L-shell Coster-Kronig transition probabilities in Ni, Cu, and Mo measured with synchrotron radiation

A recent technique, based on differential subshell ionization by tuned synchrotron radiation, has been applied to measurements of L-subshell Coster-Kronig yields of Ni, Cu, and Mo from ${\mathit{L}}_2$ and ${\mathit{L}}_3$ Auger spectra. Results for Ni are ${\mathit{f}}_{23}$=0.6+0.2, ${\mathit{f}}_{12}$=0.4+0.2, and ${\mathit{f}}_{13}$=0.5+0.2; for Cu, ${\mathit{f}}_{23}$=0.8+0.1, ${\mathit{f}}_{12}$=0.44+0.06, and ${\mathit{f}}_{13}$=0.3+0.2; for Mo, ${\mathit{f}}_{23}$=0.15+0.02, ${\mathit{f}}_{12}$=0.15+0.02, and ${\mathit{f}}_{13}$=0.61+0.06. Measured transition probabilities are compared with previously available information. The results are generally consistent with the body of theoretical and experimental data. For Ni and Cu, the present measurements of ${\mathit{f}}_{23}$ confirm that the ${\mathit{L}}_2$-${\mathit{L}}_3$ ${\mathit{M}}_{4,5}$ Coster-Kronig channel is accessible in the metals, even though it is energetically cut off in free atoms. Further improvements in synchrotron-radiation sources are likely to make it possible to throw light on several critical questions by means of the present method.