Gamma-KEV: Imaging the invisible

在恶劣的工作环境中，需要一种强大的传感器，能够精确识别与放射性物质相关的伽马辐射场的能量和成像。拟议的项目将汇集三个合作伙伴，利物浦大学，BAe系统潜艇解决方案和约翰·康特科学公司（JCS）。合作伙伴分别带来了伽马射线探测器系统，强大的恶劣环境包装和营销方面的专业知识。该知识交流项目将为BAe系统公司提供利物浦大学在高分辨率伽马射线系统方面的丰富经验，同时使利物浦大学熟悉强大的封装和测试程序，使他们能够在“现实工作环境”中利用学术开发的仪器。JCS为该项目带来了关键的营销经验，允许根据该项目的结果开发技术以满足未来客户的需求。目的是该系统将成为辐射检测的模块化解决方案，可用于各种各样的应用（例如用于现场清理的核分析以及将在这里进行的工作）。这里的要求是对核潜艇上可能出现的伽马辐射进行探测和成像。这包括来自反应堆的来自裂变产物和锕系元素的伽马辐射，以及来自中子散射和活化的伽马辐射。要求是覆盖60千电子伏特到10兆电子伏特的伽马射线能量范围，并具有在复杂的海底环境中识别辐射源的成像能力。这可能需要5到10毫米范围内的图像分辨率。该仪器将能够识别特定的放射性同位素，从而可以实时收集有用的植物状态信息。测量将在HMS机敏号的初始临界期间在船周围的几个位置进行。拟议的仪器将提供船上的真实数据，使BAe能够开发一系列弹性伽马光谱仪/成像仪，可用于英国/美国潜艇的进一步试验，并可由John Caunt Scientific进行商业开发。该仪器将被设计为对潜艇环境（60 keV / 10 MeV）中感兴趣的伽马射线发射成像的最佳效率，但原则上该仪器可用于其他应用，特别是在中子审讯后的犯罪和安全情况下的伽马射线探测。利物浦大学的核物理小组在原子核结构的实验研究方面有着杰出的记录。这项工作是由支持这个物理项目的最先进仪器的发展所支撑的。该集团在使用带有数字读出系统的锗半导体传感器方面处于世界领先地位。利物浦小组正在领导高级伽马射线跟踪项目（AGATA）的高度分段锗探测器晶体的表征。AGATA是一个大型的欧洲合作项目，旨在为核结构物理应用建立终极伽马射线光谱仪。直到最近，能够准确识别出发射辐射的同位素的伽马射线光谱仪一直使用锗作为主动传感器。

A robust sensor capable of precisely identifying the energy of, and imaging the gamma radiation field associated with radioactive material, is needed that will operate in hostile working environments. The proposed project will bring together three partners, the University of Liverpool, BAe Systems Submarine Solutions and John Caunt Scientific (JCS). The partners bring expertise in gamma-ray detector systems, packaging for robust hostile environments and marketing, respectively. This knowledge exchange project will provide BAe systems with access to the wealth of experience in high resolution gamma-ray systems available at the University of Liverpool, while allowing Liverpool to become familiar with robust packaging and testing procedures allowing them to exploit academically developed instrumentation in a 'realistic working environment'. JCS bring key marketing experience to the project, allowing the technologies to be developed to suit future customer needs based on the outcomes of this project. The aim is that the system will be a modular solution for radiation detection that can be used in a wide variety of applications (for example nuclear assay for site clearance as well as the work to be carried out here). The requirement here is for the detection and imaging of gamma radiation that may arise on a nuclear submarine. This includes both gamma radiation from the reactor derived from fission products and actinides and gammas arising from neutron scattering and activation. The requirement is to cover the 60 keV to 10 MeV gamma-ray energy range and to have an imaging capability to identify the source of the radiation in the complex submarine environment. This is likely to require an image resolution in the 5 to 10 mm range. The instrument will able to identify specific radioactive isotopes making it possible to collect useful plant state information in real-time. Measurements will be made at several locations around the boat during HMS Astute's initial criticality. The proposed instrument will provide real data on the boat to allow BAe to develop a family of Resilient Gamma Spectrometers/Imagers that could be used for further trials on UK/US submarines and can be commercially exploited by John Caunt Scientific. The instrument will be designed for optimum efficiency to image gamma-ray emissions which are of interest in a submarine environment (60 keV / 10 MeV), but in principle the instrument could be used in other applications, in particular gamma-ray detection in crime and security situations following neutron interrogation. The nuclear physics group at the University of Liverpool has an outstanding record for experimental research into the structure of nuclei. This work is underpinned by the development of state-of-the-art instrumentation which supports this physics programme. The group are world leaders in the use of Germanium semiconductor sensors with digital readout systems. The Liverpool group is leading the characterisation of highly segmented germanium detector crystals for the Advanced Gamma-ray Tracking Project (AGATA). AGATA is a large European collaboration which aims to build the ultimate gamma-ray spectrometer for nuclear structure physics applications. Gamma-ray spectrometers that can exactly identify the isotope emitting the radiation have until recently used germanium as an active sensor.