NEWS-G experiment is using a new type of radiation detector based on the spherical proportional counter. The detector consists of a large spherical gas volume with a central electrode forming a radial electric field. A small spherical sensor located at the center is acting as a proportional amplification structure.
Combination of sub-keV 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. Recent results obtained with a low radioactivity detector, 60 cm in diameter operated in LSM underground laboratory will be presented. First NEWS-G results with Ne as target nuclei, exclude above 4.4・1037 cm2 for a 0.5 GeV/c2 WIMP.
The next project NEWS-G, under study, is a larger detector that consists in a selected pure copper sphere of 1.4 meter of diameter to be installed at SNOLAB. This will allow benefiting from a larger volume, relative to the current detector and a much lower background level.
I will discuss the status of the project and prospects for the future.