X-ray tomography on TCV
The TCV tokamak is equipped with a soft X-ray tomography system consisting of 10 pin-hole cameras with 20-element planar Si diode arrays arranged around the plasma cross section. Successful commissioning of the system was dependent on the accurate determination of the actual camera geometries, the dimensions of which deviate within tolerances of 0.1mm from their nominal values. It was also necessary to take account of the effect of inactive 'dead' layer at the PIN diode surface causing angle and spectrally dependent additional absorption. Several different pixel methods, including a novel method based on Fisher information, have been tested, both on simulated and on experimental data. The method based on Fisher information provides the most accurate reconstructions of both the overall emissivity profile and of small perturbations due to magnetohydrodynamic (MHD) modes.
Bibliographic Reference: Article: Proceedings of the 23rd European Physical Society Conference on Controlled Fusion and Plasma Physics, Kiev (UA), June 24-28, 1996, pp. 1035-1038
Record Number: 199710348 / Last updated on: 1997-04-14
Original language: en
Available languages: en