The purpose of this project is to search for very-low WIMP mass candidates using a spherical gaseous detector with enough background rejection, redundancy and flexibility to assess or infirm a possible signal.
The detector operates at high gas gain and in a wide range of gas pressures. Sub-keV energy threshold with good energy resolution is achieved. Low-energy threshold and versatility of the target (Ne, He, H) opens the way to search for ultra light dark matter WIMPs down to 100 MeV.
Results obtained with a low radioactivity 60 cm detector operating at LSM underground laboratory will be presented. With the energy threshold set at 50 eV, measured background level is comparable to existing detectors, giving rise to competitive exclusion plots for light WIMP’s.
The next project, NEWS-SNO, is a larger detector that consists of a selected pure copper sphere of 2 meter in diameter to be installed at SNOLAB. This will allow benefiting from a 40 times larger volume, relative to the actual detector and enhanced light-WIMP sensitivity.
The detector has a unique capability to detect decays of Kaluza-Klein axions and opens the way to detect the neutrino-nucleus interaction. Other physics goals of such a device could include double beta decay, supernova detection, low energy neutrino oscillations and study of non-standard properties of the neutrino.

    Host: Prof. Kaixuan Ni