EUROnu Super Beam Studies

摘要

An optimization of the CERN SPL neutrino beam line has been performed guided by the idea of employing a graphite target. The interactions of protons of kinetic energies of 2.2, 3.5, 4.5 and 8 GeV/c~2 on a cylindrical 1.5 cm diameter carbon target have been simulated with FLUKA2008.3. Energy deposition and particle yields with mercury and carbon have been compared using for both materials a target lenght corresponding to about two hadronic interaction lengths. Power deposition and neutron fluxes are suppressed to a large extent with carbon. The transportation and decay of secondary mesons was done with GEANT3 in order to calculate the neutrino fluxes. Sensitivities were calculated with GLoBES assuming a beam power of 4 MW (HP-SPL) and a 440 ktons water Cherenkov detector (MEMPHYS) located at 130 km from the target in a new foreseen Frejus laboratory. The obtained sensitivities with the carbon target are comparable to the ones achieved with the mercury target. The full simulation has been recently rewritten using GEANT4 which allows a higher degree of flexibility for arranging the horn geometries. A detailed comparison of the algorithms has been done and a good agreement is found for the final neutrino fluxes. A preliminary comparison of the sensitivities to sin~2 2θ_(13) and CP violation with an optimized horn are also presented.