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Title: NCSX Trim Coil Design

The National Compact Stellarator Experiment (NCSX) was being constructed at the Princeton Plasma Physics Laboratory in partnership with Oak Ridge National Laboratory before work was stopped in 2008. The objective of this experiment was to develop the stellarator concept and evaluate it's potential as a model for future fusion power plants. Stellarator design requires very precisely positioned Modular Coils of complex shape to form 3D plasmas. In the design of NCSX, Trim Coils were required to compensate for both the positioning of the coils during assembly and the fabrication tolerances of the Modular Coils. Use of the Trim Coils allowed for larger tolerances increasing ease of assembly and decreasing overall cost. A set of Trim coils was developed to suppress the toroidal flux in island regions due to misalignment, magnetic materials, and eddy currents. The requirement imposed upon the design forced the toroidal flux in island regions below 10% of the total toroidal flux in the plasma. An analysis was first performed to evaluate candidate Trim Coil configurations iterating both the size, number, and position of the coils. The design was optimized considering both performance and cost while staying within the tight restraints presented by the space limited geometry. Themore » final design of the Trim Coils incorporated a 48 Coil top bottom symmetric set. Fabrication costs were minimized by having only two coil types and using a planar conventional design with off the shelf commercial conductor. The Trim Coil design incorporated supports made from simple structural shapes assembled together in a way which allowed for adjustment as well as accommodation for the tolerance build up on the mating surfaces. This paper will summarize the analysis that led to the optimization of the Trim Coils set, the trim coil mechanical design, thermal and stress analysis, and the design of the supporting Trim Coil structure.« less
Authors:
Publication Date:
OSTI Identifier:
963982
Report Number(s):
PPPL-4443
TRN: US0903383
DOE Contract Number:
DE-ACO2-09CH11466
Resource Type:
Conference
Resource Relation:
Conference: 23rd Symposium on Fusion Engineering, San Diego, CA May 31-June 4, 2009
Research Org:
Princeton Plasma Physics Lab. (PPPL), Princeton, NJ (United States)
Sponsoring Org:
USDOE Office of Science (SC)
Country of Publication:
United States
Language:
English
Subject:
70 PLASMA PHYSICS AND FUSION TECHNOLOGY; DESIGN; EDDY CURRENTS; FABRICATION; GEOMETRY; MAGNETIC MATERIALS; MATING; OPTIMIZATION; PHYSICS; POSITIONING; POWER PLANTS; RESTRAINTS; STELLARATORS; STRESS ANALYSIS; TOLERANCE; NCSX, Trim Coil Design