we present the thereto-mechanical analyses of the CO2-laser interferometer retro-reflectors, the diamagnetic loops and the soft X-ray multi camera tomography system (XMCTS).