In-core thermal and fast neutron measurements with 4H-SiC P+N junction diodes in the JSI TRIGA Mark II research reactor

Valentin Valero; Laurent Ottaviani; Abdallah Lyoussi; Christophe Destouches; Vladimir Radulović; Luka Snoj; Adrien Volte; Michel Carette; Christelle Reynard-Carette

doi:10.1051/epjn/2025024

2024 Impact factor 1.7

Nuclear Sciences & Technologies

Open Access

EPJ Nuclear Sci. Technol. 11, 23 (2025)
https://doi.org/10.1051/epjn/2025024

Regular Article

In-core thermal and fast neutron measurements with 4H-SiC P+N junction diodes in the JSI TRIGA Mark II research reactor

Valentin Valero¹^*, Laurent Ottaviani¹, Abdallah Lyoussi², Christophe Destouches², Vladimir Radulović³, Luka Snoj³, Adrien Volte¹, Michel Carette¹ and Christelle Reynard-Carette¹

¹ Aix Marseille Univ, Université de Toulon, CNRS, IM2NP Marseille France
² CEA/DES/IRESNE/DER, Section of Experimental Physics, Safety Tests and Instrumentation Cadarache F-13108 Saint Paul-lez-Durance France
³ Reactor Physics Division, Jožef Stefan Institute Ljubljana Slovenia

^* e-mail: valentin.valero@univ-amu.fr

Received: 12 July 2024
Received in final form: 5 February 2025
Accepted: 23 April 2025
Published online: 4 June 2025

Abstract

Accurate online in-core parameter measurements, such as neutron and photon fluxes and nuclear heating rates, are essential for fusion and fission applications. Wide bandgap semiconductors, particularly Silicon Carbide (SiC), have demonstrated strong potential for radiation detection over six decades. Despite this, challenges persist in optimizing detector performance under extreme in-core conditions. Our study focuses on 4H-SiC-based detectors, developed within a joint laboratory between Aix-Marseille University and the CEA, aiming to address these challenges and provide high-precision measurements for advanced nuclear facilities. Following previous measurements in ZPRs and with D-T neutron generators, this paper focuses on in-core experimental results obtained with such detectors in the Triangular Irradiation Channel (TIC) of the TRIGA Mark II-type research reactor at the Jožef Stefan Institute (JSI) in Slovenia. These in-core measurements were done by using two types of diodes. One with a Neutron Converter Layer (NCL) of Boron-10 for thermal neutron detection, and the other one without NCL in order to discriminate thermal and fast neutrons by studying ¹⁰B reaction versus scattering. Thanks to various Pulse Shape Analyses (PSA) and count rate studies the influence of bias voltage, NCL and neutron fluence on the detector performances were determined. The highest neutron flux and fluence for these detectors were reached: 1.2 × 10¹³ cm⁻²·s⁻¹ and 1.2 × 10¹⁷ cm⁻², respectively.

© V. Valero et al., Published by EDP Sciences, 2025

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