Neutrino flux calculations for the ISIS spallation neutron facility

The neutrino flux produced by the spallation neutron source ISIS at the position of the KARMEN neutrino experiment is calculated to an accuracy of 6.7%. Contributions from the spallation and μSR targets to the νμ, νe, and ν ¯ μ fluxes, due to π+ and μ+ decay at rest, are evaluated. Results are presented in terms of neutrinos per proton for incident proton beams of 750 and 800 MeV. The contamination of ν ¯ e, from the π− decay-in-flight and μ− decay-at-rest chain, is found to be 0.06% with an accuracy of 12%.