High-Speed Detection of X-ray Pulses Using a Digital Counter Coupled with Perovskite Composite Scintillators

Area of Science:

• Materials Science
• Radiation Detection
• Medical Physics

Background:

• Accurate pulse-resolved detection of ionizing radiation at megahertz frequencies is crucial for advanced radiotherapy and X-ray monitoring.
• Conventional bulky single-crystal scintillators (e.g., lutetium-yttrium oxyorthosilicate - LYSO) face limitations in flexibility and integrability.
• Perovskite scintillators often suffer from afterglow, causing signal pile-up in high-flux environments.

Purpose of the Study:

• To develop novel scintillator materials for high-frequency, pulse-resolved radiation detection.
• To overcome the limitations of conventional bulky detectors and afterglow issues in perovskite scintillators.
• To create a compact, flexible, and scalable solution for real-time radiation monitoring.

Main Methods:

• Fabrication of thin polymer composite scintillator films incorporating LYSO and (PEA)2PbBr4.
• Characterization of intrinsic decay times and signal enhancement via optical scattering in the polymer matrix.
• Integration with silicon photomultipliers and field-programmable gate array (FPGA)-based digital counters for real-time pulse counting.

Main Results:

• Composite films retained intrinsic decay times (LYSO ~37 ns, (PEA)2PbBr4 ~6 ns).
• LYSO/PMMA composite detected signals up to 2 MHz; (PEA)2PbBr4/PMMA composite reached 5 MHz with amplification.
• The system achieved a dead time of ~20 ns, enabling pulse-by-pulse readout from low to multimegahertz rates without pile-up.

Conclusions:

• Thin, inhomogeneous composite scintillator films offer enhanced signal output and fast response times.
• FPGA-based digital processing enables compact, scalable, high-frequency radiation detection systems.
• This technology addresses limitations of traditional detectors, paving the way for advanced applications in radiotherapy and monitoring.