Abstract
Observations of bright spots on the JET divertor aprons during lower
hybrid current drive experiments are described. These bright spots are
important because they can potentially cause damage to large tokamaks.
The bright spots arise due to the impact of a fast particle beam. This
beam originates from the front of the lower hybrid launcher, where
thermal particles are accelerated according to theory by interaction
with the high spatial harmonics of the lower hybrid wave. The bright
spots are clearly related to the lower hybrid power as they disappear
when the lower hybrid power is switched off. According to the analysis
versus various parameters, the brightness of the spots clearly decreases
with increasing plasma–wall distance, i.e. the distance between the
last closed flux surface and the poloidal limiter. This is clearly
beneficial for ITER, as it is designed to operate at a large plasma–wall
distance.
Original language | English |
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Pages (from-to) | 1101-1108 |
Journal | Plasma Physics and Controlled Fusion |
Volume | 47 |
Issue number | 7 |
DOIs | |
Publication status | Published - 2005 |
MoE publication type | A1 Journal article-refereed |
Keywords
- JET
- plasma
- fusion energy
- fusion reactors
- tokamak
- ITER
- lower hybrid current drive
- divertor
- divertor tiles
- first wall
- plasma-wall interactions