https://doi.org/10.1140/epjc/s10052-021-09834-x
Regular Article - Experimental Physics
A measurement of the mean electronic excitation energy of liquid xenon
Department of Physics, University of Zurich, Winterthurerstrasse 190, 8057, Zurich, Switzerland
Received:
22
September
2021
Accepted:
13
November
2021
Published online:
1
December
2021
Detectors using liquid xenon as target are widely deployed in rare event searches. Conclusions on the interacting particle rely on a precise reconstruction of the deposited energy which requires calibrations of the energy scale of the detector by means of radioactive sources. However, a microscopic calibration, i.e. the translation from the number of excitation quanta into deposited energy, also necessitates good knowledge of the energy required to produce single scintillation photons or ionisation electrons in liquid xenon. The sum of these excitation quanta is directly proportional to the deposited energy in the target. The proportionality constant is the mean excitation energy and is commonly known as W-value. Here we present a measurement of the W-value with electronic recoil interactions in a small dual-phase xenon time projection chamber with a hybrid (photomultiplier tube and silicon photomultipliers) photosensor configuration. Our result is based on calibrations at 
with internal 
and 
sources and single electron events. We obtain a value of 
, with negligible statistical uncertainty, which is lower than previously measured at these energies. If further confirmed, our result will be relevant for modelling the absolute response of liquid xenon detectors to particle interactions.
© The Author(s) 2021
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Funded by SCOAP3
