On the accuracy of L subshell ionization cross sections. II. Coster-Kronig transition probabilities

Complete text of publication follows. Recently the experimental data on the fluorescence yields and Coster-Kronig probabilities were reviewed and recommended values were adopted. Since they are widely used in nuclear and atomic physics, beside their vital importance in x-ray based analytical methods, it is perhaps justifiable to check the internal consistency of the data. The L1 subshell fluorescence yield (ω1) is the ratio of X-ray rate (X) to the total decay rate. The total decay rate is the sum of radiate (X) and non radiate yields. The non radiate yields can be separated to Coster-Kronig rates (f12+f13) and the non Coster-Kronig Auger rates (A). The f12 and f13 rates are the L1 to L2 and L1 to L3 Coster-Kronig transition rates. Therefore ω1 can be expressed as ω1=X/(X+A+f12+f13). For the Z>70 atomic number range probably the sum of f12 and f13 is above 50%, and can reach 80% therefore, it can be considered as the dominant process. At certain Z numbers around Z=75 the L1- L3M5 Coster-Kronig transitions become energetically allowed, and the probability will have a jump to a higher value from about 50% to 70%. A second jump when the L1- L3M4 Coster-Kronig transitions become energetically allowed is expected around Z=78. Since X and A do not have jumps, and are rather smooth functions of Z, therefore when f13 jumps upwards, we would expect a drop in the ω1 value. The data from is plotted in fig. 1. The theoretical Dirac Hartree Slater values represented by symbols filled with black, while the experimental values from are presented with symbols filled with white. The f12+f13 values are denoted by circle, while the omega1 values with squares. The theoretical values pass the simple expectations. When the DHS (f12+f13) jumps at Z=75 omega1 drops. If we increase the denominator, the ratio should decrease. Similarly at Z=78, the upward jump in the denominator, coincides with the drop in the ratio. The experimental data do not follow such a trend, and remained to be explained. It should be noted, that the experimental data is from a very extensive review, therefore could be considered as the experimental data either need to be explained or had to be accepted that there is a methodological problem. (author)