Open AccessCoil Tolerance Impact on Plasma Surface Quality for NCSX
Author(s) -
A. Brooks,
W. Reiersen
Publication year - 2003
Language(s) - English
Resource type - Reports
DOI - 10.2172/820107
Subject(s) - electromagnetic coil , trim , stellarator , plasma , symmetry (geometry) , approx , flux (metallurgy) , field (mathematics) , volume (thermodynamics) , quality (philosophy) , magnetic field , physics , ranging , computational physics , mechanics , electrical engineering , engineering , materials science , nuclear physics , computer science , geometry , structural engineering , mathematics , telecommunications , thermodynamics , quantum mechanics , pure mathematics , metallurgy , operating system
The successful operation of the National Compact Stellarator Experiment (NCSX) machine will require producing plasma configurations with good flux surfaces, with a minimum volume of the plasma lost to magnetic islands or stochastic regions. The project goal is to achieve good flux surfaces over 90% of the plasma volume. NCSX is a three period device designed to be operated with iota ranging from {approx}0.4 on axis to {approx}0.7 at the edge. The field errors of most concern are those that are resonant with 3/5 and 3/6 modes (for symmetry preserving field errors) and the 1/2 and 2/3 modes (for symmetry breaking field errors). In addition to losses inherent in the physics configuration itself, there will be losses from field errors arising from coil construction and assembly errors. Some of these losses can be recovered through the use of trim coils or correction coils. The impact of coil tolerances on plasma surface quality is evaluated herein for the NCSX design. The methods used in this evaluation are discussed. The ability of the NCSX trim coils to correct for field errors is also examined. The results are used to set coils tolerances for the various coil systems