Electron temperature and electron density profiles measured with a thermal He-beam in the plasma boundary of TEXTOR
A diagnostic technique has been developed for electron temperature T(e)(r) profiles, based on the measurement of the radial intensity profiles of selected lines emitted by an injected thermal He-atom beam. For this purpose 4.8 x 1.0 E18 atoms/s at 150 C are injected into the plasma through a collimating hole structure. Due to the high ionisation potential of 24.59 eV, the He-atoms penetrate several centimetres beyond the limiter radius into the plasma. The line intensities at two wavelengths (706.52 nm and 728.13 nm) are recorded simultaneously with linear 128 elements array cameras, and their intensity ratio is compared with values calculated from a collisional radiative model in order to obtain T(e)(r). The accessible range is from 10 eV to 150 eV, which nearly closes the gap between the outer channel of the core diagnostics and probe measurements in the plasma edge. By selecting another line at 667.82 nm and taking the line intensity ratio, the electron density profiles can be obtained simultaneously.
Bibliographic Reference: Article: Journal of Nuclear Materials, Vol. 196-198 (1992) pp. 174-178
Record Number: 199310281 / Last updated on: 1994-11-29
Original language: en
Available languages: en