Fast online trigger using FPGA-based event classification for the COMET Phase-I

Yu Nakazawa, Tai Thanh Chau, Yuki Fujii, Ewen Gillies, Masahiro Ikeno, Satoshi Mihara, Masayoshi Shoji, Tomohisa Uchida, Kazuki Ueno, Myeong Jae Lee

Research output: Chapter in Book/Report/Conference proceedingConference PaperResearch


The COMET Phase-I experiment searches for a neutrinoless muon-to-electron conversion which has never been observed yet. The world's highest intensity muon beam is applied, and it leads to an unacceptable trigger rate of O(106) Hz. For stable data collection, the trigger rate must be reduced to O(103) Hz. This requirement is met using online event classification in the detector system which holds 99% of signal events. This classification is performed by an FPGA-based trigger system, and its processing time is set to less than 5 µs by a buffer size of the detector readout electronics. A prototype board for the trigger system was developed, and communication systems for related electronics devices were also constructed. From test results, the total processing time is estimated to be 2.8 µs, which meets the requirement. We have also developed an online self-trigger system for cosmic-rays and confirmed the feasibility of this hardware logic. The trigger electronics were installed in a setup for cosmic-ray measurement, and the data acquisition was successfully done using the self-trigger system.

Original languageEnglish
Title of host publicationProceedings of Science
Place of PublicationItaly
PublisherProceedings of Science
Number of pages7
Publication statusPublished - 12 Nov 2020
EventEuropean Physical Society Conference on High Energy Physics, 2019 - International Convention Center of Ghent / Ghent University, Ghent, Belgium
Duration: 10 Jul 201917 Jul 2019

Publication series

NameProceedings of Science
PublisherSissa Medialab, SRL
ISSN (Print)1824-8039


ConferenceEuropean Physical Society Conference on High Energy Physics, 2019
Abbreviated titleEPS-HEP 2019
Internet address

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