Precise measurement of K-shell fluorescence yield in iridium: An improved test of internal-conversion theory
Abstract
We have measured the total intensity of K x rays relative to 129.4-keV gamma rays from decay of the second excited state in Ir-191. This (M1+E2) transition was observed following the beta decay of 15.4-d Os-191. Our measured ratio yields the result alpha(K)omega(K)=2.044(11). When combined with a recent measurement of the same ratio for the 80.2-keV M4 transition from Ir-193(m), this result strongly confirms the need for the K-shell hole to be included in calculations of internal-conversion coefficients alpha(K). Since the alpha(K) value calculated for the Ir-191 transition is virtually independent of the hole treatment, our result also yields a model-independent value for the iridium fluorescence yield, omega(K)=0.954(9).
Description
Journals published by the American Physical Society can be found at http://publish.aps.org/Subject
MONTE-CARLO CALCULATIONSEFFICIENCY CALIBRATION
HPGE DETECTOR
COEFFICIENTS
TRANSITIONS
IR191
Physics