A new high-background-rejection dark matter Ge cryogenic detector

TL;DR

This paper introduces a novel cryogenic germanium detector design that significantly enhances background rejection for dark matter searches, enabling exploration of extremely low WIMP-nucleon cross-sections.

Contribution

The paper presents a new detector design utilizing coplanar grid technique for improved background discrimination in dark matter detection.

Findings

Achieved background rejection efficiency approaching 10^5 for low-energy beta particles.

Demonstrated the detector's potential to probe WIMP-nucleon cross-sections below 10^-8 pb.

Validated the detector's performance in the EDELWEISS II setup at Modane.

Abstract

A new design of a cryogenic germanium detector for dark matter search is presented, taking advantage of the coplanar grid technique of event localisation for improved background discrimination. Experiments performed with prototype devices in the EDELWEISS II setup at the Modane underground facility demonstrate the remarkably high efficiency of these devices for the rejection of low-energy $\beta$, approaching 10$^5$ . This opens the road to investigate the range beyond 10$^{-8}$ pb in the WIMP-nucleon collision cross-sections, as proposed in the EURECA project of a one-ton cryogenic detector mass.