Speaker
Akihiro Shimizu
Description
See the full Abstract at http://ocs.ciemat.es/EPS2018ABS/pdf/P1.1053.pdf
Design study of the magnetic field coils and configuration for
the Chinese First Quasi-axisymmetric Stellarator
A. Shimizu1, H. Liu2, M. Isobe1,3, S. Okamura1, Y. Xu2, X. Zhang2, B. Liu2,
J. Huang2, X. Wang2, H. Liu2, C. Tang2,4, D. Ying5, Y. Wang5 and CFQS team1,2
1
National Institute for Fusion Science, National Institutes of Natural Sciences, Toki, Gifu,
509-5292, Japan
2
Institute of Fusion Science, School of Physical Science and Technology,
Southwest Jiaotong University, Chengdu 610031, China
3
SOKENDAI (The Graduate University for Advanced Studies), Toki, Gifu 509-5292, Japan
4
School of Physical Science and Technology, Sichuan University, Chengdu 610041, China
5
Hefei Keye Electro Physical Equipment Manufacturing Co., Ltd, Hefei 230000, China
The Chinese First Quasi-axisymmetric Stellarator (CFQS) is a future quasi-axisymetric (QA)
stellarator device, which will be constructed in Southwest Jiaotong University (SWJTU) in
China. This is the international joint project of National Institute of Fusion Science in Japan
and SWJTU, and its design work has been continued jointly. A QA stellarator has mainly
axisymmetric magnetic field components in the special magnetic coordinates (Boozer
coordinates), which determine the guiding centre orbit, therefore, the neoclassical properties
of the QA stellarator are similar to tokamak although inductive current is not required. About
ten years ago, CHS-qa, has been designed as a post CHS device, which is a low aspect ratio
(~3.2) QA stellarator. Based on this design, new configuration for the CFQS is obtained. The
present parameters of magnetic field strength, the major radius, the aspect ratio and the
toroidal periodic number are 1.0 T, 1.0 m, 4.0, and 2 respectively. The 16 modular coil
system is optimized by the NESCOIL code for this configuration. By using this coil system,
the free boundary equilibrium calculation by the VMEC is conducted, and the Shafranov
shift and bootstrap current are estimated. The bootstrap current reaches 30 kA at ~1.5 %,
and the good QA properties are maintained up to this . For the flexibility of the magnetic
field configuration, 3 pairs of poloidal field coils are considered. The Shafranov shift is
suppressed by the vertical field produced by those coils.
