Two million gallons in the NOvA detector

Kyle Wood (left) and James Hoffman, both of the University of Minnesota, work to fill the 14-kiloton far detector with liquid scintillator. The crew just reached the 2-million-gallon mark, with 700,000 gallons to go. The far detector, which is being constructed in northern Minnesota, is scheduled to be completed next summer. Photo: William Miller, NOvA installation manager

The construction of the 14-kiloton NOvA far detector in Minnesota hit a major milestone this week: Collaboration members poured the 2 millionth gallon of scintillating oil into the detector.

The NOvA detector, when completed early next year, will stand 50 feet high, 50 feet wide and span more than 200 feet. It is constructed of PVC modules, each wired with light-sensing fiber-optic cable, and will be filled with a liquid scintillator. According to Deputy Project Manager Rick Tesarek, the liquid — which emits detectable light when charged particles interact with it — is cheaper by weight than solid plastic scintillator.

Workers are constructing the NOvA far detector near Ash River in Minnesota, just south of the Canadian border. The last of 28 plastic blocks is scheduled to be completed and placed by March, with all 2.7 million gallons of liquid scintillator poured by April and the final bank of electronics installed by June. The detector is already receiving neutrino beam from Fermilab’s particle accelerator complex, and the first detector modules are recording data.

Andre Salles

NOvA is on track to finish filling the detector with scintillator oil by spring.