Voltage multiplier inside vacuum chamber

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fruitytuter
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Voltage multiplier inside vacuum chamber

Post by fruitytuter » Sat Jul 02, 2011 4:53 pm

Question:

Has any one ever constructed a fusor whereby high voltage ac was fed into the vacuum/fusion chamber then multiplied inside the chamber via a Cocroft voltage multiplier? This would involve small form factor capacitors and diodes encased in insulating resin housed inside a glass or acrylic tube. This tube would span from the outside edge of the chamber to the center where it would attach to the electrode.

This design would have some advantages:

The high voltage dc would be in the very center of a grounded metal chamber reducing shock hazard, corona losses outside the chamber, and the size ( cost ) of the high voltage feed through because only the HV ac would need to be insulated.
Say for instance a 4 stage voltage multiplier is inside of the chamber. 40 kv dc can be achieved inside while the feed through only has ~10 kv.
Because the voltage multiplier is inside the chamber it becomes easy to experiment with multiple grids by attaching grids to various stages of the multiplier.

This design would have one disadvantage:

High voltage components are large and building a voltage multiplier inside of the vacuum/fusion chamber would require a large chamber and small HV components. Also run time would be short because of the low heat dissipation of the diodes in a near-vacuum environment.

I am considering this design because very high voltage dc can be achieved inside the grounded chamber with less shock hazard and with a lower voltage feed through, maybe even a spark plug.

Does this design seem practical and are there factors other than those stated above that would effect the feasibility of this design?

Wilfried Heil
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Re: Voltage multiplier inside vacuum chamber

Post by Wilfried Heil » Sat Jul 02, 2011 5:43 pm

Hello and yes, something like that has been done. Have a look under "Dynamitron" high voltage generators.
This is not a vacuum chamber, but one filled with an insulating gas like SF6.
http://accelconf.web.cern.ch/Accelconf/ ... 5_0227.PDF

It would be feasible to do this in a fusor, but in general, one would like to keep the chamber as clean as possible, with no plastic parts exposed to the plasma. Like you noted, the components would need to be mounted in such a way that the heat from the multiplier can be dissipated.

fruitytuter
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Re: Voltage multiplier inside vacuum chamber

Post by fruitytuter » Sat Jul 02, 2011 6:20 pm

Thank you very much, the dynamitron seems to be a very compact particle accelerator compared to other designs. I am also curious about the use of a van de graff generator as a voltage source. It has the ability to create very high voltage but at very very low amperage. Because the voltage determines the kinetic energy of the ions, a van de graff generator should be able to produce high ion energies at a lower flux because of the low amperage.
Oh and one other question, Has any one ever used lightening as a power source for a fusor? Lightening packs an incredible amount of high voltage electrical power which would be nearly impossible to recreate at those power levels. Of course the reactor would go out with a BANG and have to be rebuilt but it could produce record breaking neutron fluxes and valuable data not found in the current power input levels of 2011 in even the highest energy labs around the world.

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Chris Bradley
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Re: Voltage multiplier inside vacuum chamber

Post by Chris Bradley » Sat Jul 02, 2011 6:34 pm

Josh Cherek wrote:
> I am also curious about the use of a van de graff generator as a voltage source.

Thorough searching on the site [use the 'seach' button] will yield the best results, especially as you are very new here. More reading, less questions - for now.

If you had done the search you should've found;

viewtopic.php?f=18&t=7842#p55801

but the first key to a good search is to spell what you are looking for correctly; 'Van de GRAAFF'.

Good luck with your bountiful reading!

fruitytuter
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Re: Voltage multiplier inside vacuum chamber

Post by fruitytuter » Sat Jul 02, 2011 6:40 pm

Thanks, I'll use the search feature next time. Also what do you think about the use of lightening as mentioned in my second posting?

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Chris Bradley
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Re: Voltage multiplier inside vacuum chamber

Post by Chris Bradley » Sat Jul 02, 2011 7:22 pm

Josh Cherek wrote:
> what do you think about the use of lightening as mentioned in my second posting?

....use... the.... >>search button<< !!
viewtopic.php?f=15&t=7194#p49066


As for coupling a lightning rod to your fusor, or some such, well, a bit Frankenstein-bonkers, really, isn't it? This site is intended for the presentation of practical experiments, not wishful fanatasies.

Tyler Christensen
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Re: Voltage multiplier inside vacuum chamber

Post by Tyler Christensen » Sat Jul 02, 2011 7:27 pm

I'm quite curious, how is this not a practical amateur experiment? One would probably want a tall collector rod, then shoot a rocket up with a thin wire attached to the top of the rod (the standard way to induce lightning). If this rod ran through a fusor before getting to the ground, it could make momentary fusion. Total cost, about $30 for a rocket kit, and the cost of a fusor.

I would support someone in trying this if they so desired, however I don't think it would yield many neutrons if any.

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Chris Bradley
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Re: Voltage multiplier inside vacuum chamber

Post by Chris Bradley » Sat Jul 02, 2011 8:19 pm

Tyler Christensen wrote:
> I'm quite curious, how is this not a practical amateur experiment?

OK, so I should clarify that this is just my opinion.

If lighting storms overhead are common for you, and you can reasonably anticipate maintaining and readying a live rocket at the same time as preparing your chamber, evacuating it, flowing in the D and getting all the RFI hardened neutrometry ready in anticipation of your rocket launch, all taking place in, presumably, a remote shed that you can operate remotely (for fear of piping in a direct lighting bolt into your house), then I guess it is practical.

...Just seemed a tad towards the impractical side, to me. It's probably a walk in the park for a well seasoned amateur.

fruitytuter
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Re: Voltage multiplier inside vacuum chamber

Post by fruitytuter » Sat Jul 02, 2011 9:22 pm

I think the easiest way to perform this experiment would involve creating a vacuum, injecting deuterium to the correct pressure, and then (assuming that the chamber and valves are well sealed) all valves would be shut and the sealed chamber would be unbolted and transported to a suitable location during a storm.

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Richard Hull
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Re: Voltage multiplier inside vacuum chamber

Post by Richard Hull » Tue Jul 05, 2011 2:40 pm

I have discussed this ludicrous and dangerous ideal in the main discussion. You have to warrant the proper polarity or no fusion will occur and a lighning rod will operate a small electrostatic motor only. I have done this.

However the fusor requires current in milliamps from such a rod and you will never get it and then there is that polarity thingy.

If lightning hits, you will get the amps alright, but (polarity???) Most of those amps will never go in the fusor though as there are a thousand other sweeter and bekoning lower impedance paths in and around this hypothetical lighting operated fusor.

Stupid, stupid, stupid. How many here have generated and seen real 12 foot arcs crawl all over every thing in sight except where you want the energy to go. No experience just pipe dreams and wild ideas.

My Tesla Magnifier 10E Circa 1996 @ 6KW ten foot arcs one hits my Nikon lens. Bye-Bye Nikon electronics.

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