Impurity transport in tokamaks in the banana-plateau regime
Impurity transport in tokamaks in the banana-plateau regime
复制标题
香蕉高原区域托卡马克中的杂质传输
DOI：
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发表时间：
1974
期刊：
影响因子：
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通讯作者：
T. B. Moore
中科院分区：
文献类型：
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作者：
F. Hinton;T. B. Moore
将离子和杂质通量及其能量通量与密度和温度梯度相关的传输系数源自新古典理论。假设离子的平均自由程比环面连接长度长得多。香蕉-高原转变取决于电子-离子问题中不存在的附加参数。仅考虑两种不同的离子质量，但较重的离子可以具有任意数量的不同的可能电离态。质量比任意；然而，小质量比限制被详细考虑。在该限制下，由于离子-杂质碰撞而导致通量从香蕉态过渡到平台态的碰撞参数 υ1* 的临界值是 ~(n1/ni)(m1/mi)1/2，其中 i 表示轻离子，I 表示杂质。相应传输系数的平台状态值与该参数成正比，在典型情况下，该参数可能远小于统一值。还讨论了由于杂质而导致的电子传输性质的改变。
Transport coefficients, relating ion and impurity fluxes, and their fluxes of energy, to the density and temperature gradients, are derived from neoclassical theory. The ions are assumed to have mean free paths much longer than the torus connection length. The banana-plateau transition is shown to depend upon additional parameters which are not present in the electron-ion problem. Only two different ion masses are considered, but the heavier ions may have an arbitrary number of different possible ionization states. The mass ratio is arbitrary; the small mass-ratio limit is considered in detail, however. In that limit, the critical value of the collisionality parameter υ1*, for the transition from banana regime to plateau regime for the fluxes due to ion-impurity collisions, is shown to be ∼(n1/ni)(m1/mi)1/2, where i denotes light ions and I denotes impurities. The plateau regime values of the corresponding transport coefficients are proportional to this parameter, which may be much smaller than unity, in typical cases. The modification of electron transport properties due to impurities is also discussed.