Inner Bremsstrahlung ofCs131

Abstract

The continuous gamma-ray spectrum (inner bremsstrahlung), accompanying orbital electron capture in ${\mathrm{Cs}}^{131}$, has been observed by the method of scintillation spectrometry. The absolute intensity of the gamma radiation has been measured and compared with the total disintegration rate. The end point of the gammaray distribution was found to be 320±10 kev. The experimentally determined shape of the spectrum, as well as the intensity of the continuum, is compared with theoretical calculations. The disagreement exceeds considerably that which might be expected from a consideration of the probable errors of the observations. The growth of the 12-day isomer of ${\mathrm{Xe}}^{131}$ was not detected.