标题： 托卡马克几何中非线性生成纬向流的统一介观图景 显示英文标题

标题： Unified mesoscale picture of nonlinear generation of zonal flows in toroidal geometry

摘要： 最近关于极限环振荡的实验发现表明，在环形几何中，湍流极向雷诺应力对环向流的非线性驱动并不是一个显著因素，这在聚变界引发了根本性的争议。 通过使用全局非线性gyrokinetic模拟，我们提出了离子温度梯度湍流中环向流非线性驱动的统一介观图景。 环向流由湍流能量通量和湍流极向雷诺应力非线性驱动。 湍流能量通量在非线性驱动环向流时不会被环形几何效应屏蔽。 湍流极向雷诺应力在短于离子回旋周期的时间尺度上不会被屏蔽；然而，在长于离子回旋周期的时间尺度上，湍流极向雷诺应力确实会被环形几何效应屏蔽。 显示英文摘要

摘要： Recent experimental findings on limit-cycle-oscillations indicate that the nonlinear driving of the turbulent poloidal Reynolds stress to zonal flows is not a significant factor in the toroidal geometry, sparking fundamental controversial issues within the fusion community. By using the global nonlinear gyrokinetic simulations, we propose a unified mesoscale picture of nonlinear driving of zonal flows in the ion-temperature-gradient turbulence. Zonal flows are nonlinearly driven by the turbulent energy flux and the turbulent poloidal Reynolds stress. The turbulent energy flux is not shielded by the toroidal geometry effect in nonlinearly driving zonal flows. The turbulent poloidal Reynolds stress is not shielded on the time scale shorter than the ion bounce period; however, on the time scale longer than the ion bounce period, the turbulent poloidal Reynolds stress is indeed shielded by the toroidal geometry effect.