DISTINGUISH: Detection of explosive substances by tomographic inspection using neutron and gamma-ray spectroscopy

需要有一种检查系统，能够探测到隐藏在行李中的爆炸物（或毒品）。如果这些系统可以在不需要人工检查的情况下检查物体，那么它们是最有效的。一个人不必搜查每件行李或容器。炸药几乎普遍由不同比例的氢、碳、氮和氧组成。探测这类元素的系统是基于向系统中发射一束中子。不同的元素会发出不同能量的伽马射线，这是同位素所特有的。这些伽马射线可以用锗伽马射线探测器精确测量，从而确定每种元素的含量。这些信息可以用来确定四种元素的比例，从而确定是否存在爆炸物（或毒品等）。通过使用现代技术，锗探测器也可以用来制作被调查物体的图像，类似于机场行李扫描仪。在这种情况下，伽马射线和散射中子将同时被探测到，以获得更清晰的图像。在项目结束时，我们希望在实验室中证明这些想法是有效的，并确定潜在的灵敏度。

There is a need for inspection systems that are able to detect explosives (or drugs) hidden in for example luggage. These systems are most efficient if they can inspect the object without having to investigate by hand. e.g. a person does not have to search each piece of luggage or container. Explosives almost universally comprise hydrogen, carbon, nitrogen and oxygen is different ratios. A system that will detect elements like these is based on sending a beam of neutrons into the system. The different elements will emit gamma rays of different energies which are unique to the isotopes concerned. These gamma rays can be measured accurately with a germanium gamma-ray detector and hence the amount of each element determined. This information can then be used to determined the ratios of the four elements and hence whether explosives (or drugs etc.) are present. By using modern technology the germanium detector can also be used to make an image of the object under investigate, similar to an airport baggage scanner. In this case the gamma-rays and scattered neutrons will be detected simultaneously to make a clearer image. By the end of the project we hope to have demonstrated in the laboratory that these ideas are effective and to determine the potential sensitivity.