Search results
Results from the WOW.Com Content Network
In physics, electron emission is the ejection of an electron from the surface of matter, [1] or, in beta decay (β− decay), where a beta particle (a fast energetic electron or positron) is emitted from an atomic nucleus transforming the original nuclide to an isobar.
The photoelectric effect is the emission of electrons from a material caused by electromagnetic radiation such as ultraviolet light. Electrons emitted in this manner are called photoelectrons. The phenomenon is studied in condensed matter physics, solid state, and quantum chemistry to
In this regime, the combined effects of field-enhanced thermionic and field emission can be modeled by the Murphy-Good equation for thermo-field (T-F) emission. [35] At even higher fields, FN tunneling becomes the dominant electron emission mechanism, and the emitter operates in the so-called "cold field electron emission (CFE)" regime.
Notably, the effect can be either heating or cooling of the surface emitting the electrons, depending upon the energy at which they are supplied. [4] Above the Nottingham inversion temperature, the emission energy exceeds the Fermi energy of the electron supply and the emitted electron carries more energy away from the surface than is returned by the supply of a replacement electron, and the ...
Emission spectrum of a ceramic metal halide lamp. A demonstration of the 589 nm D 2 (left) and 590 nm D 1 (right) emission sodium D lines using a wick with salt water in a flame The emission spectrum of a chemical element or chemical compound is the spectrum of frequencies of electromagnetic radiation emitted due to electrons making a ...
Energy emission can occur when a moving electron is deflected by a charged particle, such as a proton. The deceleration of the electron results in the emission of Bremsstrahlung radiation. [115] An inelastic collision between a photon (light) and a solitary (free) electron is called Compton scattering.
However, meaningful investigations had to wait until after J.J. Thomson's [3] identification of the electron in 1897, and until after it was understood – from thermal emission [4] and photo-emission [5] work – that electrons could be emitted from inside metals (rather than from surface-adsorbed gas molecules), and that – in the absence of ...
The term −eϕ is the energy of an electron at rest in the vacuum nearby the surface. Plot of electron energy levels against position, in a gold-vacuum-aluminium system. The two metals depicted here are in complete thermodynamic equilibrium. However, the vacuum electrostatic potential ϕ is not flat due to a difference in work function.