The expansion of the University of Minnesota’s Soudan underground laboratory is now complete. Installation of the Main Injector Neutrino Oscillation Search (MINOS) far detector began in summer 2001. The Soudan laboratory is located 710 m underground in north-east Minnesota and also houses the Soudan 2 proton-decay detector and the Cold Dark Matter Search experiment (CDMSII), which is searching for weakly interacting massive particle candidates for dark matter.
The new MINOS far detector experimental hall at Soudan includes an upper-level gallery for first-hand observation of physics research by the public. The laboratory is located in a state park, which offers tours of the historic mine workings. Regularly scheduled public visits to the underground science facility will begin in summer 2002.
The MINOS far detector (to the rear of the photograph) is now about 25% complete. It is an octagonal magnetized-steel and plastic-scintillator cylinder 8 m in diameter, with a total design mass of 5400 tonnes. The assembly area for the far detector’s 484 planes can be seen in the foreground of the image.
A unique element of the Soudan laboratory is the 18 m long by 9 m high mural that is mounted on the wall opposite the public gallery. The mural depicts the artist Joseph Giannetti’s perception of neutrinos and neutrino science. The art work is now about half finished and completion is expected in time for the summer tours.