The first dual-phase xenon TPC equipped with silicon photomultipliers and characterisation with 37Ar.

For the first time, a small dual-phase (liquid/gas) xenon time projection chamber was equipped with a top array of silicon photomultipliers for light and charge readout. Here we describe the instrument in detail, as well as the data processing and the event position reconstruction algorithms. We obtain a spatial resolution of  ∼ 1.5 mm in the horizontal plane. To characterise the detector performance, we show calibration data with internal 83mKr and 37Ar sources, and we detail the production of the latter as well as its introduction into the system. We finally compare the observed light and charge yields down to electronic recoil energies of 2.82 keV to predictions based on NEST v2.0.