Theory

beam interactions automated mineralogy utilizes information from the characteristic and background x ray emissions resulting from either an electron beam or x ray beam interactions with the specimen the bremsstrahlung and characteristic x rays contain information and can be used in mappings the image data collected from either backscattered or secondary electrons can also be useful in matching unknown mineral areas to known mineral or material definitions continuum or bremsstrahlung (braking radiation) results from the deceleration of beam electrons in the electromagnetic field of the atom core combined with energy loss and the creation of an x ray with the same energy characteristic x rays are formed by the excitation of inner shell electrons inner shell electron is ejected, and an outer shell electron replaces it the energy difference is released as an x ray x rays are characteristic because their specific energies are characteristic of the excited element moseley’s law defines the relationship between the x ray lines and the atomic number of the emitted atom xrf vs eds diffrent excitation profiles excitation probability for photons (x ray source) is different than for electrons (sem) excitation, with photons significantly more sensitive for heavier elements eds is more appropriate for light elements, while xrf excels at trace elements however, x ray sources provide information from depth in the specimen, while e beam sources are mostly surface measurements this can be advantageous and complicated for automated mineralogy conducted with x ray sources e