Fast Neutron Spectrum Unfolding Using 4H-SiC-Based Detectors

Wide-bandgap semiconductor-based fast neutron detectors, such as silicon carbide (SiC), show strong potential for meeting the stringent implementation and performance requirements in fusion and fission environments, including radiation hardness and thermal/mechanical stability. However, qualifying their response over a broad energy range in multi-energetic neutron fields remains a significant challenge. In this work, we propose an approach based on response functions for neutron spectrum unfolding. Due to limitations in simulation tools, which rely on nuclear data with large uncertainties for the studied reactions, experimental calibration was required. Time-of-Flight (ToF) measurements performed at the Neutron For Science facility (NFS) enabled the construction of a response matrix with sufficient energy resolution to support iterative deconvolution methods. The results demonstrate promising performance across the entire neutron energy spectrum, with deviations of approximately 10% over most energy ranges. This experimental campaign confirms the capability of SiC-based sensors to estimate neutron flux in continuous, high-energy neutron fields using an experimentally derived response matrix.