How does the Contraband Detection System work?

Gamma rays are produced when speeding protons collided with a target, much the same as x-rays are produced when high-speed electrons collide with a target in an x-ray tube. To obtain the rapidly moving protons, CDS uses a proton accelerator called a tandem. The CDS tandem shown on the right is a state of the art accelerator capable of accelerating greater than 10 mA of protons to an energy of 2 MeV. To do this, a power supply maintains the centre terminal at a voltage of 1 million volts. Imaging the gamma rays also requires special detectors and special computer software of the kind developed by TRIUMF for creating high-resolution images from Positron Emission Tomography (PET) scans.

TRIUMF is probably the only site in Canada where all three of these technologies - proton accelerators, position sensitive gamma ray detection systems, and tomography software - are all in use in different parts of the TRIUMF program, allowing for the development of a "combination product".

This novel type of contraband detector may find applications at airports, docks, border crossings, and post offices. At present, TRIUMF is licensees and/or partners to collaborate in the further development of this system.

Enlarged Labelled Photo ( 90 Kb )