The performance of a tokamak-type fusion power plant in term of energy gain will be limited by turbulent transport. The instability of trapped electron modes is one of the main instabilities causing turbulence in tokamaks. Furthermore, electron cyclotron resonance heating (ECRH) is the generic heating system in current and future tokamaks. Both physical processes are based on resonant interactions with electrons, in space and velocity. Since heating has the effect of depopulating the resonant interaction zone of its electrons, superimposing its resonance on that of the instability can theoretically lead to a stabilisation of the trapped electron modes.
The objective of the thesis is twofold: (i) to construct scenarios where this mechanism exists and validate it using linear simulations, then (ii) to characterise its effect and quantify its effectiveness in non-linear regimes where linear effects compete with the self-organisation of turbulence, with collisional processes and with the dynamics of average profiles. Potentially, this entirely new control technique could improve the performance of tokamaks at no additional cost. The PhD thesis will require a detailed theoretical understanding of the two resonant processes and their various control parameters. It will be based on the use of the high performance computing gyrokinetic code GYSELA dedicated to the study of transport and turbulence in tokamak plasmas, which has recently been enhanced with an ECRH heating module. An experimental component is also planned on the WEST and/or TCV tokamaks to validate the identified most promising turbulence control scenario(s).