Journal of Plasma Physics


Collisionless damping of geodesic acoustic modes

H. SUGAMA a1 and T.-H. WATANABE a1
a1 National Institute for Fusion Science/Graduate University for Advanced Studies, Toki 509-5292, Japan

Article author query
sugama h   [Google Scholar] 
watanabe t   [Google Scholar] 


Collisionless time evolutions of geodesic acoustic modes (GAMs) in tokamaks are investigated by the gyrokinetic theory and simulation. It is shown that the collisionless damping of the GAM oscillations is enhanced when the ratio of the typical drift orbit width of passing ions to the radial wavelength of the zonal flow increases.

(Received August 10 2005)
(Accepted January 7 2006)