Design and characterization of a near-field gamma imager for in situ measurements of fuel rod deformations

Guillaume Amoyal (1) , Vincent Schoepff (1) , Frédérick Carrel (1) , Maxime Morenas (1) , Dorin Dusciac (2)

1 LCAE (CEA, LIST) - Laboratoire Capteurs et Architectures Electroniques (CEA, LIST)
2 LNHB (CEA, LIST) - Laboratoire National Henri Becquerel (CEA, LIST)

A prototype of gamma imager system has been developed for detecting fuel rod deformations, based on the WidePIX hybrid pixel detector, associated with a collimator. The WidePIX detector used in the frame of these developements is made of 2×5 Timepix devices hybridized with a 1 mm-thick cadmium telluride semiconductor. A specific collimator was designed, offering the best compromise between mechanical feasibility, cost, signal-to-noise ratio and angular resolution, and making it possible to visualise the the fuel rod deformations. In this work, we present the design of the collimator carried out by numerical Monte-Carlo simulations, and experimental results obtained with this prototype on a Cs-137 and Co-60 metrological irradiator.

Keywords: instrumentation; nuclear instrumentation; Gamma imaging; Electronic architecture; detector; gamma-rays; ionizing radiation; radioactivity; gamma spectrometry; spectrometry; collimator; signal-to-noise ratio; angular resolution; Monte Carlo; simulation; irradioator; metrology; 137Cs; 60Co; Near-field gamma imaging; Hybrid pixel detectors; Highly irradiating measurements; Fuel rod deformations

Domains: Instrumentation and Detectors [physics.ins-det]; Nuclear Experiment [nucl-ex]; Electronics

Guillaume Amoyal, Vincent Schoepff, Frédérick Carrel, Maxime Morenas, Dorin Dusciac. Design and characterization of a near-field gamma imager for in situ measurements of fuel rod deformations. Nuclear Instruments and Methods in Physics Research Section A: Accelerators, Spectrometers, Detectors and Associated Equipment, 2023, 1050, pp.168164. ⟨10.1016/j.nima.2023.168164⟩. ⟨cea-04015993⟩