Hot tail runaway electron generation in tokamak disruptions
Hot tail runaway electron generation in tokamak disruptions
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DOI：
10.1063/1.2949692
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发表时间：
2008-07
影响因子：
2.2
通讯作者：
Håkan Smith;E. Verwichte
中科院分区：
文献类型：
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作者：
Håkan Smith;E. Verwichte
热尾逃逸电子的产生是由等离子体快速冷却过程中电子速度分布的不完全热化引起的。如果热猝灭相足够快，则逃逸电子是托卡马克破裂中的一种重要机制。产生逃逸电子的密度的分析估计得出的情况下，指数状的温度衰减的冷却速率低于碰撞频率。数值模拟，辅助分析结果，被用来比较强度的热尾失控代与Dreicer机制不同的中断参数（冷却速率，热淬火后的温度，和电子密度）假设没有损失的失控电子发生。可以看出，热尾失控产生将是ITER中两种主要失控机制中的主导机制[R。Aymar等人，Plasma Phys.Controlled Fusion 44，519（2002）]。
Hot tail runaway electron generation is caused by incomplete thermalization of the electron velocity distribution during rapid plasma cooling. It is an important runaway electron mechanism in tokamak disruptions if the thermal quench phase is sufficiently fast. Analytical estimates of the density of produced runaway electrons are derived for cases of exponential-like temperature decay with a cooling rate lower than the collision frequency. Numerical simulations, aided by the analytical results, are used to compare the strength of the hot tail runaway generation with the Dreicer mechanism for different disruption parameters (cooling rate, post-thermal quench temperature, and electron density) assuming that no losses of runaway electrons occur. It is seen that the hot tail runaway production is going to be the dominant of these two primary runaway mechanisms in ITER [R. Aymar et al., Plasma Phys. Controlled Fusion 44, 519 (2002)].