Mechanisms of arc formation have been analyzed and the critical electric fields for the multipactor effect calculated, compared to the experimental values and found to be within the normal operational space of the LH system on JET. It has been shown that the characteristic electron energy (20-1000)eV for the highest multipactor resonances (N=4-9) a…
Detailed measurements of the rotation profile in L-mode plasmas heated by ICRF only (H minority in D), show a distinct off-axis maximum in the co-current direction. There is a slight dependence on the position of the resonance layer: the off-axis maximum in the rotation profile is modestly higher for a high field side position of the resonance laye…