Development of Light-X ray Hybrid CT System for Plasma Diagnosis

1991年，为确定所开发系统的规格，进行了基本实验。在基础实验中，研究了光发射CT技术重建图像的定量精度和空间分辨率。1992年，在1991年基础实验的基础上，设计了光- X射线混合CT系统，并制作了部分光发射CT。在本部分中，镜面在准直器前高速旋转，镜面和准直器都围绕物体放电管旋转，从而在几秒内收集到重构分布所需的投影数据。接下来，将光发射CT系统与其中一位研究员Yuge先生提供的X射线CT系统结合，然后构建混合系统。在混合系统中，光发射CT系统的数据测量条件与X射线CT系统的数据测量条件一致，因此两种系统之间的数据兼容性是混合系统的重要因素。利用所研制的混合系统，测量了发光强度在放电管内分布的投影数据和玻璃管的形状。然后利用所研制的系统得到的玻璃形状，修正了在管的草的边界处的光折射的影响。从而提高了光强分布重建图像的定量精度。

In 1991, the basic experiment was performed for deciding the specifications of the developed system. In the basic experiment, the quantitative accuracy and the spatial resolution of the reconstructed image obtained by the light emission CT technique are investigated.In 1992, the light - X ray hybrid CT system was designed according to the basic experiment performed in 1991, and then the part of the light emission CT was produced. In this part, the mirror is rotated at high speed in front of the collimator, and both the mirror and the collimator are rotated around the object discharge tube, so that the projection data required for reconstructing the distribution can be collected in several seconds. Next, the light emission CT system was combined with a X ray CT system provided by one of the investigators, Mr. Yuge, and then the hybrid system was constructed. In the hybrid system, the data measuring condition of the light emission CT system agrees with that of the X ray CT system, so that the compatibility of the data between both systems is important factor for the hybrid system.Using the developed hybrid system, both the projection data of the luminous intensity's distribution in the discharge tube and the shape of the glass tube were measured. Then influence of the light refraction at the boundary of the grass of the tube was corrected using the shape of the glass obtained by the developed system. Consequently, the quantitative accuracy of the reconstructed image of the luminous intensity's distribution was improved.