Re: airport explosive detection systems

["CAPT Jerry A. Thomas, MSC, USN" <thomas@bob.usuf2.usuhs.mil>]

The airport explosive detection systems I have seen use X-rays NOT gamma
rays.  One such system, a large package scanner is manufactured by Imatron.
It is a spiral (or helical) CT type scanner.   The mass attenuation
coefficient of explosives differes from that of other materials.  Using that
along with other parameters the display offers a pseudo color picture of the
contents of the bag/package.  Explosives and flammable materials all have a
"given" color.  Additonally, the packaging can be taken in to account.

There are also belt type scanners ... just like you have at the airport
security stations.  The principle is the same.  X-rays are transmitted
through the package and detected by a solid state detector.  The resulting
image data set is analyzed by a computer system.

Let me know if you need to learn more and I will see if I can find a contact
for you.

JERRY THOMAS

At 13:12 6/19/96 -0500, you wrote:
>
>Hello everyone,
>
>	I had a question from an employee involving new airport detection 
>systems designed to detect explosives.  Apparently these detectors use 
>gamma radiation.  The questions put to me were:  How do these detectors 
>work?  How do the gamma rays aid in detecting explosives?  Any info on 
>these questions would be appreciated!  Thanks.
>
>					Jen Wilson
>					R.S.O.
>					UNBC
>
>
>