Second Ballooning Stability Access in a Quasi-Poloidal Stellarator
Abstract
Access to second ballooning regions in quasi-poloidal symmetric (qps) stellarators is investigated. Recent theoretical work by Hegna and Hudson has suggested that regions of second ballooing stability do not exist for three-dimensional magnetic equilibria.(C. C. Hegna and S. R. Hudson, Phys. Plasmas, 9), 2014 (2002). This is in contrast to recent computational work on high-β qps plasmas which displayed regions of second stability.(A. S. Ware, et al., Phys. Rev. Lett, accepted for publication (2002).) In this work, we investigate the link between qps and second stability access in three-dimensional equilibria. Overlap (or lack thereof) between regions of weak magnetic shear and bad curvature is explored and the effect of degrading quasi-poloidal symmetry on this region of overlap is investigated. This is done both for very high-β reactor plasmas as well as Quasi-Poloidal Stellarator (QPS) plasmas.
- Publication:
-
APS Division of Plasma Physics Meeting Abstracts
- Pub Date:
- November 2002
- Bibcode:
- 2002APS..DPPCP1089H