Particle orbits in magnetic islands and chaotic magnetic field

The magnetic geometry is of the central concern in a magnetic confinement fusion device. The magnetic field in these machines does not always stay as axisymmetric (2D) and “well-behaved”. For example, the field ripples or externally added 3D perturbative in a tokamak render the equilibrium of the magnetic field fully 3D, not to mention the stellarators, which are intrinsic 3D in nature. Large scale magnetic island and chaos as part of the magnetic field, as captured by the MRxMHD model and the Stepped Pressure Equilibrium Code (SPEC) (co-)developed by the ANU and Princeton.

Another major concern is particle confinement in a magnetic field. The goal of a fusion reactor is to confine the very hot fuel particles (Deuterium and Tritium) for a sufficient long time to interact with each other. Because of the complication of the islands and chaotic regions, the confinement will be less efficient compared to the fully layered magnetic field. The goal of this project is to compute the particle orbits in a MRxMHD equilibrium with fully 3D field and quantify the impact of the islands and chaos to particle confinement. The student will need to couple the particle orbit code VENUS-LEVIS to SPEC and run simulations with both codes. The VENUS-LEVIS code solves the particle orbit in 3D and is available from the University of Western Australia.

This project is suitable for Honours and Master students.

The Poincare plot of the magnetic field of a tokamak, showing laminated layers, magnetic islands and chaotic regions

The Poincare plot of the magnetic field of a tokamak, showing laminated layers, magnetic islands and chaotic regions.