Electron gun design using faraday cage like setup

In summary, it is possible to design an electron gun that utilizes a Faraday cage setup, but careful consideration and design are necessary for its success.
  • #1
scientist1234
6
0
I have designed an electron gun that incorporates a faraday cage setup and I would like anyone's opinion if this setup could actually work.

See attachment for image or here is a link to the image of the electron gun http://yfrog.com/j7electrongundesignbj

Explanation of image

There is a faraday cage which is connected to a negative high voltage source. A wire which is shielded from the electric field of the faraday cage is going into the faraday cage to supply power to the cathode (electron emitter).

Since the faraday cage has the principles that when there is only an electric field on the outside there is no electric field on the inside but when there is an electric field on the inside there will be an equal an opposite charge on the inside of the faraday cage surface.

So if the cathode has a voltage of -100 then the inside of the faraday cage will be +100 volts even though the outside of the faraday cage may be at negative 10 kilovolts.

By the way the area around the cathode and the outside tube on the faraday cage are in a high vacuum

My question would be is this setup possible, is it possible to emit electrons inside a faraday cage accelerate them to a positive voltage on the inside of the faraday cage and exit through a hole in the faraday cage and be then accelerated again by the negative voltage on the outside of the faraday cage.

My idea is very similar to the setup of an van de graaff accelerator (http://www.lbl.gov/abc/wallchart/chapters/11/2.html) which has a penning ion source to generate positively or negatively charged ions and to accelerate them. I can not however find very much information on the design of penning ion sources other then extremely complicated designs.

Any ideas/suggestions are highly appreciated.
 

Attachments

  • electron gun design.jpg
    electron gun design.jpg
    18.2 KB · Views: 416
Physics news on Phys.org
  • #2
It is possible to design an electron gun that incorporates a Faraday cage setup. The idea is similar to the setup of a Van de Graff accelerator, where positively or negatively charged ions are produced and accelerated. The Faraday cage will provide a region of 0 electric field inside, so the electrons will not be affected by any outside electric fields. With the right setup, it is possible to accelerate the electrons in this region, and then exit through a hole in the cage and be further accelerated by the negative voltage on the outside. However, there are some considerations that need to be taken into account for this setup to work properly. For example, the position of the cathode in relation to the cage walls can affect the performance of the electron gun, as well as the size of the hole in the cage. Additionally, the vacuum pressure inside the cage needs to be maintained to ensure that the electrons are able to travel freely without being impeded by air molecules. Overall, this setup is definitely possible, but further research and design considerations need to be taken into account in order to ensure that it functions properly.
 

FAQ: Electron gun design using faraday cage like setup

1. How does an electron gun work?

An electron gun is a device that generates a beam of electrons. It works by using a cathode (a negatively charged electrode) to emit electrons, which are then accelerated towards an anode (a positively charged electrode) by an electric field. The electrons then pass through a small hole in the anode, forming a focused beam.

2. What is the purpose of using a Faraday cage in electron gun design?

A Faraday cage is used in electron gun design to shield the electron beam from external electric fields. This is important because external electric fields can distort or deflect the beam, affecting its accuracy and precision. The Faraday cage helps to ensure that the electron beam remains focused and directed towards its intended target.

3. How does a Faraday cage work in an electron gun setup?

A Faraday cage works by creating a conductive shield around the electron gun. This shield, usually made of metal, creates an electrically neutral environment inside the cage. When external electric fields come into contact with the Faraday cage, the charge is distributed evenly along the surface of the cage, effectively canceling out the electric field inside. This allows the electron beam to pass through without any interference.

4. What are the benefits of using a Faraday cage in electron gun design?

Using a Faraday cage in electron gun design has several benefits. It helps to improve the accuracy and precision of the electron beam by shielding it from external electric fields. This is especially important in scientific experiments and applications where precise control of the electron beam is necessary. Additionally, the Faraday cage also serves as a safety measure, protecting operators from potential electric shocks.

5. Are there any limitations to using a Faraday cage in electron gun design?

While a Faraday cage is an effective solution for shielding an electron beam from external electric fields, it does have some limitations. The cage can only protect the electron beam from electric fields that are parallel to its surface. If the electric field is perpendicular, it may be able to penetrate the cage and interfere with the electron beam. Additionally, the Faraday cage can also introduce unwanted magnetic fields, which may affect the trajectory of the electron beam.

Similar threads

Back
Top