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XPS requires high vacuum (residual gas pressure p ~ 10 −6 Pa) or ultra-high vacuum (p < 10 −7 Pa) conditions, although a current area of development is ambient-pressure XPS, in which samples are analyzed at pressures of a few tens of millibar. When laboratory X-ray sources are used, XPS easily detects all elements except hydrogen and helium.
Electron spectroscopy refers to a group formed by techniques based on the analysis of the energies of emitted electrons such as photoelectrons and Auger electrons.This group includes X-ray photoelectron spectroscopy (XPS), which also known as Electron Spectroscopy for Chemical Analysis (ESCA), Electron energy loss spectroscopy (EELS), Ultraviolet photoelectron spectroscopy (UPS), and Auger ...
Three regions of XAS data. Extended X-ray absorption fine structure (EXAFS), along with X-ray absorption near edge structure (), is a subset of X-ray absorption spectroscopy ().
Extreme-ultraviolet photoelectron spectroscopy (EUPS) lies in between XPS and UPS. It is typically used to assess the valence band structure. [8] Compared to XPS, it gives better energy resolution, and compared to UPS, the ejected electrons are faster, resulting in less space charge and mitigated final state effects. [9] [10] [11]
Principle of EDS. The excess energy of the electron that migrates to an inner shell to fill the newly created hole can do more than emit an X-ray. [3] Often, instead of X-ray emission, the excess energy is transferred to a third electron from a further outer shell, prompting its ejection.
In principle, the lightest element that can be analysed is beryllium (Z = 4), but due to instrumental limitations and low X-ray yields for the light elements, it is often difficult to quantify elements lighter than sodium (Z = 11), unless background corrections and very comprehensive inter-element corrections are made.
X-ray absorption near edge structure (XANES), also known as near edge X-ray absorption fine structure (NEXAFS), is a type of absorption spectroscopy that indicates the features in the X-ray absorption spectra of condensed matter due to the photoabsorption cross section for electronic transitions from an atomic core level to final states in the energy region of 50–100 eV above the selected ...
The U.S. management did not want the laboratory to be converted to a manufacturing unit so it decided to set up a commercial unit to further develop the X-ray instrumentation market. In 1953 Norelco Electronics was established in Mount Vernon, NY, dedicated to the sale and support of X-ray instrumentation.