A measurement of the neutrino flux from a stopped-pion source

Using an instrumented proton beam stop, consisting of copper, lead, and water, the distribution and number of stopped π+ per incident proton was measured for proton energies of 716, 766, and 797 MeV. The decay sequence of stopped pions and muons produce a well defined spectrum of νe, νμ and anti νμ. The present experiment determines the neutrino production from stopped π+ decay by measuring the ratio of stopping pions per incident proton to an uncertainty of 8%. (orig.)