Performance evaluation of the FastIC readout ASIC with emphasis on Cherenkov emission in TOF-PET

Area of Science:

• Medical Imaging Physics
• Detector Technology
• Nuclear Instrumentation

Background:

• Efficient use of prompt photons, such as Cherenkov emission, is crucial for next-generation, cost-effective, ultra-high-sensitivity time-of-flight positron emission tomography (TOF-PET) scanners.
• Previous research demonstrated sub-300 ps FWHM timing with large BGO crystals using high-power electronics, but these results are not scalable to full systems.
• Scalability challenges necessitate exploring new readout electronics for TOF-PET systems with thousands of detector elements.

Purpose of the Study:

• To evaluate the performance of the FastIC ASIC in conjunction with Cherenkov-emitting Bismuth Germanate (BGO) scintillators for TOF-PET applications.
• To assess the timing capabilities of the FastIC ASIC with state-of-the-art Silicon Photomultiplier (SiPM) detectors.
• To compare the FastIC ASIC's timing performance against high-power consuming discrete readout electronics.

Main Methods:

• Utilized the FastIC ASIC, a configurable 8-channel chip with low power consumption (12 mW/channel) and excellent linearity, for detector readout.
• Integrated the FastIC ASIC with BGO crystals and FBK's metal-trenching SiPMs.
• Conducted comparative measurements against high-power discrete electronics to benchmark timing performance.

Main Results:

• Achieved a best timing resolution (CTR) Full Width at Half Maximum (FWHM) of 330 ps for 2x2x3 mm³ BGO crystals and 490 ps for 2x2x20 mm³ BGO crystals using the FastIC ASIC.
• Measured CTR FWHM values of 129 ps with 20 mm long LSO:Ce:Ca crystals using the FastIC ASIC, closely matching the 95 ps achieved with discrete high-frequency electronics.
• Demonstrated the FastIC ASIC's capability to provide excellent timing with BGO crystals, a key scintillator for TOF-PET.

Conclusions:

• The FastIC ASIC shows significant potential for developing cost-effective TOF-PET scanners with excellent timing characteristics.
• This study represents the first evaluation of BGO crystal timing performance using a scalable ASIC.
• The findings support the integration of the FastIC ASIC in future ultra-high-sensitivity TOF-PET systems, addressing scalability limitations of previous approaches.