Core-excited resonances widths

A = 5 Fig. 63. Phase shift analysis of the (pa) and (na) scattering experiments (Fig. 28) indicates that the ground and first excited states of these nuclei form an inverted doublet, Pij. These states are formed by addition of a -nucleon to the alpha particle core and if the -phase shifts are calculated from resonance theory (Adair ), the reduced widths obtained are near to the single particle value. There is no distinction in this case between LS and // coupling. The simplicity of the system suggests also a direct treatment in terms... 

Although valence band information could be acquired by conventional X-ray sources, analysis of the valence band region is not as simple as the core region, since all the components in the sample contribute in this narrow region (with E of 30 eV or less). Due to the broad line width of conventional X-ray sources and the low ionization cross section. X-ray-excited valence band spectroscopy is less commonly used for surface analysis. Instead, ultraviolet sources (e.g.. He I and He II) are adopted to acquire the valence band spectra, a surface technique called ultraviolet photoelectron spectroscopy (UPS). He I and He n resonance lines have inherently narrow widths of only a few meVs and high ionization cross sections in the valence band. This technique is widely used in the study of adsorption phenomena and valence band structure of metals, alloys, and semiconductors. Work functions can be derived from the Fermi level and the secondary electron (SE) cutoff of the UPS spectrum. 

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