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The leading-order Feynman diagrams for electron capture decay. An electron interacts with an up quark in the nucleus via a W boson to create a down quark and electron neutrino . Two diagrams comprise the leading (second) order, though as a virtual particle , the type (and charge) of the W-boson is indistinguishable.
Example of inner shell ionization edge (core loss) EELS data from La 0.7 Sr 0.3 MnO 3, acquired on a scanning transmission electron microscope. There are several basic flavors of EELS, primarily classified by the geometry and by the kinetic energy of the incident electrons (typically measured in kiloelectron-volts, or keV).
An electron spectrometer is a device used to perform different forms of electron spectroscopy and electron microscopy. This requires analyzing the energy of an incoming beam of electrons. Most electron spectrometers use a hemispherical electron energy analyzer in which the beam of electrons is bent with electric or magnetic fields. Higher ...
When an atom is probed by an external mechanism, such as a photon or a beam of electrons with energies in the range of several eV to 50 keV, a core state electron can be removed leaving behind a hole. As this is an unstable state, the core hole can be filled by an outer shell electron, whereby the electron moving to the lower energy level loses ...
Later, Richard Smalley modified the technique and used a UV laser to excite the sample, in order to measure the binding energy of electrons in gaseous molecular clusters. Angle-resolved photoemission spectroscopy (ARPES) has become the most prevalent electron spectroscopy in condensed matter physics after recent advances in energy and momentum ...
The wavelength of electrons is related to their kinetic energy via the de Broglie equation, which says that the wavelength is inversely proportional to the momentum. Taking into account relativistic effects (as in a TEM an electron's velocity is a substantial fraction of the speed of light, c [17]) the wavelength is
The sample must be illuminated on the same side of the imaging optics, i.e. through the objective lens, because samples are not transparent to low-energy electrons; In order to separate the incident and elastically scattered low energy electrons, scientists use magnetic “electron prism” beam separators which focus electrons both in and out ...
The investigation of short-lived radioactive nuclei (RI) by means of electron scattering has never been performed because of an inability to make these nuclei a target, [46] now with the advent of a novel self-confining RI technique at the world's first facility dedicated to the study of the structure of short-lived nuclei by electron ...