2 research outputs found
Precision measurements of the scintillation pulse shape for low-energy recoils in liquid xenon
We present measurements of the scintillation pulse shape in liquid xenon for
nuclear recoils (NR) and electronic recoils (ER) at electric fields of 0 to 0.5
kV/cm for energies 15 keV and 70 keV electron-equivalent, respectively.
The average pulse shapes are well-described by an effective model with two
exponential decay components, where both decay times are fit parameters. We
find significant broadening of the pulse for ER due to delayed luminescence
from the recombination process. In addition to the effective model, we fit a
model describing the recombination luminescence for ER at zero field and obtain
good agreement. We estimate the best performance of a combined S2/S1 and pulse
shape ER/NR discrimination and show that even with 2 ns time resolution, the
improvement over S2/S1 discrimination alone is marginal, so that pulse shape
discrimination will likely not be useful for future dual-phase liquid xenon
experiments looking for elastic dark matter recoil interactions