The Automatic Calibration Unit in JUNO

TL;DR

This paper details the design and implementation of an automated calibration system for the JUNO detector, enabling precise energy calibration, timing alignment, and monitoring of detector variations.

Contribution

It introduces a fully automated mechanical calibration unit capable of deploying multiple sources into the JUNO detector along its central axis.

Findings

Successful deployment of radioactive sources and UV laser for calibration

Enhanced precision in energy scale calibration and timing alignment

Partial monitoring of position-dependent energy variations

Abstract

This paper describes the design and construction of the automatic calibration unit (ACU) for the JUNO experiment. The ACU is a fully automated mechanical system. It is capable of deploying multiple radioactive sources, an ultraviolet (UV) laser source, or an auxiliary sensor such as a temperature sensor, one at a time, into the central detector of JUNO along the central axis. It is designed as a primary tool to precisely calibrate the energy scale of detector, aligning timing for the photosensors, and partially monitoring the position-dependent energy scale variations.