NEWS-G: Search for Light Dark Matter with a Spherical Proportional Counter
Résumé
The NEWS-G collaboration is searching for light dark matter candidates using a spherical proportional counter. Access to the mass range from 0.1 to 10 GeV is enabled by the combination of low energy threshold, light gaseous targets, and radiopure construction. The current status of the experiment is presented, including the first NEWS-G results obtained with SEDINE, a 60 cm in diameter spherical proportional counter operating at LSM (France). The next generation, 140 cm in diameter, spherical proportional counter that is currently being installed in SNOLAB, Canada, is presented. Its construction at LSM, using C10100 copper and the electroplating of a 500 μm ultra-pure copper layer to the inner detector surface, will be discussed, along with the latest advances in instrumentation, simulation, and gas purification.