Angular correlation betweenKandLx rays in tantalum

Angular correlations between $K$ and $L$ x rays in Ta obtained from the electron-capture decay of ${}_{}{}^{181}{}_{}{}^{}\mathrm{W}$ were measured using two different experimental systems. High-resolution Si(Li) x-ray detectors were used to detect $L$ x rays. $K$ x rays were detected with a high-resolution Ge(Li) spectrometer in one experiment and a NaI(T1) crystal in the other experiment. The adopted values for the $K{\alpha }_1-Ll$ $K{\alpha }_1-L{\alpha }_{1+2}$, and $K{\alpha }_1-L\beta$ cascades are $A_{22}=(24\mathrm{}\pm 3)\times {10}^{-2\mathrm{}}$, $A_{22}=(3.2\mathrm{}\pm 0.2)\times {10}^{-2\mathrm{}}$, and $A_{22}=(3.4\mathrm{}\pm 0.9)\times {10}^{-2\mathrm{}}$, respectively. The results for the $K{\alpha }_1-L\alpha$ cascade agree with theoretical predictions but the results for the $K{\alpha }_1-Ll$ and $K{\alpha }_1-L\beta$ cascade are slightly lower than predicted.