DarkSide is a proposal to develop and deploy a liquid argon detector that has high sensitivity for direct detection of WIMP collisions. Liquid argon is a promising medium for WIMP detection due to its efficient conversion of energy from WIMP-induced nuclear recoils into both ionization and scintillation. In a Time Projection Chamber (TPC), scintillation and ionization can be independently detected and spatially resolved through large volumes of liquid. The relative size and time dependence of these signals permits discrimination of nuclear recoils from background events.
DarkSide builds on past experience and introduces innovative features that will allow it to operate in a background-free mode for more than three years and thereby achieve a significant science result in spite of its relatively small size. At the same time this detector will serve as a prototype for a future multi-ton detector. The main innovations introduced in this proposal are:
- Underground argon depleted in radioactive 39Ar;
- Low background, high-quantum-efficiency Qupid photo detectors;
- A compact high-efficiency external veto for neutrons.
These innovations, together with the powerful two-parameter background rejection features of argon will result in a detector of unprecedented background-free performance. With a mass of 50 kg (33 kg fiducial) and three years of operation, the DarkSide-50 detector will reach a cross-section sensitivity of ~10−45 cm2 for WIMP-nucleon scattering, an improvement of more than a factor of 10 over published results on spin-independent cross sections for WIMPs of 100GeV mass, and competitive with the projected sensitivity of Super-CDMS at SNOLab, Lux-350, and Xenon-100.
- Stephen Pordes
- Jonghee Yoo
- Yann Guardincerri