Nonlocal effects in gyrokinetic turbulence simulations using GENE

Modeling of anomalous transport, typically based on gyrokinetic theory, is an essential tool for better understanding and possibly improving the confinement of magnetic fusion plasmas. A well-benchmarked and established implementation of the gyrokinetic Vlasov-Maxwell system of equations can, for instance, be found in the software package GENE. This Eulerian code has recently been enhanced to optionally consider full radial temperature, density, and geometry variations allowing for investigations of nonlocal effects instead of using the radially local flux-tube approximation. First investigations on the importance of finite-size effects are presented and compared with results from the gyrokinetic Lagrangian PIC code ORB5 [S. Jolliet et al. 2007 Comput. Phys. Commun. 177 409, B.F. McMillan et al. 2008 Phys. Plasmas 15 052308]. Special attention is drawn to a specific nonlocal effect, namely heat flux avalanches.