Security personnel carry out random checks for explosives on people and objects at airports and major events. Up until now, this has been done by wiping a special test strip over items like bags or laptops, then examining the test strip using an analysis device. This takes a few minutes and requires adequate numbers of personnel. Researchers at the German Aerospace Center (Deutsches Zentrum für Luft- und Raumfahrt; DLR) are currently developing and testing a laser-based process for this purpose. This is completely contactless and thus enables fast and reliable checking of a significantly larger number of people.
Anyone who handles explosives will end up with tiny particles on their skin, clothing, shoes or objects that they have touched, even if they take great care. It is vital to identify such traces as quickly and accurately as possible in a security check. Researchers at the DLR Institute of Technical Physics in Lampoldshausen are using laser spectroscopy to perform this task. The principle behind this detection method is that an eye-safe system specially developed for this purpose emits a laser beam via a telescope. This beam strikes the object under examination and triggers a physical effect, scattering the light in a manner that is characteristic of the explosive substance. This scattered light is then observed via the telescope and analysed using an integrated spectrometer. This allows conclusions to be drawn as to whether explosives are present and, if so, which type.
The research team has named its system PHYLAX, which stands for personal hybrid laser-based explosive detection. In Ancient Greek, this word means guardian or protector. The laser system is intended to fulfil precisely that task, protecting people and critical infrastructure. “As PHYLAX is portable and also suitable for outdoor use, it could be used, for instance, at entrances to public buildings and facilities, as well as at events with a high number of attendees,” says Frank Duschek, Head of the Department of Atmospheric Propagation and Effect, setting out the potential application scenarios.
The goal of the DLR researchers is to improve preventive control measures and to implement them with fewer restrictions, greater convenience and a higher level of discretion. “In future, PHYLAX will enable screening of people as they walk past the system, at a distance of about two metres, without making contact, in the space of seconds, and with a high degree of reliability,” says Duschek, underlining the advantages of the laser-based technology. As a compact and robust unit, the system should easily integrate into existing infrastructure and be able to be combined with other control elements, such as X-ray devices for checking hand luggage or security scanners like those found at airports today.
Following successful initial feasibility studies supported by DLR Technology Marketing, the researchers are currently working on advancing the technology and carrying out initial system tests.
In security research at DLR, research and development activities relevant to defence and security are planned and controlled in coordination with partners in government, science, industry and international organisations. The cross-sectoral area 'security research' combines the core competencies of the established DLR programmes in aeronautics, space, energy, digitalisation and transport. More than 20 DLR institutes and facilities are contributing to the development, testing and evaluation of technologies, systems and concepts, as well as to the analysis and assessment of safety-relevant applications.