Status of the Design of the LBNE Neutrino Beamline

The Long Baseline Neutrino Experiment (LBNE) will utilize a neutrino beamline facility located at Fermilab to carry out a compelling research program in neutrino physics. The facility will aim a beam of neutrinos toward a detector placed at the Homestake Mine in South Dakota, about 1300 km away. The neutrinos are produced as follows: First, protons extracted from the MI-10 section of the Main Injector (60-120 GeV) hit a solid target above grade and produce mesons. Then, the charged mesons are focused by a set of focusing horns into a 200 m long decay pipe, towards the far detector. Finally, the mesons that enter the decay pipe decay into neutrinos. The parameters of the facility were determined taking into account several factors including the physics goals, the modelling of the facility, spacial and radiological constraints and the experience gained by operating the NuMI facility at Fermilab. The initial beam power is expected to be ∼700 kW, however some of the parameters were chosen to be able to deal with a beam power of 2.3 MW in order to enable the facility to run with an upgraded accelerator complex. We discuss here the status of the design and the associated challenges.