Aging research of the LAB-based liquid scintillator in stainless steel container

TL;DR

This study investigates the aging effects of LAB-based liquid scintillator stored in stainless steel containers, finding minimal impact on properties and confirming stainless steel's suitability for storage in neutrino experiments.

Contribution

It provides experimental data on aging effects of LAB-based liquid scintillator in stainless steel containers at different temperatures, supporting material choice for long-term storage.

Findings

Light yield and absorption spectrum remain stable after aging.

Attenuation length decreases by 6-12% after aging.

No significant change in Fe concentration in the scintillator.

Abstract

Stainless steel is the material used for the storage vessels and piping systems of LAB-based liquid scintillator in JUNO experiment. Aging is recognized as one of the main degradation mechanisms affecting the properties of liquid scintillator. LAB-based liquid scintillator aging experiments were carried out in different material of containers (type 316 and 304 stainless steel and glass) at two different temperature (40 and 25 degrees Celsius). For the continuous liquid scintillator properties tests, the light yield and the absorption spectrum are nearly the same as that of the unaged one. The attenuation length of the aged samples is 6%~12% shorter than that of the unaged one. But the concentration of element Fe in the LAB-based liquid scintillator does not show a clear change. So the self aging has small effect on liquid scintillator, as well as the stainless steel impurity quenching. Type 316 and 304 stainless steel can be used as LAB-based liquid scintillator vessel, transportation pipeline material.