Precise Test of Internal-Conversion Theory: alpha_K Measurements for Transitions in Nine Nuclei Spanning Z values from 45 to 78

TL;DR

This study precisely tests internal-conversion theory by measuring alpha_K values across nine nuclei, confirming the accuracy of Dirac-Fock calculations that include vacancy effects in electron wave functions.

Contribution

The paper provides high-precision measurements of alpha_K values for various nuclei, supporting the validity of Dirac-Fock calculations with vacancy considerations in internal-conversion theory.

Findings

Results favor Dirac-Fock calculations with vacancy effects

Measurements span a wide range of nuclei and Z values

Precision better than +/-2% in alpha_K measurements

Abstract

We have been testing the theory used to calculate internal-conversion coefficients (ICCs) by making a series of measurements of alpha_K values with precision better than +/-2%. So far we have measured E3 transitions in three nuclei, 103Rh, 111Cd and 134Cs; and M4 transitions in six nuclei, 119Sn, 125Te, 127Te, 137Ba, 193Ir and 197Pt. Together, these span a wide range of A and Z values. In all cases, the results strongly favor Dirac-Fock calculations in which the final-state electron wave function has been computed in an atomic field that includes the vacancy created by the internal-conversion process.