Determination of relative intensities of M internal conversion lines in pure E2 transitions

Accurate measurements have been performed on the relative intensities of the M internal conversion lines of three pure E2 transitions in nuclei in the rare-earth region. The results are compared with theoretical values obtained from the calculations by Bhalla and by Hager and Seltzer. Discrepancies of about 6% between experiment and theory are reported for the M_I/M_II and M_I/M_III ratios of the 80.57 keV transition in ¹⁶⁶Er. The M_II/M_III ratios of the 84.26 keV transition in ¹⁷⁰Yb and of the 100.09 keV transition in ¹⁸²W are significantly lower than predicted by theory.