R & D for Future Zeplin

TL;DR

This paper proposes a novel low-background, multi-ton liquid xenon detector design for dark matter detection, featuring concentric spheres, internal photocathodes, and combined scintillation and ionisation measurements to enhance sensitivity.

Contribution

It introduces a new detector concept with concentric spheres and internal photocathodes, aiming for improved background rejection and full SUSY parameter space coverage.

Findings

Design achieves ultra-low background levels

Simulations show effective background discrimination

Expected to probe the entire SUSY parameter space

Abstract

We propose a new concept for a very low background multi-ton liquid xenon Dark Matter experiment. The detector consists of two concentric spheres and a charge readout device in the centre. Xenon between the two spheres forms a self-shield and veto device. The inner surface of the central sphere is coated with CsI to form an internal photocathode with minimum of 2\pi coverage for any event in the active volume. Photoelectrons from the CsI photocathode drift toward the charge readout micro-structure in the centre of the detector. Both scintillation and ionisation are measured simultaneously for background rejection and 3-D event mapping. In addition to external shielding, the low background is achieved by eliminating PMTs and by using low radioactivity pure materials throughout the detector. We present detailed calculations of the charge readout system and design details. The detector is expected to probe the full SUSY parameter space.