Accelerating ions using Van de Graaff help

In summary, two friends successfully converted a CRT television into a high voltage source using its flyback transformer. They created a purple glow and noticeable wind by attaching the HV source to a thin wire and a curved grounded foil piece. However, their attempt to enhance the effect by introducing a large external electric field using a Van de Graaff machine did not work, possibly due to the electrons from the ground wire shorting the electric field. They are seeking ideas on how to get their experiment working.
  • #1
blainiac
50
2
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:
 

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  • #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.
 

1. What is a Van de Graaff generator?

A Van de Graaff generator is a device that uses static electricity to generate high voltages and create electrostatic charges on its surface.

2. How does a Van de Graaff generator accelerate ions?

A Van de Graaff generator accelerates ions by using electrostatic repulsion. The generator has a large metal dome that becomes positively charged, and a belt or roller that carries negative charges to the dome. The positively charged dome then attracts the negatively charged ions, giving them energy and accelerating them to high speeds.

3. What are the applications of accelerating ions using Van de Graaff generators?

Van de Graaff generators are used in various fields of research, such as particle physics, nuclear physics, and materials science. They can also be used in medical imaging and cancer treatment, as well as in industrial processes like coating and painting.

4. How does Van de Graaff acceleration compare to other methods of ion acceleration?

Van de Graaff acceleration is a relatively simple and efficient method of accelerating ions compared to other techniques like particle accelerators or laser-driven acceleration. It can produce high energies without needing huge facilities or complex setups.

5. What are the limitations of using Van de Graaff generators for ion acceleration?

One limitation of using Van de Graaff generators for ion acceleration is the maximum energy that can be achieved. The generator can only produce energies up to a few million electron volts, which may not be enough for certain research applications. Additionally, the ions can only be accelerated in one direction, limiting their range of applications.

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