The Continuous Gamma-Ray Spectrum Accompanying Beta-Decay

Abstract

The spectral distribution and absolute intensity of the internal bremsstrahlung emitted in beta-decay was investigated in ${\mathrm{P}}^{32}$, ${\mathrm{Y}}^{91}$, and RaE. The gamma-radiation was detected by means of a NaI(Tl) crystal, phototube, linear amplifier and one-channel discriminator. Care was taken to avoid spurious effects, and corrections were made for several factors. Both the spectral distributions and the absolute intensities of the continua are in excellent agreement with theoretical predictions. The differences in the spectra due to allowed or forbidden types of the beta-transition and to different forms of interaction are too small to be detected in these experiments. Observations on the angular correlation of the internal bremsstrahlung of beta-emitters and on the internal bremsstrahlung emitted in $K$ capture are also reported.