LKX-Ray Intensity Ratio in the Decay ofTl204andL-Shell Florescence Yields of Hg

Abstract

The Hg $\frac{L}{K}$ x-ray intensity ratio in the decay of ${\mathrm{Tl}}^{204}$ has been determined with proportional and scintillation counters, using Ag $K$ x rays for intercomparison of detector efficiencies. Beta rays were stopped before they entered the detectors. The shape of the bremsstrahlung spectrum under the x-ray peaks was determined with ${\mathrm{Cl}}^{36}$ beta rays. The result is $\frac{I_L}{I_K}=0.52\mathrm{}\pm 0.02$. The mean $L$ fluorescence yield of Hg following electron-capture decay of ${\mathrm{Tl}}^{204}$ then is ${\overline{\omega }}_L=0.40\mathrm{}\pm 0.05$, if the $\frac{L}{K}$ capture ratio is 0.42 as measured by Joshi and by Leutz and Ziegler. The partial $L$-shell fluorescence yield of Hg following $K_{\alpha }$ x-ray emission was measured as ${\omega }_{\mathrm{KL}}=0.41\mathrm{}\pm 0.02$ from $K$ and $L$ x-ray coincidences. The partial $L$-shell fluorescence yield of Hg following $L$ capture only of ${\mathrm{Tl}}^{204}$ is ${\omega }_{\mathrm{LL}}=0.39\mathrm{}\pm 0.06$, as determined by the same method.