THEORETICAL DESCRIPTION OF SPIN-RESOLVED APPEARANCE-POTENTIAL SPECTROSCOPY

A theoretical description of spin-resolved appearance potential spectr oscopy is presented on the basis of a single-particle description of t he underlying electronic structure. The final expression for the signa l intensity turns out to be essentially a cross-section-weighted self- convolution of the density of states above the Fermi energy, in close analogy to the result for core-valence-valence Auger electron spectros copy. Application of the formalism presented to bce Fe and fee Ni lead s to results in very satisfying agreement with corresponding experimen tal data. Because this is achieved only by treating the involved trans ition matrix elements in a proper way, their properties are discussed in some detail.