American Institute of Physics;Melville: AIP Publishing
摘要:
摘要： Effects of system nonuniformities and kinetic dispersiveness on the spontaneous excitation of Geodesic Acoustic Mode (GAM) by Drift Wave (DW) turbulence are investigated based on nonlinear gyrokinetic theory. The coupled nonlinear equations describing parametric decay of DW into GAM and DW lower sideband are derived and then solved both analytically and numerically to investigate the effects on the parametric decay process due to system nonuniformities, such as nonuniform diamagnetic frequency, finite radial envelope of DW pump, and kinetic dispersiveness. It is found that the parametric decay process is a convective instability for typical tokamak parameters when finite group velocities of DW and GAM associated with kinetic dispersiveness and finite radial envelope are taken into account. When, however, nonuniformity of diamagnetic frequency is taken into account, the parametric decay process becomes, time asymptotically, a quasi-exponentially growing absolute instability. 出版者： Melville: AIP Publishing 出版日期： 2014-02-01 出處： Physics of Plasmas, 2014-02, Vol.21 (2), p.22304 資源來源： AIP Journals (American Institute of Physics) 版權： 2014 AIP Publishing LLC. 識別號： ISSN: 1070-664X 識別號： EISSN: 1089-7674 識別號： DOI: 10.1063/1.4863973
