Overestimation of Mach number due to probe shadow
Overestimation of Mach number due to probe shadow
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DOI：
10.1063/1.4954820
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发表时间：
2016-07-01
影响因子：
2.2
通讯作者：
Tynan, G. R.
中科院分区：
文献类型：
--
作者：
Gosselin, J. J.;Thakur, S. C.;Tynan, G. R.
在受控的剪切去相关实验中，对MACH探针和激光诱导的荧光进行了血浆离子流量速度测量值的比较。我们显示探针的存在导致探针下游的低密度几何阴影，如果离子中不中性平均自由路径短于探针阴影长度，则探针在碰撞等离子体中收集的电流密度，L-g = w（2）v-drift/d+，导致错误的手机数量。然后，我们提出一个简单的校正项，该校正项可从探针数据中提供校正后的MACH数，当知道等离子体的声速，离子中性平均自由路径和垂直扩散系数。每当线性设备中的探针阴影长度和融合设备的敞开线区域的探针阴影长度上，必须考虑探针阴影效果。由AIP Publishing出版。
Comparisons of the plasma ion flow speed measurements from Mach probes and laser induced fluorescence were performed in the Controlled Shear Decorrelation Experiment. We show the presence of the probe causes a low density geometric shadow downstream of the probe that affects the current density collected by the probe in collisional plasmas if the ion-neutral mean free path is shorter than the probe shadow length, L-g = w(2) V-drift/D+, resulting in erroneous Mach numbers. We then present a simple correction term that provides the corrected Mach number from probe data when the sound speed, ion-neutral mean free path, and perpendicular diffusion coefficient of the plasma are known. The probe shadow effect must be taken into account whenever the ion-neutral mean free path is on the order of the probe shadow length in linear devices and the open-field line region of fusion devices. Published by AIP Publishing.