Abstract
A small-scale, two-phase (liquid/gas) xenon time projection chamber (Xurich II) was designed, constructed and is under operation at the University of Zürich. Its main purpose is to investigate the microphysics of particle interactions in liquid xenon at energies below 50 keV, which are relevant for rare event searches using xenon as target material. Here we describe in detail the detector, its associated infrastructure, and the signal identification algorithm developed for processing and analysing the data. We present the first characterisation of the new instrument with calibration data from an internal ^{83mathrm {m}}Kr source. The zero-field light yield is 15.0 and 14.0 photoelectrons/keV at 9.4 and 32.1 keV, respectively, and the corresponding values at an electron drift field of 1 kV/cm are 10.8 and 7.9 photoelectrons/keV. The charge yields at these energies are 28 and 31 electrons/keV, with the proportional scintillation yield of 24 photoelectrons per one electron extracted into the gas phase, and an electron lifetime of 200 upmu s. The relative energy resolution, sigma /E, is 11.9 and 5.8% at 9.4 and 32.1 keV, respectively using a linear combination of the scintillation and ionisation signals. We conclude with measurements of the electron drift velocity at various electric fields, and compare these to literature values.
Highlights
As part of our R&D studies related to rare event searches, we have designed, constructed and are operating a new, small liquid xenon time projection chamber (TPC) (Xurich II) at the University of Zürich
We present first results obtained with the Xurich II TPC
We show the anti-correlation between the scintillation and ionisation signals for the 32.1 keV line with data from one calibration run. By performing these measurements at various drift fields, we can observe the anti-correlation between scintillation light and ionisation in the TPC, as illustrated by the S1 and
Summary
As part of our R&D studies related to rare event searches, we have designed, constructed and are operating a new, small liquid xenon TPC (Xurich II) at the University of Zürich. This builds upon our experience with larger TPCs, such as employed in XENON10/100/1T, and with a previous, smallscale TPC (Xurich I). The latter instrument demonstrated the capability of a spatially uniform calibration of liquid xenon detectors with 83mKr [17] and was used to study the response of liquid xenon to electronic recoils down to 1.5 keV [18].
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Free) 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
