Performance of the 1-ton Prototype Neutrino Detector at CJPL-I

TL;DR

This paper reports on the performance, calibration, background measurement, and technical improvements of a 1-ton prototype neutrino detector at CJPL-I, providing insights for future large-scale neutrino experiments.

Contribution

It presents the first detailed performance evaluation and background control methods for a prototype detector at CJPL-I, informing future detector design.

Findings

Radon background levels were characterized and mitigated.

Nitrogen sealing effectively reduced radon contamination.

Calibration and simulation validated detector performance.

Abstract

China Jinping Underground Laboratory provides an ideal site for solar, geo-, and supernova neutrino studies. With a prototype neutrino detector running since 2017, containing 1-ton liquid scintillator, we tested its experimental hardware, performed the detector calibration and simulation, and measured its radioactive backgrounds, as an early stage of the Jinping Neutrino Experiment (JNE). We investigated the radon background and implemented the nitrogen sealing technology to control it. This paper presents the details of these studies and will serve as a key reference for the construction and optimization of the future large detector of JNE.