Free electron beam inducing an EM field in a target?

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SUMMARY

The discussion centers on the interaction between a free electron beam, tuned to frequencies between 200 and 1000 MHz, and various target materials, including conductive metals, salt or clay, and non-conductive silica. It is established that free electrons induce time-varying electric and magnetic fields in these materials, leading to the generation of currents in conductive targets that produce their own electromagnetic fields. The response frequency of the materials correlates with the pulse frequency of the electron beam, although this can be influenced by the material's characteristic response time. Additionally, it is confirmed that the electromagnetic properties of the target material can be detected through this method.

PREREQUISITES
  • Understanding of electromagnetic fields and their generation
  • Familiarity with electron beam technology, specifically klystron tubes and free electron lasers
  • Knowledge of material conductivity and its impact on electromagnetic interactions
  • Basic principles of signal detection and antenna functionality
NEXT STEPS
  • Research the principles of electromagnetic field induction in conductive materials
  • Explore the operational mechanics of klystron tubes and free electron lasers
  • Study the effects of pulse frequency on material response times
  • Investigate methods for measuring electromagnetic properties of various materials
USEFUL FOR

This discussion is beneficial for physicists, electrical engineers, and researchers involved in electromagnetic field studies, as well as those interested in the applications of electron beam technology in material analysis.

TheIdeanator
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Consider the following experimental setup: the front half of a klystron tube (the electron gun and resonent cavity) or perhaps a free electron laser, several different targets consisting of a highly conductive(metal) object, a possibly conductive object(salt or clay), and a non-conductive object(silica), both in air and under a few feet underground(rock or dirt), as well as a reciever antenna.

If I tuned this electron beam to an equavelent frequency somewhere between 200 and 1000MHz, how would each target instance respond? Would an EM field of the same or similar frequency as the electron groupings be induced such that the receiving antenna could pick up the signal?
 
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Basically what I'm asking is if free electrons cause a target material to generate a magnetic field and that if the electrons arrived in pulses, would the strength of the field fluctuate similarly.
 
Yes. The free electrons would induce time varying electric and magnetic fields in the materials. In the conductive materials those fields would result in some currents which would also produce their own fields.
 
Many mechanisms can induce an electromagnetic field in materials. Which ones are the most relevant depends on the electron energy. You should say what energy you have in mind.
The response frequency of the material will certainly be the same as the pulse of your beam but this can be masked by the characteristic time with which the response last, if this one is much longer than 1/(pulse frequency). Characteristic times vary widely.
 
joly said:
The response frequency of the material will certainly be the same as the pulse of your beam but this can be masked by the characteristic time with which the response last, if this one is much longer than 1/(pulse frequency). Characteristic times vary widely.

Are you saying that I could not only detect the target's presence, but the material it's made of as well?
 
At least you could detect some of the electromagnetic properties of the target material.
 

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