Two Results from the Freiburg Astroparticle Lab

We just published two papers covering results from experiments we have conducted in our astroparticle physics laboratory in Freiburg. They mainly focus on R&D for future large-scale dark matter detectors and were funded by the ERC grant ULTIMATE.

The XeBRA platform for liquid xenon time projection chamber development

• D. Baur et al, arXiv:2208.14815
  

XeBRA is the versatile detector platform to perform R&D for liquid xenon detectors installed and operated in our laboratory. In this article we present the platform and introduce two detectors (dual-phase liquid xenon (LXe) TPCs) operated on it, Using data from these detectors, we determine some basic properties of LXe as detector medium: the field-dependence of the electron drift velocity as well as relative light and charge yields for different electric drift fields. 

Reduction of ²²²Rn-induced Backgrounds in a Hermetic Dual-Phase Xenon Time Projection Chamber

• J. Dierle et al., Eur. Phys. J C 81, 9 (2023), arXiv:2209.00362
  

In this work we built and operated a small detector prototype to test the possibility to reduce the background from ²²²Rn, the dominant background source in current LXe-based dark matter searches, by a novel detector design which mechanically separates the dark matter target from the detector regions which emanate more ²²²Rn. By scaling up the result to the scale of a multi-ton.scale detector such as DARWIN, we can show that such hermetic detector design is very promising, even if full hermeticity cannot be achieved.