首页> 外文期刊>Nuclear fusion >Simulation study of particle transport by weakly coherent mode in the Alcator C-Mod tokamak
【24h】

Simulation study of particle transport by weakly coherent mode in the Alcator C-Mod tokamak

机译:Alcator C-Mod托卡马克弱相干模式粒子输运的仿真研究

获取原文
获取原文并翻译 | 示例
获取外文期刊封面目录资料

摘要

A simulation study has been conducted of the physical mechanisms behind the weakly coherent mode (WCM) and its produced particle transport in the I-mode edge plasmas by using the BOUT++ code. The WCM is identified in our simulations by its poloidal and radial distributions as well as its frequency and wavenumber spectra. Its produced radial particle flux is calculated and compared with the experimental value. The good agreement indicates that the WCM is an important particle transport channel in the I-mode pedestal. It is found that the WCM can transport particles across the strong outer shear layer of the E ( r ) well established in the formation of I-mode, based on which a possible explanation is provided why I-mode does not feature a density pedestal. The key point lies in the change of the cross-phase between the electric potential and density fluctuations induced by the E x B Doppler shift. In the strong shear layer, although the electric potential fluctuation is significantly suppressed, the cross-phase is close to pi/2, resulting in a strong drive of the density fluctuation and particle transport. To identify the physical nature of the WCM, a linear dispersion relation for drift Alfven modes is derived in the slab geometry. A drift Alfven wave instability is found to have similar dependence to the simulated linear instability behind the WCM on the resistivity and the parallel electron pressure gradient and thermal force terms in the parallel Ohm's law.
机译:利用BOUT++代码对弱相干模态(WCM)的物理机理及其在I模边缘等离子体中产生的粒子输运进行了仿真研究。在我们的仿真中,WCM通过其极化和径向分布以及频率和波数谱来识别。计算其产生的径向粒子通量,并与实验值进行比较。良好的一致性表明WCM是I模基座中重要的粒子输运通道。研究发现,WCM可以传输颗粒穿过在I型形成过程中建立的E(r)的强外剪切层,据此提供了I型不具有密度基座的可能解释。关键在于E×B多普勒频移引起的电势和密度波动之间的交叉相位的变化。在强剪切层中,虽然电势涨落受到明显抑制,但交叉相接近pi/2,导致密度波动和粒子输运的强烈驱动。为了确定WCM的物理性质,在板几何中推导了漂移Alfven模态的线性色散关系。在平行欧姆定律中,漂移阿尔文波不稳定性与WCM后面模拟的线性不稳定性对电阻率以及平行电子压力梯度和热力项的依赖性相似。

著录项

获取原文

客服邮箱:kefu@zhangqiaokeyan.com

京公网安备:11010802029741号 ICP备案号:京ICP备15016152号-6 六维联合信息科技 (北京) 有限公司©版权所有
  • 客服微信

  • 服务号