The Detection of Explosive Substances Using Spectroscopy

The Detection of Explosive Substances Using Spectroscopy

In early 2021, PaCCS Communications Officer Kate McNeil sat down with the University of Lancaster’s Professor Malcolm Joyce to discuss his work on the detection of explosive substances by tomographic inspection using neutron and gamma-ray spectroscopy. This work, which was conducted in collaboration with several partners from industry between 2006-2009, was funded by the EPSRC and was accredited as part of the Global Uncertainties Programme.

Kate McNeil: Thank you for taking the time to speak with me today! Would you mind getting started by telling me a bit about your research background, and how you ended up working on the detection of explosive substances by tomographic inspection using neutron and gamma-ray spectroscopy (DISTINGUISH)?

Professor Malcolm Joyce: I began my career with a PhD in nuclear physics at Liverpool, and I then left academia and worked in industry for four years before returning to work on nuclear engineering at Lancaster. During my years in industry, I worked in the area of neutron detection and neutron spectrometry. This work measuring the energy of neutrons is important in the use of nuclear reactors, as well as being relevant to the detection of explosives and contraband.

When I returned to Lancaster 22 years ago, I had a half a dozen ideas in terms of the research that I would do, one of which weas about nuclear safety and security. Before 9/11, this was mostly an area of academic interest, but after 9/11 there was a great deal of investments – especially in the USA – to improve the detection of neutrons non-intrusively. Meanwhile, after Lockerbie in 1988, there had been an acceptance of the need to screen baggage in order to combat the risk that a small amount of explosive materials might be loaded onto a passenger aircraft. Those two events stimulated some interest into research into looking at the management of threats to mass transport mechanisms, and the development of measurement and detection techniques.

Over the years, I have conducted research and developed several products for application in radiation measurement and the neutron measurement space. In 2003, I set up a spin-out business based on my research called Hybrid Instruments, which is still in operation today.

For those of us who do not have a science background, would you mind describing some of the basics of what this research involves?

Basically, you start with a clever idea and a whole host of reasons why it might not work. There are so many potential ways by which contraband or explosives might be measured, but it can be difficult to do so in practice because – at least prior to the pandemic – there were a reported billion pieces of luggage in transit at any one time which need to be scanned. That scan might need to be quite comprehensive, and there is a time limit associated with how quickly the people involved need to get some information about whether or not there is a reason to be concerned. Moreover, the people administering the technology are generally not going to be highly skilled or educated in the underlying science, so they need to be able to use the technology without understanding how it works. Then, there is also something called the limit of detection constraint. Your technology will not be useful unless it can detect something we regard as being a threat or danger, but there are conflicting requirements. If you can measure for an infinite amount of time, you can detect something quite small. However, if you are constrained to something like standing in an airport queue, you might need that scan to be done in 30 seconds, which means you are limited to larger risks in terms of system design, validation checks, and fundamental measurements.

There are also significant costs involved along the way to getting a system fully deployed. Several years ago, for example, Manchester Airport over Christmas had to change all of their scanning systems because of an event related to a liquid explosives issue, and that rollout cost millions of pounds to supply different systems.

Can you tell me a bit more about the Distinguish project specifically?

The Distinguish project involved a collaboration with several partners from industry, including a company called NIS Limited, BAE Systems, John Caunt Scientific Limited, the Police Scientific Development Branch, and Manchester Airport. I also collaborated with a colleague at Manchester University, Dr Anthony Peyton. Together, we realized we needed a different electronic system to measure neutrons, and this project gave us the opportunity to develop that unit. While in the end our findings were not used for explosives detection, we established a collaboration with the International Atomic Energy Agency that lasted for five years, and they deployed our units as part of their electronic systems. We also developed another product that is supplied by my company Hybrid Instruments. We had set out with safeguards and a security application in mind, but in this field the opportunities to see your technology used often come out of left field, and that is what happened in this case.

Where has your research taken you in the security space in the years since this project?

I have done a lot of subsequent work associated with the assessment of nuclear materials, rather than explosives. This is a space where there was initially concern about a broad range of potential future threats in the aftermath of 9/11 with the most significant threat being the risk that nuclear material would be dispersed or that a nuclear weapon would fall into the wrong hands. Because a lot of countries are now building nuclear power plants, there has been more interest in research associated with the assessments of nuclear materials. Recently, for example, I have been working with ETH Zurich on assessing plutonium in soils. More broadly, my expertise has ended up in the nuclear material security space as a result.

My understanding is that a lot of your research has been on Fukushima – what has it been like conducting research in the aftermath of a disaster?

The positives have been that collaboration with Japan before Fukushima was not easy. The Japanese universities were regarded as extremely good, and Japan did not really appreciate the added value that there might be in working with universities elsewhere, such as in the UK. Prior to Fukushima, the decommissioning program in Japan was not as advanced as that in the UK. That is not a criticism of Japan mind you – the reason the UK’s decommissioning program is so advanced is because we have to sort out the problem of the Sellafield site, whereas Japan does not have the same type of nuclear weapons legacy. After Fukushima, Japan opened the door for collaboration in seeking to resolve some of challenges they now face. This has largely been a positive experience, though it is in part patently a technology transfer activity to some extent. Japan needs to internalize the knowledge and expertise that they gather through these collaborations so that they can then challenge themselves somewhat independently in this area.

The Fukushima work has also involved a lot of robotics work, and that has actually spawned quite a lot of research back in Britain associated with robotics. Here in the UK, we identified robotics as an important area for investment several years ago, but the Fukushima link has really accelerated those programs, some of which are in part still linked with Japan.