Tests of photocathode quantum efficiencies using Cherenkov radiation of electrons from 90Sr (original) (raw)

Cherenkov photons emitted by electrons from a 90 Sr source in NaF and quartz radiators, have been measured with Philips photomultipliers XP2020 and XP2020Q. On a logarithmic scale the pulse height distribution is linear, with the slope sensitive to the absolute value of the photocathode quantum efficiency integrated over wavelength . The agreement between measured and simulated pulse height distributions confirms the validity of the simulation procedure as well as the input data taken from the literature . For the XP2020Q photomultiplier our results support the data of Dorenbos and de Haas, who found that the quantum efficiency below 250 run is higher than stated by the manufacturer.