Discrepancies among theoretical and experimental internal conversion coefficients

Abstract

Abstract. A reported discrepancy of 3 ~o between experimental K conversion coefficients for E3 and M4 transitions and those calculated by Hager and Seltzer is reduced here to a level consistent with numerical errors by using RHFS wave functions with Rosen Lindgren exchange. We find that variation of the exchange term is insufficient to explain reported discrepancies among different calculations near threshold. Comparison of measured and calculated values near threshold indicates that present experimental data can not distinguish between the Hager and Seltzer values and those computed here.

TheK-shell conversion coefficient of the 135.5 keVM4 transition in193m Pt decay

“…The theoretical prediction of ~K by Hager [3], even though the accuracies in the individual experimental M4 cases [1,3,9] is not sufficient to select the most successful theory.…”

“…Campbell and Martin [3] more recently showed that these discrepancies can be reduced to 0.8 % for M4 transitions by using the Rosen-Lindgren exchange potentials instead of those of Kohn in the theoretical calculations of Hager and Seltzer. However, the number of precision measurements is insufficient to decide whether or not these discrepancies are functions of atomic number or of the transition energy, or both.…”

Internal conversion coefficients in the Hartree-Fock atomic model. Calculations and experiments for199Hg

“…iv) We conclude that the interpretation of the current nuclear spectroscopy measurements does not require the ICC calculated in the HF atomic model. This need not be necessarily true for the ICC near the threshold where the theoretical predictions differ substantially [23] and their discrepancies cannot be explained by the variation of the exchange term [24].…”

Intensity ratios ofL, M, N, O subshell conversion electrons inM3 andE4 transitions

“…Hager and Seltzer use the Kohn-Sham form of the Slater exchange potential [13]: two of the present authors show elsewhere [14] that use of the original Slater exchange or the more sophisticated Rosen-Lindgren exchange [13] affects ICCs significantly only at transition energies within a few keV of threshold and for high multipolarity. One higher order effect namely vacuum polarization, is included in the calculation but its influence on the ICCs is not explicitely stated.…”