SiC Neutron Detectors: Enhancing the Dynamic Range through Partial Depletion Operation

Abstract Silicon carbide (SiC) detectors are promising candidates for neutron diagnostics in fusion environments, where instruments must endure intense neutron and gamma fluxes, high temperatures, and restricted accessibility. Partial depletion operation enables online control of detector efficiency by varying the applied bias voltage, thereby tuning the response to adapt to the widely changing neutron fluxes expected in future tokamak experiments. In this work, the functionality of two 4H-SiC detectors with different thicknesses (100 μm and 250 μm) is investigated under partial depletion conditions. Measurements are performed with 2.5 MeV and 14 MeV neutrons produced at the Frascati Neutron Generator and benchmarked against Geant4 simulations. Results show that detector efficiency can be predictably controlled within a factor of five without degrading energy resolution. Full depletion in the 100 μm device was reached at lower voltages than expected, possibly due to doping variations or irradiation effects. These findings confirm the potential of partial depletion as a tool for real-time tuning of SiC detector response, with significant implications for neutron diagnostics in future fusion reactors.