Integration of Decay Time Analysis and Radiation Measurement for Quantum-Dot-Based Scintillator’s Characterization

Abstract

In this study, we demonstrated the process of an integrated apparatus for decay time analysis and gamma radiation measurement with a liquid-scintillator-based cadmium-doped zinc oxide (CZO) nanomaterial. Generally, time-resolved photon counting is an essential analysis method in the field of precision measurement in the quantum domain. Such photon counting equipment requires a pulse laser that can be repeated quickly while having a sharp pulse width of picoseconds or femtoseconds as a light source. Time-correlated single photon counting (TCSPC) equipment, which is currently a commercial product, is inconvenient for recent development research because the scintillator size and shape are limited. Here, neodymium-doped yttrium aluminum garnet (Nd/YAG) laser TCSPC equipment was constructed to analyze the fluorescence characteristics of scintillators having various sizes and shapes. Then, a liquid scintillator added with CZO nanomaterial was prepared and the Nd/YAG laser TCSPC equipment test was performed. As a result of measuring the scintillator using the manufactured Nd/YAG laser TCSPC equipment, the non-CZO liquid scintillator was analyzed at 2.30 ns and the liquid scintillator equipped with CZO-loaded nanomaterial was analyzed at 11.95 ns. It showed an error within 5% when compared with the result of commercial TCSPC equipment. In addition, it was verified that the Nd/YAG laser TCSPC system can sufficiently measure the decay time in nanoseconds (ns). Moreover, it was presented that the Compton edge energy of Cs−137 is 477.3 keV, which hardly generates a photoelectric effect, and Compton scattering mainly occurs.