Measure the scattering and absorption lengths of the NoWaSH scintillator

Measure the scattering and bulk absorption lengths of the approximately 9 wt% wax NoWaSH scintillator used in the BPULSE detector, which are required to determine its optical transport properties.

Background

The BPULSE target uses a NoWaSH scintillator consisting of linear alkylbenzene, PPO, bis-MSB, and approximately 9 wt% micronized wax. Its millimeter-scale scattering and meter-scale absorption determine how scintillation light is confined and collected by the wavelength-shifting fibers.

The detector response and timing model depend on these optical constants, but the experiment treats them only as order-of-magnitude estimates. Determining them would enable more accurate prediction of absolute light collection, vertex localization, and timing-response kernels.

References

The scattering and absorption lengths of this mixture have not been measured, so they are treated as order-of-magnitude estimates (Table~\ref{tab:detector}).

— Energy, vertex, and time response of a LiquidO detector with an opaque-scintillator target to Compton-tagged electrons  (2610.18849 - Collaboration et al., 13 Oct 2026) in Section 2.1, “The BPULSE Detector”; Section 3.2, “Optical and Sensor Model”