New technique for easily identifying explosives in luggage

Jan 24, 2007
Prof. Itozaki, Dr Tachiki and Dr He
Prof. Itozaki, Dr Tachiki and Dr He

Scientists in Japan have developed a new technique for sensing explosives in luggage and landmines. The paper, published today in the Institute of Physics journal Superconductor Science and Technology describes how radio waves can be used to identify specific explosives, such as TNT. The new method could be used in future to screen baggage at airports.

The new technique has advantages over traditional methods of detection: unlike x-rays that are currently used in airport security, it can distinguish between different types of white powder from flour and salt to drugs and explosives. It can also be used to detect landmines, an advance on the traditional method of using a metal detector which cannot distinguish between bits of metal in the ground and an actual mine.

Professor Hideo Itozaki, one of the authors of the paper at Osaka University said: “Until now it has been very difficult to detect specific explosives such as TNT because they contain atoms of nitrogen that vibrate at very low frequencies.

The natural frequency at which the nucleus of an atom vibrates at is called its resonant frequency and the lower this is, the harder it is to detect what atoms are present in a molecule which in turn makes it harder to define what the molecule or substance is.”

The technique relies on nitrogen nuclear quadrupole resonance (NQR) which detects atoms of nitrogen (an element found in many explosives, including TNT) in different positions in a molecule. For example an atom of nitrogen attached to a carbon atom will have a different resonance to one attached to an oxygen atom. Because the molecular structure of each explosive is different, the resonant frequency will be different.

Professor Itozaki continued: “We have successfully developed a machine that can pick up very low resonant frequencies by using a SQUID (superconducting quantum interference device). The SQUID operates at a temperature of 77 Kelvin (minus 196 degrees centigrade) which we achieve by using liquid nitrogen. This will not hinder the equipment from being used in places such as airports as liquid nitrogen is becoming much easier to deal with and is already routinely used in hospitals and laboratories.”

Source: Institute of Physics

Explore further: Information storage for the next generation of plastic computers

add to favorites email to friend print save as pdf

Related Stories

Supercomputers capture turbulence in the solar wind

Dec 20, 2013

As inhabitants of Earth, our lives are dominated by weather. Not just in the form of rain and snow from atmospheric clouds, but also a sea of charged particles and magnetic fields generated by a star sitting ...

Diamond imperfections pave the way to technology gold

Nov 04, 2013

(Phys.org) —From supersensitive detections of magnetic fields to quantum information processing, the key to a number of highly promising advanced technologies may lie in one of the most common defects in ...

Measuring molecules in their undistorted form

Jul 08, 2013

Using a special electron beam apparatus, scientists at Bielefeld University can determine the precise three-dimensional structure of gaseous molecules. To do this, Professor Dr Norbert Mitzel's research team ...

Recommended for you

How to test the twin paradox without using a spaceship

Apr 16, 2014

Forget about anti-ageing creams and hair treatments. If you want to stay young, get a fast spaceship. That is what Einstein's Theory of Relativity predicted a century ago, and it is commonly known as "twin ...

User comments : 0

More news stories

Robotics goes micro-scale

(Phys.org) —The development of light-driven 'micro-robots' that can autonomously investigate and manipulate the nano-scale environment in a microscope comes a step closer, thanks to new research from the ...

Turning off depression in the brain

Scientists have traced vulnerability to depression-like behaviors in mice to out-of-balance electrical activity inside neurons of the brain's reward circuit and experimentally reversed it – but there's ...