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B Cyclotron design question

  1. Jul 24, 2017 #1


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    I'm trying to work out what velocity and magnetic field strength one needs to capture the charged particle in a circle of comfortable lab size - say 5cm ( 0.05m).

    For a sodium ion ( mass = 3.8175407 × 10-26 kg) with charge q = 1.60217653 x 10 -19 , velocity 183234 m/s, C in a magnetic field of 2 Tesla the radius of the circle ##R=mv/qB## is 0.0218m.

    The velocity requires a 4000v potential and seems a bit big. Have I made an error ?

    [I'm not actually building a cyclotron, just a magnetic deflector.]
  2. jcsd
  3. Jul 24, 2017 #2

    Vanadium 50

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    2 Tesla is a huge field. (And please, significant figures!)
  4. Jul 24, 2017 #3


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    My understanding of magnetic field strength comes from this
    Code (Text):

          Smallest value shielded        10^-14 Tesla      10^-10 Gauss
          Interstellar space                  10^-10 Tesla      10^-6 Gauss
          Earth's magnetic field           0.00005 Tesla      0.5 Gauss
          Small bar magnet                 0.01 Tesla      100 Gauss
          Within a sunspot                   0.15 Tesla      1500 Gauss
          Small NIB magnet                0.2 Tesla      2000 Gauss
          Big electromagnet                1.5 Tesla      15,000 Gauss
          Strong lab magnet                10 Tesla      100,000 Gauss
          Surface of neutron star        10^8 Tesla        10^12 Gauss
          Magstar                                10^10 Tesla      10^15 Gauss
    and the strongest I saw in a (small) cyclotron was 9 T.

    With U = 1000V, B = 0.2T one gets R = 0.109m

    In the ball park ( absent errors ).

    (sorry about the redundant digits )
    Last edited: Jul 24, 2017
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