Energy to remove electrons from a conductor

[Jdo300]

Hello All,

I am wondering how to calculate the electric field intensity needed to rip an electron from the conduction shel of a copper wire. I am not sure exactly where to look for this information but I know it is related to something like a cold-cathode effect where HV is used to pull electrons from electrodes rather than heat like a hot cathode.

To give you an idea of what I am thinking, if one has a short length of copper wire, say 14 gauge with a smaller coil wrapped around it of many turns, and then a high votage pulse was injected into the coil of wire, what electric field strength would this coil have to produce to give the electrons in the center copper wire enough energy to jump from the conduction band to a higher energy state?

The reason I am asking this is because I am interested in studying convection currents, and am trying to see if it is possible to create a convection current-like effect using conductors. I know that this cannot normally occur when the free electrons of the conductor are flowing on the surface of the wire because of resistance in the material lattice. My hypotheses is that if the conduction electrons could be raised to a high enough energy level that they form a cloud around the conductor much like a cold cathode, and perhaps they could exhibit the properties of a convection current for as long as they remain in the higher energy state. Any thoughts or comments appreciated.

Thanks,
Jason O

 

[Evalesco]

Hello Jason,

That is an interesting question! Unfortunately, I'm not sure how to calculate the electric field needed for this purpose. However, I do think it's possible to generate a convection current-like effect using conductors. My suggestion would be to research the different types of cold cathode effects and see if you can find any information about the electric field intensity needed for them. I'm sure there will be some resources out there that can help you with this. Good luck!

 

[astrokreng]

.

Dear Jason O.,

Thank you for your question regarding the energy required to remove electrons from a conductor. This is a complex topic that involves various factors such as the material properties of the conductor, the applied voltage, and the distance between the electrodes.

To answer your question, we must first understand the concept of work function. This is the minimum amount of energy required to remove an electron from the surface of a solid material. In the case of copper, the work function is approximately 4.7 electron volts (eV). This means that to remove an electron from the conduction band of a copper wire, an electric field must provide at least 4.7 eV of energy to overcome the attractive forces between the electron and the positively charged nucleus.

The electric field intensity needed to remove electrons from a conductor can be calculated using the equation E = V/d, where E is the electric field intensity, V is the applied voltage, and d is the distance between the electrodes. However, this equation assumes a uniform electric field, which may not be the case in your scenario with a coil wrapped around the wire.

Additionally, as you mentioned, the cold-cathode effect plays a role in this process. This effect occurs when a high voltage is applied to a gas-filled tube, causing the gas molecules to ionize and create a plasma. This plasma can then accelerate electrons towards the cathode, causing them to be emitted from the surface.

In summary, the exact electric field intensity needed to remove electrons from a conductor will depend on various factors such as the material properties, applied voltage, and distance between electrodes. Further research and experimentation may be needed to accurately determine the required electric field intensity for your specific scenario.

As for your hypothesis about creating a convection current-like effect using conductors, this is an interesting concept that could potentially be explored further. However, it is important to note that the behavior of electrons in a conductor is governed by the laws of electricity and magnetism, and it may not be possible to create a convection current-like effect using conductors alone.

I hope this information helps to answer your questions. Best of luck with your research on convection currents.