Design Study for a Future Laguna-LBNO Long-Baseline Neutrino Facility at CERN

The Large Apparatus studying Grand Unification and Neutrino Astrophysics (LAGUNA) study [1] investigated seven pre-selected underground sites in Europe (Finland, France, Italy, Poland, Romania, Spain and UK), capable of housing large volume detectors for terrestrial, accelerator generated and astrophysical neutrino research. The study was focused on geo-technical assessment of the sites, concluding that no show-stoppers exist for the construction of the required large underground caverns in the chosen sites. The LAGUNA-LBNO FP7/EC-funded design study extends the LAGUNA study in two key aspects: the detailed engineering of detector construction and operation, and the study of a long-baseline neutrino beam from CERN, and possibly other accelerator centres in Europe. Based on the findings of the LAGUNA study, the Pyh¨asalmi mine in Finland is chosen as prime site for the far detector location. The mine offers the deepest underground location in Europe (-1400 m) and a baseline of 2’300 km from CERN (Fig. 1). Two large caverns for LArgon (2 50 kt) and magnetised detectors are foreseen, and a third large cavern housing a 50 kt Liquid Scintillator detector is also planned.