Speaker
Description
High-precision time-resolved detectors are core technologies in fields such as particle physics, nuclear physics, and medical imaging, with their performance critically depending on the decay time, light yield of ultrafast scintillation crystals, and the temporal response characteristics of fast photomultiplier tubes (PMTs). Traditional materials like LYSO and BGO, which suffer from slow response speeds or insufficient light yields, are unable to meet the demands of ultrafast imaging. In recent years, novel fast-decay crystals such as BaF₂, GAGG:Ce, and the perovskite Cs₃Cu₂I₅:Mn have shown potential, but their environmental stability and detector compatibility still need to be optimized.
Ultrafast PMTs have demonstrated excellent single-photon detection capabilities, providing strong support for high-precision time measurements. The MCP-PMT collaboration has developed a series of fast PMTs (FPMTs) with single-photon detection capabilities, featuring a rise time (RT) of less than 300 ps and a transit time spread (TTS) of less than 30 ps.
Coupling ultrafast scintillation crystals with FPMTs is expected to achieve higher-precision coincidence time resolution, breaking through the sub-100 picosecond time resolution bottleneck. Experimental tests were conducted on the time performance of BaF₂ crystals with different doping concentrations (1%, 3%, 5%, and 10%) coupled with FPMTs, focusing on their rise time (RT), fall time (FT), and pulse width. The results show that as the doping concentration increases, the detector's counting rate and peak voltage change, and the rise and fall times exhibit different characteristics. These data indicate that doping concentration significantly affects the time resolution performance of the detector, providing important experimental evidence for optimizing the doping concentration of ultrafast scintillation crystals to enhance detector performance. Further experiments coupling more ultrafast crystals with FPMTs are ongoing, with results being analyzed progressively. The complete findings will be presented in formal reports or publications.
