An adjoint-based method for optimizing MHD equilibria against the infinite-n, ideal ballooning mode

Autor:	Gaur, Rahul, Buller, Stefan, Ruth, Maximilian E., Landreman, Matt, Abel, Ian G., Dorland, William D.
Rok vydání:	2023
Předmět:	Physics - Plasma Physics
Druh dokumentu:	Working Paper
Popis:	We demonstrate a fast adjoint-based method to optimize tokamak and stellarator equilibria against a pressure-driven instability known as the infinite-$n$ ideal ballooning mode. We present three finite-$\beta$ (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 MHD, we construct a technique to rapidly calculate the change in the growth rate, a measure of ideal ballooning instability. Using the~\texttt{SIMSOPT} framework, we then implement our fast adjoint gradient-based optimizer to minimize the growth rate and find stable equilibria for each of the three initially unstable equilibria. Comment: 24 pages, 8 tables, 9 figures
Databáze:	arXiv
Externí odkaz:	http://arxiv.org/abs/2302.07673 Zobrazit plný text záznamu View this record from Arxiv