Simultaneous optimisation of tokamaks for passive tearing stability and fusion power

We are scoping the design space of high-field pilot-plant tokamak equilibria to find scenarios that maximise passive tearing stability without sacrificing fusion power. A database of equilibria with realistic pressure and current profiles is being generated with Monte-Carlo methods, where the plasma's tearing stability is being analysed via a heuristic neoclassical tearing drive term, rational surface curvature[1], and the linear ideal plasma response through RDCON[2]. We have constrained ourselves to tearing physics entirely specified by the MHD equilibrium, forgoing self-organising ion polarisation current and rotation effects (for now). Fusion power is being calculated using a 0D power-balance POPCON code to ensure the database is constrained to economically viable scenarios. The linear resistive plasma response is being validated against simulations within M3D-C1. Possible outcomes include a reduced framework to quantify the passive stability afforded by an equilibrium, that may be applied to machine-learning data analysis, or scenario optimisation using adjoint methods.

[1] Schlutt & Hegna, PoP (2012)
[2] Glasser et al., PoP (2016)