Direct Detection of theK-Shell Perturbation Caused by the Static Nuclear Quadrupole Moment

It was found that $K$ x rays accompanying $K$ conversion of retarded 177-keV (predominantly $M1\mathrm{}$) transitions from the 316-keV ($T_{\frac{1}{2}}=0.66\mathrm{}$ μsec) nuclear state of highly deformed ${}_{}{}^{169}{}_{}{}^{}\mathrm{Tm}$ have small anisotropic angular distributions with respect to the direction of $\gamma$ radiations emitted subsequent to $K$ conversion. The result is explained as a first-order effect of the static quadrupole moment of the nucleus on the $K$-shell electron wave function.