Abstract. WIMPs (Weakly Interacting Massive Particles) are considered the main candidates for Cold Dark Matter. The ArDM experiment aims at measuring signals directly induced by WIMPs in liquid argon. A 1-ton prototype is currently developed with the goal of demonstrating the feasibility and performance of a detector with such a large target mass. ArDM aims at acting as a liquid argon TPC and additionally measuring the scintillation light. The principle of the experiment and the conceptual design of the detector are described.

The Argon Dark Matter (ArDM) experiment is a ton-scale liquid argon (LAr) doublephase time projection chamber designed for direct Dark Matter searches. Such a device allows to explore the low energy frontier in LAr. After successful operation on surface at CERN, the detector has been deployed underground and is presently commissioned at the Canfranc Underground Laboratory (LSC). In this paper, we describe the status of the installation and present first results on data collected in gas phase.