Abstract
A description is given of measurements of the variation of sensitivity and reflection coefficient of the photocathode of an EMI 9558B photomultiplier with angle of the incident beam. They were made for three wavelengths, 0.69 μm, 0.56 μm, and 0.42 μm, and both p and s polarization states. Theoretical computations for each of the experimental measurements are given and compared with the experimental data.