Jun 25 – 29, 2023
Ole-Johan Dahls Hus
Europe/Oslo timezone

P2.73: Position-sensitive semiconductor detectors for nuclear fuel imaging

Jun 28, 2023, 5:57 PM
Ole-Johan Spiseri (Ole-Johan Dahls Hus)

Ole-Johan Spiseri

Ole-Johan Dahls Hus

Ole Johan Dahls Hus - Oslo Science Park Gaustadalléen 23B, 0373 Oslo


Prof. Peter Dendooven (Helsinki Institute of Physics, University of Helsinki)


The Passive Gamma Emission Tomography (PGET) device was approved by the IAEA for spent nuclear fuel safeguards inspections at the end of 2017. It is based on a collimator, consisting of a linear array of narrow slits with a pitch of 4 mm, with a relatively small CZT (cadmium-zinc-telluride) gamma ray detector behind each slit. Larger detectors would have a higher probability for detecting the full energy of gamma rays, increasing the effective sensitivity and image quality (in terms of statistics and contrast-to-noise ratio). However, a larger detector would cover more than one collimator slit, requiring position sensitivity to determine through which slit a gamma ray travelled in order to maintain image spatial resolution. We are studying the use of state-of-the-art 3D position-sensitive CZT and germanium gamma ray detectors. In addition to utilizing the position sensitivity along the direction of the collimator, which gives transaxial position information, we are investigating to what extent Compton imaging can provide information on the origin of a gamma ray along the axis of a spent fuel assembly. This opens the prospect of creating 3D images with the PGET device in a single axial position, adding axial information to the current 2D transaxial images. The technology being developed is also useful for other than safeguards applications, such as the non-invasive post-irradiation examination of nuclear fuel to characterise its important properties.

A Monte Carlo simulation framework has been developed using the Geant4 toolkit and measurements using point-like and rod-shaped Cs-137 sources, the latter mimicking spent nuclear fuel, have been performed. The status and prospects of the project will be reported.

Primary author

Prof. Peter Dendooven (Helsinki Institute of Physics, University of Helsinki)


Dr Matti Kalliokoski (Helsinki Institute of Physics, University of Helsinki) Dr Mounia Laassiri (Helsinki Institute of Physics, University of Helsinki) Dr Peter Andersson (Department of Physics and Astronomy, Uppsala University,) Mr Vikram Rathore (Department of Physics and Astronomy, Uppsala University)

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