A theory of a possible method of fusion

It may be difficult to separate "theory" from "application," but let''s see if this helps facilitate the discussion.
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Richard Hull
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Re: A theory of a possible method of fusion

Post by Richard Hull » Sat Dec 10, 2016 7:26 pm

Steve, Did you ever think of actually doing any hands-on experiments with your ideas. I think the reason no one has commented much on this is that all sorts of magnetic fusion schemes have been tried for the last 70 years by folks a lot smarter than us and, thus far. all of those ideas have produced a glorious and multi-billion dollar zero power fusion result. I would forget magnetics in the area of fusion. Nice to think about, but with no real hands-on effort, all ideas remain pie-in-the-sky.

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Fusion is the energy of the future....and it always will be
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Re: A theory of a possible method of fusion

Post by steventw » Sat Dec 10, 2016 8:45 pm

Because I'm on a pension and after paying rent and bills and food I have no cash left over
And would be fairly simple to test for someone with a fusor already to test only need 2 perm Magnets

I've tryed to get a small vacuum chamber built but never pans out
And family won't help even tho they could easily help

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Richard Hull
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Re: A theory of a possible method of fusion

Post by Richard Hull » Sun Dec 11, 2016 9:40 pm

Sorry about your situation, but getting a small glass chamber maybe not even a demo fusor will allow a lot of simple magnetic experiments with plasma to be performed. Magnetics just isn't a path to fusion, though the big boys continue to spend the billions on it. It sure looks impressive I will say that, even in the small. But, looks can be deceiving, as we all know.

Richard Hull
Progress may have been a good thing once, but it just went on too long. - Yogi Berra
Fusion is the energy of the future....and it always will be
Retired now...Doing only what I want and not what I should...every day is a saturday.

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Bob Reite
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Re: A theory of a possible method of fusion

Post by Bob Reite » Fri Dec 16, 2016 3:06 am

Somebody likened containing plasma with a magnetic field to trying to hold Jello with rubber bands.
The more reactive the materials, the more spectacular the failures.
The testing isn't over until the prototype is destroyed.

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Richard Hull
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Re: A theory of a possible method of fusion

Post by Richard Hull » Fri Dec 16, 2016 5:44 pm

Nice analogy!

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Progress may have been a good thing once, but it just went on too long. - Yogi Berra
Fusion is the energy of the future....and it always will be
Retired now...Doing only what I want and not what I should...every day is a saturday.

steventw
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Re: A theory of a possible method of fusion

Post by steventw » Sun May 27, 2018 7:44 am

Got some money saved and will be building a simple version of a newer better design in a few weeks when back from holiday with parents
Will start build in about a month :)

Been doing a bit of research of costs
The bit that getting me is the plasma creation that’s simple to suit the design

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Dennis P Brown
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Re: A theory of a possible method of fusion

Post by Dennis P Brown » Sun May 27, 2018 1:33 pm

Remember, there are inexpensive methods to obtain vacuum pumps; besides getting high end pumps dirt cheap on ebay from time to time (I got two high end, two stage vacuum pumps in perfect working order for $10 each; they pull under two microns and handle huge loads. Shipping cost much more.) One can convert old refrigerator compressors in-order to create a plasma level vacuum. One can get these free by checking for junk thrown away. An old microwave unit may have a usable transformer and diodes (but remember, those x-formers are lethal and all wiring must handle that voltage.)

I encased an old microwave x-former and used it (in a cap based voltage multiplier stack) to create a 100 kV unit. It worked far too well and I abandoned it; far too dangerous.

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Re: A theory of a possible method of fusion

Post by steventw » Sun May 27, 2018 2:21 pm

Well I know a friend of a friend has 2 stripped down magnetrons from microwaves
Would do for proof of concept I guess

A vacuum chamber big enough is hard part and pricey
I have seen a 16gallon vacuum chamber and 2 stage pump for 960 aus

Not sure on what sorta power supply to get
Was thinking of just usen 2 copper wires and dc power to get hydrogen plasma started
Just a small amount and nothin to dangours like a magnetron might be

Just thinking of going small for proof of concept
Prob gona cost about 1500 - 2000 au
Then ramp upto a prototype
Have a mate that interested in investing in prototype if concept gos well

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Re: A theory of a possible method of fusion

Post by Dennis P Brown » Sun May 27, 2018 4:57 pm

You say
"2 stripped down magnetrons "


One does NOT use magnetrons for plasma excitation due to the danger. Any attempt is most likely to be fatal. Electrically sealing any such chamber properly is not something anyone is likely to succeed at and failure means exposure to a deadly level of microwave energy. That is not something you should consider nor attempt - using electrical excitation or RF is the only method that can be done in a safe manner.

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Re: A theory of a possible method of fusion

Post by Michael Bretti » Sun May 27, 2018 7:02 pm

Magnetrons can be exceptionally dangerous devices, and should not be taken lightly by the inexperienced. However, (as purely a scientific example and not an endorsement to do this yourself), it is certainly very possible to excite plasmas with a magnetron, and indeed magnetrons at this range are often used for high frequency rf plasma excitation. This can be accomplished through several means - direct coupling into a chamber through a waveguide, often through a microwave transparent alumina window, or a safer alternative of using a waveguide to coaxial transition. If using a sealed fully stainless chamber where rf cannot leak, it is quite possible with minimal risk of rf exposure. However this is only with a properly designed and well engineered system. Magnetron power can also be modulated to an extent, and I have even modified a old thyratron pulser to drive microwave oven magnetrons in a pulsed mode for short bursts of rf.

All this being said, it is still very dangerous for someone with no high power rf experience. I work at an accelerator facility so a magnetron at this level is rather trivial, but most people do not have training to use these devices for plasma excitation uses, and is still very dangerous regardless of any experience level. Not to mention you would require a circulator, stub tuner, and probably an absorbing water load at the outlet of the excitation region to absorb any leftover radiation. I also have numerous papers on the use of these magnetrons for direct excitation of atmospheric microwave plasma torches, where the plasma itself absorbs nearly all the rf from the magnetron. However, the system still needs to be well engineered and precisely matched to avoid losses. Unless you work professionally in the high power rf field, I would strongly advise against such endeavors. The info I provided above is for the sake of example of what is done in the laboratory setting, and in no means of any encouragement to pursue it oneself.

I did have the opportunity to mentor several senior capstone teams for a project using a magnetron for open-air heating applications with rf susceptors, but this was under strict supervision with significant laboratory safety requirements. Again, not something to pursue without the strictest safety requirements in place.

A much safer way of rf excitation if you wanted to pursue this route would be to use a triode tube oscillator. It takes very little power, and plasmas can be sustained at only 100W, not a kw that the magnetron outputs. Also the much lower frequency (several Mhz) poses much less risk, especially to the eyes which are highly efficient absorbers at 2.45Ghz.

As Dennis P. Brown suggests above, it is better and safer to stick with dc or low level rf excitation. Magnetrons pose too many unseen risks, and the damage will be done before you know it has even happened.

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