Effect of temperature anisotropy on the dynamics of geodesic acoustic modes. (6th February 2023)

• Record Type: Journal Article
• Authors: Sama, J.N.; Biancalani, A.; Bottino, A.; Chavdarovski, I.; Del Sarto, D.; Ghizzo, A.; Hayward-Schneider, T.; Lauber, Ph.; Rettino, B.; Vannini, F.
• Is Part Of: Journal of plasma physics. Volume 89:Number 1(2023)
• Publication Date: 2023-02-06
• Subjects: fusion plasma -- plasma instabilities -- plasma simulation; Plasma (Ionized gases) -- Periodicals; 530.4405
• DOI: 10.1017/S0022377823000016
• Languages: English
• ISSNs: 0022-3778

Abstract

Abstract : In this work, we revisit the linear gyro-kinetic theory of geodesic acoustic modes (GAMs) and derive a general dispersion relation for an arbitrary equilibrium distribution function of ions. A bi-Maxwellian distribution of ions is then used to study the effects of ion temperature anisotropy on GAM frequency and growth rate. We find that ion temperature anisotropy yields sensible modifications to both the GAM frequency and growth rate as both tend to increase with anisotropy and these results are strongly affected by the electron to ion temperature ratio.