Study on Two-Phase Flow in Small Metal Pipe Tube using Proton Radiography

研制了高灵敏度、高分辨率的实时质子放射成像系统。当工作流体为不透明流体且测试截面为金属材料时，不能使用光学方法对沸腾气泡进行可视化。由于高速事件，如沸腾气泡的行为，用x射线或中子束很难可视化。在这种情况下，质子x线摄影可能是有用的。因为质子放射照相依赖于质子电离功率随距离接近其极限的快速变化，并与高通量的质子束一起使用。本研究利用质子射线照相技术，研究了小金属管内沸腾气泡等动态事件的可视化。采用14mev的单色质子束。试验段用约10^<11>粒子/cm^2的质子束辐照。S分别为直径0.94,1.54和1.94mm，然后在测试截面附近的荧光屏上对沸腾气泡进行质子射线照相。高速摄像机记录的气泡图像（最高每秒4000帧）。

High sensitive and high resolution real-time proton radiography system has been developed.When an opaque fluid is used as a working fluid and the test section is made of metal, optical method cannot be used for the visualization of the boiling bubbles. It has been difficult to visualize with X-ray or neutron beams because of the high speed events such as behaviors of boiling bubbles. In these case, it may be expected that proton radiography is useful. Because proton radiography depends on the rapid change of ionizing power of proton with distance near the end of their range and is used with a high flux of proton beams. In this study, the visualization of the dynamic events such as boiling bubbles in a small metal pipe was investigated by using proton radiography.The monochromatic proton beam of 14 Mev was used. Test section were irradiated with proton beam flux of about 10^<11> particles/cm^2.s for 0.94, 1.54 and 1.94mm in diameter, and then proton radiography of boiling bubbles were taken on the fluorescent screen near by the test section. Images of bubbles recorded with the high speed video camera (maximum 4000 frames per second).