Study on a phoswich detector consisting of Li-composed crystal scintillator and BGO for neutron measurement

For high-sensitivity neutron measurement, we developed a phoswich detector consisting of LiYF₄ (Ce 1%) and BGO crystals. Light outputs of LiYF₄ excited from ¿-ray (simulating neutron excitation) have the faster decay-time constant ¿~50 ns, compared with that from the shielding BGO crystal (¿~300 ns), and these waveforms output from a preamplifier are clearly distinguished each other. When the waveforms with the faster rise-time were selected, the spectrum was obtained with only the peak of 5.49 MeV ¿-ray from ²⁴¹Am detected at the neutron-sensitive LiYF₄ scintillator.