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X-rays & Electrons

  1. Nov 20, 2004 #1


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    @ howstuffworks.com, it says:

    I thought that only photons could knock and electron loose.

    How do electrons do the same?


    Actually, I was viewing http://www.cvm.okstate.edu/~groups/students/web/2001/diagimag/Physics_of_Radiology.ppt [Broken], and on slide 22-23, it shows the knocking loose of an electron with another electron as similar to a inelastic collision.

    Is this indeed the case?
    Last edited by a moderator: May 1, 2017
  2. jcsd
  3. Nov 20, 2004 #2
    I hope this will help you


    Your electron is interacting with electrons of your atom of tungstem through the electromagnetic force.
    He is changing is momentum and losing kinematic energy during this interaction. This energy loss goes to electrons of the tungsten and makes them change of orbitals.

    So, indeed, it is an inelastic collision, as in the photoelectric effect (exept that in our case, the photon interacting with the elctron is virtual...)

    If you're looking for further informations, you can read the books of Knoll or Leo (interactions of particles and matter)

  4. Nov 23, 2004 #3


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    You may also want to look up the principle of Secondary Electron Emission. Photomultipliers, scanning electron microscopes, and many other devices make use of the emission of electrons by other electrons. So no, photons are not the only "agent" that can knock out electrons from solids or atoms.

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