  The ArDM experiment, a 1 ton liquid argon TPC/Calorimeter, is designed for
the detection of dark matter particles which can scatter off the spinless argon
nucleus, producing nuclear recoils. These events will be discerned by their
light to charge ratio, as well as the time structure of the scintillation
light. The experiment is presently under construction and commissioning on
surface at CERN. Cryogenic operation and light detection performance was
recently confirmed in a test run of the full 1 ton liquid argon target under
purely calorimetric operation and with a prototype light readout system. This
note describes the experimental concept, the main detector components and
presents some first results.
