DarkSide-50: results from first argon run

DarkSide (DS) at Gran Sasso underground laboratory is a direct dark matter search program based on TPCs with liquid argon from underground sources. The DS-50 TPC, with 50\,kg of liquid argon is installed inside active neutron and muon detectors. DS-50 has been taking data since Nov 2013, collecting more than 107107 events with atmospheric argon. This data represents an exposure to the largest background, beta decays of 3939Ar, comparable to the full 3\,y run of DS-50 with underground argon. When analysed with a threshold that would give a sensitivity in the full run of about 10−4510−45 cm22 at a WIMP mass of 100\,GeV, there is no 3939Ar background observed. We present the detector design and performance, the results from the atmospheric argon run and plans for an upscale to a multi-ton detector along with its sensitivity.