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Samson4
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Can it be done with technology available today? How would you begin to formulate the forces needed? I am assuming the work function is needed.
Samson4 said:Can it be done with technology available today? How would you begin to formulate the forces needed? I am assuming the work function is needed.
DaveThermionic emission is the thermally induced flow of charge carriers from a surface or over a potential-energy barrier. This occurs because the thermal energy given to the carrier overcomes the work function of the material. The charge carriers can be electrons or ions, and in older literature are sometimes referred to as "thermions". After emission, a charge that is equal in magnitude and opposite in sign to the total charge emitted is initially left behind in the emitting region. But if the emitter is connected to a battery, the charge left behind is neutralized by charge supplied by the battery as the emitted charge carriers move away from the emitter, and finally the emitter will be in the same state as it was before emission.
The classical example of thermionic emission is the emission of electrons from a hot cathode into a vacuum (also known as thermal electron emission or the Edison effect) in a vacuum tube. The hot cathode can be a metal filament, a coated metal filament, or a separate structure of metal or carbides or borides of transition metals. Vacuum emission from metals tends to become significant only for temperatures over 1,000 K (730 °C; 1,340 °F).
Samson4 said:Then why does thermionic emission happen before melting points?
And it contains field emission information. Thank you.ZapperZ said:Look up the Richardson-Dushman model.
http://web.missouri.edu/~kovaleskis/ApplEMandEP/Lectures/Lecture-7.pdf
Unless you understand what a Fermi function is and how temperature changes the metal electronic occupation number, this will all be Greek to you.
Zz.
Yes, conductors can be accelerated to high enough velocities to emit electrons. This process is known as the photoelectric effect, in which photons of light transfer their energy to electrons in a conductor, causing them to be emitted.
The acceleration of electrons in conductors can be affected by a few factors, including the intensity and wavelength of the incident light, the properties of the conductor (such as its work function), and the angle of incidence of the light.
No, the emission of electrons from conductors is not a continuous process. It occurs in discrete packets of energy, known as photons. Each photon must have enough energy to overcome the work function of the conductor in order to emit an electron.
The velocity of the conductor is directly related to the energy of the emitted electrons. As the velocity of the conductor increases, so does the energy of the emitted electrons. This is due to the kinetic energy gained by the electrons through the acceleration process.
No, not all conductors can emit electrons when accelerated. The ability to emit electrons depends on the properties of the conductor, such as its work function and the energy of the incident light. Only conductors with low work functions and high enough energy of incident light can emit electrons when accelerated.