A Comparison of Photon Counting and Current Measuring Techniques in Spectrophotometry of Faint Sources

Abstract

The component of dark noise produced by Cerenkov pulses in photomultipliers due to cosmic ray mu mesons is discussed. It is shown by integration of pulse height spectra that this source of noise can be the limiting factor in de measuring spectrophotometry of faint astronomical sources. Direct current methods of photometry are compared with photon counting, and the advantage of photon counting is demonstrated under various operating conditions.