Linac energy

  1. 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
     
  2. jcsd
  3. Bill_K

    Bill_K 4,157
    Science Advisor

    The 2-mile long linac you may be speaking of was the one at SLAC, which achieved 90 GeV center-of-mass energy.
     
  4. i meant two meters. 1.5 Mev posible using only electrostatic aceleration?
     
  5. Bill_K

    Bill_K 4,157
    Science Advisor

    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!
     
  6. mfb

    Staff: Mentor

    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.
     
  7. 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?
     
  8. oh, and could i use a flyback transformer coupled to a cfl circuit instead of a van de graff generator?
     
  9. mfb

    Staff: Mentor

    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.
    This is nothing you should do at home. It is very dangerous, and probably illegal.
     
  10. 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?
     
  11. mfb

    Staff: Mentor

    The police station won't tell you how to avoid getting killed, or injured.
    There is. If you know enough to build such a device safely, you will know the answer to that question.
     
  12. 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.
     
  13. so if you could just tell me the name of the detector needed. Please.
     
  14. berkeman

    Staff: Mentor

    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.
     
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