Angular correlation of K-L x-ray cascades in gadolinium.

Abstract

Angular correlation parameters (${\mathit{A}}_{22}$) between the K${\mathrm{\ensuremath{\alpha}}}_{1}$ and ${\mathit{L}}_{3}$ x rays were measured for gadolinium in the electron-capture decay of the isotope $^{157}\mathrm{Tb}$. The results are ${\mathit{A}}_{22}$(K${\mathrm{\ensuremath{\alpha}}}_{1\mathrm{\ensuremath{-}}}$Ll)=0.272\ifmmode\pm\else\textpm\fi{}0.042, ${\mathit{A}}_{22}$(K${\mathrm{\ensuremath{\alpha}}}_{1\mathrm{\ensuremath{-}}}$L\ensuremath{\alpha})=0.032\ifmmode\pm\else\textpm\fi{}0.015, ${\mathit{A}}_{22}$(K${\mathrm{\ensuremath{\alpha}}}_{1\mathrm{\ensuremath{-}}}$L${\mathrm{\ensuremath{\beta}}}_{2,15}$)=0.061\ifmmode\pm\else\textpm\fi{}0.018. These values are in very good agreement with the theoretical calculations of Scofield [Lawrence Livermore Laboratory Report No. UCRL 51231, 1972 (unpublished)]; however, they differ from the earlier experimental data for the K${\mathrm{\ensuremath{\alpha}}}_{1\mathrm{\ensuremath{-}}}$Ll cascade in the 60Z70 atomic-number region.