  When using Ion Cyclotron Range of Frequency (ICRF) heating, enhanced
heat-fluxes are commonly observed on some plasma facing components close to the
antennas. Experiments have recently been carried out on JET with the new
ITER-Like-Wall (ILW) to characterize the heat flux to the JET ICRF antennas.
Using Infra-Red thermography and thermal models of the tiles, heat-fluxes were
evaluated from the surface temperature increase during the RF phase of L-mode
plasmas. The maximum observed heat-flux intensity was ~ 4.5 MW/m2 when
operating with -{\pi}/2 current drive strap phasing at power level of 2MW per
antenna and with a 4 cm distance between the plasma and the outer limiters.
Heat-fluxes are reduced when using dipole strap phasing. The fraction of ICRF
power deposited on the antenna limiters or septa was in the range 2-10% for
dipole phasing and 10-20% with +/-{\pi}/2 phasing.

Plasma Physics