Experiments with a demo-fusor

It may be difficult to separate "theory" from "application," but let''s see if this helps facilitate the discussion.
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Matt Salek
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Experiments with a demo-fusor

Post by Matt Salek »

What are some experiments that can be preformed using a demo-fusor? What can be measured and what varibles could there be? Thank you for your help.
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Richard Hull
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Re: Experiments with a demo-fusor

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The demo fusor can teach a lot about the action of plasma in a vacuum. Pressure is critical here. This is why you must have a good vacuum pressure gauge. Voltage is needed to break down the electrical resistance of the gas under study. This is why a method of accurately measuring the applied voltage is demanded. Current varies wildly based on pressure and voltage. This is why an accurate current meter is demanded. Without all three instrumentalities no real experiments of lasting, quantitative value can be performed. Your eyes coupled with the mental integration of the three main plasma variables mentioned above are your key to owning, internally, at a gut level, what plasmas are all about. At this point you are in command of the plasma at our level of its use.

The experimenting can take a year! It did for me, as I was boundlessly curious in my first two demos fusors. Being an engineer I knew measurements were key. I read the book Ionized Gases.
The book taught me that the ideal is rarely met. The experimentation taught me the hands-on dynamics of plasmas at the lower current levels where self-generated magnetic effect just do not interfere with the plasma, but that strong local external magnetic fields will.

I also learned about external breakdown effects due to strong electric fields as well. There is so much to learn, it took two years of experiment with my demo systems and a lot of study and reading from books before I dared to tackle fusion. Remember, there was no amateur fusion extant on the internet. I was all alone with only a spark planted in me. I did bring a vast array of skills gathered over my 52 years of life to the effort back then. I am still getting smarter, I think, I hope at 75. I worked slowly then and even slower now.

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
The more complex the idea put forward by the poor amateur, the more likely it will never see embodiment
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Liam David
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Re: Experiments with a demo-fusor

Post by Liam David »

There are many, many things to study.

The most basic: cathode voltage, current, pressure, and their behaviors.

A myriad of others:

Various chamber/cathode geometries
Breakdown voltage (vs. pressure, geometry) (Paschen's Law)
Voltage hysteresis in maintaining the glow discharge
Plasma spectroscopy
Cathode temperature (vs. voltage, current, pressure, geometry)
Poissor radius (vs. voltage, current, pressure, geometry)
Effects of asymmetry
Light output during initial discharge (ns timescale)

It all depends on your access to equipment, budget, and experimental design.
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