Research Report NIFS Series: NIFS-959

Abstract

A new gyrokinetic Vlasov simulation code, GKV-X, is developed for investigating the turbulent transport in magnetic confinement devices with non-axisymmetric configurations. Effects of the magnetic surface shapes in a three-dimensional equilibrium obtained from the VMEC code are accurately incorporated. Linear simulations of the ion temperature gradient instabilities and the zonal flows in the Large Helical Device (LHD) [ 0. Motojima, N. Oyabu, A. Komori et al., Nucl. Fusion 43, 1674 (2003) ] configuration are carried out by the GKV-X code for a benchmark test against the GKV code [ T.-H. Watanabe and H. Sugama, Nucl. Fusion 46, 24 (2006)]. The frequency, the growth rate, and the mode structure of the ion temperature gradient instability are influenced by the VMEC geometrical data such as the metric tensor components of the Boozer coordinates for high poloidal wave numbers, while the difference between the zonal flow responses obtained by the GKV and GKV-X codes is found to be small in the core LHD region.