Design study of pion and muon beam transport line for MOMENT

摘要

A MuOn-decay Medium-baseline NeuTrino beam facility (MOMENT) was proposed for the leptonic CP violation determination and other potential neutrino physics by offering extremely high flux neutrinos decayed from muons without cooling and acceleration. The huge transverse and large momentum acceptances are needed for the secondary beamline of MOMENT and the beam dynamics has been studied in detail. The whole beamline based on large-aperture superconducting solenoids is composed of several sections: charge selection section, pion decay channel, bending section, adiabatic taper and muon decay channel. To improve particles transmission and neutrino flux while maintaining low background at the far detector of 150 km, the curved solenoids with additional vertical dipole field are applied in the charge selection and bending sections. The adiabatic parameter changes between the sections are also adopted to enhance the neutrino flux. The endto-end simulations have been carried out and the muon antineutrino flux at the far detector can reach 4.1x10(11)/m(2)/year with a low background of unwanted neutrino species.