Analytical collisionless damping rate of geodesic acoustic mode. (9th August 2016)

• Record Type: Journal Article
• Authors: Ren, H.; Xu, X.Q.
• Is Part Of: Nuclear fusion. Volume 56:Number 10(2016:Oct.)
• Publication Date: 2016-08-09
• Subjects: geodesic acoustic mode -- collisionless -- Landau damping; Nuclear fusion -- Periodicals; 621.48405
• DOI: 10.1088/0029-5515/56/10/106008
• Languages: English
• ISSNs: 0029-5515

Abstract

Abstract: Collisionless damping of geodesic acoustic mode (GAM) is analytically investigated by considering the finite-orbit-width (FOW) resonance effect to the 3rd order in the gyro-kinetic equations. A concise and transparent expression for the damping rate is presented for the first time. Good agreement is found between the analytical damping rate and the previous TEMPEST simulation result (Xu 2008 et al Phys. Rev. Lett .100 215001 ) for systematic q scans. Our result also shows that it is of sufficient accuracy and has to take into account the FOW effect to the 3rd order.