1. Limited time only! Sign up for a free 30min personal tutor trial with Chegg Tutors
    Dismiss Notice
Dismiss Notice
Join Physics Forums Today!
The friendliest, high quality science and math community on the planet! Everyone who loves science is here!

Linear particle accelerator design

  1. Dec 24, 2015 #1
    I have a qustion about two types of accelerating designs.

    In these types of design the plates get longer or spaced apart because the frequency of the RF power is constant but the particle is acclerated so it covers more distance in less time.

    The other type of design looks like this:

    My question is, is why in these superconducting Rf accelerators that the units do not get place farther apart or grow in lenght as the beam go through.

    What im thinking is that the design with the plates increasing in spacing is for slow moving particle charged particles where acceleration is very large, and that the other design is for when the particles are already traveling very fast and acceleration very little so spacing is less important.

    Is that right? or is there a different reason?
  2. jcsd
  3. Dec 24, 2015 #2


    User Avatar
    Staff Emeritus
    Science Advisor
    Education Advisor

    You need to double check if these are all standing wave structure or if one of them is a traveling wave structure. The rf frequency used can also be a determining factor here. In addition, are these linacs used at the very beginning of the acceleration (i.e. Such as at the photoinjector) or are they where the particle bunches are already relativistic?

    There are a lot of details here that are missing.

    BTW, topics on accelerator science normally belongs in the Classical Physics forum, since classical E&M is usually the main subject area involved, such as in this one.

  4. Dec 24, 2015 #3


    User Avatar
    2017 Award

    Staff: Mentor

    I moved the thread.
    The superconducting RF cavities are typically used for electrons in the hundreds of MeV to GeV range, where the difference to the speed of light is negligible. It has to be, because frequency and wavelength in those cavities are linked via the speed of light (with some corrections due to the shape of the cavities).
Share this great discussion with others via Reddit, Google+, Twitter, or Facebook