Measurement of Electron Collision Cross Section in Shock-Wave Heated MHD Plasma by an FIR Laser

利用 FIR 激光器测量冲击波加热 MHD 等离子体中的电子碰撞截面

• 批准号: 08650212
• 负责人: MASUDA Mitsuharu
• 金额: $ 1.6万
• 依托单位: KYUSHU UNIVERSITY
• 依托单位国家: 日本
• 项目类别: Grant-in-Aid for Scientific Research (C)
• 财政年份: 1996
• 资助国家: 日本
• 起止时间: 1996 至 1997
• 项目状态: 已结题
• 来源: https://kaken.nii.ac.jp/grant/KAKENHI-PROJECT-08650212/
• 关键词: MAGNETOHYDRODYNAMICS; MHD; FAR-INFRARED; LASER

To estimate the performance of a large scale MHD generator, it is necessary to develop the theoretical methods that can predict correctly the plasma behavior in the MHD channel.In these methods, the accuracy of the estimation depends strongly on the data of the fundamental plasma parameters ; one of these is the collision cross-section for momentum transfer of electrons to the neutral particles, which is directly related to the conductivity of the plasma. This cross-section has been measured by electrostatic or RF probes. However, these probes inevitably disturb the flow field and the obtained values are thought to have large errors. In addition, the cross-section data currently used inthe analyzes are based on the experimental and/or theoretical values obtained over 20 years ago, and the accuracy of these has not been confirmed by the recent diagnostic technique.In the present research, the electron collision cross-section against the neutral argon atom is evaluated experimentally by using the HCN far-infrared (FIR) laser. The target plasma is obtained with the shock tunnel. The driver and driven sections of the shock tunnel are filled with helium and argon, respectively. The shock Mach number is varied by changing the gas pressure, and the plasma generated in the stagnation section upstream of the channel is used as a target. The Michelson interferometer is used to measure the fringe shift due to the plasma, from that the electron density is calculated. Also, the transmissivity of the FIR laser beam through the plasma is measured, and the electron collision cross-section is determinedfrom the measured electron density and transmissivity.

为了估计大型MHD发生器的性能，有必要发展能够正确预测MHD通道中等离子体行为的理论方法。在这些方法中，估计的准确性很大程度上取决于基本等离子体参数的数据；其中之一是电子向中性粒子的动量转移的碰撞横截面，这与等离子体的电导率直接相关。该截面已被测量静电或射频探头。然而，这些探头不可避免地干扰了流场，并且得到的值被认为有很大的误差。此外，目前在分析中使用的横截面数据是基于20多年前获得的实验和/或理论值，这些数据的准确性尚未得到最近诊断技术的证实。本研究利用HCN远红外（FIR）激光对中性氩原子的电子碰撞截面进行了实验计算。靶等离子体是用激波隧道获得的。激波隧道的驱动段和被驱动段分别充满氦气和氩气。通过改变气体压力来改变激波马赫数，以通道上游停滞段产生的等离子体为靶。迈克尔逊干涉仪用于测量等离子体引起的条纹位移，由此计算出电子密度。同时，测量了FIR激光束通过等离子体的透射率，并根据测量的电子密度和透射率确定了电子碰撞截面。

项目成果

UKON,Tetsuya: "Measurement of Shock-Wave Heated MHD Plasma Parameters by an FIR Laser" Proc., 96 Symposium on Advanced Research of Energy Technology. 59-66 (1996)

UKON，Tetsuya：“通过 FIR 激光器测量冲击波加热 MHD 等离子体参数”Proc.，96 年能源技术高级研究研讨会。

井上雅弘: "レーザ蛍光法による遷音速キャビティ流れ場の三次元構造の測定" 日本機械学会流体光学部門講演会講演論文集. 96・9. 197-198 (1996)

Masahiro Inoue：“利用激光荧光法测量跨音速空腔流场的三维结构”，日本机械工程学会流体光学分会论文集，197-198（1996）。

井上雅弘: "レーザー蛍光法によるキャビティのある遷音速内部流れ場の温度揺らぎ測定" 可視化情報. 16・2. 83-86 (1996)

Masahiro Inoue：“使用激光荧光法测量跨声速内部流场的温度波动”可视化信息 16・2（1996）。

KASHITANI,Masashi: "Structures of the Correctrly Expanded Supersonic Freejets from Axisymmetric Nozzles (Effect of the Reynolds Number on Pitot Impact Pressure)" JSME Journal. B613-616. 3905-3912 (1997)

KASHITANI,Masashi：“轴对称喷嘴正确扩展的超音速自由喷射的结构（雷诺数对皮托冲击压力的影响）”JSME 期刊。

T.Ukon: "Measurement of Shock-Wave Heated MHD Plasma Parameters by an FIR Laser" Proc.'96 Symposium on Advanced Research of Energy Technology. 59-66 (1996)

T.Ukon：“通过 FIR 激光器测量冲击波加热 MHD 等离子体参数”Proc.96 能源技术高级研究研讨会。