Speaker
Alessandro Biancalani
Description
See the full Abstract at http://ocs.ciemat.es/EPS2018ABS/pdf/P2.1003.pdf
Nonlinear gyrokinetic investigation of energetic particle driven geodesic
acoustic modes
A. Biancalani1 , A. Bottino1 , N. Carlevaro2 , A. Di Siena1 , T. Görler1 , G. Montani2 , I. Novikau1 ,
and D. Zarzoso3
1 Max-Planck-Institut für Plasmaphysik, 85748 Garching, Germany
2 ENEA C.R. Frascati - ENEA for EUROfusion, C.P. 65 - 00044 Frascati, Italy
3 Aix-Marseille Université, PIIM, UMR 7345, 13397 Marseille, France
Geodesic acoustic modes [1] (GAM) are zonal, i.e. axisymmetric oscillations of the radial
electric field, typically observed in tokamaks in the presence of turbulence. GAMs can be driven
unstable by the presence of energetic particles (EP), i.e. fast ions which can be present as the
product of fusion reactions or external heating mechanisms. A possible role of these EP-driven
GAMs (EGAM) [2] in the nonlinear saturation of turbulence, has been recently emphasized
by means of gyrokinetic (GK) semi-lagrangian simulations [3]. In this work, the nonlinear dy-
namics of EGAMs is investigated with the GK particle-in-cell code ORB5 [4, 5]. The EGAM
saturation due to wave-particle nonlinearity [6] and wave-wave nonlinearity is compared. The
radial structure of EGAMs is also investigated. Finally, the nonlinear interaction of EGAMs
and turbulence is studied. Comparisons with reduced models and with the GK codes GENE and
GYSELA, are presented.
References
[1] N. Winsor, J. L. Johnson and J. M. Dawson, Phys. Fluids 11, 2448, (1968)
[2] G. Y. Fu, Phys. Rev. Letters 101 (18), 185002 (2008)
[3] D. Zarzoso, et al. Phys. Rev. Letters 110 (12), 125002 (2013)
[4] S. Jolliet, et al. Comput. Phys. Commun. 177, 409 (2007)
[5] A. Bottino, et al. Plasma Phys. Controlled Fusion 53, 124027 (2011)
[6] A. Biancalani, et al. J. Plasma Phys. 83 725830602 (2017)
