Fusor V - yet another whack at it.

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Richard Hull
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Fusor V - yet another whack at it.

Post by Richard Hull » Fri Nov 13, 2020 8:04 pm

Well it begins anew! The 6 way 6-inch cross seen here cost me a gang o' bucks used, but in great shape. (Typical 3 rotatable and 3 fixed flanges.) It will cost another gang o' bucks to put the "stoppers" in this "bottle". I might try coiled 1/4" copper tubing soldered to the arms for cooling. much to mull over. Lots more room in this one compared to that little 2.75" cross.

Richard Hull
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6-inch cross (1).JPG
6-inch cross (2).JPG
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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Mark Rowley
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Re: Fusor V - yet another whack at it.

Post by Mark Rowley » Fri Nov 13, 2020 8:25 pm

That’s a beaut Richard!
The diameter of the arms look big enough where coiling copper tubing won’t be a problem.

Mark Rowley

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Jim Kovalchick
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Re: Fusor V - yet another whack at it.

Post by Jim Kovalchick » Sat Nov 14, 2020 6:23 am

My current fusor is a 4-way 6 inch cross. No matter how much I tried, I struggled with getting classic symmetrical star beams. I plan to go back to a ring grid that points its open ends into the center, unflanged portion of my cross. Assuming symmetry enhances fusion rates, I think this is my best path of success.
Richard, you may want to consider a different grid shape for Fusor 5a.
As for me, my efforts are stalled by work demands. I am currently in quarantine in Europe in advance of a two week plant evaluation. Maybe I can work in parallel with your own 6 inch cross efforts when I return to my lab in December.
Jim K
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20201114_081156.jpg

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Richard Hull
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Re: Fusor V - yet another whack at it.

Post by Richard Hull » Sat Nov 14, 2020 2:59 pm

I am not going to be a speed demon on this one. It could be spring or later before it is in operation. Sorry to hear about the quarantine. Got some good books to read?

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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Richard Hull
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Re: Fusor V - yet another whack at it.

Post by Richard Hull » Mon May 31, 2021 3:50 am

In keeping with my Nov last post here, the speed is slow. I have done nothing on fusor V until this past week. I only today gave the old insulator a refurbish, mounted it and ran it just long enough to hit about 20kv with 4.5 microns of D2 and it was very sad as this is the first Run since Dec 2020. But it is coming along about as expected. I attach the images taken today.

Richard Hull
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May30 21.JPG
Modified the insulator a bit. Keeping my fingers crossed
may30 21 #2.JPG
star with new grid system easy to get but still It will take a few days operation to bring the system back if at all.
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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Re: Fusor V - yet another whack at it.

Post by Dennis P Brown » Mon May 31, 2021 11:24 am

The turtle wins over the 'too careless" faster hare.

I am guessing you are getting your new fusor ready for the October HEAS meeting? I certainly do not want to miss this one.

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Richard Hull
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Re: Fusor V - yet another whack at it.

Post by Richard Hull » Mon May 31, 2021 6:31 pm

I will not even start on the 6" cross! I am looking at about $800 for the 6" blanks and a lot of machining on all but two. If the current system seen in the images above is restored to full functionality, that will be the fusor shown at HEAS! The big cross might be in the flea market for $600! (what I paid for it). Lots to do and to mull over. Lots of my inventory will be up for sale as well. I just have too much stuff!

I am also looking at a possible cylindrical fusor if I sell the giant cross. (only two big end CF plates. All the rest can be 2.75 conflats or even KF fittings)

The big cross ain't dead yet, but on life support. FACT!... I have bought three used Lincoln Continentals for less money "each" in the past than it will cost me to outfit those cross arms!

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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Richard Hull
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Re: Fusor V - yet another whack at it.

Post by Richard Hull » Fri Jun 04, 2021 2:26 am

Today was an illumination. I was working fusor V and didn't like how it was advancing. 6 microns 28kv 8ma yielded only 450 counts on the neutron counter. The star was weak and diffuse. While the Deuterium pressure seemed good, I should have more counts. I did two things. For the first time ever (that is in 16 years), I fully evacuated my entire D2 line back to the tank! It had no leaks. The line consists of about 1.5 feet of 1/16-inch bore copper lines the sapphire leak, a small swagelock leak valve, a main line cutoff valve, and CO2 cartridge reservoir and the tank gauges. I re-pressurized the line's gauges, valves and reservoir to my usual 2 psig with pure D2.

Next, I pinched off the flow to the turbo to a lesser degree than usual, (will gobble up more D2, but allow for good flow against the turbo.)

I started over and brought the pressure in the fusor up to 8 microns so it would light off at a lower voltage. I figured around 15kv. I took the voltage up to 25kv, no light off. I took it up to 12microns. At 30kv no light off. I worried something was wrong and checked all the instruments, lines and supply. I took it up to 15 microns and BOOM! At 26kv it lit off with a razor sharp star and tiny dot at the center. the Neutron counter roared to over 25,000 cpm. I inched the voltage up to 30kv @ only 7 ma and counted 31,000 cpm and finally hit 36 KV @ 5ma and 16 microns yielding 36,661 CPM. (with my conversion factor obtained last HEAS, that meant 143,000 n/s TIER.) All the time, the star was razor sharp with tiny bright dot at the center. I figured I would call it a day after photographing the star and instrument panel. there is not much dynamic range in the video image and a photo of the monitor screen is not indicative of the razor sharp visual image seen by the eye.

I can't say whether the flushing of the gas lines or the faster flow of D2 with less pinch-off was the cause of this stunning difference. I tend to feel the major agent was flushing of lines and the higher flow rate added to the effect. Still, look at what I had in the top line as the best I could do and then look at the results of what I did! It took about 1/2 hour of work to make the difference. Wow! Fusor V is coming back!

Images below

Richard Hull
Attachments
June 3 21.JPG
I stopped using the big counter after the bad runs and used only the NIM bin Ortec counter.
June 3 21 star.JPG
No where near what I saw as razor sharp lines. a double xfer screen to camera loss is obvious. Wow, it looks like a super nova in a star field due to the forever damaged individual camera pixels.(Neutrons and x-rays)
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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Aidan_Roy
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Re: Fusor V - yet another whack at it.

Post by Aidan_Roy » Fri Jun 04, 2021 2:58 am

Wow! Even with the quality degradation, I can tell that must have been an incredible sight! Did you make any changes at all to the grid geometry since last October? If not then I would hazard a guess that it was primarily the flow rate causing that awesome star, with the increased purity from the freshly purged line as the helping factor. Given those numbers I would try for a quick run as close to the upper operational pressure limit of your chamber as you can get without changing how much the turbo is pinched and see if that’ll really throw it into high gear. It sounds like you may have found a sweet spot for that set up.

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Re: Fusor V - yet another whack at it.

Post by Gunnar Mein » Fri Jun 04, 2021 3:59 am

Very inspirational picture!

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