Introduction of the CDEX experiment

TL;DR

The CDEX experiment at CJPL aims to detect low-mass WIMPs using germanium detectors, with recent progress in detector development, environmental monitoring, and setting the stage for future dark matter searches.

Contribution

This paper introduces the CDEX experiment, detailing its detectors, environment, and physics goals, marking progress in low-mass WIMP detection at CJPL.

Findings

Measurement of muon flux and radioactivity at CJPL

Performance of 1 kg and 10 kg germanium detectors

Future plans for CDEX-1T detector

Abstract

Weakly Interacting Massive Particles (WIMPs) are the candidates of dark matter in our universe. Up to now any direct interaction of WIMP with nuclei has not been observed yet. The exclusion limits of the spin-independent cross section of WIMP-nucleon which have been experimentally obtained is about 10^{-7}pb at high mass region and only 10^{-5}pb} at low mass region. China Jin-Ping underground laboratory CJPL is the deepest underground lab in the world and provides a very promising environment for direct observation of dark matter. The China Dark Matter Experiment (CDEX) experiment is going to directly detect the WIMP flux with high sensitivity in the low mass region. Both CJPL and CDEX have achieved a remarkable progress in recent two years. The CDEX employs a point-contact germanium semi-conductor detector PCGe whose detection threshold is less than 300 eV. We report the measurement results of Muon flux, monitoring of radioactivity and Radon concentration carried out in CJPL, as well describe the structure and performance of the 1 kg PCGe detector CDEX-1 and 10kg detector array CDEX-10 including the detectors, electronics, shielding and cooling systems. Finally we discuss the physics goals of the CDEX-1, CDEX-10 and the future CDEX-1T detectors.