Studies on the video imaging of radioactivity distribution

迄今为止，对放射性和辐射的测量主要是强度和能量的测量。今后，在钚污染检测、放射自显像和中子显像中，希望能在视频监视器上快速成像其分布。本研究的目的是对放射性和辐射的分布进行成像，对图像进行处理，并定量评价其分布。一种用于α -活动分布的成像视频监控系统，包括检测单元、视频成像单元、图像集成单元和图像处理单元。视频成像单元是在目前研究的基础上新建的。图像集成单元的监视器显示图像的分布逐渐清晰。将所述集成图像传输到所述图像处理单元以对所述图像进行处理。集成后的图像具有低噪声的特点。图像畸变小于2.5%，空间分辨率为1.4 lp/mm。虽然对系统进行了改进，使视频成像单元与检测单元接触，但集成图像的不均匀性仍然存在。为了对综合后的图像进行定量评价，重新编制了均匀过程和斑点过程。将成像视频监控系统应用于钚污染的检测。将图像集成单元得到的斑点图像处理为均匀图像。均匀性和ROI的过程给出了整个样品的α活性。此外，还可以用点法得到钚粒子的α活度和尺寸分布。这些结果表明，成像视频监测器是检测钚污染和评价钚暴露的有效手段。在中子射线照相中的应用是今后研究的课题。

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.