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

Alpha particle generator.

  1. Dec 16, 2009 #1
    I am looking to source (build) a large alpha particle generator that creates (mostly) He++ and not He+ particles. Thanks.
     
  2. jcsd
  3. Dec 16, 2009 #2

    vanesch

    User Avatar
    Staff Emeritus
    Science Advisor
    Gold Member

    Most alpha decay sources generate He-++ alpha particles as far as I know.
     
  4. Dec 16, 2009 #3
    Yes, but the percentage is low 1-3%. I need a very high percent of He++. Thanks.
     
  5. Dec 16, 2009 #4
    What energy alphas do you need? 10 eV or 5 MeV? Bend the alpha particles through a dipole magnet, and keep only those with the highest e/M ratio. I saw some desktop/portable setups like this with radioactive alpha emitters and electro magnets at LBL Berkeley a few years ago.
    Bob S
     
  6. Dec 16, 2009 #5

    Astronuc

    User Avatar
    Staff Emeritus
    Science Advisor

    There are four possibilities:

    1) Simply take He gas and strip the atom of 2 electrons to accelerate alpha particles to the desired energy. That's a non-radioactive source.

    2) (n, α) Li-6 which requires a neutron source and is radioactive

    3) alpha decay of various Ra, Rn, Po isotopes and transuranics, but is radioactive
    http://hyperphysics.phy-astr.gsu.edu/hbase/nuclear/radser.html

    4) (d,t) fusion -> (n, α), but that produces a 14.1 MeV neutron, and a 3.5 MeV alpha, but is radioactive
     
  7. Dec 16, 2009 #6
    Thanks for the answers

    Astronuc, How do I do 1? 2,3,4 are radioactive, so they are not preferred.

    Bob S, Would like the total extracted CW beam current to be above 30 mA, extracted through a 6 mm diameter aperture at 40 keV or more, all or mostly He++. It will go through a linac from there.

    Thanks for the answers.
     
  8. Dec 17, 2009 #7
    You are talking about a serious alpha particle source (30 milliamps cw at 40 KeV = 1.2 kW of alphas). You will probably need an ECR (electron cyclotron source), a LEBT (low energy beam transport) with a magnetic bend (momentum filter), probably followed by a RFQ (RF quadrupole accelerator) before a linac. 40 KeV is too low a velocity for a standing wave (DTL or drift tube) linac. What frequency is your DTL?
    Bob S
     
Share this great discussion with others via Reddit, Google+, Twitter, or Facebook