Beam optics and target conceptual designs for the NuMI project

Abstract A summary is presented of the conceptual design of the focusing system for the Neutrinos at the Main Injector (NuMI) beamline at Fermilab. The 120 GeV primary proton beam with intensity of 4×10 13 protons per 1.9 s from the Main Injector will be used to produce pions in a graphite target. Two 200 kA pulsed horns will be used to magnetically focus the resulting pion beam down a drift space where pions will decay to muon-neutrinos. The MINOS experiment will use the neutrino beam together with two detectors, one located on the Fermilab site and the other 735 km away in the Soudan mine in Minnesota, to study neutrino oscillation phenomena. Several neutrino beam optics configurations and target designs have been studied with the goal of producing a facility with high efficiency while retaining flexibility.