Physics of high power ICRH on Jet

Ion Cyclotron Resonance Heating (ICRH) experiment have been carried out in a wide range of Jet Plasmas. A high confinement region in the plasma core has been discovered during on‐axis heating of pellet fueled discharges. Sawttoth‐free periods and improved heating efficiency have been achieved in high current plasmas by heating during the current rise. Combined ICRH and neutral beam injection (NBI) in double null X‐point plasmas has yields D‐D fusion rates up to 2×1016 s−1 and electron and ion temperatures of 11keV and 17 keV respectively. Non‐thermal fusion reaction rates from (He3) D minority ICRH have been reproduced by a model which predicts Q∼0.7 for (D)T minority ICRH in JET. RF modulation studies have yielded power deposition profiles and heat transport coefficients inside the q=1 surface. Alignment of the antenna screen to the magnetic field minimises nickel impurity release.