Long baseline neutrino beams at Fermilab

Fermilab has had a very active long baseline neutrino program since initiation of the NuMI project in 1998. Commissioned in 2005, the NuMI beam with 400 kW design power has been in operation for the MINOS neutrino oscillation program since that time. Upgrade of NuMI to 700 kW for NOvA is now well advanced, with implementation of the beam upgrades to be accomplished in 2012–2013. Design development for the next generation LBNE neutrino beam is now a major ongoing effort. We report here salient features and constraints for each of these beams, as well as significant challenges both experienced and expected.