基于切伦科夫探测器的高能双能X射线物质有效原子序数检测

Employing Cerenkov Detectors in Material Effective Material Atomic Number Detection of Dual-energy X-ray Beams

介绍了采用切伦科夫探测器在高能双能X射线物质有效原子序数检测中的应用优势。采用电子加速器产生的X射线源的双能物质有效原子序数检测中,由于能量较低的X射线(低于0.5 M eV)占有重要的份额,其光电效应的存在干扰物质有效原子序数的检测,故一般需要加滤波材料降低其数量从而改善检测效果。切伦科夫探测器由于对X射线有探测阈值要求,可以不用加滤波材料即可实现物质检测功能;另外,对高能X射线有更好的相对能量响应是其在此方面应用的另一个优势。通过在一个双能检查系统(采用6 M eV和3 M eV电子加速器)的实验证明了这种设想,实验结果和预期的设想以及模拟计算结果相吻合。

The advantages of employing Cerenkov detectors in material effective atomic detection of dual-energy X-ray beams are reported. As the megavoltage X-ray beams produced in electron linae have lots of photons below 0.5 MeV that will distort final results, the filtered material is often required. Cerenkov detector having the deteetion threshold can perfectly avoid their influence and fulfill the aim. Another Cerenkov deteetor＇s advantage is that have relatively higher response for X-ray photon with higher energy, which means better discrimination in material atomic number detection. The idea is verified by an experiment in an inspeetion system employing a dual-energy electron linac with 6 MeV and 3 MeV gears, in coincidence with Monte Carlo simulation.