The CNGS underground structures

The protons supplied by the SPS will travel along a transfer line some 800 metres in length before entering a 125-m long target chamber, where they will bombard a graphite target. This process will produce pions and kaons, which will decay into muons and muon neutrinos inside the 1000-metre decay tube. The neutrinos will then commence their 730-km journey through the earth's crust to the detectors at the Gran Sasso Laboratory.