Speaker
Mr
Sion Richards
(University of Surrey)
Description
A thick segmented cadmium tungstate scintillator array has been developed at the Rutherford Appleton Laboratory in partnership with the University of Surrey. The array was 1.2 cm x 1.1 cm x 4.4 mm and consisted of 25x24 segments with a 400 µm pitch. This array was created using a novel laser ablation technique. The GATE Monte-Carlo simulation package was used to understand key aspects of its measured performance, in particular the effect of segment pitch and thickness on the mean path length of scintillation photons and the number of reflections that the scintillation photons undergo in the segment. It was found that the mean path length of a scintillation photon was dominated by the optical coupling method which is key in high refractive index scintillators such as cadmium tungstate. The effect of the atomic number and density of the material separating each segment was studied. The higher density, higher atomic number materials had a signal enhancement effect and also reduced amount of cross-talk due to secondary radiation. The measured performance of the prototype array is shown and compared to an ideal array modelled using GATE.
![An image of the prototype array being irradiated using a cone beam X-ray set][1]![An image of the prototype array imaging a lead edge][2]
[1]: https://www.dropbox.com/s/wssz1t42ve8osz3/array.jpg
[2]: https://www.dropbox.com/s/7h302zq3nplff8g/array-edge.jpg
Primary author
Mr
Sion Richards
(University of Surrey)
Co-authors
Annika Lohstroh
(University of Surrey)
Dr
Mark Baker
(Univeristy of Surrey)
Matthew Wilson
(STFC)
Paul Seller
(RAL)
