Wire tomography in the H-1NF heliac for investigation of fine structure of magnetic islands

Journal Article · Mon Jan 01 04:00:00 EST 2007 · Review of Scientific Instruments

DOI:https://doi.org/10.1063/1.2424453· OSTI ID:931964

Kumar, S. T.A. ^[1]; Blackwell, B. ^[1]; Harris, Jeffrey H ^[2]

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1. Australian National University, Canberra, Australia
2. ORNL

Electron-beam wire-tomography in the H-1NF heliac enables high resolution mapping of vacuum flux surfaces without significant disruption of plasma operations. Recent experimental results have proved this technique to be a highly accurate and high resolution method for mapping vacuum magnetic islands. Islands of width as small as 8 mm have been measured, providing estimates of the internal rotational transform of the island. Point-to-point comparison of the mapping re- sults with computer tracing, in conjunction with an image warping technique, enables systematic exploration of magnetic islands and surfaces of interest. Recent development of a fast mapping technique significantly reduced the mapping time and made this technique suitable for mapping at higher magnetic fields. This paper presents recent experimental results and associated techniques.

• Research Organization: Oak Ridge National Laboratory (ORNL)
• Sponsoring Organization: ORNL LDRD Director's R&D
• DOE Contract Number: AC05-00OR22725
• OSTI ID: 931964
• Journal Information: Review of Scientific Instruments, Journal Name: Review of Scientific Instruments Journal Issue: 1 Vol. 78
• Country of Publication: United States
• Language: English