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Accelerating ions using Van de Graaff help

  1. Sep 19, 2010 #1
    First, let me say hello to everyone on the forums!

    A friend and I have converted a 36" CRT television into a HV source using its flyback transformer. We discharged the tube before taking anything else apart. We have the HV source attached to a thin wire, which causes the air around it to glow purple from ionization. When the wire is set to a certain distance from a larger curved grounded foil piece, you can feel the wind the ions create by bumping into neutral air, as well as a beautiful purple flow between the wire and foil.

    Now, we had an idea to 'lengthen' the gap between the HV source wire and the ground and create a more noticeable wind by introducing a very large external electric field near the HV source wire. We decided to buy a Van de Graaff machine with the dome constantly being vacated of electrons, so both the Van de Graaff dome and HV source wire would be (+).

    Our hope was that as our model (which had the grounded foil and HV TV wire at a fixed distance) would become more purple and eventually create an arc the closer we brought it to the huge (400 kV) field, because both the HV TV wire's electric field and the Van de Graaff machine's electric field being added together by the superposition principle for vector fields. It didn't do anything. :cry:

    Any ideas? The only thing I can think of is the electrons from the ground wire are going past the HV TV wire and shorting the Van de Graaff machine's large electric field and negating any useful effect from it... Any ideas on how to get this thing working?

    Here's a pic:

    Attached Files:

    • idea.png
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  2. jcsd
  3. Sep 28, 2010 #2
    what you have created by placing the vdg terminal close to the hv wire of the flyback transformer is a second electric field between the two. because the hv wire of the flyback is also a conductor the two electric fields (vdg terminal one side and ground other side) will concentrate their charge on the hv wire. Also since you have a very high positive voltage on the vdg terminal and a lower positive voltage on the hv wire of the flyback you essentially create an electron stream from the flyback wire towards the vdg terminal (electrons will always flow from the most negatively charge part to the most positively charged part, relatively speaking and something charged less positvely than something else is relatively speaking negatively charged) besides the original stream of electrons from the flyback wire to ground.
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