The recent success in coupling lower hybrid (LH) waves in high
performance plasmas at JET together with the first demonstration on FTU
of the coupling capability of the new passive active multijunction
launcher removed major concerns on the possibility of using LH on ITER.
LH exhibits the highest experimental current drive (CD) efficiency at
low plasma temperature thus making it the natural candidate for off-axis
CD on ITER where current profile control will help in maintaining
burning performance on a long-time scale. We review recent LH results:
long internal transport barrier obtained in JET with current profile
sustained and controlled by LH acting under real time feedback together
with first LH control of flat q-profile in a hybrid regime with Te ~ Ti.
Minutes long fully non-inductive LH driven discharges on Tore Supra
(TS). High CD efficiency with electron cyclotron in synergy with LH
obtained in FTU and TS opening the possibility of interesting scenarii
on ITER for MHD stabilization. Preliminary results of LH modelling for
ITER are also reported. A brief overview of ITER LH system is reported
together with some indication of new coming LH experiments, in
particular KSTAR where CW klystrons at the foreseen ITER frequency of
5 GHz are being developed.
- fusion energy
- fusion reactors
- lower hybrid grill
- lower hybrid waves
- lower hybrid current drive