Particle accelerator

Discussion in 'Physics' started by Robin Mitchell, Nov 26, 2010.

  1. Robin Mitchell

    Thread Starter Well-Known Member

    Oct 25, 2009
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    Hi everyone,

    I plan on making a linear particle accelerator. it would consist of an electron gun to get electrons and a long chamber to accelerate and focus the beam. The only thing is how would you accelerate the electrons once they have left the gun?
    Thanks
     
  2. retched

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    Dec 5, 2009
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    Little jet engines... REAL little. ;)
     
  3. Robin Mitchell

    Thread Starter Well-Known Member

    Oct 25, 2009
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    Comon retched be serious :/
     
  4. jpanhalt

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    Jan 18, 2008
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    Do you really need an electron gun? What about a pointed needle or hot filament? Or, harvest the source from a TV tube or other CRT. If you have access to a library that has past issues of Scientific American, I mean really past issues, check Amateur Scientist, circa 1954 -1957. There were complete plans for a high-vacuum pump and linear accelerator. I made one. They were quite popular for science fair projects then. I used mine to irradiate some plastics (beta) and see whether it affected their melting point.

    Oh, BTW, being able to do a little glass blowing will help, but is not necessary. You can use various waxes for sealing. The SA article suggests a mixture of beeswax and rosin.

    John
     
  5. Robin Mitchell

    Thread Starter Well-Known Member

    Oct 25, 2009
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    If i have two sets of two plates to accelerate electroncs through like this:

    ---- ----

    ---- ----

    Each having a PD of 1V, when the electron travels all the way through does it have 2eV of energy?
    Thanks
     
  6. jpanhalt

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    Jan 18, 2008
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    You lost me there. What direction are the electrons traveling? One volt potential difference is 1 eV, right?

    If your acceleration potential is 50,000 to 500,000 volts, why worry about a few volts for your source. Get the hard part (accelerator, vacuum system, no leaks) built first, then you can mess with the source. A source without the rest of the system is worthless. BTW, getting rid of leaks is a real challenge. What are you using for your vacuum system? How will you find leaks? How will you measure the pressure?

    John
     
  7. Robin Mitchell

    Thread Starter Well-Known Member

    Oct 25, 2009
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    No idea, im getting a group of friends to do this with me. We will deal with that, what i want to know is if an electron accelerates through a PD of 1v and then through a pd of 2v, does it get 3ev of energy?
     
  8. jpanhalt

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    You showed a drawing, but omitted the electron.

    Maybe this will help. Seems pretty clear to me.

    John
     
  9. Robin Mitchell

    Thread Starter Well-Known Member

    Oct 25, 2009
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    mmmm

    Here is the story

    One day an electron accelerates through a pd of 1v. This means he has gained 1ev.

    Now, while traveling through the accelerator, he goes through another pair of plates which have a pd of 1v....does this mean he now has 2ev?

    ----
    e-->
    ----
    1V

    E now has 1v
    ---- -----
    e-------------------->
    ---- -----
    1V 1v

    when he leaves the next plate, does he have 2ev?
    Please try and understand
     
  10. bertus

    Administrator

    Apr 5, 2008
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  11. R!f@@

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    Apr 2, 2009
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    I must be missing something here....
     
  12. retched

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    For leak checking, smoke is good.

    In the HVAC field, we used smoke to check for leaks regularity.

    HVAC Schrader valves are your friend. You can get them cheap and they are designed to hold a vacuum down to 25 micron.

    Find a friend who works in the HVAC field to join your project group.

    They will have access to vac pumps and fittings that can produce and hold the vacuum.

    Dont skimp on your valves. The HAVE TO hold the vacuum.
     
  13. beenthere

    Retired Moderator

    Apr 20, 2004
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  14. retched

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    Dec 5, 2009
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    You need somewhere to start. ;)

    The more people you get on-board, the less each has to spend.

    Yeah, you are going to need some serious vacuum pumps.
     
  15. Robin Mitchell

    Thread Starter Well-Known Member

    Oct 25, 2009
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    Cool
    Im doing A2 physics at the moment and we are looking a quarks, some great stuff!
    I originly wanted to make a proton/alpha particle accelerator but i dont know how to get a stream of protons :/
     
  16. Robin Mitchell

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    Oct 25, 2009
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  17. jpanhalt

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    Once you get your electron source working in your particle accelerator, just introduce a little hydrogen into the source and reconfigure as a mass spectrometer. Simple.

    John
     
  18. BillO

    Well-Known Member

    Nov 24, 2008
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    Well, if the pairs of plates have 1v WRT each other, then yes, but if there is 1V PD between the plates and ground then no. Or if the PD is across the plate pair then that will just delfect the beam.

    See the attached. Each stage is a circular plate with a hole in its centre, like a washer. There is 100KV PD between each plate.

    [​IMG]
     
  19. Robin Mitchell

    Thread Starter Well-Known Member

    Oct 25, 2009
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    i think i get it billO
    So the electrons accelerate through the hole towards the ground plate at the end?
    what if i had one 100kv source, can it still be done like that?

    What can high energy electron collisions be used to do then?
     
  20. jpanhalt

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    Jan 18, 2008
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    They are called beta rays. You can also make X-rays.

    John
     
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