Development of Magnetic Field Distribution Measurement in a Plasma by Means of Beam Probe/Laser Spectroscopy

研究了一种利用塞曼效应结合粒子束注入和激光诱导荧光法提高等离子体磁场分布测量精度的技术。然而，得出的结论是，激光诱导的荧光强度不足以达到良好的时间和空间分辨率。然后，我们将我们的努力转移到提高那些利用运动斯塔克效应(MSE)的准确度上。本文编制了一个模拟H&lt；α&gt；的MSE谱的程序，该程序准确而精确地考虑了相关的原子过程以及束流注入和观察视线的几何形状。考虑了等离子体中电离和电荷交换引起的束流衰减以及电子密度对激发的影响。离子束源的配置、束的发散、托卡马克的磁配置、观测的支撑角度以及…的狭缝功能从模拟程序中得到的结果如下：对于MSE诊断程序的优化设计，1)长宽比为2的椭圆对于离子源配置是最佳的，2)诊断光束应该从垂直方向倾斜25度，并且应该从与光束成70度角的环口处观察。作为MSE谱计算的应用，已经表明：1)从MSE谱可以得到电子密度，2)用4个极化方向分别为0、45、90和135度的线性偏振器同时测量等离子体中的极向磁场；3)利用由于束流发散引起的光谱红移和蓝移的不对称性，较小地测定了JFT-2M装置上加热中性束发散角1.3°

A technique of improving the accuracy of magnetic field distribution measurement in a plasma utilizing the Zeeman effect with a combination of the particle beam injection and laser induced fluorescence method was investigated. It is, however, concluded that the intensity of laser-induced fluorescence is not enough to achieve good time-and space-resolution. Then, we have shifted our effort to the improvement of the accuracy of those which utilize the Motional Stark Effect (MSE). A code has been developed to simulate the MSE spectrum of H_<alpha>, taking accurately and precisely into account the related atomic processes as well as geometries of the beam injection and observation line of sight. A beam attenuation by ionization and charge exchange in the plasma and an electron density dependence of the excitation are regarded. Configuration of the ion beam source, divergence of the beam, magnetic configuration of the tokamak, sustaining angle of the observation, and a slit function of the … More spectrometer are also taken into account.The results obtained from the simulation code are as follows :As for the optimum design of MSE diagnostics, 1) an ellipse of aspect ratio 2 is optimum for the ion source configuration, and 2) the diagnostic beam should be tilted by 25 degrees from the perpendicular direction, and should be observed from a port located at the toroidal angle of 70 degrees apart from the beam.As applications of the MSE spectral calculation, it has been shown that 1) it will be possible to obtain the electron density from the MSE spectrum, 2) poloidal magnetic field in a plasma can be determined from a simultaneous measurement with 4 linear polarizers having the polarization direction of 0,45,90, and 135 degrees with respect to the horizontal direction, and 3) utilizing the fact that the spectrum shows an asymmetry between red-shifted pi line and blue-shifted one due to the finite divergence of the beam, a divergence angle of 1.3 deg.of the heating neutral beam on the JFT-2M tokamak at JAERI was determined Less