Dismiss Notice
Join Physics Forums Today!
The friendliest, high quality science and math community on the planet! Everyone who loves science is here!

Building a particle accelerator

  1. Dec 15, 2008 #1
    I would like to build a particle accelerator as a science project. I know it may be unrealistic, but depending upon the size and complexity that I choose, it should be possible. If anyone could help with the construction process of a small particle accelerator(preferably circular), I would appreciate it.
     
  2. jcsd
  3. Dec 15, 2008 #2
  4. Dec 15, 2008 #3

    Vanadium 50

    User Avatar
    Staff Emeritus
    Science Advisor
    Education Advisor
    2015 Award

    I'm not sure this is a good idea. One reason is that this requires a pretty good vacuum, and getting a good vacuum takes some experience. A second reason is that one involves exposed high voltage, which is dangerous. Finally, how do you plan on demonstrating that this device actually accelerates? That's a job at least as hard as building the accelerator itself.
     
  5. Dec 15, 2008 #4
    I am not sure how "building" a good vaccum takes experience? i understand it is a very precise process, and is going to take a lot of time and patience and parts will be hard to find, but i am looking for a solution, not questions on how i am going to apply it...
     
  6. Dec 15, 2008 #5
    So I heard you were going to build a particle accelerator in your garage with a drill, a hammer, and commercial magnets, man... You are going to waste months (if not years) of effort, tons of money, and risk your own life. And what's you reward? A big, fat 'A' on a science project, that you could get, in college, by combining an old microwave and a neon lamp to see how radiation affects ionized gases, or in school (please don't tell me you were going to build a particle accelerator for a school science project)... well, in school you could get an A by making a light bulb turn on...
     
    Last edited: Dec 15, 2008
  7. Dec 16, 2008 #6
  8. Dec 16, 2008 #7
    The science fair is the least of my worries. I could care less if there was a sciene fair, what I want is to build a particle accelerator. What I dont understand is why people feel the need top post their concerns? I do not care, if you can help with my problem then help, otherwise why are you replying?
     
  9. Dec 16, 2008 #8
    Try to build a cyclotron. You need a strong electromagnet, a vacuum pump, a simple high-frequency generator circuit, some hydrogen, and a suitable enclosure to house the system. You will be only able to push particles into a keV range, but it will work and it will not involve deadly voltages.

    http://www.physics.rutgers.edu/cyclotron/theory_of_oper.shtml

    These guys have a cyclotron that pushes protons to 1.1 MeV, but their setup is far bigger and more expensive than you can pull off for your science fair (4,600 lb water-cooled magnet that eats 4 kW of energy), so you won't be able to approach that energy. Careful calibration of the magnet and a precise power source will be required, because protons will need constant magnetic field across a wide area.

    Have fun.
     
    Last edited: Dec 16, 2008
  10. Dec 16, 2008 #9
    check out Review of Scientific Instruments.
     
  11. Dec 16, 2008 #10

    Vanadium 50

    User Avatar
    Staff Emeritus
    Science Advisor
    Education Advisor
    2015 Award

    First, pointing out potential problems is help. Second, If you don't care about your own safety, maybe we shouldn't give you any more help.
     
  12. Dec 16, 2008 #11
    Why would I want advice or help from someone who only points out the negatives and the can't of a situation? I have a little common sense and don't plan on building some crazy unsafe machine and using it without precaution. I am looking for a guideline, like the cyclotron idea, which I like because it doesn't depend on having a large room for length. I don't see how when you say I might waste money and time how that is useful. Or how I am going to apply it? If I can manage to build one of these I think I will be able o explain how it works.... But anyways thanks hampster143. Where might I find an electromagnet or high frequency generator circuit?
     
  13. Dec 16, 2008 #12
    You will have to build them :) If you don't know how to build an electromagnet, then perhaps the cyclotron is too big a project for you at this stage. Once you learn how to do that, move on to bigger things.
     
    Last edited: Dec 16, 2008
  14. Dec 16, 2008 #13

    berkeman

    User Avatar

    Staff: Mentor

    Here's a basic intro to particle accelerators: http://en.wikipedia.org/wiki/Particle_accelerator

    and click on the link for "Synchrocyclotrons" down in the explanation of Cyclotrons. Dr. Lawrence built a small cyclotron that you could use as your initial goal -- it was about hand-sized IIRC.

    On the safety issues, please understand that we get all kinds of requests here on the PF for advice on how to build things or try things, and sometimes we are worried that the poster does not understand all of the ramifications and safety issues for what they are asking about. I see it a lot in the EE forum, where folks will ask about how to build something that uses AC Mains electrical power, but they have no experience or understanding of the shock safety and fire hazard issues involved with AC Mains power. Or we've gotten questions from posters who want to take apart a CRT display tube, to get access to the electron gun for various electron accelerator projects, but that's just plain not safe, and when we point that out, sometimes the reaction is "I don't care, I can take care of myself."

    So the warnings and advice that you were getting above aren't just aimed at discouraging you from your current goal. They are instead meant to educate you to some of the potential safety issues involved, and to make sure that you understand the depth of what you are looking to do. It would not be responsible of us to give you some tips on how to build a particle accelerator without making sure that you understand that they generate X-rays (which are bad for you), for example.

    And Vanadium's comment about (hard) vacuums being hard to generate and hold, was meant to keep you from wasting a lot of time trying to build a small accelerator that won't work because you can't pump it down far enough without invesing 10x the money in the enclosure and pump system.

    I wasted many hours of work back in high school trying to build a gas laser that looked to be a pretty easy job of glasswork. But I didn't appreciate how important things like gas purity and the parallelism of the mirrors were, and after much work and frustration, I finally gave up. If I'd had a talented mentor at the time, I could have picked a different project to try, or could have done more up-front work to understand the subtleties of laser construction before starting to cut glass.

    I do think that a small Lawrence cyclotron might be a do-able project for you, but you will be doing a lot of learning (which is the fun part, right?) along the way. And please pay particular attention to safety issues (electrical and radiation) along the way. If you can find a mentor in your local area, that will also help you out a lot more than an on-line discussion forum can.

    Good luck!
     
  15. Dec 16, 2008 #14
    Haha the exact reply I was looking for. Iv'e had no drive in school whatsoever I can't try it's pointless.. but as soon as i thought about what I accually wanted to do with my life all I've wanted to do is advance my mind. Learning is what this is about, and honestly how cool would it be to have an atom smasher, or a miniature version? But a mentor is exactly what I'm looking for, rather than piecing fragments of what people tell me, some of which being untrue possible, but I'm trying to find out how:P
     
  16. Dec 16, 2008 #15

    dlgoff

    User Avatar
    Science Advisor
    Gold Member

    I just want to repeat berkeman here. (but I wouldn't call it wasted hours:wink:)
    I am a total believer in trying to make things (using your hands). It's not always the suscess of the project but the act of using your mechanical ability to put things together from your ideas.
     
  17. Dec 17, 2008 #16

    Vanadium 50

    User Avatar
    Staff Emeritus
    Science Advisor
    Education Advisor
    2015 Award

    Why do you say this? The Rutgers system uses 320V DC on the ion source, and the RF puts out 2000 W at 18 kV.
     
  18. Dec 17, 2008 #17

    Vanadium 50

    User Avatar
    Staff Emeritus
    Science Advisor
    Education Advisor
    2015 Award

    The key to any project like this is to have worked it out a couple of times on paper before you start to bend metal (or cut glass, in your case). You don't want to start down this path and then realize that, e.g. you can't achieve the precision you need on one item because you made it too small, or that you can't afford another one because you made it too big.
     
  19. Dec 17, 2008 #18
    Because RF voltage scales with the target energy, and he does not need the ion source at all (unless he intends to transmute lead into gold). So he can start small. Especially if he tries to accelerate electrons.

    Contrast with fusor from an earlier post, which absolutely requires a voltage of tens of kV or else it will not work at all.
     
  20. Dec 17, 2008 #19
    Thanks. Any tip on how small to start? I understand this is dangerous, so some kind of scale would be very helpful.
     
  21. Dec 17, 2008 #20

    Vanadium 50

    User Avatar
    Staff Emeritus
    Science Advisor
    Education Advisor
    2015 Award

    The smaller the RF voltage, the smaller the acceleration per turn, the more turns per given energy, so the longer the particle's path length. This means a) the better the vacuum you need, b) the higher precision you need on the mechanical aspects of the device, and c) the more trouble you will have with stray fields.

    The smaller the injection energy, the more difficult the injection: the particle accelerated can get easily moved by stray fields, the field quality at the center of the dees needs to be higher, and the closer the dees have to be placed together (beware of arcing). A rule of thumb is that the acceleration per stage should be no more than a factor of 20, and 10 is better.

    An industrial version of this accelerator would require some sort of lock-out mechanism if there is more than 50V anywhere or more than 1J of stored energy, I think it would be difficult to make a working accelerator subject to this constraint.
     
Know someone interested in this topic? Share this thread via Reddit, Google+, Twitter, or Facebook

Have something to add?



Similar Discussions: Building a particle accelerator
  1. Particle Accelerators. (Replies: 8)

  2. Particle acceleration (Replies: 7)

Loading...