@article{oai:nifs-repository.repo.nii.ac.jp:00010714, author = {YANAGI, Nagato and GOTO, Takuya and MIYAZAWA, Junichi and MIYAZAWA, Jun-ichi and TAMURA, Hitoshi and TERAZAKI, Yoshiro and ITO, Satoshi and TANAKA, Teruya and HASHIZUME1, Hidetoshi and SAGARA, Akio}, issue = {1}, journal = {Journal of Fusion Energy}, month = {Oct}, note = {0000-0002-4489-8241, 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.}, pages = {147--161}, title = {Progress in the Conceptual Design of the Helical Fusion Reactor FFHR-d1}, volume = {38}, year = {2018} }