In current tokamaks, the electron distribution is heavily influenced by external heating systems, like Electron Cyclotron Resonance Heating (ECRH) or Lower Hybrid (LH) heating, which generate a large population of fast electrons. This is expected also in next-generation tokamaks, such as ITER, where a substantial part of input power is deposited on electrons. A significant population of fast electrons can destabilize high-frequency instabilities, including Alfvén Eigenmodes (AEs), as observed in various tokamaks. However, this phenomenon remains understudied, especially regarding the specific resonant electron population triggering these instabilities and the impact of electron-driven AEs on the multi-scale turbulence dynamics in the plasma complex environment.
The PhD project aims to explore the physics of high-frequency electron-driven AEs in realistic plasma conditions, applying insights to WEST experiments for in-depth characterization of these instabilities. The candidate will make use of advanced numerical codes, whose expertise is present at the IRFM laboratory, to analyze realistic plasma conditions with fast-electron-driven AE in previous experiments, to grasp the essential physics at play. Code development will also be necessary to capture key aspects of this physics. Once such a knowledge is established, predictive modeling for the WEST environment will guide experiments to observe these instabilities.
Based at CEA Cadarache, the student will collaborate with different teams, from the theory and modeling group to WEST experimental team, gaining diverse expertise in a stimulating environment. Collaborations with EUROfusion task forces will further provide an enriching international experience.