Development and application of a hybrid MHD-kinetic model in JOREK

TL;DR

This paper extends the JOREK MHD code to simulate energetic particle-driven instabilities at high pressures, enabling more accurate modeling of future fusion plasmas with significant energetic particle effects.

Contribution

The work introduces a hybrid MHD-kinetic model in JOREK that incorporates realistic energetic particle distributions and anisotropic pressure coupling, validated against experimental and benchmark data.

Findings

Good agreement with other codes in linear benchmarks

Reproduced experimental instability features in ASDEX Upgrade

Extended the code to support non-linear simulations (future work)

Abstract

Energetic particle (EP) driven instabilities will be of strongly increased relevance in future burning plasmas as the EP pressure will be very large compared to the thermal plasma. Understanding the interaction of EPs and bulk plasma is crucial for developing next-generation fusion devices. In this work, the JOREK MHD code is extended to allow for the simulation of EP instabilities at high EP pressures using realistic plasma and EP parameter in a full-f formulation with anisotropic pressure coupling to the bluid background. The code is first benchmarked linearly for the ITPA-TAE as well as the experiment based AUG-NLED cases, obtaining good agreement to other codes. Then, it is applied to a high energetic particle pressure discharge in the ASDEX Upgrade tokamak using a realistic non-Maxwellian distribution of EPs, reproducing aspects of the experimentally observed instabilities. Non-linear applications are possible based on the implentation, but will require dedicated verification and validation left for future work.