First Light from Beam Neutrinos on an LAPPD in ANNIE

TL;DR

This paper demonstrates the first successful detection of neutrino-induced Cherenkov light using an integrated Large Area Picosecond Photodetector (LAPPD) in a neutrino beam experiment, validating its potential for future large-scale detectors.

Contribution

It reports the first operational deployment of a fully integrated LAPPD in a neutrino beam, showcasing its performance and synchronization with existing detector systems.

Findings

First detection of neutrino-induced Cherenkov light with an LAPPD

Successful integration and synchronization of LAPPD with other detector subsystems

Validation of LAPPD performance under realistic experimental conditions

Abstract

The Accelerator Neutrino Neutron Interaction Experiment (ANNIE) is both a physics experiment and a technology testbed for next-generation light-based neutrino detection. In this paper, we report the first demonstration of a fully integrated Large Area Picosecond Photodetector (LAPPD) operating in a running neutrino beam experiment. Particular focus is given to the design, commissioning, and successful deployment of the Packaged ANNIE LAPPD (PAL), a waterproof, self-triggering module incorporating fast waveform digitization and precision timing synchronized to the ANNIE detector subsystems. We identify beam-correlated LAPPD data frames consistent with charged-current neutrino interactions observed in multiple detector subsystems, establishing the first detection of neutrino-induced Cherenkov light with an LAPPD. These results validate the system-level performance of LAPPDs under realistic experimental conditions-including long-term stability, timing synchronization, and event matching with conventional PMT and muon detector systems-marking a critical step toward their deployment in future large-scale neutrino and particle detectors.