Resonant Behaviour of X‐Ray Intensities in Metallic Nickel Near the 2p Threshold

The Lα and Lβ lines of metallic nickel and the X‐ray isochromats recorded at quantum energies in the vicinity of these lines are reported. An X‐ray spectrum with constant energy of the final state (XCEF) is defined and yields resonance‐like intensity variations of the bremsstrahlung similar to the rare earth metals. The energy dependence of the resonances is in qualitative agreement with the model of Wendin and Nuroh showing the importance of transitions involving normally empty localised d‐states.