Maximising D − T fusion power by optimising the plasma composition and beam choice in JET

JET has a neutral beam injection as well as a radio frequency (RF) system for bringing plasmas to fusion-relevant temperatures. The former allows D as well as T birth energies of the order of 100-120 keV while the latter has the flexibility to heat a variety of populations by adjusting the antenna frequency. In this paper it is illustrated that - when the JET plasma is heated - the power harvested from D - T fusion reactions favours operating away from the 50-50 D - T balance and that exploiting pure D beams is more beneficial than combined D and T beams as well as pure T beams. Although beam heating dominates the overall behaviour in JET - as much more beam power than wave power can be coupled to the plasma - RF heating allows efficient heating of the very core.