Precise measurement of αK and αT for the 109.3-keV M4 transition in

Abstract

We have measured the K-shell and total internal conversion coefficients (ICCs), αK and αT , for the 109.3-keV M 4 transition in 125 Te to be 185.0(40) and 350.0(38), respectively. Previously this transition's ICCs were considered to be anomalous, with measured values lying below calculated ones. When compared with Dirac-Fock calculations, our new results show good agreement. The αK result agrees well with the version of the theory that takes account of the K-shell atomic vacancy and disagrees with the one that does not. This is consistent with our conclusion drawn from a series of measurements on high multipolarity transitions.

Precise test of internal-conversion theory: αK measurements for transitions in nine nuclei spanning 45 ≤ Z ≤ 78

“…The former can thus be accounted for without seriously degrading the precision with which the latter can be extracted. The situation is quite similar for the case of 125 Te (Nica et al, 2017b).…”

Precise measurement of αK and αT for the 39.8-keV E3 transition in Nica1, Hardy2, Iacob3 et al. 2018Phys. Rev. CSelf Cite6000View full textAdd to dashboardCite

“…where P ec,K is the probability per parent decay for electron capture out of the atomic K shell; we take its value for this decay to be 0.8595 (10) based on a calculation with the LOGFT code available at the NNDC website [23]. Although the probability of K-capture determines the contribution of 103 Pd decay to the K x ray peak, it is the electron capture from all shells that determines the population of the 39.8-keV level.…”

“…In our analysis of the data, we followed the same methodology as we did with previous source measurements [1][2][3][4][5][6][7][8][9][10]. We first extracted areas for essentially all the x-and γ-ray peaks in the background-subtracted spectrum.…”

“…For over a decade we have been systematically measuring K-shell Internal Conversion Coefficients (ICCs) for E3 and M 4 transitions with a precision of ±2% or better [1][2][3][4][5][6][7][8][9][10]. Our goal throughout has been to test the accuracy of the calculated ICCs [11] and, in particular, we sought to distinguish between two versions of the theory, one that ignored the atomic vacancy left behind by the emitted electron, and another that took the vacancy into account.…”