Abstract
Electron beam wire tomography in the H-1NF heliac enables high resolution mapping of vacuum flux surfaces with minimal disruption of the plasma operations schedule. Recent experimental results have proven this technique to be a highly accurate and high resolution method for mapping vacuum magnetic islands. Islands of width as small as δ∼8 mm have been measured, providing estimates of the internal rotational transform of the island. Point-to-point comparison of the mapping results 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 article presents recent experimental results and associated techniques.
| Original language | English |
|---|---|
| Article number | 013501 |
| Journal | Review of Scientific Instruments |
| Volume | 78 |
| Issue number | 1 |
| DOIs | |
| State | Published - 2007 |
Funding
The authors would like to thank John Wach for his technical help in fabricating the electron gun and for H-1 operation. They also thank Mark Gwynneth for developing the motor drive and LABVIEW control and data acquisition code for the standard and fast mapping system. This work was performed on the H-1NF National Plasma Fusion Research Facility established by the Australian Government, and operated by the Australian National University, with support from the Australian Research Council Grant No. DP0344361.