Discovering the Energy of Accelerated Electron Beams by Jonty

[joker_900]

Hey guys

Apparently I have to know how to find the energy of accelerated electron beams for a test, and I'm not sure how. Any help?

I'm assuming it's talking about electron guns: I think this consists of a heated cathode which emits electrons via thermionic emission, and an anode which accelerates them. But how do you actually get the cathode and anode (i.e. what are the circuits and how does one make each electrode charged). Is the electron beam energy just the voltage between the cathode and anode multiplied by Q (=It)?

Thanks, Jonty

 

[OlderDan]

The energy is e*V as you suspected, charge of electron times potential difference. The circuits to create a beam for an electron gun can be quite simple. Controlling the beam to do something useful as in a cathode raty tube is a bit more involved.

http://www.matter.org.uk/tem/electron_gun/electron_gun_simulation.htm

 

[kyle8921]

Hello Jonty,

Thank you for reaching out. The energy of accelerated electron beams can indeed be calculated using the voltage and current (Q=It) between the cathode and anode. This is known as the kinetic energy of the electrons, which is equal to 1/2mv^2, where m is the mass of the electron and v is its velocity. However, there are a few other factors to consider in order to accurately calculate the energy of an accelerated electron beam.

First, the voltage between the cathode and anode must be high enough to overcome the work function of the cathode material, which is the minimum energy required for an electron to be emitted from the surface. This is typically around 4-5 volts for most materials. Additionally, the shape and design of the electrodes can also affect the energy of the electron beam, as well as any external electric or magnetic fields that may be present.

In terms of creating the necessary circuits and charging the electrodes, this would depend on the specific setup and equipment being used. It is important to follow proper safety protocols and consult with an experienced technician or scientist when working with high voltage equipment. I would recommend consulting your textbook or a trusted resource for specific instructions on how to set up and operate an electron gun.

I hope this information helps you better understand how to calculate the energy of accelerated electron beams. Best of luck on your test!

Sincerely,