K and L X-Ray Intensities in Cesium-131 Decay
1955; American Institute of Physics; Volume: 98; Issue: 5 Linguagem: Inglês
10.1103/physrev.98.1293
ISSN1536-6065
Autores Tópico(s)X-ray Spectroscopy and Fluorescence Analysis
ResumoA measurement of the relative intensities of the $K$ and $L$ x-rays following electron-capture in ${\mathrm{Cs}}^{131}$ is reported. The result may be expressed $[\frac{{L}_{\mathrm{I}}}{K}+\frac{{K}_{\mathrm{I}\mathrm{I},\mathrm{I}\mathrm{I}\mathrm{I}}}{K}+n]{\overline{\ensuremath{\omega}}}_{L}=0.106\ifmmode\pm\else\textpm\fi{}0.008$, where $\frac{{L}_{i}}{K}$ is the ratio of ${L}_{i}$-shell capture to $K$-shell capture, $n$ is the probability of an $L$-ionization following a $K$-vacancy, and ${\overline{\ensuremath{\omega}}}_{L}$ is the mean $L$-fluorescence yield of xenon. Upon combining this with recent theoretical results on electron-capture, the mean value of the $L$-fluorescence yield of xenon is found to be ${0.10}_{3}$\ifmmode\pm\else\textpm\fi{}0.01. This value is suggested as a normalization point for the relative photographic values of ${\overline{\ensuremath{\omega}}}_{L}$ in the region $Z=54$.In order to explain the observed anomalies in inner bremsstrahlung spectra of electron-capture on the basis of $p$-electron capture, one must conclude that ${L}_{\mathrm{II}}$-capture is considerably more radiative than ${L}_{\mathrm{I}}$-capture, and, furthermore, that the probability of radiative capture increases more strongly with $Z$ for ${L}_{\mathrm{II}}$-capture than for ${L}_{\mathrm{I}}$-capture.Traces of 6.2-day ${\mathrm{Cs}}^{132}$ and 13.6-day ${\mathrm{Cs}}^{136}$ were found in the first cesium fraction from pile-irradiated barium nitrate, presumably induced by ($n, p$) reactions.
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