Soft X-ray appearance potential

Soft X-ray appearance potential spectroscopy. Another name for APXPS. 

Soft X-ray appearance potential spectroscopy (SXAPS) studies of radiant coil alloys were carried out to determine surface compositions resulting from exposure to a range of environments. 

Figures. Simplified schematic of the soft X-ray appearance potential spectrometer. S is the sample and F is the filament. Signal is extracted by the potential modulation technique.

Figure 3 The soft X-ray appearance potential spectrometer. S, sample F, filament E, collector electrode D, X-ray detector G, grid R, reference signal L, induction coil C, condenser.

Park RL, Houston JE, and Schreiner DG (1970) A soft X-ray appearance potential spectrometer for the analysis of solid surfaces. Review of Scientific Instrumentation 41 1810-1812. 

Chopra, D.R., and G. Martin, 1982, Study of M4 5-level soft X-ray appearance potential of selected rare earths, in The Rare Earths in Modern Science and Technology, Vol. 3, eds B.M. McCarthy, H.B. Silber and J.J. Rhyne (Plenum, New York) p. 131. 

Soft X-Ray Appearance Potential Spectroscopy. In SXAPS the X-ray photons emitted by the sample are detected, normally by letting them strike a photosensitive surface from which photoelectrons are collected, but also— with the advent of X-ray detectors of increased sensitivity— by direct detection. Above the X-ray emission threshold from a particular core level the excitation probability is a function of the densities of unoccupied electronic states. Since two electrons are involved, the incident and the excited, the shape of the spectral structure is proportional to the self-convolution of the unoccupied state densities. 

Surface resonance Raman spectroscopy Surface Raman spectroscopy specular reflectance speetroscopy Scanning tunneling microscope Sinface-unenhanced Raman spectroscopy Soft X-ray appearance potential spectroscopy Soft X-ray emission spectroscopy Thermodesorption mass spectroscopy Thermal energy atom scattering Third harmonic generation Thin layer cell... 

---