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

Simple questions about alpha particles

  1. Oct 6, 2004 #1
    1. Can any other atom besides helium be completely stripped of all its electrons? Are these ever encontered? Can they (C +12, or Fe +26, or U +92 etc.) be isolated and produced as a stream? How do these compare (stability) to alpha particles?

    2. As for alpha particles themselves, how long do they last before becoming helium? There must be some half-life related to this and that would depend on local environment, especially the pressure of the gas in which it resides. Surely, an alpha particle would last longer in a vacuum than it would in 1 atm.
  2. jcsd
  3. Oct 6, 2004 #2


    User Avatar
    Science Advisor
    Gold Member

    A major factor in stripping electrons is the temperature. It is practical problem. For example at the center of the sun everything is completely ionized. Also gas density does play a role, as you indicated. In outer space electrons are sparse.
  4. Oct 7, 2004 #3
    Hydrogen atoms are often stripped of thier electron, its usually how we isolate a proton for use. Basis and Acids work on the principal of the Ionisation of A hydrogen atom.

    I couldnt tell you about the others... But yes i have heard that everything is completely ionised at the centre of a star. So id agree with that

    An alpha particle will only last going through a few mm of air before ionising... and into solid mattar about [tex]~10^-2mm[/tex]
  5. Oct 7, 2004 #4
    sorry, that was a few cm in air
  6. Oct 7, 2004 #5


    User Avatar
    Staff Emeritus
    Science Advisor
    Gold Member

    As mathman said, yes - it depends upon things like temperature and pressure. These are encountered 'all the time' (e.g. in cosmic rays), and yes, they can be 'isolated and produced as a stream' (e.g. in many particle accelerators around the world; in fact, that's how the few super-heavy elements have been produced!)
  7. Oct 7, 2004 #6
    Thanks, but I would also be interested in where the number comes from and perhaps the function depth(pressure, type of gas, etc.) or a table if anything of the sort is available.
  8. Oct 25, 2004 #7
    Here is a link to an old report on Electron Cyclotron Resonance (ECR) ion sources. These are used to produce high charge state ions for accelerators like cyclotrons or linacs.
    Take a look at Table 1. You can see that they managed to fully ionize Argon, and produced a small current of Ca +19 (all but one electron gone.) I think that newer ECRISes can remove more than half the electrons for a Uranium ion.
  9. Oct 25, 2004 #8
    Thanks everybody.
Know someone interested in this topic? Share this thread via Reddit, Google+, Twitter, or Facebook

Have something to add?

Similar Discussions: Simple questions about alpha particles
  1. Alpha particles (Replies: 1)