L‐shell Coster–Kronig yields for Pb

The f 13 Coster–Kronig yield for Pb was determined as 0.60±0.03 using measured intensities of the Lα x‐rays emitted following selective ionization in the L 3 sub‐shell by the Rb K x‐rays ( B   L   3< E inc. < B   L   2) and of those emitted following ionization in the L i ( i = 1, 2, 3) sub‐shells by 59.54 keV γ‐rays ( B   L   1< E inc. < B K ), B K and B   L   ibeing the K shell and L i sub‐shell ionization thresholds of Pb, respectively. The measurements were performed using a 241 Am annular source in direct excitation mode and in secondary excitation mode along with an RbNO 3 secondary exciter as photon sources and an Si(Li) detector. Measurements of the f 12 and f 23 Coster–Kronig yields using similar experimental set‐ups are also discussed. It is concluded that the f 12 and f 23 Coster–Kronig yields for 12 elements with 59 ≤ Z ≤ 90 measured by Oz et al. using a similar experimental set‐up are not reliable. Copyright © 2002 John Wiley & Sons, Ltd.