You are here: Homepage NKS Reports View document |
|
NKS Programme Area: | NKS-R | Research Area: | Decommissioning and waste | Report Number: | NKS-473 | Report Title: | Position-sensitive detectors for nuclear fuel imaging (POSEIDON) | Activity Acronym: | POSEIDON | Authors: | Mounia Laassiri, Vikram Rathore, Matti Kalliokoski, Peter Andersson, Peter Dendooven, | Abstract: | The passive gamma emission tomography (PGET) device presently used for spent fuel safeguards inspections uses very small cadmium-zinc-telluride (CZT) detectors. Better imaging performance is possible using larger detectors, provided that these detectors are position-sensitive. Such detectors add the option to use Compton imaging to obtain axial imaging information. In the NKS_R_2022_136A project "POSEIDON", a pilot feasibility study of a PGET device that makes use of a state-of-the-art 3D position-sensitive semiconductor detectors (both germanium and CZT are considered) has been performed.
The Monte Carlo radiation transport software package Geant4 was used to simulate the performance of a small scale PGET device. The performance of small and large CZT detectors was compared. The total detection efficiency for the large CZT detector is almost 30 times larger. The fraction of the events, in which the full energy of the initial photon is deposited, is only 12% for the small and 40% for the large CZT detectors. The ratio of ideal Compton imaging events for large and small CZT detectors is close to 200. All of this shows the immense improvement that is possible when using large instead of small CZT crystals.
The experiments performed in Uppsala and Helsinki with two different position-sensitive germanium detectors provide proof-of-principle evidence that excellent imaging is possible with a large detector covering multiple collimator slits and demonstrate that it is possible to combine multi-slit imaging in one direction with Compton imaging in the perpendicular direction. | Keywords: | passive gamma emission tomography, PGET, position-sensitive detector, semiconductor detector, CZT detector, germanium detector, Compton imaging, spent fuel | Publication date: | 12 Jun 2023 | ISBN: | 978-87-7893-568-7 | Number of downloads: | 757 | Download: | NKS-473.pdf |
|
|