Parameterisation of the angular response of the R1408 Hamamatsu eight-inch photomultiplier tube to be used in the Sudbury Neutrino Observatory

This paper describes measurements made on Hamamatsu R1408 8-in. photomultiplier tubes in order to parameterise the cesium bialkali photocathode in terms of a complex refractive index ñ and a thickness τ. The extracted parameters have been used to predict the angular response of the photomultiplier tubes, and this prediction has been experimentally verified. Measurements were taken on a number of photomultiplier tubes from the start and end of a 10 000 photomultiplier tube production run to investigate any systematic drift in parameterisation.