The fast pressure crash associated with the nonlinear evolution of DTMs is investigated using a three-dimensional toroidal and nonlinear MHD code CLT. Our simulation results indicate that the fast pressure crash is not directly related to the explosive growth of DTM because the explosive growth of the DTM takes place in the earlier nonlinear phase and the fast pressure crash happens in the much later nonlinear stage. It is also found that the explosive growth lasts much longer than the fast pressure crash. At almost the end of the explosive growth phase, the magnetic fields around the magnetic axis become stochastic, and a strong radial flow is generated. The radial flow can effectively transfer the hot plasma around the magnetic axis into the outer cold region and consequently leads to the fast crash of the pressure in the core. As a result, the dependence of the crash time on the resistivity is very weak. It is also found that the geometry of Tokamaks has very weak influence on the fast pressure crash.

中文翻译：

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与双撕裂模式相关的快速压力碰撞的数值研究

使用三维环形和非线性 MHD 代码 CLT 研究了与 DTM 非线性演化相关的快速压力碰撞。我们的模拟结果表明，快速压力崩溃与 DTM 的爆炸性增长没有直接关系，因为 DTM 的爆炸性增长发生在早期的非线性阶段，而快速压力崩溃发生在更晚的非线性阶段。还发现爆炸式增长的持续时间比快速压力崩溃要长得多。在爆炸性增长阶段几乎结束时，磁轴周围的磁场变得随机，并产生强烈的径向流。径向流可以有效地将围绕磁轴的热等离子体转移到外冷区，从而导致核心压力的快速崩溃。因此，碰撞时间对电阻率的依赖性非常弱。还发现托卡马克的几何形状对快速压力碰撞的影响非常小。