The LHD-type helical fusion reactor FFHR has been studied to realize steady-state fusion power generation without a need for current drive and free from disruption. The conceptual design studies of FFHR are steadfastly progressing based on the presently ongoing experiments in the Large Helical Device (LHD). In order to enhance the attractive features of the base option of FFHR-d1A, which is similar to LHD, configuration optimization is being considered for FFHR-d1C. Slight modification of the helical coil trajectory gives an improved condition both for the plasma confinement and the MHD stability. In order to overcome the difficulty for construction and maintenance associated with the three-dimensional structure, innovative ideas are being explored for the superconducting magnet, divertor, and blanket. For the superconducting helical coils, the joint-winding method confirms a fast manufacturing process. The helical divertor is reexamined and practical feasibility is discussed. The maintenance method of the helical divertor and the helically-segmented breeder blanket is a serious issue and a plausible solution is proposed.

中文翻译：

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螺旋聚变反应堆FFHR-d1概念设计进展

研究了LHD型螺旋聚变反应堆FFHR，以实现稳态聚变发电，无需电流驱动，不受干扰。基于目前正在进行的大型螺旋装置 (LHD) 实验，FFHR 的概念设计研究正在稳步推进。为了增强 FFHR-d1A 与 LHD 类似的基本选项的吸引力，正在考虑对 FFHR-d1C 进行配置优化。螺旋线圈轨迹的轻微修改为等离子体约束和 MHD 稳定性提供了改进的条件。为了克服三维结构带来的施工和维护困难，超导磁体、偏滤器和覆盖层正在探索创新思路。对于超导螺旋线圈，联合缠绕方法证实了快速的制造过程。重新检查了螺旋偏滤器并讨论了实际可行性。螺旋偏滤器和螺旋分段繁殖毯的维护方法是一个严重的问题，并提出了一个合理的解决方案。