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Difference Between Plasma and Radiation

  1. Mar 20, 2012 #1
    Hi all

    In general sometimes we talk about plasma effects on satellites and radiation effects on satellites. Can someone tell the difference between the two?

    Thanks and Best Regards
    Hamza
     
  2. jcsd
  3. Mar 20, 2012 #2

    Chronos

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    Plasma consists of electrically charged particles, whereas radiation is EM photons. Plasmas are more destructive. Energetic EM radiation can, however, generate plasmas in earth's atmosphere.
     
  4. Mar 21, 2012 #3

    Drakkith

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    I'm assuming that the term radiation is used in this way only for talking about the two effects on satellites? As radiation can also be charged particles.
     
  5. Mar 22, 2012 #4
    Yes normally when we look at the two effects we talk about plasma and radiation.
    But another thing I don't understand is Van Allan Radiation Belt. The name says its a radiation belt but it is a constituent of plasma. And then there is another plasma sheet which trails at the dark side of the earth in outerspace.
     
  6. Mar 22, 2012 #5

    Astronuc

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    A plasma is simply an ionized gas in which electrons are separated from nuclei or ions. The energies required to ionize atoms is on the order of eV. Some plasmas, particularly fusion plasmas would have temperatures in the keV range, which is low energy for radiation. Radiation would encompass ions, electrons and photons, over a broad range of energies.

    High energy radiation has energy in the high keV to MeV range.

    The Van Allen radiation belts are a collection of plasma or radiation that are thought to originate from the solar wind and cosmic radaition. It appears they are mostly protons and electrons, which are somewhat confined by the Earth's magnetic field.

    http://en.wikipedia.org/wiki/Van_Allen_radiation_belt

    http://rbsp.jhuapl.edu/science/overview.php
     
  7. Mar 24, 2012 #6
    Hi good question. A plasma is a collective group of charged particles. It consists of both positive and negative particles and there has to be enough particles present in a volume so that they interact in a collective way.

    So if a space ship meets a plasma the plasma particles will move to shield the electrical field from the space ship so that the field is zero inside the plasma. This is called Debye shielding.

    Radiation can be single particles of either positive or negative charge and of course photons. There is no collective behaviour. You can get radiation from a plasma. In fact a little plasma radiation brightens up everybody on the beach.

    Plasmas can cause damage by their collective behaviour. By trying to shield an electrical field they can charge up a space craft and cause particles from the plasma to strike the space craft at high speeds and damage the space craft.
     
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