STRAW-Strings for Absorption Length in Water Pathfinder for a Potential New Neutrino Telescope Site in the Pacific Ocean

STRAW-STRings for Absorption Length in Water is a project aimed at investigating the optical properties (scattering and absorption length, in particular) of the deep-sea water at Cascadia Basin (British Columbia, Canada). This is the first step of a broader feasibility study for a future large-scale neutrino telescope in the Pacific Ocean. Two strings equipped with 5 modules for light detection (sDOM-Straw Digital Optical Module) and 3 modules for light emission (POCAM-Precision Optical CAlibration Module) have been deployed in June 2018 and connected to the deep-sea infrastructure of Ocean Networks Canada (ONC). The work has covered the process of designing, building and calibrating of the sDOM and the POCAM (already deployed with success in GVD-Baikal in March 2017). An accurate description of the system follows, with special focus on the used technologies and on preliminary results of data-taking.