latest attept

Current images of fusor efforts, components, etc. Try to continuously update from your name, a current photo using edit function. Title post with your name once only. Change image and text as needed. See first posting for details.
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steventw
Posts: 49
Joined: Fri Jan 24, 2014 1:45 pm
Real name: Steven Whittam
Location: Melbourne/Australia

latest attept

Post by steventw » Mon Jun 17, 2019 10:14 am

hey

heres picture of latest attempt
test1.jpg
left on for a min, melted grid, think where soldered.
was 2 kinda tube shaped grids
and 8kv neon transformer...

older bros friend from work came over to have a look, was like sure both looked in and was doing nothing, relised grid had melted in a spot.

funny thing i noticed how plasma seemed to be traveling to outer wire and was more present there.
not sure if vacuum or power issue past -30hg.
not sure if should turn magnets around other way which would be really hard give there magnatised to bolt, with 25kg pull, but i know moving power cables around didnt change anything.

steventw
Posts: 49
Joined: Fri Jan 24, 2014 1:45 pm
Real name: Steven Whittam
Location: Melbourne/Australia

Re: latest attept

Post by steventw » Mon Jun 17, 2019 10:36 am

would really love to try my idea with tho's bowl shaped magnets. the the primer fields videos on youtube.
2 rows of magnets spin up to lead into middle.
already got that built.
anyone know the person with the bowl magnets?
would be nice to be able to combine the 2.
heck i'd send my prototype to someone with more experience and able to test.....

from steven

older test that shows my prototype well. little out of alignment because of previous chamber that bent out of shape when got to -20hg and sucked lid in cause because wasn't centre. thanks to my older bro david who fixed it, tho he also built the frame for me to start with. was basically dead centre when first made.
oldertest1.jpg

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Richard Hull
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Re: latest attept

Post by Richard Hull » Mon Jun 17, 2019 5:45 pm

I think we have mentioned there is not enough vacuum, (too much pressure), in your system. You can never use a stock round vacuum gauge in any real serious vacuum system to read the true pressure. Inches of vacuum is not an indicator of vacuum. Air pressure is typically 760mm (29.92126 inches). A round vacuum gauge can be in error by 60mm or more and can read 30 inches of vacuum. Plasma vacuums are always less than 1mm. 1mm of pressure is 1 torr, that is, 1/760th of an atmosphere. Really nice usable plasma pressures are 1/100th of a millimeter...1/100th of 1torr. This is about ten millionths of normal atmospheric pressure.

Only electronic vacuum gauges can read this low and are scaled in microns. A micron is one millionth of an atmosphere. 10 microns is a nice plasma vacuum. However some crude vacuum plasmas are noted to begin at 100 microns. Real fun stuff starts around 25 microns.

Such vacuums are never obtained in large chambers using only a good refrigeration pump. A really superb refrigeration pump with fresh oil can pull a 6" diameter, well sealed, stainless steel ball down to 50 microns in 5 to 10 minutes. A professional scientific pump can pump the same ball down to 10 microns in a minute or two. To the eye, a refrigeration pump and a scientific pump look identical. The differences are a matter of tolerances within.

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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Dennis P Brown
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Real name: Dennis P Brown
Location: Glen Arm, MD

Re: latest attept

Post by Dennis P Brown » Tue Jun 18, 2019 9:02 pm

A few comments; first, glad you are building a working system. That is the first step towards getting towards one's research goal. Second, plastic connectors on wire that supports an arc is not a good idea. Ceramic holders are rather important to both insulate and handle the high temps that plasma's produce. Third, the level of vacuum one needs depend's on what one wants to achieve. If you want a large plasma (not an isolated arc), then what Richard is telling you is important.

Relative to the later two issues I mentioned, having materials that can't handle vacuum (wood, plastic, and also many oils/greases and the list goes on relative to many unacceptable materials) is not something that belongs in any system meant for vacuum operation. Use glass, ceramics, uncoated wires, and clean metals (avoid any brass) and keep the system clean. These things will better enable one to both pull and keep the desired vacuum they require.

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