Manual Calibration System for Daya Bay Reactor Neutrino Experiment

TL;DR

The paper details the design and performance of a manual calibration system for the Daya Bay neutrino detectors, improving calibration precision to enhance neutrino measurement accuracy.

Contribution

It introduces a novel manual calibration system with high positional accuracy for neutrino detectors, aiding precise response characterization.

Findings

Calibration source placement accuracy of 25 mm radially, 20 mm vertically, and 0.5° angular.

Successful deployment and operation of the calibration system during the shutdown.

Enhanced understanding of detector response through detailed calibration.

Abstract

The Daya Bay Reactor Neutrino Experiment has measured the last unknown neutrino mixing angle, {\theta}13, to be non-zero at the 7.7{\sigma} level. This is the most precise measurement to {\theta}13 to date. To further enhance the understanding of the response of the antineutrino detectors (ADs), a detailed calibration of an AD with the Manual Calibration System (MCS) was undertaken during the summer 2012 shutdown. The MCS is capable of placing a radioactive source with a positional accuracy of 25 mm in R direction, 20 mm in Z axis and 0.5{\deg} in {\Phi} direction. A detailed description of the MCS is presented followed by a summary of its performance in the AD calibration run.