With a view to heating a 50/50 D-T reactor plasma, ion-cyclotron resonance heating (ICRH) at a power level of 10MW has been demonstrated in the JET tokamak for minority hydrogen concentration as high as nH/nHe31. In high minority ICRH experiments using (H)-He3 plasmas, improved bulk-ion heating has been observed as the minority-ion tail temperature was successfully lowered to a level below the critical energy so that the tail gave more than 50% of its power to the bulk ions. At a Ptot/ne0 @ 2.3¥10­19 MW¥m3, Ti0 @ Te0 @ 7keV has been obtained in limiter L-mode discharges where the global energy confinementisimilar to that found in other ICRH L-mode discharges. Here, Ptot is the total input power, ne0, Te0 and Ti0 refer to the central electron density, electron and ion temperatures respectively. Also, it is shown that the results of observed tail temperature, fast-ion energy and minority density are well understood in terms of minority ICRH physics and the Stix theory. Further, it has been shown theoretically that when the wave is launched by an antenna in (0, p)-phasing from the low-field side in large and hot reactor-like plasmas, strong single-pass damping can be maintained at minority concentrations approaching that of majority and the occurence of ion-ion hybrid mode conversion-cutoff layers would be of no consequence as most of the wave power is absorbed before it reaches this region.