Relative Scintillation Intensity of Some Cerenkov Counter Media

Selected transparent media were bombarded with the 40 mev alpha particle beam from the 60-inch cyclotron. The ratio of the photomultiplier output current to the alpha particle beam current was taken as a measure of the relative scintillation intensity. The output current from an RCA type 6342 photomultiplier was read on a 50 microampere (full scale) meter. The alpha particle beam current was monitored by counting alpha particles elastically scattered from a 0.005-inch gold foil. Preliminary results on the light output from some media relative to that for distilled water are tabulated in Table I. Background appeared to give negligible contribution to the scintillation intensity. The background measurement was made by stopping the alpha beam with a 1/16-inch aluminum plate inserted ahead of the substance studied.