Development and performance of a low-cost, solid-state, thermal neutron sensor with a 10B converter

Abstract

This study demonstrates the construction and operation of a portable, solid-state thermal neutron sensor that utilizes a photodiode coated with a thin layer of boron-10 (10B). The boron layer was created using pulsed laser deposition and analyzed with neutron depth profiling (NDP) and scanning electron microscopy (SEM). The sensor's response to both thermal and cold neutrons was evaluated under varying neutron fluence rates. Additionally, the impact of the angles between the neutron beam and the sensor surface was examined. SEM results showed a porous 10B film structure, while NDP indicated a nearly uniform distribution of the isotope throughout the film. The electronic signal generated by the sensor exhibited a linear response to neutron fluence rates. However, the measured intrinsic efficiencies were lower than those of commercially available gas-phase detectors, with thermal neutrons yielding an efficiency of (1.17 ± 0.01) % and cold neutrons at (1.78 ± 0.01) %. Potential design upgrades that could increase the sensor's efficiency in the future are also discussed.