EFDA-JET-CP(01)02/88
Improvement of LH-power coupling in H-mode and ITB Plasmas at JET
Lower Hybrid (LH) power on JET has long suffered for bad coupling efficiency, with Reflection Coefficient (RCLH) of up to 20-30% during the main heating phase of the discharge. As a result, the roughly 7MW of available electron heating have essentially remained weakly used. However, LH is certainly the most efficient tool to drive non-inductive current in the discharge. As such, this heating scheme offers a powerful way to modify the q-profile.