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PolyWell Fusion Reactor

Posted: Sat Nov 28, 2015 9:10 pm
by Josh Hess
I have decided to start building my very own small scale polywell nuclear fusion reactor. It is very similar to a farnsworth fusor but with some key differences that I would like to investigate. I have done copious research on this particular reactor design and I personally believe that this has huge potential and may even holds the key to clean, sustainable energy for the world. Unfortunately, due to the limitations financially, this will be a relatively small scale project and therefore is not projected to break even (or come close). However, this is not the goal of this project. The main goal is to learn as much as possible about plasma physics and the other technologies that make this reactor and others like it work. Once that is done, the final goal will be to show both the feasibility and scalability of this design for larger break even models that are capable of providing power for cities, homes, or even vehicles. Also due to budget limitations, most of the parts will be acquired in non ideal condition. Aka, used/damaged. Since I am not afraid to get my hands dirty, I will try to get the best quality parts for the best price and repair/rebuild them. This repair process will add time to overall project duration, but should yield the best results for the project. I anticipate that this project will take at least a year to get up and running, and an unknown amount of time to acquire knowledge and improve upon the design.

- Learn as much as possible about plasma physics/fusion as possible.
- Fully understand the polywell design and perhaps improve upon.
- Demonstrate the feasibility and scalability of this design.

Begin Build Log:

Vacuum Chamber:
The vacuum chamber is a stainless steel Varian vacuum chamber I purchased from Skycraft Surplus, a local electronics surplus store, for a bargain of ~$300. Similarly sized stainless vacuum chambers range from 4-8 thousand dollars online. It is approximately 3' tall, 17 inches in diameter and weighs around 200lbs. It has minor damage on a flange and some of the electrical feedthroughs, but nothing a tig wield and some new caps wont fix. The chamber is from what I can tell, designed to be a bell jar. That is, to be set on a table with a gasket. I have no idea what it was used for, it had a pulley in one of the flanges and a weird dish or bowl mounted near the top. Also 6 or 7 solid 1/2" copper rod electrical feedthroughs near the bottom. For my uses, the chamber will be mounted on its side with the largest flange facing down. I will have a plate machined to seal it which will also have the vacuum inlets/outlets and may eventually be used to mount a turbomolecular pump if needed. A 3/4" acrylic window will be cut and mounting system devises for the large opening on the bottom (now side) of the vessel. I will also attempt to repair the broken electrical feedthroughs but may end up having to replace them. Also something to note, there are copper ring gaskets on all of the bolted feedthoughs. I believe that these have to be replaced each time they are removed to create a new seal but more research is necessary on my part. Anyway, here are some pictures of it:
In the car:

Laying Down:



Electrical Feedthrough (Broken):



At some point, I would like to build a cart to sit this on with castors. Below it could be shelving for the vacuum pumps, electrical equipment and perhaps even gas processing parts. This will for sure will be discussed in an update to come.
While I was at Skycraft, I also picked up an old Welch DuoSeal 1400 Vacuum pump that was sitting next to the chamber for $25. I figured it is a great pump, and even if I couldn't get it working, for $25, I would enjoy rebuilding it and seeing how it works. Well the rebuild seems to be going well so I I will be posting my rebuild log of that here: /viewtopic.php?f=8&t=10
Anyway, that's it for now!

Re: PolyWell Fusion Reactor

Posted: Thu Dec 03, 2015 12:20 am
by Josh Hess
I did a bit of research today in my study breaks and found some good parts from suppliers and on ebay. I also started to plan out the cart, acrylic door, and saw a picture showing a very nice lighting setup. This is going to be a short post showing some brief ideas regarding the door and the lighting.
Door Hinge design examples:



This design offers excellent ease of use while still being economical and easy to implement in the current design.It looks to be an adjustable dual hinge mechanism welded on the side of the chamber. This would be fairly easy to implement as I am already needing to get the chamber welded for repair. A hinge and perhaps mounting brackets like the ones showed on the cart could be manufactured and welded to the chamber. Also, the cart design is very similar to what I had in mind and looks to me made out of 8020.

Lighting setup:

I'm not quite sure what kind of lighting that is. It almost looks like a flexible led strip of sorts. More research will be done to determine what those are as I really like no only the way it looks, but also how it improves the functionality of the chamber.

Re: PolyWell Fusion Reactor

Posted: Fri Dec 04, 2015 12:26 am
by Josh Hess
I got to work on repairing the original electrical feedthoughs. The chamber must have been knocked around quite a bit because not only were a few of the feedthroughs broken off, but the solid copper rods (over 1/2" in diameter) were substantially bent. I started by mounting them in a vice and carefully bending them back with a rubber mallet. Here is a rod after straightening:

The next thing to do was to straighten out the flange that the ceramic broke off of. This was accomplished by carefully prying it with a screwdriver, hammering, and comparing with the ceramic. Here is a picture of the flange before fixing.

Once that flange matched up with the ceramic, it was JB welded and then clamped. This was repeated for four of the damaged flanges.


JB weld was a suitable bonding adhesive due to its strength and low outgassing properties. Information on this and many other materials are available here:
That's about it for now. More updates to come!

Re: PolyWell Fusion Reactor

Posted: Sat Dec 05, 2015 6:24 pm
by Josh Hess
I did a bit of research today on parts to get and specifics regarding the polywell magrid design. I found this site: This was actually a crowd funded polywell project. Unfortunately, the project has been since stopped indefinitely, but there is a TON of helpful information regarding specifics. I haven't read through it entirely, but will definitely use it as reference and may even attempt to get in contact with Mark, the owner of the site for advice in the future.