Operational properties of photomultiplier tubes in the MiniBooNE experiment

Photomultiplier tubes are the main detector component for many neutrino physics experiments. A signal\´s position and angle relative to a photomultiplier tube\´s axis can affect tube performance; understanding this effect is important for analyzing and modeling tube behavior in large neutrino detectors. Collaborators on the MiniBooNE experiment at Fermilab developed a light-tight test enclosure to measure photomultiplier output as signal position and angle were varied. Results show a decrease in "signal visibility," or relative quantum efficiency, of roughly 15%.