A Precise Measurement of D-T Neutrons With a Single-Crystal Diamond Detector

Single-crystal diamond (SCD) detectors show promise as neutron spectrometers. They have been increasingly used for neutron monitoring of high-flux deuterium plasmas. In this article, a high-performance SCD detector is exposed to D-T neutrons at different angles to measure the energy spectra. The results show that the diamond detector is stable under neutron irradiation fluence of $1.63\times10$ ¹⁰ n/cm² during the 2 h testing. Its detection efficiency for ¹²C (n, $\alpha$ ) ⁹Be is (3.31 ± 0.11) $\times \,\, 10$ ⁻⁴ counts/n, which is in good agreement with a Monte Carlo simulation predicted by a Geant4 simulation. The deviation in the detection efficiency between the simulation and experimental results is as low as 0.61%. In addition, a response matrix is created and Gaussian broadening has been applied to obtain a good alignment between the measured and simulated results. Finally, a variety of neutron spectrum unfolding methods, namely, the non-negative least-squares algorithm, the Gravel algorithm, the Gold algorithm, and the Lucy–Richardson algorithm, are applied and compared in detail, demonstrating that using a SCD detector, the precise energy distribution of the D-T neutrons from different angles can be obtained by exploiting the spectrum unfolding methods.