Development of equilibrium control technic for the spherical tokamak plasmas from initial phases to steady state phase

本课题的目的是开发一种识别和控制球形托卡马克上等离子体位置及其形状的技术。为了识别它们，通常使用磁信号。由于这些信号是通过积分来计算的，所以被称为漂移误差的误差在长时间的等离子体放电中堆积起来。因此，其想法是利用可见光、软X射线等获取等离子体图像，并根据图像实时识别等离子体位置。从该位置估计磁信号并校正误差。在本课题中，用手电筒代替等离子体进行了运行试验，确认了良好的位置检测及其漂移误差修正。此外，还开发了实时平衡计算程序。

The purpose of this task is to develop the technic to identify and control plasma position and its shape on spherical tokamaks. In order to identify them, the magnetic signals are generally used. Since these signals are calculated with integration, errors called as drift errors are piled up in the long time plasma discharge. Thus, the idea is to acquire the images of plasma with visible lights, soft x-ray, and so on, and the plasma position is identified with the image in real-time. From this position, magnetic signals are estimated and errors are corrected. In this task, the operation test is done with a flashlight instead of plasma, and the good position detection and its drift error correction are confirmed. Furthermore, the real-time equilibrium calculation code is developed.