2023/10/01 by Rahul Gaur, S. Buller, Stefan Buller +7
Physics and Astronomy · #Magnetic confinement fusion research #Physics of Superconductivity and Magnetism #Solar and Space Plasma Dynamics
paper · pdf · doi:10.1017/s0022377823000995
We demonstrate a fast adjoint-based method to optimise tokamak and stellarator equilibria against a pressure-driven instability known as the infinite- n ideal ballooning mode. We present three finite- β (the ratio of thermal to magnetic pressure) equilibria: one tokamak equilibrium and two stellarator equilibria that are unstable against the ballooning mode. Using the self-adjoint property of ideal magnetohydrodynamics, we construct a technique to rapidly calculate the change in the eigenvalue, a measure of ideal ballooning instability. Using the SIMSOPT optimisation framework, we then implement our fast adjoint gradient-based optimiser to minimise the eigenvalue and find stable equilibria for each of the three originally unstable equilibria.