Words to the wise

For posts specifically relating to fusor design, construction, and operation.
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Richard Hull
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Real name: Richard Hull

Words to the wise

Post by Richard Hull »

It was recently noted by Richard Hester in a post that one should tread lightly in using higher voltages on the fusor.
I couldn't agree more.

All Builders should strive to start small and work up.

If I had and order of construction and acquistion it would be as follows.

Acquire:

vacuum pump
vacuum gauge (simple TC type)
Hv supply 0-5kv 20ma. This should be metered. (make or build)
Some sort of vacuum chamber

Build:

Fusor demo using air to study gaseous discharges and how they react at different voltage and current drive levels. Work on and refine vacuum techniques. Get a feel for the multiplicity of conditions and adjustments in a simple demo system. (it only gets more difficult from here.)

Acquire:

geiger counter
Better chamber preferably metal for real fusor vessel.
Make second supply 0- 20kv or more with a minimum of 10 ma capability. ( build it yourself or modify an X-ray supply) Make absolutely sure you have full control over the voltage from 0 volts to its maximum. Also make sure it is fully metered (milliamps and volts)

Build:

Real fusor, but run on air.

Again study the new higher voltage regimes and gain tighter control over vacuum technique. Achieve star mode. start measuring X-rays in the 10kv and above regions with the geiger counter. Become familiar with your X-ray leak points. Shield these points and continue to monitor. Enjoy these "happy times" for it only gets more complicated.

Acquire:

Deuterium
gas handling plumbing, regulators, valves fittings.
Try and get or make a neutron counter.

Build:

Gas handling system

Run fusor for real using knowledge gained at earlier stages. Note that easily measurable fusion begins after 15kv.
If your supply goes above 25 kv you should easily get 100,000 n/s from the fusor. Monitor really closely the X-rays with the geiger counter above 20kv for NEW leaks or inadequate shielding already in place. Above 30kv X-rays are really super dangerous. Be ever mindful of new exposure points.

Above 40kv you are in a special class where you might consider a separate outbuilding away from the kids and pets.
You now have to worry about "skyshine" or "basement shine" if you have inhabited areas above or below the fusor for both neutron and X-radiations.

The key is to not just start from zero and make a full blown fusor with a 100kv industrial X-ray supply. You will not have a real easy time of it.

Make the slow and logical progression and you will find success easy at each stage.

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
guest

Re: Words to the wise

Post by guest »

I' ve already retooled on higher voltages.
Im going to stick to below 20 kv for the time being.
( I will set up but not run my xray supply )
I will conduct pulse but at reduced levels.
I've just now got my vacuum measurements and gauges working good.
Got the geiger counter rolling.
Pmt is just waiting on a schintilator.
Got 2 different power supplies.
I have a glass bell jar.
I'm having a metal chamber built for me.
Requirements for safety were getting hairy.
I never quit proceeding towards a continous fusor.
My deuterium gas is on order finally.
Just need a good vacuum pump now and will be pretty set.
I had in mind to do your list anyway.
I've reduced my expectations for now on high power stuff till I get more setup and practiced in my new local.
I'm a dry run freek.
Gathering more tools... more materials..... more EBAY.
My EBAY skills are rising.
Nothing has come in any order of project need so far.
I'm a patient guy.
I've waited almost 4 years now...A year won't kill me
... but impatience might.
Are the natives getting restless Richard?
This stuff is fun for me... why miss any of it?.
Fusion is fun after all.

Larry Leins
Physics Teacher
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