Speaker
Description
While many current world-leading experiments utilise dual-phase noble element time projection chambers (TPC) to perform direct dark matter searches, a potential alternative that may be simpler and easier to scale-up is a single-phase TPC. However, achieving similar background discrimination and event localisation capabilities as current experiments is made challenging due to the requirement of proportional scintillation and charge amplification directly in the liquid. Methods to achieve such amplification have been demonstrated using thin wires and micro pattern detector structures, but how they might be incorporated into an experiment remains elusive. We present a new approach to this, with the first results with a novel method for charge amplification in liquid xenon that could be scaled to the size required for a direct dark matter search experiment. A thin needle-like electrode was used to provide a sufficiently high electric field in a liquid xenon time projection chamber test bench, read-out by two PMTs. The experimental set-up will be presented, along with measurements of the proportional scintillation in the liquid phase at several voltages. Progress towards a scalable design, where the electrodes are incorporated into a multi-anode structure, like that employed by the spherical proportional counter used by NEWS-G, will be discussed, as will how this could be implemented in a single-phase xenon detector like XMASS-I.
| Main Contribution topic | Instrumentation for Dark Matter searches |
|---|---|
| Secondary contribution topic | Direct detection |