Evaluation of axial decay length of plasma pressure in detached plasma
Evaluation of axial decay length of plasma pressure in detached plasma
复制标题
分离等离子体中等离子体压力轴向衰减长度的评估
DOI：
10.1016/j.nme.2020.100812
复制
发表时间：
2020
影响因子：
2.6
通讯作者：
and Y. Imaeda
中科院分区：
文献类型：
--
作者：
H. Tanaka;N. Ohno;S. Kajita;H. Takano;S. Hattori;and Y. Imaeda
本研究提出了一种方法，用于评估轴向衰减长度的等离子体压力在分离氦等离子体与固定点激光汤姆逊散射和光谱测量的线性偏滤器等离子体模拟器NAGDIS-II。通过控制中性气体压力，被称为“复合前沿”的高度体积复合区域沿磁场沿着移动。得到了电子压力和复合前沿位置相对于中性压力的微分项。利用这两项定性地计算了等离子体压强的衰减长度。此外，从可移动朗缪尔探针的测量结果，讨论了复合前沿附近的局部估计的衰变长度与宽轴范围内的衰变长度之间的差异。所提出的方法可以适用于即使在巨大的热通量的条件下，直接接触测量，如朗缪尔探针是不可用的。
This study proposes a method for evaluating the axial decay length of the plasma pressure in detached helium plasmas with a fixed-point laser Thomson scattering and spectroscopic measurements in the linear divertor plasma simulator NAGDIS-II. By controlling the neutral gas pressure, the highly volume-recombining region called the “recombination front” was moved along the magnetic field. The differential terms for the electron pressure and the recombination-front position with respect to the neutral pressure were obtained. By using these two terms, the decay length of the plasma pressure was qualitatively calculated. In addition, from the movable Langmuir probe measurement, difference between the locally estimated decay length around the recombination front and the decay lengths over a wide axial range was discussed. The proposed method can be applied even in the huge heat flux condition where direct-contact measurements such as the Langmuir probe are not available.