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Explanation of Canal Rays

  1. Aug 20, 2014 #1
    I know how the canal rays are produced. As I looked from wikipedia;

    "The process by which anode rays are formed in a gas discharge anode ray tube is as follows. When the high voltage is applied to the tube, its electric field accelerates the small number of ions (electrically charged atoms) always present in the gas, created by natural processes such as radioactivity. These collide with atoms of the gas, knocking electrons off of them and creating more positive ions. These ions and electrons in turn strike more atoms, creating more positive ions in a chain reaction. The positive ions are all attracted to the negative cathode, and some pass through the holes in the cathode. These are the anode rays."

    My question is, when did this explaination discovered? Did Goldstein offered this explanation when he discovered the canal rays, or somebody else did years later?



    One more question: How can we be so sure that the positive ions are +1, can't it collide with one more electron on its way and become +2?
     
    Last edited: Aug 20, 2014
  2. jcsd
  3. Aug 23, 2014 #2
    Any answer?
     
  4. Aug 26, 2014 #3
    Even a guess is really appreciated
     
  5. Aug 26, 2014 #4

    jtbell

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    I would think that there are indeed some +2 ions (and possibly even +3 etc.), but only very few of them. The number of ions is probably actually very small compared to the number of un-ionized atoms, so an electron from the cathode is much more likely to hit an un-ionized atom than a +1 ion.
     
  6. Aug 27, 2014 #5

    mfb

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    In addition to the difference in numbers, removing a second electron often takes much more energy than removing the first one (because you have to remove an electron from an already positively charged atom).
     
  7. Sep 3, 2014 #6
    Thanks for the answers. So if the colliding electrons energy is enough, the +1 ion can loose one more electron (even if its very unlikely). And what about the first question? When and how did the explanation of canal rays discovered?
     
  8. Sep 5, 2014 #7

    mfb

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    Right. If the electron is high-energetic, then it is not an unlikely event.
    I don't know, but the literature should cover that.
     
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