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| A general representation of the total x-ray reflection fluorescence process is sketched out below. Numerous physical processes occur together and further details on these processes can be provided by clicking on the image map. As a general summary, it can be seen that incident photons impinge on a surface at a glancing angle and are totally externally reflected. This reflection creates standing waves on the surface and within the near surface layer due to constructive interference from the incoming and reflected wave. Core electrons from atoms can be excited by the evanescent wave, which then decays through the emission of auger electrons or fluorescence x-rays. Aside from the fluorescence, elastic and inelastic scattering occurs, along with Thomson scattering from gaseous atoms present in the chamber. Bremsstrahlung radiation is also emitted from the deceleration of the free core photoelectrons that penetrate the bulk. All of these process work together to create a background that increases the minimum detection limit (MDL) achievable in TXRF.
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