Europium doped Gd2O3 and GdBO3 scintillators for thermal neutron detection

Abstract

Neutron detectors used in various applications in nuclear security and nuclear safety are mostly based on the 3He technology. Unfortunately, in the last few years, the market of 3He has encountered huge problems in matching the supply and demand leading to an exponential increase in the price and a serious strategic problem of resources. To guarantee the availability of detection systems for nuclear security, the last decade has been driven by the quest for exploring alternative technologies to replace 3He based detectors. Gadolinium (natGd) is a promising rare earth element which has the largest capture cross-section for thermal neutrons among all stable elements due to the contributions of the isotopes 155Gd and 157Gd. This paper describes the fabrication of Gd2O3:Eu3+ and GdBO3:Eu3+ phosphors as scintillators for thermal neutron detection. The samples were evaluated using photoluminescence, SEM analysis, and pulse height spectra recorded from a D–D neutron source. The recorded spectrum was compared to a FLUKA simulation of the characteristic K X-ray emission following neutron capture.