Exploring the intrinsic energy resolution of liquid scintillator to approximately 1 MeV electrons

TL;DR

This paper introduces a new method to measure the intrinsic energy resolution of liquid scintillators for electrons around 1 MeV, revealing a resolution of 1.83% at 976 keV, and investigates the underlying causes of this resolution.

Contribution

It presents a novel approach combining coincidence detection and the WACC method to accurately determine the intrinsic energy resolution of liquid scintillators.

Findings

Intrinsic energy resolution at 976 keV is 1.83%.

Luminescent nonlinearity weakly affects energy resolution.

Large intrinsic resolution may stem from energy transfer fluctuations.

Abstract

We proposed a novel method for exploring the intrinsic energy resolution of a liquid scintillator (LAB + 2.5 g/L PPO + 3 mg/L bis-MSB) for approximately 1 MeV electrons. With the help of coincidence detection technology, single-energy electrons of Bi 207 were effectively selected. With careful measurement and analysis of the energy resolution of a small liquid scintillator detector, the intrinsic energy resolution to 976 keV electrons was extracted to be 1.83%. We used the wide-angle Compton coincidence (WACC) method to measure the luminescent nonlinearity of the liquid scintillator and found that it contributes only weakly to the intrinsic energy resolution of electrons. Such an unexpected large intrinsic energy resolution may come from fluctuations in energy transfer processes.