【International Papers】Gallium oxide (Ga₂O₃) as a radiation detector distinguishing neutrons and gammas

      Researchers from the University of Nevada, Las Vegas have published a dissertation titled "Gallium oxide (Ga₂O₃) as a radiation detector distinguishing neutrons and gammas" in APL Materials.

Abstract

      Gallium oxide (Ga₂O₃) is a promising ultrawide bandgap semiconductor for radiation detection with the potential of integrating electronic and scintillation functions within a single crystal device. This study establishes the scintillation response of β-Ga₂O₃ gamma irradiation from yttrium-88 (⁸⁸Y). Then, californium-252 (²⁵²Cf) is used as a spontaneous fission source of mixed neutron and gamma radiation field to measure scintillation signals. Pulse shape discrimination and constant fraction discrimination techniques were used to separate neutron and gamma interaction events. Further investigation indicates that the prompt temporal responses of β-Ga₂O₃ for gammas and neutrons may enable discrimination of the two by prompt pulse fitting methods, focused around the initial peak. For gamma irradiation, we observed a rise time (τ_r) of 2.1 ns, decay time (τ_d) of 9.5 ns, and a full width at half maximum (FWHM) of 6.2 ns. For neutrons, it showed a τ_r of 2.3 ns, a τ_d of 12.1 ns, 9.4 ns FWHM, and reduced peak intensity. A diamond detector exhibited a more symmetrical τ_r and τ_d for both gamma and neutron signals and therefore is less effective at discriminating between the two by this method. This draws attention to β-Ga₂O₃’s ability to distinguish neutron and gamma particles. These findings showcase Ga₂O₃’s potential as a next-generation semiconductor for applications in nuclear safety and medical imaging, where precise discrimination between neutron and gamma interactions is essential.