ITER Thermal Shield (TS) reduces radiation heat loads from vacuum vessel and cryostat to superconducting magnet structure. One of the key process among the fabrication of TS is the silver electroplating to reduce the emissivity. Requirement on emissivity of TS surface after silver coating is below 0.05 at the room temperature. In practice, inevitable non-coated areas exist due to the intrinsic geometry of TS. These local defects can be repaired by attaching thin silver coated patch with spot welding. This paper treats structural characteristics on the spot welding of silver coated plates. Strength of spot welding is measured by tensile shear test. Distances between spot welding are verified by finite element analysis considering temperature deviation between TS surface and patch. Finally, thermal stress analysis for the several applications to TS main components are presented.

中文翻译：

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ITER热屏蔽镀银贴片点焊研究

ITER 热屏蔽 (TS) 减少了从真空容器和低温恒温器到超导磁体结构的辐射热负荷。TS制造的关键工艺之一是电镀银以降低发射率。镀银后的TS表面发射率要求在室温下低于0.05。在实践中，由于 TS 的固有几何形状，不可避免地存在非涂层区域。这些局部缺陷可以通过点焊贴上薄银涂层补丁来修复。本文研究了镀银板点焊的结构特点。点焊强度通过拉伸剪切试验来测量。考虑TS表面和补片之间的温度偏差，通过有限元分析验证点焊之间的距离。最后，介绍了 TS 主要部件的几种应用的热应力分析。