Guidance

Market Exploration Document: Nuclear Quadrupole Resonance and Electron Spin Resonance for Explosives and Drugs Detection

Updated 27 October 2023

The Defence and Security Accelerator (DASA) is running a Market Exploration to identify technological solutions to detect Nuclear Quadrupole Resonance (NQR) Signals with atomic magnetometers (AM) and modelling/studies on radiation induced Electron Spin Resonance (ESR) measurements.

1. Summary

On behalf of the Defence Science and Technology Laboratory (Dstl) Counter Terrorism and Security Division, DASA is running a Market Exploration to identify technologies between Technology Readiness Level (TRL) 3 to 6 to provide a better understanding of existing market capabilities and less mature lines of development across UK and international industry and academia.

One focus of this call is developing atomic magnetometers to detect NQR signals typical from explosives and drugs in a practical realisation. The other focus is on modelling the feasibility of using ionising radiation to generate free radicals, in explosives which do not naturally contain any, and then detect those radicals with an ESR measurement.

Whilst potentially successful technologies and concepts may be exploited within any future acquisition programmes, please note that this request for information is not a commitment to subsequently launch a formal DASA competition. However, as Dstl programmes in this area work closely with international partners, submissions may get exposure to wider international government audiences.

2. Background

There is a requirement to detect explosives and drugs in a variety of operational contexts. Many technologies and techniques exist to detect these illicit substances; each with different pros and cons for different applications. One class of techniques are based on magnetic resonance (MR), which are accessed using radio frequency (RF) radiation. The particular frequencies provide information about a given material providing a means of chemical-specific detection and identification.

NQR is a magnetic resonance technique that has been developed to detect explosives and drugs. However, NQR sensors require tens of seconds to acquire sufficient signal-to-noise (SNR) for detection applications. This is too long for most users.

Many methods have attempted to overcome this limitation resulting in incremental gains, for example, improved circuit design and modified pulse sequences. Recently there has been an interest in alternative methods to increase the SNR, including new sensors based on AM. The intrinsic sensitivity of these devices has been demonstrated in lab-based experiments but it is not known how this translates into the real world when practical aspects of NQR are considered.

Although NQR can detect a number of explosives and drugs, alternative MR techniques are needed to cover other important illicit substances. One such MR technique is ESR, which can detect liquids or solids that do not contain chlorine and nitrogen. This has been achieved in niche cases by irradiating materials with ionising radiation to produce detectable free radicals. Despite this, key questions remain about how to use this to detect materials of interest in the real world. The main question is: can free radicals be generated in a material and remain long enough to be detected by ESR without using methods that significantly modify the sample (e.g. cooling or spin traps).

3. What we want

For this call we are interested in two strands which can be addressed individually:

3.1 Strand 1: Atomic Magnetometers

We are interested in developing AM to detect NQR responses from materials (tens of grams and above) placed at a distance of 10 to 20 cm from the detector using typical pulsed NQR methods. We are also interested in understanding how an AM could cover the spectrum of detectable NQR lines ranging from 400 kHz to 5 MHz. This should also include a consideration of the sensor’s ability to detect fast decaying NQR signals (e.g. from TNT) after a large excitation pulse. We are also interested in methods to enable the AM to detect an NQR signal in the presence of radio frequency broadcast signals that may occur in the same frequency band as typical NQR frequencies. In addition, we are interested in exploring the development of hardware to make AMs smaller, lighter and more durable so that instrumentation is suitable for measurements out of the lab. Examples include chip-scale AM cells or solid state laser diodes.

3.2 Strand 2: Electron Spin Resonance

We are interested in the use of detailed modelling or theory to understand if free radicals can be generated with ionising radiation and remain long enough to be detected in an ESR experiment. Key requirements are that the sample cannot be otherwise modified (e.g. spin traps or cooling). At this stage there is no requirement for the hardware to be single-sided; this is a study of feasibility rather than if it can be practically realised. However, proposals of how hardware could be developed would be welcome to inform future competitions should feasibility be demonstrated.

4. What we don’t want

4.1 Atomic Magnetometers

In the case of AM-based sensors, proposals should not focus on the fundamental sensitivity of the sensor in isolation of external factors, i.e. a sensor contained in mu-metal shielding which cannot be moved. The focus of a submission should, in contrast, seek to apply the gains seen in lab experiments to a more practical focus in the context of NQR.

4.2 Electron Spin Resonance

For ESR we are not interested in any techniques that requires the use of spin traps, cooling of samples or otherwise modification of the sample to increase the lifetime of induced free radicals. We are also not interested in studies of UV-induced radicals in samples that already contain free radicals.

We are not interested in submissions based on alternative methods that sit outside the NQR and ESR techniques.

We are not interested in literature reviews, paper-based studies, consultancy, non-technical solutions or marginal improvements to existing capabilities.

This is not a competition and therefore we are not asking for costed proposals at this stage. While this exercise may help us direct future funding in these areas, this is a market engagement request for information and we do not commit to subsequently launch a formal DASA competition.

5. How to submit a Market Exploration Submission to DASA

Responses to this Market Exploration must be submitted via the DASA submission service, for which you will need to register. We recommend you use a Google Chrome browser to access the DASA submission service.

You will be asked for a title and short summary of your innovation, along with questions related to your organisation, your idea and technology maturity. We are seeking to understand what and how much further development is required for a complete solution to meet requirements, or whether a combination of separate solutions is required. The information you provide will assist in developing a statement of requirements for potential future activities.

Submissions must be submitted by 12:00 hours GMT 05 December 2023. Unfortunately we are unable to accept any submissions after this point.

Please only provide details of one product/capability/line of development per submission. If you have a number of potential solutions, then please submit multiple forms.

If you have any questions then please email accelerator@dstl.gov.uk with ‘Nuclear Quadrupole Resonance and Electron Spin Resonance for Explosives and Drugs Detection’ in the subject line.

6. How we use your information

Information you provide to us in a Market Exploration Submission, that is not already available to us from other sources, will be handled in-confidence. By submitting a Market Exploration Submission you are giving us permission to keep and use the information for our internal purposes, and to provide the information onwards, in-confidence, within UK Government and international government partners. The Defence and Security Accelerator will not use or disclose the information for any other purpose, without first requesting permission to do so.