NEWS-G experiment resumes installation
With the final cleaning of SNOGLOBE, the NEWS-G detector installation has resumed
With COVID-19 lockdowns enforced earlier this year, the installation of the New Experiments With Spheres-Gas (NEWS-G) detector at SNOLAB was put on pause. The pieces needed to complete the installation had arrived from France in early 2020, and now, with restrictions relaxed, can be prepped and installed.
The first phase of the installation, chemical etching of the inner surface of the copper sphere (SNOGLOBE), was successfully completed. This is the second round of chemical etching, as the first attempt was found to be insufficient. 500µm of extremely pure copper was deposited on the interior surface of SNOGLOBE at Laboratoire Souterrain de Modane (LSM) in 2018, however a testing experiment at LSM in 2019 demonstrated the need for a second round of chemical etching. Chemical etching of SNOGLOBE is done with a solution of hydrogen peroxide and sulfuric acid.
The inner layer of SNOGLOBE is the only material that comes in contact with the gas used for the experiment. Therefore, all contaminants and impurities (especially of the radioactive variety) must be completely removed and nullified.