FEU-49 photomultiplier sensitivity to Cherenkov radiation

With the aim of verifying the possibility of applying the FEU-19 photomultiplier in large installations for recording the Cherenkov radiation in water, the quantum sensitivity of four specimens of FEU-49 has been measured. The measurements are carried out at a maximum thickness of a distilled water layer equal to 4 cm. The Cherenkov radiation has been produced in water by cosmic muons. Presented are flowsheets used for measuring quantum efficiency of the FEU-49 photocathode and dispersion of its amplification coefficient. By comparing the results of measurements performed with the calculated estimates, a conclusion has been drawn on their good agreements and on suitability of FEU-49 for recording the Cherenkov radiation in water