Internal conversion of valence shell electrons: Measurement and analysis for the 10.84 keV transition in206Bi

Abstract

Conversion electrons of the 10.84 keV transition in 2~were measured with the ironfree magnetic spectrometer. The conversion line of the valence shell was observed to be narrower than those of the inner ones. The computer program which optimizes the line profiles given numerically is outlined and used for the spectrum analysis. The studied transition was proved to be pure M1 with the nuclear structure parameter 2= 1.7_+0.7. The internal conversion coefficients were calculated using the relativistic Hartree-Fock model for neutral atoms as well as various isolated ions. Altogether, 15 different valence-shell configurations were considered. The prediction for the 6s2/2 configuration (Bi 3+) is in accord with the measured conversion intensities. This is consistent with probable chemical form Bi20 3 of bismuth atoms in the radioactive source.

Nuclear structure and chemical effects in internal conversion of the 35 keVM1+E2 transition in125Te

“…Within the quoted errors, no differences among the conversion intensities were observed between the Agt2SI and Cut2SI sources. When the spectra decompositions with the program DECOS 1 were completed, there appeared the code ACSEMP [4] in which the line shapes were expressed numerically. This approach seemed more…”

On the reliability of the theoretical internal conversion coefficients

“…The atom bound, for example, in a molecule certainly is not a free ion. In spite of this the ICC for free ions were calculated [36][37][38][39] (for 125 52 Te, 83 36 Kr, 206 83 Bi and 142 59 Pr, respectively) and it turned out that the experimental outer-shell ICC ratios lay within the range of theoretical values for reasonably ionized atoms. This gives us an argument to use the dispersion of ICC calculated for several ionic states as a measure of the uncertainty caused by the chemical bond.…”