The $\frac{K{\beta }_3}{K{\beta }_1}$ transition probabilities have been measured for the following elements: ${}_{49}{}^{}{}_{}{}^{}\mathrm{In}$, ${}_{50}{}^{}{}_{}{}^{}\mathrm{Sn}$, ${}_{52}{}^{}{}_{}{}^{}\mathrm{Te}$, ${}_{58}{}^{}{}_{}{}^{}\mathrm{Ce}$, ${}_{65}{}^{}{}_{}{}^{}\mathrm{Tb}$, ${}_{73}{}^{}{}_{}{}^{}\mathrm{Ta}$, ${}_{75}{}^{}{}_{}{}^{}\mathrm{Re}$, ${}_{79}{}^{}{}_{}{}^{}\mathrm{Au}$, ${}_{82}{}^{}{}_{}{}^{}\mathrm{Pb}$, ${}_{90}{}^{}{}_{}{}^{}\mathrm{Th}$, ${}_{92}{}^{}{}_{}{}^{}\mathrm{U}$, ${}_{93}{}^{}{}_{}{}^{}\mathrm{Np}$, ${}_{94}{}^{}{}_{}{}^{}\mathrm{Pu}$, and ${}_{95}{}^{}{}_{}{}^{}\mathrm{Am}$. This has been accomplished using a spectrometer with a bent quartz crystal in conjunction with a Ge(Li) detector. The measured transition probabilities for elements of medium atomic numbers are in good agreement with calculations based on the relativistic Hartree-Slater potential, while in the region of high atomic number the measured values seem to favor theoretical values obtained assuming a Coulomb potential with the electron screening effect prescribed by Burns.

• Received 27 October 1969

DOI:https://doi.org/10.1103/PhysRevA.1.1563