Measures of quasisymmetry for stellarators

E. Rodríguez, E. J. Paul, A. Bhattacharjee

Research output: Contribution to journalArticlepeer-review

9 Scopus citations


Quasisymmetric stellarators are an attractive class of optimised magnetic confinement configurations. The property of quasisymmetry (QS) is in practice limited to be approximate, and thus the construction requires measures that quantify the deviation from the exact property. In this paper we study three measure candidates used in the literature, placing the focus on their origin and a comparison of their forms. The analysis shows clearly the lack of universality in these measures. As these metrics do not directly correspond to any physical property (except when exactly quasisymmetric), optimisation should employ additional physical metrics for guidance. It is suggested that close to QS minima, one should treat QS metrics through inequality constraints so that additional physics metrics dominate optimisation. The impact of different quasisymmetric measures on optimisation is presented through an example, for which the standard metric that weights the asymmetric Fourier modes of the field magnitude appears to perform best.

Original languageEnglish (US)
Article number905880109
JournalJournal of Plasma Physics
Issue number1
StatePublished - Feb 28 2022

All Science Journal Classification (ASJC) codes

  • Condensed Matter Physics


  • fusion plasma
  • plasma devices


Dive into the research topics of 'Measures of quasisymmetry for stellarators'. Together they form a unique fingerprint.

Cite this