Neutral beam operations for JET TT and DT campaigns

Neutral beam injection (NBI) is a flexible auxiliary heating method for tokamak plasmas, capable of being efficiently coupled to the various plasma configurations required in the Tritium and mixed Deuterium-Tritium Experimental campaign 2 on the Joint European Torus (JET) device. High NBI power was required for high fusion yield and alpha particle studies and to provide mixed Deuterium-Tritium (D-T) fuelling in the plasma core, it was necessary to operate the JET NBI systems in both deuterium and tritium. Further, the pure tritium experiments performed required T NBI for high isotopic purity and reduced 14 MeV neutron yield. The use of NBI in tritium presents further challenges compared to standard NBI operation. The experience of preparing, commissioning and operating NBI across the 2021 and 2023 JET D-T experiments are explored in detail in this paper.