Abstract
Kinetic ballooning modes in magnetically confined toroidal plasmas are investigated putting emphasis on specific stellarator features. In particular, we propose a Mercier criterion which is purposely designed to allow for direct comparison with local flux-tube gyrokinetics simulations. We investigate the influence on the marginal frequency of the mode of a magnetic curvature which is inhomogeneous on the magnetic flux surface due to the fieldline-label dependence. This is a typical (surface) global effect present in non-axisymmetry. Finally, we propose an artificial equilibrium model that explicitly retains the fieldline-label dependence in the magnetic drift, and analyse the stability of the system by introducing a representation of the perturbations similar to the flux-bundle model of Sugamaet al. (Plasma Fusion Res., vol. 7, 2012, 2403094). The coupling of flux bundles is shown to have a stabilising effect on the most unstable local flux-tube mode.
Publisher
Cambridge University Press (CUP)
Reference41 articles.
1. Zocco, A. , Xanthopoulos, P. & Helander, P. 2018. Geometric stabilization of the electrostatic ion-temperature-gradient driven instability. II. Non-axisymmetric systems. (in preparation).
2. Geometric stabilization of the electrostatic ion-temperature-gradient driven instability. I. Nearly axisymmetric systems
3. Intrinsic turbulence stabilization in a stellarator;Xanthopoulos;Phys. Rev. X,2016
4. Modified Mercier criterion
Cited by
4 articles.
订阅此论文施引文献
订阅此论文施引文献，注册后可以免费订阅5篇论文的施引文献，订阅后可以查看论文全部施引文献