Study of trapped electron instabilities driven by magnetic curvature drifts
Study of trapped electron instabilities driven by magnetic curvature drifts
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DOI：
10.1063/1.861920
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发表时间：
1977-04
影响因子：
4.6
通讯作者：
D. Ross;W. Tang;J. Adam
中科院分区：
文献类型：
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作者：
D. Ross;W. Tang;J. Adam
本文对托卡马克装置中的俘获电子不稳定性进行了数值研究，在大纵横比展开式不适用的物理参数范围内。频率和增长率被确定为e=r/R，et=（R dlnTe/dr）−1，ηe =dlnTe/dlnn，B=（k ρi）2/2的函数。特别是，通常的漂移波的关系，被困电子朗道共振或碰撞驱动，由Coppi和Rewoldt描述的非共振模式进行了研究。它被证实，后者，一方面，获得作为前大B的延续，另一方面，有一个定性的不同的行为。对于足够小的et和正常的密度梯度（ηe <$0），模式可以反转并在离子抗磁方向上传播。出现这种情况的明确的标准推导，并得到大B的增长率的缩放。在无碰撞极限下，这些非共振增长率可以超过通常的漂移波。因此，有必要…
The trapped electron instability in tokamaks is investigated numerically for a range of physical parameters in which the large aspect ratio expansion is not valid. The frequency and growth rate are determined as functions of e=r/R, et= (R dlnTe/dr)−1, ηe =dlnTe/dlnn, and b= (k⊥ρi)2/2. In particular, the relationship of the usual drift wave, driven by trapped electron Landau resonances or collisions, to a nonresonant mode described by Coppi and Rewoldt is studied. It is verified that the latter, on the one hand, is obtained as a continuation of the former to large b, and, on the other hand, has a qualitatively different behavior. For sufficiently small et, and for normal density gradients (ηe⩾0), the mode can reverse and propagate in the ion diamagnetic direction. Explicit criteria for this to happen are derived, and the scaling of the resulting growth rates for large b is obtained. In the collisionless limit, these nonresonant growth rates can exceed those of the usual drift waves. It is therefore necessa...