Fusor V construction - the process long running

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Richard Hull
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Re: Fusor V construction - the process long running

Post by Richard Hull » Sat Mar 28, 2020 2:01 am

During the great Chinese coronavirus outbreak and economic crisis of 2020, I have been busy during my sequestration. I supply some images of the latest effort. Busy, busy, busy....

I have put a lot of thought...(I think) into the mounting of the chamber and have allowed myself plenty of low conductance opportunity in the vacuum system so the the fusor, itself can garner all the glory on a pedestal all to itself. One can guess and only wonder about my passion for the Glidden ancient blue color "captain" to set off the appearance. What used to be plain unpainted wood, now has a splash of color. I find that this "new thing" in addition to $8.25 entitles me to a supreme, mocha latte grande at Starbucks.

The cross is mounted and my cathode to be tested in my first pass operation is a 0.5 inch bored copper sphere. (see photo)

I have over much space allowed to the fusor V table for whatever comes to mind later, (detectors, and extra bits and bobs).

You may find this tedious and my simplistic and obvious annotations tiring, but this is done for the newbies who might, in future, like to see the various slow and often necessary steps in planning and assembling a system. This also serves to show what some of the components look like being labeled. Most newbies can see the pretty pictures even if they seemingly refuse to read the FAQs.

Sadly, in spite of total confidence in the vacuum sealing of the fore line, turbo and high vacuum line up to and including the fusor chamber valve, the cross will have 6 points to seal, 36 bolts to tighten correctly before it can be proof against leaks. These must be tested en mass. Blessedly, this one final thing to complete in the vacuum system is all I need worry with.

Somethings are yet to be done: gas and control lines, chamber pressure metering, camera/viewport mechanism, targeting options and possibilities. (the latter will just be two blank offs during testing and first run-ups)

There is far more tedious assembly and crafting that is yet to be done, so I "remain calm and carry on".

Richard Hull
Attachments
FusorV cathode1.jpg
Fusor V 3.28 (1) Anno.jpg
Fusor V 3.28 (3) Anno.jpg
Fusor V 3.28 (4) Anno.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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Jim Kovalchick
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Re: Fusor V construction - the process long running

Post by Jim Kovalchick » Sat Mar 28, 2020 10:07 am

Richard,
Have you thought about shielding? The crosses can really scream at 40 kV. Of course, my viewpoint is the worst, but I had to shield the cross itself.

I'm curious about your choice of copper for the grid. You're not worried about melting it?

Jim K

Roberto Ferrari
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Re: Fusor V construction - the process long running

Post by Roberto Ferrari » Sat Mar 28, 2020 1:23 pm

Richard
I am a bit confused about the image of your HV feedthrough.
The CF flange (a Varian one) seems to lack the sharp edge to seal against the copper washer.
Please comment.
Roberto

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Scott Moroch
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Re: Fusor V construction - the process long running

Post by Scott Moroch » Sat Mar 28, 2020 4:55 pm

Robert,

It is likely a rotatable conflat. He will have to insert the inner SS ring with the knife edge. It looks like the feedthrough is welded or Silver Soldered to the outer SS ring. Look at the picture I attached for reference.

Scott
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2-75-od-conflat-flange-193.png
2-75-od-conflat-flange-193.png (45.76 KiB) Viewed 1430 times
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Roberto Ferrari
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Re: Fusor V construction - the process long running

Post by Roberto Ferrari » Sat Mar 28, 2020 5:38 pm

Scott
Understood!
thanks
Roberto

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Richard Hull
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Re: Fusor V construction - the process long running

Post by Richard Hull » Sat Mar 28, 2020 8:12 pm

Scott caught it. It is rotatable. I took the ring off to protect it while handling and photographing it. Kinda' paranoid about keeping that stuff nick free.

Actually, it mates to another rotatable on the cross as the insulator is not on the insert, but on the flange itself. This would make it only rotatable to the next bolt hole angle on a fixed mating flange. Thus I chose one of the crosses rotatables for fine alignment.

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 construction - the process long running

Post by Richard Hull » Mon Mar 30, 2020 9:15 am

First light with air! I managed to seal all the flanges on the cross really well, apparently. Images tell the tale. I also reworked the plywood board power system for the baratron into a smart looking metal box. I also machined a mount for the camera that allows for 3-point spring loaded alignment and ran a #4 ground line to the fusor plate base.

I was smart. I let the mechanical pump drag the entire system with all the valves wide open, down over 20 minutes, As the entire system went from a temporary stall at 14.3 microns, all the way down to 9 microns where it truly seemed to bottom out, I powered fusor V up on residual air. No sparking or sparkling flashed were seen and the beaming is obvious. I ran up to 15kv into the system at 10ma. This was to glow clean a bit and heat the target flanges. Even with 150 watts going in for about 4-5 minutes, the copper Ball nor its copper stalk glowed. I am sure this will change when doing fusion. We will see. My next mission is to install the D2 gas metering system.

Damned turbo pump!! In spite my trying to kill the conductance with long lines, it is too deep a pumper and fast! Rats! I did ultimately turn it on only to see how long it would take to extinguish the glow. I did this at 10kv applied with 9 microns of air. From the time I pressed the on-button on the turbo pump I clicked my stop watch and when it stopped glowing I hit the stop watch and it took the pump 7 seconds to hit extinction. I quickly looked at the speed gauge and it was just off, zero maybe one tenth full speed still deep in the red zone. the baratron went into minus micron territory within 12 seconds about the time the pump hit its slow resonant point, buzzing the table mildly for a second or two. I continued to drop deeper into the minus zone until it settled down after the 4 minute wind up. I tried to seal the cross off with its valve and it dropped showing the baratron negative numbers dropping as it approached positive micron readings. The wait was a couple of minutes for it to hit 10 microns. I barely cracked the chamber valve and the baratron went negative (sub micron). There is going to be a trick operating this puppy without blasting D2 up like it is going out of style. I wish my turbo had a speed control.

I got to thinking....(always an iffy process here)... perhaps if I put a valve at the turbo, I could keep the pressure in the long KF 25 line down and then manage with the valve under the cross. I hate the thought of putting some sort of small holed diaphragm in one of the KF coupling ring centers to strangle the turbo.

Oh well, Enjoy the two pix. I did touch out the 20 or more little white pixels from the picture on the Monitor. Fusor IV killed a those pixels. I have a lot of cleaning up to do as the lab has almost no usable table space. The bench surfaces are all filled with the many hand tools, drills, etc.

Richard Hull

P.S. Sorry Jim, I did not respond to your shielding question. I imagine this smaller system will be a screamer X-ray wise! I will measure with air in a day or two once I put the Polyethylene collar around the base of the insulator, (as on fusor IV), so I can get the voltage up to x-ray level.
Attachments
Fusor V 1 3.30.20.jpg
Fusor V 2 3.30.20.jpg
Fusor V 2 3.30.20.jpg (40.8 KiB) Viewed 2001 times
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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Jim Kovalchick
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Re: Fusor V construction - the process long running

Post by Jim Kovalchick » Mon Mar 30, 2020 3:04 pm

Richard,
Congrats on the new fusor. One nice thing about using air to glow clean is the ability to start your work at lower voltages without having to use a massive chamber pressure to light the plasma. To get 7 kV to light with d you would be pushing over 50 microns in that cross. I have to go higher than 25 kV to get to a pressure I think is reasonable for running my turbo.

Jim K

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Richard Hull
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Re: Fusor V construction - the process long running

Post by Richard Hull » Mon Mar 30, 2020 9:35 pm

Thanks Jim for your input. I not only have a lot left to do, but a lot of fresh and different operational procedures to learn if this effort is to pay off to my satisfaction. I am a hard guy to please. Harder on myself than one might imagine. I am instantly willing to chuck a bad move to either return to an old venue or to try yet another approach. I am fully committed to make the most of the cross effort. I feel I am far better armed, outfitted and capable in assembling systems. When I look back at the 1997 first efforts by myself, as a neophyte, with no support beyond books, the many skills and accumulated knowledge I brought to the effort, I now realize just how much I had yet to learn.

I am drawn to this system due to the possibility of easy experimental alterations that the larger spheres lack, even if the neuts are not what I would like in the end.

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 construction - the process long running

Post by Richard Hull » Wed Apr 01, 2020 7:57 am

I show some X-ray data here in the single image attached. I have straightened up a bit and moved the TCP-40 turbo controller to the extreme left of the table, mounted the neutron counter and decided to operate to a decent x-ray level. With the Turbo on and fine tuning the chamber valve I operated at up to 20kV @10ma.
I was amazed at the near zero x-rays left, right and forward of the system. the camera is on the rear of the cross. directly behind the camera at the grey wall I read about 7 mr/hr, however at the top of the deuterium tank pointing down at the window I measured 50 mr/hr. on the 100 mr/hr range. For measuring front, right and left I used the 1mr/hr range and read no more than 0.2 mr/hr. Not bad yet as the rear wall is taking it on the chin.

No reading at all was apparent at the power panel.

Richard Hull
Attachments
Fusor V 3.31.20 X-ray (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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