An Absolute Measurement of Cherenkov Emission by Relativistic Muons in Pure Water

Abstract

Relativistic cosmic ray muons passing through triple distilled water have been used to examine the absolute number of Cherenkov photons emitted between 250 and 650 nm. It is shown that almost all of the theoretically predicted photon number can be experimentally accounted for, provided that the apparatus is specifically designed to minimize losses due to reflection, absorption and coupling. It is noted that significant corrections need to be made for internal photomultiplier tube effects.