Dec 20 2019
A major risk factor in airport security is the smuggling of contraband items such as drugs and explosives. In modern times, these threats have gone up with the increase in parcel delivery. However, there have not been many advances in techniques used for security inspection.
A 3D view and a photograph of the spiral EDXRD system. Image Credit: Baozhong Mu.
Scientists from Tongji University and Zhejiang University City College have put forward a new method that ensures efficient security detection of contraband goods. The study has been reported in the AIP Advances journal, published by AIP Publishing.
In general, X-ray imaging is used in airport security to rapidly scan through baggage. However, this technique has a number of drawbacks.
In the field of security inspection, the X-ray apparatus is the most important device. However, an X-ray apparatus can’t distinguish explosives, drugs and raw materials from usual organic matter.
Baozhong Mu, Professor, Tongji University
This is overcome by using a technique known as energy-dispersive X-ray diffraction (EDXRD) to perform supplementary screening of luggage with suspicious X-ray results. When EDXRD is used, each material exhibits its own distinctive fingerprint. Therefore, it would be possible to use the pattern of light developed by the scan to recognize a suspicious substance in a bag.
Although EDXRD exhibits such a vital capability, it can cover only thin, small areas. Hence, it is inefficient as a primary screening mechanism.
The research team created an EDXRD system with the potential to investigate thicker items without requiring a number of scans at various locations. The total detection area is increased by positioning a series of detectors into a spiral configuration.
The researchers used a test spiral configuration of five detectors. They were able to recognize the EDXRD fingerprints of illicit drugs and hidden items located at any place inside a bag with a thickness of about 4 inches. It would be possible to increase the detection depth to cover the average luggage size through the incorporation of more and more detectors into the spiral configuration.
Accurately identifying explosives and drugs without opening the bag was thought to be impossible.
Baozhong Mu, Professor, Tongji University
By increasing the detection depth, it would be feasible to use the EDXRD spiral array configuration to differentiate between individual items inside an entire suitcase. “This technology is expected to be widely used in five years,” Mu added.