Time response of water-based liquid scintillator from X-ray excitation

Abstract

Water-based liquid scintillators (WbLS) present an attractive target medium for large-scale detectors with the ability to enhance the separation of Cherenkov and scintillation signals from a single target. This work characterizes the scintillation properties of WbLS samples based on LAB/PPO liquid scintillator (LS). X-ray luminescence spectra, decay profiles, and relative light yields are measured for WbLS of varying LS concentration as well as for pure LS with a range of PPO concentrations up to 90 g L⁻¹. The scintillation properties of the WbLS are related to the precursor LAB/PPO: starting from 90 g L⁻¹ PPO in LAB before synthesis, the resulting WbLS have spectroscopic properties that instead match 10 g L⁻¹ PPO in LAB. This could indicate that the concentration of active PPO in the WbLS samples depends on their processing.