Aidan Roy - My Fusor Progress

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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Aidan_Roy
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Aidan Roy - My Fusor Progress

Post by Aidan_Roy »

Today marks the beginning of my documented fusion efforts.

Background:
I recently won a leybold trivac D2.5E pump from the San Jose auction that was posted about in the items for sale section. Thanks to help from Richard Feldman I was able to cheaply ship the pump to myself here in Massachusetts so here’s a huge and well deserved shout out to him.
The pump arrived here yesterday and I changed the oil and cleaned up the basic parts and some internals. After a few chats with leybold customer service I was able to get my hands on a wiring diagram for the motor, which is a dual voltage motor that uses a 7 pin amphenol connector, and power it up today. I connected it to what is the beginning of my system that was made from parts that I have been collecting since March and ran a full test of the pump’s and my system’s abilities. What follows is a picture of my set up and then some more information. This will be my running post of progress from here on out.
Initial set up - Diff. Pump, Foreline, and mechanical pump
Initial set up - Diff. Pump, Foreline, and mechanical pump
The whole thing was set up on the counter in my kitchen and was temporary as it was only intended as a test. The pump ran smoothly and I attained 11 microns at the lowest. It was pumping the entire volume of what was pictured. You may have noticed that the diffusion pump is sitting upside down and that was because I was also using the opportunity to chase leaks in my brazing job that attached my valve to the pump outlet. The diffusion pump only has its jet stack in it currently. I measured pressure with an MKS901P gauge over the serial connection on my computer. No pictures were taken of the pressure readout because I forgot and didn’t think it was too important for this time. I think that if I also took apart the motor of the leybold pump I would have been able to go to a lower Pressure but I don’t know that it is worth the effort to do so. Comments on this front are welcome.

Thanks for reading.
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Richard Hull
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Re: Aidan Roy - My Fusor Progress

Post by Richard Hull »

If you have an honest 11 microns at the head of the pump do not touch it! With fresh oil, it is doing well.

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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Dennis P Brown
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Re: Aidan Roy - My Fusor Progress

Post by Dennis P Brown »

Agree with Richard.

You have a outstanding start on your fusor project. The vacuum system is the backbone of any system and 11 microns at the diffusion pump foreline is well within the desired range.

Your KF fittings are solid and your brazing weld is holding up very well. Do realize that much of that 11 microns is likely due to out gassing of water vapor - likely that system will do far better once it is mostly closed off from air access.

I've used a water cooled D.P. for years and prefer it over my turbo. Your D.P. also looks like it has a water cooling connectors for the oil - mine does and I have a valve connected so I can quickly cool the oil to protect it after I shut my system down. That ability to cool the oil has come in handy.

I guess your next test will be adding D.P. oil, water cooling and then testing that unit (assuming you have a high vac gauge.)

Is that a cold trap on the D.P.'s inlet? Also, do you have a gate valve yet?

I look forward to your future posts.
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Aidan_Roy
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Re: Aidan Roy - My Fusor Progress

Post by Aidan_Roy »

Thanks Richard and Dennis.

The only reason I suggested a complete tear down was because according to the maintenance sticker on the side of the pump, it was last worked on in 2012 with another full work up scheduled for 2015. As far as I know, some of those components haven’t seen light in nearly 8 years. Even with the good performance that worries me a little.

Dennis, that is indeed a cold trap on the diff. pump. Contrary to some of my previous postings, it was actually far easier to leave the thing on because, unlike the pump, it has a standard ISO63 inlet and was made for attaching to the diff. pump inlet so no need to do any kind of advanced machining of a custom adaptor. I have already acquired a right angle bellows valve for that part as well. Sadly, my gauges only measure reliably down to 1x10^-5 torr but I’m going to work with them for now because measuring much lower than that isn’t needed for my work quite yet. Interestingly, they have a few different emulations that can technically read down around 10^-8 but anything lower than that 10^-5 and you quickly lose accuracy and reliability.

Aidan

Edit: I actually do have a picture of the pressure readout, I never turned off the program just disconnected the gauge.
Pressure readout in Torr
Pressure readout in Torr
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Richard Hull
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Re: Aidan Roy - My Fusor Progress

Post by Richard Hull »

I am currently using a precision D5 pump. I bought it in 1994 at a hamfest for $20 because it was seized up. ( the guy said the price was for the working motor).

I dumped the old oil and put in a quart of Marvel's Mystery oil. I let it sit for 1 month. I then tapped the large pully wheel with a hammer in the indicated direction of rotation. It immediately moved. I then turned the pump's large pulley wheel rather freely by hand for 5 or 6 revolutions. I put on the belt and ran the pump with the mystery oil in it. It ran for 10 minutes. Dumping the oil showed a good bit of fine rust and some debris. I then filled the pump with TKO flushing oil (Lesker). I ran it for 3 hours. I dumped that oil and very little rust discoloration was seen. I filled with proper belt drive vacuum oil and ran it for about 5 minutes. I mounted the TC gauge that I had at the head and it pulled to below 10 microns! I have never taken the pump apart! It has been the main pump for fusors III and IV since 1999 and is still my main mechanical pump. I think I changed the oil about 5 times since 1999 and it runs free of grit on dumping. It is merely discolored like honey. It can still yank the entire system down to 10 microns or so.

Never ever rebuilt or opened in 26 years of service since I found it totally seized up sitting on the ground at that 1994 hamfest. Do not touch a pump that is running below 20 microns on first test with new oil.

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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Aidan_Roy
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Re: Aidan Roy - My Fusor Progress

Post by Aidan_Roy »

Richard,

Solid advice, I will listen. It think that this is a prime example of how plain experience can outshine initial intuition. I won’t fix what isn’t broken.

My next course of action is to load the diff pump, start assembling my main chamber and begin work on my inner grid.

Aidan
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Re: Aidan Roy - My Fusor Progress

Post by Aidan_Roy »

Hello,

After the last of what is almost everything I need for the chamber got here today, I put together the main chamber. It was connected to the diff. pump inlet without a valve between the two because that is the one thing for the chamber that hasn't arrived yet. I turned on the mechanical pump and was able to get down around 95-100 microns. Not great but chasing leaks was to be expected. I was honestly fairly happy because I had added a fair volume to the system and with 6 new joints I was expecting it to be worse. You'll have to excuse the horrid mess of a garage that is in the background but with all the clutter from our shed that had to be stuffed in there it could be worse. Comments welcome.

Aidan
Initial Fusor Set up.jpg
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Mark Rowley
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Re: Aidan Roy - My Fusor Progress

Post by Mark Rowley »

Looking good Aidan. You’ll have those leaks figured out soon, no doubt. First light is right around the corner.

Couple things...
What kind of gasket are you using on your CF connections?

KF clamps sometimes require what some would call abnormal tightness. Not saying to tighten it to the point of breaking the clamp or stripping the screw, but you may want to try tightening things up a bit more.

Mark Rowley
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Re: Aidan Roy - My Fusor Progress

Post by Aidan_Roy »

Hello Mark,

Thanks for the encouragement. I am using copper gaskets for all of the conflats and have tightened a few of the easily accessible KF fittings. The joint I soldered, to connect the KF valve to the diff pump, was broken accidentally last night while I was fumbling with the cold trap. This could not have been better for me. I saw how bad that first solder job was and realized it was a huge leak source. I cleaned everything up and re-soldered it back into place but I did a far better job this time and can now get the system to hover between 10 and 11 microns of pressure. This was where I was at with the system before I added the chamber on to it. I expect to be a bit better than this by the end of today and maybe I'll even try for a rough plasma on a copper wire grid.

Aidan
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Re: Aidan Roy - My Fusor Progress

Post by Dennis P Brown »

Redoing a weld is certainly a good idea now, rather than later, if you are unhappy with it.

Your vacuum system looks good. What is that long glass cylinder going to be used for?
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Re: Aidan Roy - My Fusor Progress

Post by Mark Rowley »

Dennis, I'd venture a guess that it is a version of Liam David's excellent HV Feedthru design.

viewtopic.php?f=6&t=13220

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Re: Aidan Roy - My Fusor Progress

Post by Dennis P Brown »

I hope it isn't a high voltage (HV) feed-thru; the lower section will easily short through that thin piece of glass tubing; assuming it does far enough pass the steel bushing. That type of arrangement won't hold except for lower voltage systems - in which case its very long length is not needed. Thick ceramic tubing is what most people use - thin walled glass tubing also tends to fail in a very bad way when the arc through occurs. The arrangement in the pic appears to have two glass tubes but again, the plasma tends to leak around the ends and find the nearest ground that is in contact with the glass - as such, glass isn't ideal for that reason.
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Re: Aidan Roy - My Fusor Progress

Post by Aidan_Roy »

Hi Dennis and Mark,

The glass tube is for the DIY feedthrough as mentioned by you Mark. I have to disagree with you Dennis on your most recent post however because the feedthrough that I and Liam David and likely many others have made has demonstrably gone to and above the 50kV mark. The tube is 2 mm thick quartz glass and is at least 1/4 inch clear of the threaded rod, that will be seen passing through the center of the tube in later photos, on all sides.

I will have pictures tonight of my first plasma. I did it with 2 loops of copper wire, each loop being 3/8 inch in diameter, attached stupidly crudely to the end of a threaded rod that goes down into the chamber through the glass tube. The tube cap is the electrical connection which, currently, is running just fine around 7,500 volts from a rectified 15kV transformer. Much more detail and specifics will be provided when I post the pictures later.

Aidan
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Re: Aidan Roy - My Fusor Progress

Post by NickBarsley »

Really great Aidan! I'm a month or so behind you, but working to a very similar design (and similar components from ebay!).
I hope to be in a position to do my first vacuum tests in the coming weeks when the final connections i need arrive.
Will keep watching with great interest!
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Re: Aidan Roy - My Fusor Progress

Post by Liam David »

I can still vouch for the glass feedthrough design. I've tested it up to 60kV both with and without plasma, and my only limitation is x-ray shielding and corona on my ballast resistor. Never had any arcs or breakdowns. There have been some modifications on the plasma end, but these I'll describe in the original post rather than pollute here. Here's a picture of everything operating at 54kV without issue.

GUI 3 July 20 2020.png

The only failure mode so far is my idiocy in breaking the glass...

IMG_20200724_162759.jpg

One quick recommendation: I'd add several layers of tape around the glass like in the above image to prevent the tube from creeping into the chamber. The tape just sits against the quick-connect fitting.

Liam David
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Re: Aidan Roy - My Fusor Progress

Post by Aidan_Roy »

As promised, here are the pictures of my first plasmas established in this chamber.
IMG_4071.jpg
IMG_4069.jpg
IMG_4068.jpg
IMG_4067.jpg
IMG_4066.jpg
IMG_4065.jpg
The system was running at 6,000 volts fairly stably. No current metering set up yet but I'd be willing to assume it was somewhere between 7 and 10 mA. The pictures of the plasma creeping up the tube of the feedthrough were taken at higher pressures(150-200 microns) while the rest were taken between 10 and 45 microns. The last picture, without plasma, was of the system shut off just so the grid was clearly in sight. It is truly a terrible grid and I know this. I cobbled it up quickly and did a few runs with it, just to see if I was even ready to use the little bit of tungsten wire I have and make a good one. The threaded rod was not sheathed in a piece of aluminum or stainless tubing as it will be once the feedthrough is completely finished and it caused much corona disturbance(as expected.) Most electrical connections were crude and prettying up the whole mess is now my next step.

Liam, I used a bit of duct tape for a temporary fix while the system was under vacuum, I will switch over to kapton once I start being able to use the diff pump and once the chamber starts being able to get hot enough for the switch to be justified.

I will probably add more pictures of the entire set up once it is all prettied up and ready to be truly presented.

Aidan
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Re: Aidan Roy - My Fusor Progress

Post by Richard Hull »

Aidan, you can be in the plasma club with instrumentation, full data and photo of your system with you init. Good work so far. (updated 8/20/20)

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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Re: Aidan Roy - My Fusor Progress

Post by Aidan_Roy »

Richard,

Thanks for adding me to the list, hopefully I won't have to wait too long now for real fusion.

I also read the "Dumping the trash" thread under the announcements and admin section and would like to state very clearly that if you or any of the older guys think I'm asking for too much help or requesting information that could easily be found out on my own, please let me know. I really don't want to be an overly dependent, whiny, fusion newbie and I really do want someone to "slap" me back in check if I fall out of line and fail to use common sense before posting. Thanks.

Aidan
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Re: Aidan Roy - My Fusor Progress

Post by Aidan_Roy »

So it’s been a while since the last update, and today is really nothing spectacular, but I’m doing an update on my progress since the last post. I now have a proper grid set up, much better than the ugly mangled wire mess that was last pictured in this thread. Also, the resistor string for voltage metering is done, 1.2 gigaohms spread over one-hundred twenty 10 meg 1 watt resistors semi-coated in a rubber dielectric and wrapped around a 3 inch pvc pipe. This will be submerged under oil with my newly acquired 80 kv center tapped x-ray transformer, which will be arriving around the 16th and tested for functionality soon after. On top of this, my NIM bin is complete and everything seems to be working save for the discriminator(maybe more on this in a new post at a later date). I also have acquired a He3 tube and that seems to be in good order as well.

Seeing as this is an images thread, I include the resistor string below:
7A896460-4749-4E45-9889-0B467AAD5D31.jpeg

Hopefully before the holiday season sweeps me away as school has these last few months, there will be a follow up post on the fully* completed NIM setup and the beginnings of the gas handling for deuterium. That’s all for now.

Aidan
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Re: Aidan Roy - My Fusor Progress

Post by Richard Hull »

Good work, We like to see updates. Thanks for filling us in on your progress.

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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Re: Aidan Roy - My Fusor Progress

Post by Aidan_Roy »

Hi again everyone,

This is yet another fairly small update. The biggest news is the near completion of my xrt stuff, I have it all under oil and tested successfully to around 30 kv, disconnected from the fusor chamber. The current metering is yet to be set up but all is in place for me just to wire it in. Furthermore, I finished the second wiring of serial communication to my other mks gauge. I have almost finished plumbing the gas handling line as well. My NIM bin is ready to go but the recent excessive cold has kept me from doing much with that. Additionally, I switched out the 1/4” copper tube that was in my feedthrough for an 1/8” stainless one. This gives more clearance inside the tube between the wall and electrical contact. I also epoxied in a washer to keep everything well centered. Sadly I haven’t got any pictures to show today but I will soon have a follow up with pictures of some nice plasma and my HV control and monitoring board.

Best regards,
Aidan
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Re: Aidan Roy - My Fusor Progress

Post by Mark Rowley »

Sounds like just a matter of time before you fire it up. Keep at it and you’ll be making neuts soon!

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Re: Aidan Roy - My Fusor Progress

Post by Aidan_Roy »

Hi all,

Sorry for the absence of pictures that were promised last week. After connecting to the chamber, I started having "issues" with the GFCI in my garage. I do say issues very loosely because it was actually just doing its job and I failed to realize that I was drawing too much current and just popping the fuse. I was late to realize because I had thought that it was on a 25 or 30 amp fuse and knew that much was not being drawn. I initially had my HV line and wall line very close and assumed it was inducing a current in the line that tripped the fault detector. After I got my cable management figured out, I still had issues and figured it was something being too close to something else inside the oil filled case of the transformer and so I worked that angle and also improved a bit on the neatness of that, but still to no avail. Finally I decided to really check out the fuse it was on and discovered that it was a 15. Needless to say, having almost a dozen things plugged into an outlet or two on a single fuse doesn't work out.

After that delightful oversight, I decided to improve on my wiring for the serial connection to the vacuum gauges and turned more focus to the neutron detection effort. I got a 6 inch stove pipe and that is now filled with paraffin and will be my moderator for the SI-19N He3 tube I am using. Finally, I got back to the fun stuff only to discover that the cheap camera I am using to watch the grid is excessively sensitive to IR and would get completely overexposed at very low energies applied to the grid even with the digital exposure turned all the way down. Luckily I had some leftover solar film that was perfect for blocking a huge portion of the light reaching the camera. It is basically opaque to visible light so you can really only see the grid through the IR. This is good for operation but bad for pretty pictures. I solved this by removing the lenses from some cheap plastic sunglasses. The color accuracy is lost if both are overlapped but is decently preserved when only one is used. The trade off is the voltage that can be applied before details are lost to the light.

Below are a few pictures of the plasma I ignited earlier today as well as the control/electronics housing rack I assembled.
Attachments
NIM and Transformer metering with control.jpg
About 33kv at 20 microns viewed through solar film and output of gauges.PNG
About 14 kv at 9 microns.PNG
About 14 kv at 9 microns.PNG (50.8 KiB) Viewed 5029 times
36kv, 10 microns.PNG
36kv, 10 microns.PNG (377.59 KiB) Viewed 5029 times
13 microns at 14.6kv.PNG
13 microns at 14.6kv.PNG (30.56 KiB) Viewed 5029 times
12 kv at 12 microns.PNG
12 kv at 12 microns.PNG (135.77 KiB) Viewed 5029 times
3.6kv at 15 microns, viewed through lenses.PNG
3.6kv at 15 microns, viewed through lenses.PNG (82.75 KiB) Viewed 5029 times
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Richard Hull
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Re: Aidan Roy - My Fusor Progress

Post by Richard Hull »

Aidan, thanks for the fine display and data. You are now in the Plasma club.

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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Re: Aidan Roy - My Fusor Progress

Post by Aidan_Roy »

Thanks Richard. I still need to work on cooling the chamber and maybe making the wire diameter on the grid larger. I can push the voltage up to about 50 kv with no arcing issues but the wire gets white hot around 36. For cooling I have an old aloha breeze floor fan that moves about 5000 CFM placed roughly 4 feet away from the chamber. Unless I run at lower than average pressure for the size of my chamber, I am not sure how long I will be able to sustain voltages conducive to decent levels of easily detectable fusion. I'm thinking of using 0.032" or 0.05" wire as opposed to my current 0.02" wire for the grid.

Aidan Roy
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