The Experiment for Direct Dark Matter Searches with Liquid Ar Detector

A novel experiment for direct searches of Dark Matter with a liquid argon double-phase chamber with a mass of liquid Ar up to 10 4 tons is proposed. To suppress the β-, γ- and n 0- backgrounds, the comparison of scintillation and ionization signals for every event is suggested. The addition to liquid Ar of photosensitive Ge(CH 3 ) 4 (0.15ppm) and the suppression of the triplet component of the scintillation signals by the addition of 100ppm of Xe ensures the detection of scintillation signals with 50% efficiency and provides a complete suppression of the electron background. Highly stable and reliable GEM detectors with pin-anodes are developed for the detection of photoelectrons and the bump of ionization electrons.