Performance of a CRESST-II Detector Module with True $4\pi$-veto

TL;DR

This paper presents a novel CRESST-II detector design with a beaker-shaped silicon light absorber that significantly enhances light signal detection and enables a true 4π veto system for external background suppression in rare event searches.

Contribution

The paper introduces a new detector configuration with a beaker-shaped silicon light absorber that improves light collection and provides a true 4π veto system for background reduction.

Findings

Light signal height improved by a factor of 2.5

Successful demonstration of a true 4π veto system

Enhanced sensitivity for rare event detection

Abstract

Scintillating, cryogenic bolometers are widely used in the field of rare event searches. Their main advantages are an excellent energy resolution and particle identification on an event-by-event basis. The sensitivity of experiments applying this detector technique can be limited by the performance of the light channel and the presence of external backgrounds in the region of interest. In the framework of the CRESST-II experiment, we developed and successfully tested a novel detector design addressing both challenges. Using a large scale ($\approx$\unit[60]{cm$^2$}), beaker-shaped silicon light absorber, the signal height recorded in the light channel is improved by a factor 2.5 compared to conventional CRESTT-II detector modules. In combination with a large carrier crystal, a true $4\pi$ veto system is established which allows to tag external background sources.