Why is it hard to generate 3D MHD equilibria with smooth nested flux-surfaces ?

This talk was given at the 4th Asian-Pacific Conference on Plasma Physics on October 28 2020. I am sharing it here because it provides a rapid introduction to the business of MHD equilibria calculation. Abstract Renewed interest in stellarator design has sparked questions on the existence and accessibility of three-dimensional magneto-hydrodynamics (MHD) equilibria with “good” nested flux-surfaces. Several numerical tools exist to obtain three-dimensional MHD equilibria. These methods aspire to

A simple Vlasov-Poisson Particle-In-Cell (PIC) code

I was invited to give a tutorial at the ANU-MSI Mini-course/workshop on the application of computational mathematics to plasma physics, and I thought it would be instructive to design a Particle-In-Cell (PIC) code from scratch and solve the simplest possible equation describing a plasma, namely the Vlasov-Poisson system in 1D. The idea was to illustrate: how simple, efficient and robust such numerical schemes are; how complex the non-linear phase-space dynamics

Visualisation software for M3D-C1

M3D-C1 is the state-of-the-art for performing non-linear 3D resistive MHD simulations of tokamaks. I was using it to model VDE and disruptions during my postdoc at PPPL with more or less success. One really annoying thing was the lack of visualisation tools, especially for probing the 3D components of the plasma evolution. I thus developed a set of tools (Matlab package) to reconstruct the data from M3D-C1 native output (Finite

Elasticae and Stellarators

Motivation Stellarators are weird-looking fusion devices. The reason is that ions and electrons are better confined when the magnetic field is “twisting” around the centre-line of the device called the magnetic axis. In tokamaks, the vacuum field generated by the evenly-positioned toroidal field coils is somewhat “flat”, as shown on the figure below. In order to generate twisting, a strong toroidal plasma current (in red in the figure below) is

Having a go at Quantum Field Theory

Lectures on QFT I have been asked to contribute to a series of seminars and “informal discussions” about Quantum Field Theory (QFT). The group lead by Jingbo Wang from the Physics department of UWA is indeed interested in the connections between quantum random walks and the discretisation of the path integral formulation of QFT found in Lattice QCD. From the mathematical side, QFT is a fantastic playground for learning about