Plasma and Fusion Research

Volume 14, 1405163 (2019)

Regular Articles

Improved Design of a Cartridge-Type Helical Blanket System for the Helical Fusion Reactor FFHR-b1
Junichi MIYAZAWA1,2), Hitoshi TAMURA1), Teruya TANAKA1,2), Yukinori HAMAJI1), Makoto KOBAYASHI1), Takanori MURASE1), Sho NAKAGAWA1), Takuya GOTO1,2), Nagato YANAGI1,2), Akio SAGARA1,2) and the FFHR Design Group
National Institute for Fusion Science, 322-6 Oroshi, Toki, Gifu 509-5292, Japan
SOKENDAI (The Graduate University for Advanced Studies), 322-6 Oroshi, Toki, Gifu 509-5292, Japan
(Received 26 July 2019 / Accepted 24 October 2019 / Published 22 November 2019)


The cartridge-type helical blanket system called the CARDISTRY-B has been proposed for the helical fusion reactor FFHR-d1. The CARDISTRY-B is aimed at easy construction and maintenance. However, there remain many issues in the design. For example, these include a large number of cartridges, no tangential ports, low compatibility with the helical divertor, and others. To solve these issues, an improved design of the cartridge-type blanket is proposed and named the CARDISTRY-B2. This is composed of the tritium breeding blanket (BB) filled with the flowing molten salt and the neutron shielding blanket (SB) filled with the tungsten-carbide. The number of the BB (or, SB) cartridges in the 1/10 section of the full torus are reduced from 32 to 17 (or, from 44 to 17). Tangential ports for the neutral beam injection heating are newly equipped together with the multi-purpose blanket cartridge. Compatibility with the helical divertor is also improved. The BB cartridges are fixed on the fixing units set on the top of the SB. No other part of the BB is touching the SB except the fixing ribs. The SB cartridges surround the superconducting magnet coils and work as the cryostat inside the vacuum vessel. This makes the large bellows for the large maintenance ports unnecessary. Details of the CARDISTRY-B2 designed for a small helical fusion reactor FFHR-b1 are described in this paper.


heliotron, fusion reactor, molten salt blanket, neutron shield, thermal shield, LHD, FFHR

DOI: 10.1585/pfr.14.1405163


  • [1] A. Sagara et al., Nucl. Fusion 57, 086046 (2017).
  • [2] A. Komori et al., Fusion Sci. Technol. 58, 1 (2010).
  • [3] J. Miyazawa et al., Fusion Eng. Des. 136, 1278 (2018).
  • [4] J. Miyazawa et al., Fusion Eng. Des. 146, 2233 (2019).
  • [5] Y. Someya et al., Fusion Eng. Des. 124, 615 (2017).
  • [6] J. Miyazawa et al., Plasma Fusion Res. 12, 1405017 (2017).
  • [7] T. Goto et al., Plasma Fusion Res. 11, 2405047 (2016).
  • [8] T. Murase et al., Fusion Eng. Des. 136, 106 (2018).
  • [9] S. Hong et al., 13th ISFNT (25-29 Sep., 2017, Kyoto, Japan), P3-107.
  • [10] A. Loving et al., Fusion Eng. Des. 89, 2246 (2014).
  • [11] H. Utoh et al., Fusion Eng. Des. 124, 596 (2017).
  • [12] D.A. Petti et al., Summary Report of Japan-US Joint Project (JUPITER-II) (FuY 2001-2006) NIFS-PROC-71, 74 (2008).
  • [13] J. Miyazawa et al., Fusion Eng. Des. 125, 227 (2017).
  • [14] T. Ohgo et al., Plasma Fusion Res. 14, 3405050 (2019).