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arXiv · 2509.20029

Development of a time calibration system for the KLM upgrade in the Belle II experiment

Ziyu Liu·Xiyang Wang·Shiming Zou·Xiaolong Wang·Junhao Yin·Minggang Zhao
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Abstract

To meet the stringent time calibration requirements for the Belle II experiment upgrade, particularly for its large-size KL and Muon Detector comprising tens of thousands of scintillator channels with time resolutions better than 100 ps, we developed a compact and high-speed time calibration system. The system utilizes a laser diode as its light source, integrated with a fast pulse laser drive circuit that employs high-speed switching GaN FETs and gate drivers. A prototype was constructed and rigorously evaluated using scintillators, achieving timing resolutions of about 13 ps for a single calibration channel. Furthermore, internal deviations among calibration channels were analyzed, with most measurements remaining within 250 ps. These results highlight the system's precision, scalability, and suitability for large-scale particle physics experiments.

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Ziyu Liu, Xiyang Wang, Shiming Zou, Xiaolong Wang, Junhao Yin, Minggang Zhao. 2025-09-24. Development of a time calibration system for the KLM upgrade in the Belle II experiment. https://doi.org/10.1088/1748-0221%2F21%2F03%2Fp03015

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