Light-Based Fast Timing in Bulk CsPbBr3 Crystals for TOF-PET and Proton Range Verification

Area of Science:

• Materials Science
• Nuclear Instrumentation
• Semiconductor Physics

Background:

• Halide perovskite semiconductors like CsPbBr3 offer high energy resolution for gamma-ray detection.
• Traditional semiconductor detectors suffer from poor time resolution due to slow charge carrier drift.
• Cherenkov light emission in semiconductors presents a novel approach to enhance timing performance.

Purpose of the Study:

• To investigate the Cherenkov light component generated in CsPbBr3 for improved gamma-ray detector timing.
• To evaluate the feasibility of using Cherenkov light for fast timing applications in conjunction with charge readout.
• To achieve precise 3D localization capabilities in next-generation detectors.

Main Methods:

• Optical simulations were performed to model Cherenkov photon production in CsPbBr3.
• Experimental measurements were conducted using CsPbBr3 crystals coupled to silicon photomultipliers.
• Coincidence time resolution (CTR) was measured using a pair of identical detector crystals.

Main Results:

• Simulations predicted an average of 9.5 Cherenkov photons per 511 keV interaction in CsPbBr3.
• Experimental results showed 2-3 times more detected optical photons than simulated, possibly due to UV transparency or scintillation.
• A coincidence time resolution of 419 ps FWHM was achieved.

Conclusions:

• The Cherenkov light component in CsPbBr3 can significantly improve timing resolution in gamma-ray detectors.
• The measured CTR confirms the potential for fast timing applications, complementing charge readout.
• This approach paves the way for enhanced 3D localization in detector systems.