Trade magazine Novus Light Technologies Today said Monday that a new gamma camera created by British company Createc makes use of a much lighter collimator than previously available, making it possible to attain a 3-D picture of radioactive sources in a manner that will greatly assist nuclear plant decommissioning.
The Createc team, led by Chief Executive Officer Dr. Matthew Mellor, has overcome a few hurdles, besides bulk and weight, which could make the new camera useful with remote or robotic handling.
Prior collimators required scans limited by the need for small apertures to produce fine resolutions. This would keep the signal to interference ratio low. Another way to do that would be to increase the time of the scanning, but that just creates a problem of slowing down the process.
Createc, however, has come up with a field modulator “that modulates the radiation reaching the detector in the new camera,” the magazine reported. This modulator “comprises a sphere of dense material with a cavity at its center to accommodate a semiconductor-based radiation detector,” the magazine said. There is also a slot cut that goes to the cavity at the center of the sphere.
While the sphere is rotated, radiation is not absorbed if it comes at the sphere in a direction that is on the same plane as the slot in the sphere. This allows for an algorithm to produce an image from the gamma radiation measurements, the magazine explained.
Once measurements are taken from three sets of sensors at different locations, Createc produces a 3-D image with its own N-Visage Source Mapping Software.
"A user can use the model created by the software to virtually remove one or more of the radioactive objects, after which the software will calculate what the reduction in radioactive dosage might be. Alternatively, it can be used to install a virtual radiation shield within the computer model and the effects of lowering the dosage of the radiation that is emitted can be predicted prior to deploying any physical shielding at the plant itself,” said Dr. Mellor said, as quoted by the magazine.