Non-linear modelling of performance limiting MHD and disruptions in spherical tokamaks

点击翻译按钮获取中文摘要

For MAST-U to reach high performance, long pulse operation and contribute to the design of STEP, it is essential to understand, avoid, mitigate or control MHD instabilities which could lead to degraded confinement in spherical tokamaks. It is also important to improve our understanding of the pathways to disruptions so that we may better predict and avoid them. The project will start by analysing data from MAST-U high-performance experiments to identify important instabilities (such as neoclassical tearing modes). Non-linear 3D MHD modelling using JOREK will then be performed and compared to experiments. 3D MHD fields modelled during such instabilities will also be used to trace fast particle trajectories or in disruptions the generation of runaway electrons. Next steps of the project will be to explore strategies to avoid or mitigate these instabilities, which will inform both future MAST-U operation and help the design of STEP. It may also be possible to investigate the disruption thermal quench process and test theories, for example from the Solar Physics community or by Boozer Fast magnetic reconnection and the ideal evolution of a magnetic field.The project aligns well with the Fusion Science & Technology research performed at Durham University.The student will be mainly based at UKAEA, but it would be desirable to also include long stays at Durham throughout the project, possibly twice every 6-months. The student will attend relevant induction and research training at the university. There will be regular contact between the student, UKAEA supervisors and the university supervisor, through emails and Teams/Zoom calls (generally weekly), visits of the university supervisor to UKAEA and the student to Durham. Additional collaboration with the NSTX-U team would be highly desirable, and training on MHD codes will be given by UKAEA experts and through participation in the code annual general meeting.