학술논문
ORB5: a global electromagnetic gyrokinetic code using the PIC approach in toroidal geometry
Document Type
Working Paper
Author
Lanti, E.; Ohana, N.; Tronko, N.; Hayward-Schneider, T.; Bottino, A.; McMillan, B. F.; Mishchenko, A.; Scheinberg, A.; Biancalani, A.; Angelino, P.; Brunner, S.; Dominski, J.; Donnel, P.; Gheller, C.; Hatzky, R.; Jocksch, A.; Jolliet, S.; Lu, Z. X.; Collar, J. P. Martin; Novikau, I.; Sonnendrücker, E.; Vernay, T.; Villard, L.
Source
Subject
Language
Abstract
This paper presents the current state of the global gyrokinetic code ORB5 as an update of the previous reference [Jolliet et al., Comp. Phys. Commun. 177 409 (2007)]. The ORB5 code solves the electromagnetic Vlasov-Maxwell system of equations using a PIC scheme and also includes collisions and strong flows. The code assumes multiple gyrokinetic ion species at all wavelengths for the polarization density and drift-kinetic electrons. Variants of the physical model can be selected for electrons such as assuming an adiabatic response or a ``hybrid'' model in which passing electrons are assumed adiabatic and trapped electrons are drift-kinetic. A Fourier filter as well as various control variates and noise reduction techniques enable simulations with good signal-to-noise ratios at a limited numerical cost. They are completed with different momentum and zonal flow-conserving heat sources allowing for temperature-gradient and flux-driven simulations. The code, which runs on both CPUs and GPUs, is well benchmarked against other similar codes and analytical predictions, and shows good scalability up to thousands of nodes.