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I Can one cathode transfer electrons to multiple anodes

  1. Apr 27, 2017 #1
    what if i have a cathode at one end of a tube and multiple anodes through out the tube with argon gas, will electrons flow from the one cathode to multiple anodes like curves -ve1 to +ve1 and -ve1 to +ve2 and -ve1 to +ve3 or there has to be only one cathode and one anode for electrons to flow ( -ve1 to +ve1)
     
  2. jcsd
  3. Apr 27, 2017 #2

    berkeman

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    Are you familiar with how a Cathode Ray Tube (CRT) works? In a CRT you have a single cathode emitting the electron beam, and a large anode area that the electron beam is swept over using magnetic deflection to paint the picture on the phosphur-coated anode. You could divide the anode area up into multiple anodes if you wanted, each with its own bias power supply with respect to the cathode voltage.

    Why is your vessel filled with argon gas? That will limit the mobility of the electrons... What voltages are you wanting to use to accelerate the electrons?

    http://ecomputernotes.com/images/crt_digram.gif
    crt_digram.gif
     
  4. Apr 27, 2017 #3
    The elections will flow as long as you have one anode and one cathode more of either won't hurt. BUT if you have a row of anodes one further that the next. The first one will absorb most of the current and the next will get almost nothing.
    You might be able to get even flow if you did some sort of resistance tuning.
    This is only my best understanding I am not 100% if someone knows better please feel free
     
  5. Apr 27, 2017 #4

    sophiecentaur

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    The answer, in general is that you can have as many electrodes in the system as you want. The only caveat is that the PDs between the carious Cathodes and Anodes and the Electric Fields need to be right or one anode could hog all the current. The electrons leaving a cathode will naturally spread out and they will follow different paths unless you focus them in some way.
    I, also would like some more details of the experiment with Argon gas that you are describing.
     
  6. Apr 28, 2017 #5
    i was thinking about argon plasma in a tube and i know that breakdown voltage is all about the distance between electrodes so i was wondering if a set of anodes will help with this issue. say a tube 10 meter is to hard to establish because of the distance between electrodes but if a set of anodes is applied along the tube it will make it easier. or that what i had in mind. still not sure
     
  7. Apr 28, 2017 #6
    i'm not going to do the experiment i was just thinking about plasma and been reading alot lately and wanted to know if the breakdown voltage of the gas usually depends on pressure and distance between electrodes so i was thinking this could help with the distance problem. but as you explained that one anode could take all the electrons, how to control that issue. i have very little knowledge with electricity
     
  8. Apr 28, 2017 #7

    sophiecentaur

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    This topic is quite a sophisticated one and I think it would be better if you learned some before leaping in here. The problem with plasma is that it is non-linear (V;I characteristic); the more the current, the lower the resistance (not like metals which get higher resistance as the current increases and the temperature rises. To avoid one anode stealing all the current is could be necessary to supply it with a regulated supply voltage, in order to control the current it takes.
    A conventional flourescent tube will not strike without help. It uses a thermionic filament at each end which produces a cloud of electrons. There are attracted to the electrode the other end and produce ionisation on the way there in an avalanche effect and the long arc becomes established in a very short time. The 'heaters' are then switched off to prolong their life.
     
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