论文标题
W7-X Stellarator中电流驱动诱导的类似锯齿状崩溃的非线性磁性水力学建模
Nonlinear magnetohydrodynamic modeling of current-drive-induced sawtooth-like crashes in the W7-X stellarator
论文作者
论文摘要
在通过电子回旋电流驱动器进行的W7-X实验中，已经观察到了锯齿状的核心电子温度崩溃。我们使用M3D- $ C^1 $代码的新开发的Stellarator建模能力，介绍了这种现象的非线性单流体磁流失动力学模拟。近轴电流驱动器在均衡旋转变换曲线中引起了两个$ i = 1 $的共振，因此在模拟中可以看到连续两个连续的$（1,1）$内部纠结模式。在内部共振处发生了小振幅崩溃，这可能与实验中观察到的锯齿前体相对应。然后在外部共振上发生较大的崩溃，然后使核心温度曲线变平，该核心温度曲线显示了与某些指标（例如崩溃振幅和温度变化的反转半径）的实验测量的半定量协议。这些结果说明了W7-X中流动驱动诱导的类似锯齿状崩溃的可能机制，并在某种程度上验证了M3D- $ C^1 $的杰出人士建模能力。
Sawtooth-like core electron temperature crashes have been observed in W7-X experiments with electron cyclotron current drive. We present nonlinear single-fluid magnetohydrodynamic simulations of this phenomenon using the newly developed stellarator modeling capability of the M3D-$C^1$ code. The near-axis current drive gives rise to two $ι=1$ resonances in the equilibrium rotational transform profile so that two consecutive $(1,1)$ internal kink modes are seen in the simulations. A small-amplitude crash at the inner resonance occurs first, which may correspond to the sawtooth precursors observed in the experiments. A bigger crash at the outer resonance then flattens the core temperature profile, which shows semi-quantitative agreements with experimental measurements on certain metrics such as the crash amplitude and the inversion radius of the temperature change. These results illustrate a likely mechanism of the current-drive-induced sawtooth-like crashes in W7-X and, to some extent, validate the stellarator modeling capability of M3D-$C^1$.
