Energy measurement of fast ions trapped in the toroidal field ripple of Tore Supra
During additional heating in Tore Supra (ICRF or NBI) fast ion losses due to the toroidal field ripple were clearly measured by a set of graphite probes. During the monster sawteeth regime, achieved with ICRF, the ejection of fast ions, not correlated with any measured MHD activity, was observed. The radial distribution of these ions is quite different from that usually observed exhibiting a peak located in the central section of the plasma. In order to measure the energy distribution of these ions, a new diagnostic is under construction. The principle of the diagnostic is to discriminate the ions in energy using their Larmor radius. The detector is made of a hollow graphite cylinder with a small entrance slot, located in a vertical port on the ion drift side. An array of six metallic collectors placed inside the graphite cylinder intercepts the ions. The current on each collector was estimated at 10 to 100 nA, during ICRF heating. The energy resolution of this diagnostic is expected to be about 20 keV for the lowest energy range and 100 keV for the highest.
Bibliographic Reference: Report: EUR-CEA-FC-1498 EN (1993)
Availability: Available from CEA, Département de Recherches sur la Fusion Contrôlée, Saint-Paul-lez-Durance (FR)
Record Number: 199311588 / Last updated on: 1994-11-28
Original language: en
Available languages: en