Insight 100
(Credit: Cobalt Light Systems) Technology spun out from the CLF is being used in airports around the world to prove that liquids being taken onto planes are safe. The technology, developed by CLF spinout Cobalt Light Systems, has proven to be extremely effective, and is based on patented SORS technology for rapid and accurate chemical analysis of substances in unopened non-metallic containers. Cobalt’s systems screen a range of materials including liquids, powders and gels, with the highest detection capability and lowest false alarm rates of any European Civil Aviation Conference (ECAC)-approved scanner.
Further information: Cobalt (link opens in a new window)
X-ray backscatter imaging is currently used in a range of technologies from portal security, where it is used to scan airline passengers, vehicles and containers, to industrial inspection, studying the internal structure of low density materials, and for applications requiring single sided imaging. Currently, the application of this imaging technique to the detection of landmines is limited due to the surrounding sand or soil strongly attenuating the 10s to 100s of keV X-rays required for backscatter imaging.
In collaboration with the UK's Defence Science and Technology Laboratory the CLF have developed and demonstrated a new approach using a high energy 140 MeV short-pulse (<100 fs) electron beam, generated by laser-driven acceleration, to probe the sample. High energy electrons are able to penetrate to greater depths in a sample; these electrons will then produce X-rays via bremsstrahlung emission which then backscatter and travel back through the sample before being detected. The backscattered X-ray pulses coming from deeper within the sample will take longer to reach the detectors, therefore a depth profile can be formed. Scanning across the sample allows one to image
An experiment carried out using the Gemini laser system generated the electron beam by focusing the laser pulse in a supersonic gas jet.
A variety of detector and scintillator configurations were used to detect the backscattered X-ray pulses coming from various depths within the sample, with the main challenge being the capability of the detectors to resolve pulses that hit the detector only billionths of a second apart. Despite this extreme challenge, an X-ray backscatter image of an array of different density and atomic number items was demonstrated and is the first time a backscatter imaging has been acquired using a laser generated electron beam to generate X-ray emission in the imaging target itself.
Although this research is in its early stages, it is hoped that it will lead to a deployable system that can be used to help clear landmines.
Further information: contact Prof David Neely
