A compact neutron/gamma imager for nuclear security applications

In this project we will develop a compact, portable imaging detector for mixed-field fast neutron and gamma ray imaging for nuclear security applications. The detector uses digital data acquisition methods combined with the latest type of plastic scintillator that provides real-time neutron/gamma discrimination and imaging performance.

The proposed digital n/gamma detection technology has come from neutron/gamma detection methods developed within the STFC nuclear physics programmes. Various digital pulse processing algorithms and methods have been developed for position sensitivity and n/gamma discrimination in a variety of nuclear physics detectors, including those used in the AGATA array and the HISPEC programme at FAIR/GSI. Neutron detection techniques using liquid scintillators and pulse shape discrimination methods have been developed at the DEMON array at GANIL and have recently been upgraded for to a digital data acquisition system.

The proposed device will be developed for use in nuclear security n/gamma imaging applications, and has been designed to meet the requirements of the Nuclear Security group at AWE Aldermaston. The project will principally address the Global Challenge Security theme, in the areas of border security and nuclear containment and remediation. However the n/gamma imaging and detection capability of these device will also have application to environmental radioactivity monitoring within the Global Challenge Environment theme.

In this project we will develop a compact, portable imaging detector for mixed-field fast neutron and gamma ray imaging for nuclear security applications. The proposed device will be developed for use in nuclear security n/gamma imaging applications, and has been designed to meet the requirements of the Nuclear Security group at AWE Aldermaston. The project will principally address the Global Challenge Security theme, in the areas of border security and nuclear containment and remediation. However the n/gamma imaging and detection capability of this device will also have applications in environmental radioactivity monitoring within the Global Challenge Environment theme.

Security detection of radionuclide material covers a range of concepts of deployment which generate a variety of system requirements. To date more work has taken place on portal detectors that allow large scale, fixed detector arrangements with less stringent requirements on portability and ruggedness. Portable detectors play an important part in the security space with the obvious need for hand held detectors, and also where deployment is via small vehicles, automated systems etc. The combination of scintillator and PMT are ideal in the matching of size that maximises PSD performance and removes the need for light guides. Neutron/gamma discrimination and mixed field imaging are important contributions to assessing a detected signal. Therefore this proposal is a timely route to demonstrating a compact and highly applicable detector for addressing unsolved challenges in security requirements with AWE and MoD, not currently covered by existing scintillator/PMT technologies.

At the end of this project we will discuss the outcomes of the project with AWE, and if appropriate with commercial detector manufacturing companies. AWE maintains a programme of research and development in the area of nuclear security detection. Currently it involves fundamental research and also technology development. AWE does not seek to manufacture new technology, but instead works with detector manufactures in close collaboration to design and specify developments that come out of research. AWE enjoys close relationships with government departments around national security applications so is ideally placed to help articulate application pull.
An initial follow-up phase to this project will involve further testing of the detector within a secure laboratory at AWE where appropriate source materials are available. This will allow for testing within a real security context and for further development more closely specified by real deployment/application situations where necessary. It will also allow us to develop collaboration with detector manufactures for ultimate realisation of a commercial product.