Effects of orbit squeezing on ion transport in the banana regime in tokamaks
Effects of orbit squeezing on ion transport in the banana regime in tokamaks
复制标题
轨道挤压对托卡马克香蕉区离子输运的影响
DOI：
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发表时间：
1992
期刊：
影响因子：
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通讯作者：
R. Hazeltine
中科院分区：
文献类型：
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作者：
K. Shaing;R. Hazeltine
结果表明，在托卡马克香蕉制度中的离子输运减少在径向电场Er中的强剪切的存在下，经常观察到的边缘区域。为了简单起见，采用ρpi = ln Er /dr = 1但c = Er/Bpvti < 1的排序。这里，ρpi是离子极向回转半径，Bp是极向磁场强度，vti是离子热速度，c是光速。一个类似于凹凸环面和仿星器的动力学输运理论被发展出来，表明离子热导率χi大约减少了S−3/2，其中S = 1 −（ρpi d ln Er /dr）（cEr Bpvti）。结果不仅反映了简单的轨道压缩，还反映了S对囚禁离子分数的修正。
It is shown that ion transport in the banana regime in tokamaks is reduced in the presence of a strong shear in the radial electric field Er , as is often observed in the edge region. For simplicity, the ordering with ρpi‖d ln Er /dr‖ ≫ 1 but c‖Er‖/Bpvti < 1 is adopted. Here, ρpi is the ion poloidal gyroradius, Bp is the poloidal magnetic field strength, vti is the ion thermal speed, and c is the speed of light. A kinetic transport theory similar to those for bumpy tori and stellarators is developed to show that the ion thermal conductivity χi is reduced by a factor of roughly S−3/2, where S = 1 − (ρpi d ln Er /dr)(cEr Bpvti). The result reflects more than simple orbit squeezing: The fraction of trapped ions is also modified by S.