|Members of the NOvA crew put the final NOvA near-detector block into place in the Minos cavern. Photo: Cindy Arnold|
Since June, crews have been assembling the massive NOvA near detector in the Minos cavern, located 350 feet underground at Fermilab. On Friday, Jan. 10, the final 21,000-pound plastic block of that detector was put into place, signaling a significant milestone in what will be one of the largest and most sophisticated neutrino experiments in the world.
Construction of the near detector began in June, after the excavation of the NOvA cavern was completed in May. The detector consists of a muon catcher and eight PVC blocks standing 15 feet high and wide and about 6 feet deep. Each block was assembled at the CDF assembly building, driven to Minos on a truck and then carefully lowered down an open shaft to the cavern floor, where workers wheeled it into place.
In the coming months, the near detector will be filled with liquid scintillator and wired with the sensors needed to take neutrino data. It will weigh about 300 tons. Meanwhile, in northern Minnesota, construction is nearly complete on the 14,000-ton far detector, and the NOvA experiment is already receiving a beam of neutrinos from Fermilab’s Main Injector.