Studies on the video imaging of radioactivity distribution

到目前为止，测量放射性和辐射的主题主要是强度和能量。在今后的钚污染检测、β放射性自显影和中子照相中，需要在视频监视器上快速地将这种分布成像。为了对放射性和辐射分布进行成像、图像处理和定量评价，研制了α放射性分布图像视频监测系统，该系统由探测单元、视频成像单元、图像积分单元和图像处理单元组成。视频成像单元是在本研究中新建的。图像整合单元的监视器显示逐渐清晰的分布图像，整合后的图像被传送到图像处理单元以处理图像。积分图像是低噪声的。图像的畸变小于2.5%，空间分辨率为1.4lp/mm。虽然系统被改进为将视频成像单元与检测单元接触，但是在集成图像中留下了不均匀性。为了对α图像进行定量评价，重新编制了均匀化处理和斑点处理程序，并将其应用于钚污染检测中。利用图像积分单元获得的光斑图像被处理成均匀图像。通过均匀度和感兴趣区的处理，得到了整个样品的α-活性。此外，α放射性和钚粒子的尺寸分布可以通过斑点过程获得。这些结果表明，成像视频监测器是探测钚污染和评价钚照射的一种有用手段。中子照相的应用是未来研究的主题。

Until now, the subject of measurement for radioactivity and radiation was mainly the intensity and the energy. It is desirable hereafter that the distribution is rapidly imaged on video monitor in the detection of plutonium contamination, beta-emitter autoradiography and neutron radiography. The purpose of this study is to image the distributions of radioactivity and radiation, to process the image, and to evaluate quantitatively the distributions.A imaging video monitor system for alpha-activity distribution consists of a detection unit, a video imaging unit, a image integration unit, and a image process unit. The video imaging unit was newly constructed on present study. The monitor of the image integration unit displays the image of the distribution becoming gradually clear.The integrated image is transferred to the image process unit to process the image. The integrated image is low noise. The distortion of the image is less than 2.5 %, and the spatial resolution is 1.4 lp/mm. Although the system was improved to place the video imaging unit in contact with the detection unit, the nonuniformity in integrated image was left. In order to evaluated quantitatively the integrated alpha-image, the uniform process and spot process was newly programmed.The imaging video monitor system was applied to the detection of plutonium contamination. The spot image obtained with the image integration unit was processed to uniform image. The processes of the uniformity and ROI gave the alpha-activity on the whole sample. Moreover, the alpha-activity and size distributions of plutonium particles could be obtained by the spot process. These results indicate that the imaging video monitor is a useful means for detecting plutonium contamination and evaluating plutonium exposure. The application to neutron radiography is the subject for a future study.