skip to main content


This content will become publicly available on November 6, 2018

Title: New method to design stellarator coils without the winding surface

Finding an easy-to-build coils set has been a critical issue for stellarator design for decades. Conventional approaches assume a toroidal 'winding' surface, but a poorly chosen winding surface can unnecessarily constrain the coil optimization algorithm, This article presents a new method to design coils for stellarators. Each discrete coil is represented as an arbitrary, closed, one-dimensional curve embedded in three-dimensional space. A target function to be minimized that includes both physical requirements and engineering constraints is constructed. The derivatives of the target function with respect to the parameters describing the coil geometries and currents are calculated analytically. A numerical code, named flexible optimized coils using space curves (FOCUS), has been developed. Furthermore, applications to a simple stellarator configuration, W7-X and LHD vacuum fields are presented.
ORCiD logo [1] ;  [2] ;  [3] ;  [1]
  1. Univ. of Science and Technology of China, Anhui (People's Republic of China)
  2. Princeton Univ., Princeton, NJ (United States)
  3. Chinese Academy of Sciences, Anhui (People's Republic of China)
Publication Date:
Grant/Contract Number:
AC02-09CH11466; 201506340040
Accepted Manuscript
Journal Name:
Nuclear Fusion
Additional Journal Information:
Journal Volume: 58; Journal Issue: 1; Journal ID: ISSN 0029-5515
IOP Science
Research Org:
Princeton Plasma Physics Lab. (PPPL), Princeton, NJ (United States)
Sponsoring Org:
Country of Publication:
United States
70 PLASMA PHYSICS AND FUSION TECHNOLOGY; stellarator; coil design; nonlinear optimization
OSTI Identifier: