[en] Recently we measured the ratio of K-shell internal conversion coefficients, α_K, for the 127.5-keV E3 transition in ¹³⁴Cs and the 661.7-keV M4 transition in ¹³⁷Ba. We here report a measurement of the 165.9-keV M1 transition in ¹³⁹La, based on which we convert our earlier ratio measurement into individual α_K values for the transitions in ¹³⁴Cs and ¹³⁷Ba. These results continue to confirm the Dirac-Fock calculations of internal conversion coefficients that incorporate the atomic K-shell vacancy

[en] We have measured the K-shell internal conversion coefficient, α_K, for the 346.5-keV M4 transition in ¹⁹⁷Pt to be 4.23(7). This result differs from a previous value, which disagreed significantly from theory. Our new value agrees well with Dirac-Fock calculations and removes the earlier discrepancy as a source of concern.

[en] Using the 165.9-keV M1 transition in ¹³⁹La as a calibrant, we have determined the K-shell internal conversion coefficients (ICCs) for the 127.5-keV E3 transition in ¹³⁴Cs and the 661.7-keV M4 transition in ¹³⁷Ba to 0.6% precision. Unlike previous less-precise measurements of these ICCs, which differed significantly from calculated values, our results agree well with calculations that include the atomic K-shell vacancy and disagree with those that exclude it. These results, which are consistent with what we also found for ¹⁹³Ir, confirm our earlier conclusions but for different energies, multipolarities and atomic numbers