Magnet Design Considerations for Fusion Nuclear Science Facility
Authors: Y. Zhai, C. Kessel, L. El-guebaly and P.
Titus
Abstract: The Fusion Nuclear Science Facility (FNSF) is
the first strongly fusion nuclear confinement facility to provide
an integrated fusion environment with fully integrated components
to bridge the technical gaps of fusion plasma and fusion nuclear
science between ITER and the demonstration power plant (DEMO).
Compared to ITER, the FNSF is smaller in size but generates much
higher magnetic field, 30 times higher neutron fluence with 3
orders of magnitude longer plasma operation at higher operating
temperatures for structures surrounding the plasma. Input
parameters to the magnet design from system code analysis include
magnetic field of 7.5 T at the plasma center with plasma major
radius of 4.8 m and minor radius of 1.2 m, and a peak field of
15.5 T on the TF coils for FNSF. Both lower temperature
superconductor (LTS) and high temperature superconductor (HTS) are
considered for the FNSF magnet design based on the
state-of-the-art fusion magnet technology. The higher
magnetic field can be achieved by using the high performance
ternary Restack Rod Process (RRP) Nb3Sn
strands for toroidal field (TF) magnets. The circular
cable-in-conduit conductor (CICC) design similar to ITER magnets
and a high aspect ratio rectangular CICC design are evaluated for
FNSF magnets but low activation jacket materials may need to be
selected. The conductor design concept and TF coil winding pack
composition and dimension based on the horizontal maintenance
schemes are discussed. Neutron radiation limits for the LTS and
HTS superconductors and electrical insulation materials are also
reviewed based on the available materials previously tested. The
material radiation limits for FNSF magnets are defined as part of
the conceptual design studies for FNSF magnets.
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Presented at: 24th International Conference on Magnet
Technology, COEX, Seoul, Korea, October 2015
Published in: IEEE Transactions on Applied
Superconductivity
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Download PPPL-5206 (pdf 5.4 MB 7 pp)
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