Can a 2m Linac Accelerate Electrons to 1.5MeV for Positron Production?

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Discussion Overview

The discussion revolves around the feasibility of using a 2-meter long linear accelerator (linac) to accelerate electrons to 1.5 MeV for the purpose of positron production through pair production. Participants explore the technical aspects of acceleration methods, target materials, and detection of positrons, while addressing safety concerns associated with such experiments.

Discussion Character

  • Exploratory
  • Technical explanation
  • Debate/contested
  • Experimental/applied

Main Points Raised

  • One participant questions whether a 2-meter linac can achieve 1.5 MeV for positron production, suggesting the use of electrostatic acceleration with multiple staged electrodes.
  • Another participant mentions that achieving 1.5 MeV is possible with electrostatic acceleration, but suggests that a longer setup (3-4 meters) would be easier.
  • Concerns are raised about the practicality of generating and storing positrons, as well as the radiation produced when beams hit a backstop.
  • Participants discuss potential target materials for producing high-energy photons, with suggestions including gold, lead, and tungsten, while noting the cost and toxicity of some materials.
  • Questions arise about the detection of positrons, with one participant seeking a specific type of detector for this purpose.
  • Safety warnings are emphasized, with reminders about the dangers and potential legal issues associated with such experiments.

Areas of Agreement / Disagreement

Participants express varying opinions on the feasibility of the proposed setup, with some agreeing that 1.5 MeV is achievable while others highlight the challenges involved. There is no consensus on the best target material or detection method, and safety concerns remain a point of contention.

Contextual Notes

Participants acknowledge the limitations of their proposed setups, including the need for proper insulation and safety measures, as well as the potential legal implications of conducting such experiments.

Who May Find This Useful

This discussion may be of interest to individuals exploring particle acceleration, positron production, and experimental physics, particularly those considering small-scale setups or theoretical applications in high-energy physics.

Pseudo Epsilon
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Hi all, this is my first time posting.

This may seem too vauge but could a 2m long linac accelerating electrons (with electron gun as source) achive 1.5MeV? I.e. Could it make positrons via pair production? (0.511MeV For electron same for positron plus a litle extra to be safe) asuming it uses quadropole and sextupole magnets (copper) liquid nitrogen cooled. Electrostaticly acelerated via muliple staged electrodes (max voltage=~100 000v). Thanx to you geniuses in advace
 
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The 2-mile long linac you may be speaking of was the one at SLAC, which achieved 90 GeV center-of-mass energy.
 
i meant two meters. 1.5 Mev posible using only electrostatic aceleration?
 
Sorry, my mistake. You're actually thinking of building a table-top linac?? Good luck generating and storing the positrons. Good luck getting the beams to collide. And don't forget to watch out for the radiation produced when the beams hit the backstop!
 
1.5 MeV with 2 meters of separation is possible with electrostatic acceleration (but 3-4m would be easier), and you can use the 1.5MeV-electrons to do pair production afterwards. Focusing is neither necessary nor practical with such a small setup, I think. You just need a good insulation and a Van-de-Graaff generator. If you want to do something with the positrons, the setup will grow.
 
thanks! I wasn't planning to do anything with the positrons yet. Thanks for not being harsh. If i may ask what target should i use and could i detect the positrons?
 
oh, and could i use a flyback transformer coupled to a cfl circuit instead of a van de graff generator?
 
As target: probably something where the electrons can produce high-energetic photons, and those can be converted to electron/positron pairs afterwards - a material with heavy nuclei? Gold is expensive, lead is toxic.
I wasn't planning to do anything with the positrons yet.
This is nothing you should do at home. It is very dangerous, and probably illegal.
 
i will check with my local police station. But is there any cheap way to confirm positrons have been produced? And how about tungsten for a target?
 
  • #10
i will check with my local police station.
The police station won't tell you how to avoid getting killed, or injured.
But is there any cheap way to confirm positrons have been produced?
There is. If you know enough to build such a device safely, you will know the answer to that question.
 
  • #11
but a device with a 100% acuracy that only detects positrons? And by the way, i always do my research once i know what to research. I am familiar with high voltage safty as i have built a jacobs ladder and tesla coil in the past. I do already have lead-impregnated glass for the hard radiation from a recycling company.
 
  • #12
so if you could just tell me the name of the detector needed. Please.
 
  • #13
Pseudo Epsilon -- We do not allow discussions of dangerous activities here on the PF. This thread is closed. Please do not ask questions like this here again.