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

Leo's book [energy loss of heavy charged particles]

  1. Oct 9, 2014 #1
    Dear all,

    I am reading the "Techniques for Nuclear and Particle Physics Experiments" of W.R.Leo.
    I am confused when reading the section 2.2. Energy Loss of Heavy Charged Particles in Atomic Collisions (page 21).

    At the beginning of the second paragraph (from the bottom up), it is written that "Of the two electromagnetic processes" ? Why is it written like this? I think electromagnetic processes are X-rays, gamma-rays, etc., but not charged particles !

    Please give me some explanations or advises if you have.

    Thanks in advance !
  2. jcsd
  3. Oct 10, 2014 #2


    User Avatar
    Science Advisor
    Education Advisor

    He starts that section "These effects are primarily the result of two processes: 1) inelastic collisions with the atomic electrons of the material. 2) Elastic scattering from nuclei".

    These are the two electromagnetic processes he is referring to in that sentence, and saying that inelastic collisions on atomic electrons are the dominant process, as elastic scattering from nuclei happens much rarely, and does not transfer as much energy.

    They are electromagnetic processes as they are mediated by the electromagnetic interaction.

    Hope this helps!
  4. Oct 10, 2014 #3
    @e.bar.goum :
    Thank you for your response

    "mediated by the electromagnetic interaction" ? what do you mean about this? Could you please explain more clearly for me?
  5. Oct 10, 2014 #4


    User Avatar
    Science Advisor
    Education Advisor

    Ok, so, as I'm sure you know, there are four fundamental forces of nature - strong, weak, electromagnetic, gravitation. Anytime a physical process happens, like the scattering of nuclei off of electrons, one of the four forces needs to be responsible for making the process happen. For instance, the gravitational interaction is what keeps planets in orbit. The weak interaction is responsible for beta decay of nuclei, and the strong force is what keeps nuclei together.

    In the case of nuclear scattering, this is in the most part due to the electromagnetic interaction - the nucleus and the electron come close to each other, and exchange photons, which we say are the "force carrying" particles for electromagnetism, and the electron and the nucleus scatters off of each other.

    Another example of an electromagnetic interaction is the Coulomb repulsion of two like charges, or how particles move in magnetic fields.

    Does that clear it up?
  6. Oct 10, 2014 #5
    It is fantastic ! Thank you so much.
Share this great discussion with others via Reddit, Google+, Twitter, or Facebook