OUTGASSING OF THE LOWER-HYBRID CURRENT DRIVE ANTENNA ON JT-60U

Authors
MAEBARA S SEKI M SUGANUMA K IKEDA Y
Citation
S. Maebara et al., OUTGASSING OF THE LOWER-HYBRID CURRENT DRIVE ANTENNA ON JT-60U, Fusion engineering and design, 30(3), 1995, pp. 253-259
Citations number
10
Categorie Soggetti
Nuclear Sciences & Tecnology
Journal title
Fusion engineering and design → ACNP
ISSN journal
09203796
Volume
30
Issue
3
Year of publication
1995
Pages
253 - 259
Database
ISI
SICI code
0920-3796(1995)30:3<253:OOTLCD>2.0.ZU;2-Y
Abstract
The outgassing properties of the lower hybrid current drive (LHCD) ant enna during r.f. operation were studied on the JT-60U tokamak. The ant enna is not equipped with a differential pumping system to evacuate th e outgassing of the antenna. The pressure rise in the antenna during r .f. operation strongly depended on the r.f. power when r.f. conditioni ng was started. However, the outgassing rate was quickly reduced after several shots, and showed weak r.f. power dependence after sufficient r.f. conditioning. Finally, the outgassing rate of the LHCD antenna w as in the range of approximately 10(-6) Pa m(3) s(-1) m(-2) after four weeks operation at the working temperature of 250 degrees C. Then a p ower density of up to 25 MW m(-2) was successfully injected into the p lasma without the differential pumping system at the antenna on JT-60U .