Can conductors be accelerated enough to emit electrons?

[Samson4]

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.

 

[davenn]

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.

umm you realize you don't have to accelerate the conductor to get electron emission ?
and I'm not sure that you could anyway ??

are you familiar with...

Thermionic 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).

Dave

 

[Samson4]

Haha yes. I am asking if it could be done through momentum alone. For example, spinning a bar at one end. Could we get it to emit electrons on the opposite end? Could the centrifugal force be greater than the materials work function at any speed? Would it alter energy requirements for field emission?

 

[beamie564]

If the centrifugal force is large enough that electrons are emitted, wouldn't the parent atoms experience a larger force( being more massive) and hence break away first?

 

[Samson4]

Then why does thermionic emission happen before melting points?

 

[beamie564]

That happens for only metals with high melting points. Maybe it's easier to excite electrons than to break down the lattice of the metal ( honestly I don't know what are the factors affecting the work function for thermionic emission). But for the way you proposed, the centrifugal force is mr(omega)^2 , clearly dependent upon mass.

 

[ZapperZ]

Then why does thermionic emission happen before melting points?

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.

 

[Samson4]

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.

And it contains field emission information. Thank you.