低杂波加热的射线追踪以及全 波解模拟 杨程 等离子体所五室

OUTLINE 理论以及数值模拟方法介绍 1 ）射线追踪（ GENRAY ） 2 ）全波解（ TORLH ） 两种方法对一个物理问题 —— 低杂波的 spectral gap 的研究和比较

理论以及数值模拟方法介绍 —— 射线追踪方法

Ray tracing Ray tracing is based on WKB approximation: if the wavelength is short compared to the scale length of tokamaks, the wave quantities such as electric field is taken to be wary as Here the x axis is taken to be along the direction of the inhomogeneity. The wave propagates with fixed k y, k z, and ω and with k x (x) determined through the local dispersion relation, the parameters of which are functions of x. The WKB method can be extended to three dimensions:, where is a function of position such that, with k satisfying the local dispersion relation. The direction of energy flow is given by the group velocity. The vector k is determined by a dispersion relation of the form: and the fact that along the ray path: The ray tracing equations can be given by:

理论以及数值模拟方法介绍 —— 全波解方法

TORLH

Spectral gap problem [*]P.T. Bonoli, IEEE Trans. Plasma Sci. 12,95(1984) [#]N.J. Fisch, PRL, 41,873(1978)

Motivations of the following works: The spectral gap for LHW in EAST is expected to be very large, and the LHW is in a low single pass absorption regime, which poses a challenge for the simulation of LHCD in EAST device with large aspect ratio.

Study of the Spectral gap problem in EAST LHCD using ray-tracing (GENRAY) LHW undergoes multiple passes before toroidal effects give rise to sufficient up- shift in the parallel wavenumber Simulation results shows that the spectral gap in EAST LHCD is large and the Landau damping relies very much on the up-shift in the parallel wavenumber due to the toroidal effects, since the power is not able to be absorbed on-axis where the temperature is higher but the poloidal field ~0.

Comparisons between the GENRAY and the TORLH simulation for the LHW in EAST for the Maxwellian case Maxwellian electron distribution function assumed for both the GENRAY and the TORLH simulation: Poloidal spectrum modeled by TORLH

Comparisons between the GENRAY and the TORLH with different temperature 1.5 keV 5.0 keV

Using the same Non-Maxwellian electron distribution function provided by the iteration between GENRAY and CQL3D for both the GENRAY and the TORLH simulation: Quasi-linear results of wave electric field modeled by TORLH For the non-Maxwellian case, the two deposition profiles look similar to each other except for a slight difference between the positions of the peaks, which indicates that the discrepancy of the two codes is diminished as the results of the iteration between the GENRAY and the CQL3D being used. Comparisons between the GENRAY and the TORLH simulation for the LHW in EAST for the Non-Maxwellian case Maxwellian results of wave electric field modeled by TORLH:

Summary