LASER PHOTOELECTRON SPECTROMETRY OF FE- - ELECTRON-AFFINITY OF IRON AND THE NON-STATISTICAL FINE-STRUCTURE DETACHMENT INTENSITIES AT 488-NM

With a fixed-frequency Arii laser (488 nm), the photoelectron spectrum of Fe- has been obtained. The electron affinity of iron is 0.164 0.035 eV. It has been found that the cross section for detachment of s electrons is much larger than that for detachment of d electrons at this wavelength. Also, the various fine-structure transitions do not occur in the (2J+1) (2J+1) statistical weighting of the neutral (J) and ion (J) spin-orbit states. An explanation for this result extends previous calculations, deriving explicit, usable expressions for fine-structure transition intensities, which are then found to agree with those observed experimentally. © 1979 The American Physical Society.