Ion Landau damping and drift tearing modes. (April 2019)

• Record Type: Journal Article
• Authors: Connor, J. W.; Ham, C. J.; Hastie, R. J.; Zocco, A.
• Is Part Of: Journal of plasma physics. Volume 85:Number 2(2019)
• Publication Date: 2019-04
• Subjects: fusion plasma, -- plasma instabilities; Plasma (Ionized gases) -- Periodicals; 530.4405
• DOI: 10.1017/S0022377819000217
• Languages: English
• ISSNs: 0022-3778

Abstract

Abstract : Kinetic treatments of drift tearing modes that match an inner, resonant layer solution to an external magnetohydrodynamic (MHD) solution, characterised by $\unicode[STIX]{x1D6E5}^{\prime }$, can fail to match the ideal MHD boundary condition on the parallel electric field, $E_{\Vert }=0$ . In this paper we demonstrate how consideration of ion sound and ion Landau damping effects achieves this, placing the theory on a firm footing. These effects are found to modify the effective critical $\unicode[STIX]{x1D6E5}^{\prime }$ for instability of drift tearing modes, in particular for weak electron temperature gradients. The implications for a realistic hot plasma resonant layer model – involving large ion Larmor radius and semi-collisional electron physics (Connor et al., Plasma Phys. Control. Fusion, vol. 54, 2012, 035003) – are determined.