Development and characterization of the JNE concentrator

TL;DR

This paper presents the development and testing of a custom light concentrator for the Jinping Neutrino Experiment's photomultiplier tubes, significantly improving light collection efficiency with minimal impact on timing resolution.

Contribution

The study designs and characterizes a new light concentrator that enhances light collection efficiency by 40% for JNE's PMTs, validated through measurements and simulations.

Findings

Concentrators increase light collection efficiency by 40%.

Measurements agree with Monte Carlo simulations.

Transit-time spread increases by less than 0.3 ns.

Abstract

The Jinping Neutrino Experiment (JNE) will utilize approximately 3000 8-inch MCP-PMTs identified as GDB-6082 from North Night Vision Technology to detect neutrinos. To enhance the effective coverage of the JNE detector, mounting a custom-designed light concentrator on each PMT is a practical and economical approach. We measured angular responses of the concentration factor at four wavelengths in air medium for the concentrator with the selected cutoff angle of 70{\deg}. The measurements align with the Monte Carlo simulations. Furthermore, our results indicate that these concentrators can improve the efficiency of light collection by 40 % under parallel illumination conditions. This enhancement results in a slight increase in transit-time spread, with the full width at half maximum (FWHM) increasing by less than 0.3 ns. We conclude that the developed light concentrators are highly suitable for the JNE.