Phases and phase-transitions in quasisymmetric configuration space

E. Rodríguez, W. Sengupta, A. Bhattacharjee

Research output: Contribution to journalArticlepeer-review

9 Scopus citations


We explore the structure of the space of quasisymmetric configurations identifying them by their magnetic axes, described as three-dimensional closed curves. We demonstrate that this topological perspective divides the space of all configurations into well-separated quasisymmetric phases. Each phase is characterized by the self-linking number (a topological invariant), defining different symmetry configurations (quasi-axisymmetry or quasi-helical symmetry). The phase-transition manifolds correspond to quasi-isodynamic configurations. By considering some models for closed curves (most notably torus unknots), general features associated with these phases are explored. Some general criteria are also built and leveraged to provide a simple way to describe existing quasisymmetric designs. This constitutes the first step in a program to identify quasisymmetric configurations with a reduced set of functions and parameters, to deepen understanding of configuration space, and offer an alternative approach to stellarator optimization that begins with the magnetic axis and builds outward.

Original languageEnglish (US)
Article number105006
JournalPlasma Physics and Controlled Fusion
Issue number10
StatePublished - Oct 2022

All Science Journal Classification (ASJC) codes

  • Nuclear Energy and Engineering
  • Condensed Matter Physics


  • configuration space
  • quasisymmetry
  • stellarator


Dive into the research topics of 'Phases and phase-transitions in quasisymmetric configuration space'. Together they form a unique fingerprint.

Cite this