Can electrons "fly" between capacitor plates?

[nsaspook]

I encountered your thread today and found it interesting. I have a question: if there is a capacitor with "perfect vaccum" as dielectric part, will electrons fly through instantly and completely?

If you have perfect vacuum you also have a perfect insulator under normal operating conditions (no thermionic or field emission) in a vacuum plate capacitor so NO electrons will bridge the gap (fly) at any speed.

In devices like tubes where electrons do move from cathode to plate the speed is limited to something less than c (speed of light).

 

[Jackson Lee]

If you have perfect vacuum you also have a perfect insulator under normal operating conditions (no thermionic or field emission) in a vacuum plate capacitor so NO electrons will bridge the gap (fly) at any speed.

In devices like tubes where electrons do move from cathode to plate the speed is limited to something less than c (speed of light).

Sorry, I don't understand. Why does perfect vacuum lead to no field emission? I suppose if it is perfect vacuum between gap, then there is nothing could affect electrons to bridge the gap. Is it wrong?

 

[nsaspook]

Sorry, I don't understand. Why will those lead to your conclusion(NO electrons will bridge the gap (fly) at any speed)?

Electron flow would be current, in a perfect vacuum there is no current flow because there are no particles with charge in the gap to move from plate to plate.
https://www.physicsforums.com/threads/perfect-insulator.543656/

 

[Jackson Lee]

Electron flow would be current, in a perfect vacuum there is no current flow because there are no particles with charge in the gap to move from plate to plate.
https://www.physicsforums.com/threads/perfect-insulator.543656/

I mean before the electrons' "possible tourist", the gap between plate is in perfect vaccum. At that time, the electric field built by charges on capacitor could exist, moreover, considering there is no other dielectric material affect electrons' moving process, they will accelerate towards the opposite bank.

 

[nsaspook]

I mean before the electrons' "possible tourist", the gap between plate is in perfect vaccum. At that time, the electric field built by charges on capacitor could exist, moreover, considering there is no other dielectric material affect electrons' moving process, they will accelerate towards the opposite bank.

'Perfect' vacuum means no particles ever, anywhere in that space. So if there are particles in the space we then have http://dictionary.reference.com/browse/partial+vacuum (even if it is very high quality) and the space is not a perfect insulator. So yes, in reality there are no 'Perfect' vacuum systems and there is a extremely small current from a random electron escaping the surface of the capacitor plate, past the space charge near that plate and being accelerated to the other side but that leakage current is not the subject of this thread.
https://www.physicsforums.com/threads/can-electrons-fly-between-capacitor-plates.798051/

 

[Jackson Lee]

'Perfect' vacuum means no particles ever, anywhere in that space. So if there are particles in the space we then have http://dictionary.reference.com/browse/partial+vacuum (even if it is very high quality) and the space is not a perfect insulator. So yes, in reality there are no 'Perfect' vacuum systems and there is a extremely small current from a random electron escaping the surface of the capacitor plate, past the space charge near that plate and being accelerated to the other side but that leakage current is not the subject of this thread.
https://www.physicsforums.com/threads/can-electrons-fly-between-capacitor-plates.798051/

Thanks a lot for your answer. And I want to know further, after the dielectric material is moved out from gap, will breakdown become much easier?