Advanced Intelligent Raman System for detection of explosives and harmful substances at urban soft targets

The detection of explosives, illicit and counterfeit drugs is of increasing public importance. The protection from explosives at urban soft targets such as ports is key to future public security both from an economic and public safety perspective. There is an increasing need for a portable reliable easy to use instrument that can be deployed in the field. One potential solution to this issue is Raman observations. Raman systems provide excellent specificity with every molecule returning its own unique fingerprint that can be identified. However the weak nature of the signal and issues such has background fluorescence reduces the reliability of this systems in the field.

In this study we have examined the feasibility of developing a new Advanced Intelligent Raman System (AIRS), based on several, emerging technologies: Including a specifically adapted high throughput spectrometer, using a static Fourier Transform design. Several new technologies are being developed/used including a new approach to performing Time resolved Raman measurements which removes florescent background signals from the target Raman fingerprint by using the Single Photon avalanche photodiode array detector (SPAD).

The study has examining the technical financial and business feasibility of the developing the technology to produce a viable product for the security services. This has included conducting a number of experiments with a SPAD operating in Geiger mode, with a timing resolution of the 100 ps. The experiment have shown the concept technically feasible and a patent application has been filed. In addition the study has assessed the size of the market for such a system, where it might be deployed and analysed which obstacles will have to be overcome for market take up of the product. We estimate that potential sales could exceed € 100 million, within five years of product launch, for both the instrument and the spin products that would accrue. This would result in significant expansion of IS-instruments Ltd business allowing the company to employ key engineers and scientist spreading the benefit of the development to the wider economic area.

During the programme of work the technical and commercial feasibility were investigated, this included conducting some experiments to investigate the feasibility with a prototype Geiger Array detector (SPAD), In addition the use of a high throughput spectrometer has also been examined, to perform transmission and stand-off Raman measurements. This has included developing outline designs for deep UV and IR instruments.
The basic concept for performing time-resolved observations is as follows; When the laser strikes a target the molecules are excited in addition to the laser Rayleigh light scattering off the target ~ 1 in 106 photons are Raman in nature. These photons are emitted on fs time-scales. For organic molecules fluorescence can also be stimulated, however these are emitted on much large time-scale of 100 ps – several ns. This time difference can be exploited to separate the two returns.

In a Gieger detector the sensor responds to the first photon it observes, and essentially switches off for 50 ns. This is in effect a perfect shutter, additionally by combining the detector with suitable electronics the time of arrival of the photon can be recorded. This prinicple forms the basis of the development

In addition to above requirements the system would also require a clear easy to interpret user interface and visualisation tools and we have been investigating new techniques that could provide a clear advantage.
The final system could have one of three basic arrangements.
The first is the most attractive to potential clients, as a complete hand held unit. However it is also the most technological challenging.
The second option is a hand held probe is used to sample systems but the control box is only semi portable.
While the final option is a unit where the target samples is brought to the instrument.

After the technical feasibility was completed we conducted a review of the commercial feasibility. This included an examination of our business model, the market segment, the cost of a likely instrument, our unique selling points.
We are of the opinion that we can deliver an instrument required by our market segment and on budget

AIRS is making significant advances beyond the state of the Art and will have several unique selling points over that offered by the current system on the market:
These include
1) Ability to remove fluorescence, therefore making the system more reliable and less likely to be tricked by masking agents
2) The high throughput spectrometer will allow bulk measurements and stand-off measurement to be made with a higher Signal to Noise. This in turn will lead to the system being faster.
3) The intelligent software will allow for more complex molecules to be identified which will improve the system reliability.
4) The improvement in performance will allow more analysis to be conducted in-situ reducing the need to send samples to expensive laboratories for analysis

These features will lead to a more secure system that will meet key societal targets of enhancing the security of citizens and there well-being

Periodic Reporting for period 1 - AIRS (Advanced Intelligent Raman System for detection of explosives and harmful substances at urban soft targets)

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