Speaker
Description
The Jiangmen Underground Neutrino Observatory (JUNO) is a large-scale neutrino experiment with multiple physics goals. After its completion at the end of 2024, commissioning for data taking began, followed by the commencement of official data-taking on August 26, 2025. The raw data acquired by the JUNO DAQ system is stored in a custom binary format. After transmission to the data center, this raw data first undergoes preprocessing before subsequent reconstruction and analysis. A fundamental requirement for JUNO neutrino physics is the strict chronological ordering of events, making offline event sorting the primary goal of preprocessing. A key challenge involves events being out of order across different data files. To address this, an index-based offline sorting software has been designed and implemented. Concurrently, the preprocessing stage performs data format conversion. This step decodes the binary data, transforms it into the offline Event Data Model (EDM), and finally stores it in the same rtraw (ROOT) format used for simulated data. This ensures identical subsequent processing pipelines for both real and simulated datasets. Currently, this preprocessing procedure is applied to all JUNO raw data. Its deployment in the production pipeline has demonstrated high reliability and operational efficiency. Furthermore, research on time synchronization corrections between events from different sub-detectors is ongoing, which is expected to further enhance data quality for physics analysis.