Thermal and structural analysis of the W7-X magnet heat radiation shield

The thermal insulation of the W7-X – cryostat consists of multi-layer insulation (MLI) and an actively cooled thermal shield. The shield is cooled by He gas flowing in pipes, which are flexibly attached via copper braids. The paper presents the basic mechanical and thermal layout of the complex plasma vessel shield, which is made of a glass fibre compound with three embedded copper nets. echanical loads on the shield are electromagnetic forces resulting from rapid shut down of the magnet system, and the self weight. Design and calculations were performed iteratively to determine the number as well as orientation of electrical insulation gaps within the copper nets, and the number and positions of the supports. shown that the maximum displacements of the panels, the maximum forces on the supports, and the shield temperatures fulfil the requirements.