Global nonlinear gyrokinetic simulations of ITG modes using particles in tokamak geometry
Global nonlinear particle-in-cell (PIC) simulations are considered a useful tool for studying the time evolution and the saturation of turbulence induced by ion-temperature-gradient-driven (ITG) instabilities. However, in these simulations energy conservation is usually lost in the saturation phase even though the underlying equations are energy conserving. It has been shown that the unavoidable statistical noise in PIC simulations can be strongly reduced by optimising the loading of the markers in reduced phase-space. Using this approach in theta-pinch geometry, energy conservation could be achieved well beyond the saturation of the instability. This optimisation method has been adapted to tokamak geometry and implemented in ORB5, a fully nonlinear global delta f PIC code. In this work preliminary results are presented, in particular with respect to conservation laws (energy and particle number) and numerical convergence of physically relevant quantities.
Bibliographic Reference: A paper presented at the Joint Varenna-Lausanne International Workshop on "Theory of Fusion Plasmas", Varenna, Italy, August 27-30 2002, and published in EPFL Internal report 737/02, October 2002, pp.51-56.
Availability: Available free of charge from: École Polytechnique Fédérale de Lausanne (EPFL), Ecublens, CH-1015 Lausanne Fax +41-21-6934747 Available online on the workshop website: http://varenna-lausanne.epfl.ch/
Record Number: 200215546 / Last updated on: 2002-11-20
Original language: en
Available languages: en