After many years of preparation, the installation of the NEWS-G experiment was finally completed in early August 2021.
The achinos sensor was installed on August 4th, using a glove box under nitrogen atmosphere. This process prevents contamination of the detector’s copper vessel with the radioactive radon in the mine’s air.
On August 10th, the detector was filled with an argon gas mixture for testing. The very first signal using this detector at SNOLAB was observed. Argon is naturally radioactive, so it will produce a signal in the detector a few times per minute. This is however too much background to be used for dark matter search.
A lot of work remains to characterize and optimize the performance of the detector, before filling it. It will then be filled with gas mixtures of neon and helium, which will provide the best sensitivity to low mass dark matter.