Long belated parts list

For posts specifically relating to fusor design, construction, and operation.
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Long belated parts list

Post by pcfusor » Tue Aug 05, 2008 4:52 am

Alright, I will start with our vacuum system. Keep in mind that we had our welding department help with construction, and Atlas Vacuum systems in Port Townsend (really cool aluminum chambers) help with the leak testing for our chamber.

2 X 6 inch diameter 304 Stainless Steel hemispheres obtained at The Wagner Companies (www.wagnercompanies.com) for about $40 (with shipping included)

1 x 24 inch, 1.75 inch diameter 304 stainless steel tubing obtained from Speedy Metals (www.speedymetals.com) for about $70 (with shipping included) because we actually bought 36 inches of tubing but only used less than 24 inches. This was for the 2.75 inch Conflat port stubs on the chamber, four of which were 2 inches long (two for gas feedthroughs, one for electrical feedthrough, and 1 for a viewport), and the fifth was 6 inches long to accomodate the two KF flanges that were also on it (this is our vacuum port).

5 X 2.75 inch outer diameter, 1.75 inch inner diameter, .1 inch weld lip, non-rotatable Conflat flanges obtained from Varian Inc. (www.varianinc.com) for about $15 per flange

2 X 8 inch outer diameter, 6 inch inner diameter, .13 inch weld lip, non-rotatable Conflat flanges obtained from Varian Inc. (www.varianinc.com) for about $114 per flange

2 X 1.5 inch long KF 25 flange plus weld stub which can be obtained from any vacuum component company (Kurt Lesker, Varian, etc.) for $15 or less, but we actually ended up having these donated to us by Thermionics in Port Townsend (www.thermionics.com).

We also needed to have the copper gaskets and bolt sets for all of these flanges, which were all found at Varian Inc. as well. Be forewarned that one set of gaskets for the 8 inch flanges will run about $50, but the all the bolt sets and the 2.75 inch gaskets are not very expensive at less than $20 each. The clamps and Viton gaskets for the KF flanges can be obtained from Lesker, Varian, or any other vacuum supply company for about $8 each for the clamps and in between $10 and $20 for the gaskets depending on what material you choose (Viton or Buna-N).

We also had a vacuum hose for our system which we constructed ourselves. We needed about 5 feet of high temperature marine exhaust hose, which runs about $7 a foot from a marine equipment supplier (We got ours at Admiral Marine Supply in Port Townsend). We also needed two more KF 25 flanges with 1.5 inch weld stubs on them, which were again donated by Thermionics (www.thermionics.com), but only run about $8 a piece from vacuum component suppliers). We attached these to the marine exhaust hose with ordinary hose clamps, which can be found at Home Depot, or any other hardware store. We included a back mist filter (albeit a really simple one that didn't work very well) in the hose, which was constructed mainly by our welding department out of two pieces of 1 inch steel tube, two steel plates, and one piece of 2 inch steel tube. We stuffed it with degreased brass and steel wool to help collect excess oil back misting from our pump.

We did end up having to borrow a right angle valve from Atlas Technologies when we actually went to achieve fusion because we needed to pump our chamber down and then valve it off before introducing the deuterium to keep from pumping out the deuterium once it was introduced. This requirement was caused by the way our gas system was designed, which I will address shortly. These right angle valves, if purchased, are actually rather expensive costing anywhere from $200 to $400 dollars depending on the company you purchase one from.

Our gas system was constructed out of some really simple and easy to find stuff, with exception to the regulator we used. We used a volumetric measurement system which means that we had a small section of tubing (about 4 cm) which we released the gas into at a pressure as low as our regulator would go (about 1 psi). This translates to about 1x10^18 deuterium gas particles. We only wanted to have a maximum of 1X10^17 deuterium particles in the fusor for our attempt at fusion, so we had to then release the deuterium into a section of tubing, needle valves included, that totaled 10 times the original length(about 40 cm) to lower the pressure of the gas in that section to about .1 psi. We then actually only used the gas from a small section (about 4 cm) of this tubing,

2 X 20 ft. rolls of .25 inch copper tubing, which can be found at Home Depot or any hardware store that has plumbing supplies. These can run anywhere from $10 to $20 per roll. We used all of one roll and most of the second roll and this was with under two foot worth of copper used in mistakes made (mis-measured tubes and what not).

6 X tube to tube .25 inch brass needle valves, which can be found at Home Depot or any local hardware store that has plumbing supplies. These can be like $5-$8 a piece. We used these in our volumetric gas measurement system.

Finally we needed to have our grids and the power supplies for them. The power supplies we used were full wave voltage multipliers, one at 15 kV negative, and the other at 10 kV positive. We originally ordered 25 kV power supplies from amazing1.com, but were thoroughly unsatisfied by the arcing between the HV power supply (minimax box available on amazing1.com) and the multiplier ladder. We ended up redesigning the power supplies with lexan boxes and 12 volt fans, which Chris did an excellent job with the construction on. We used a 25 kV potential difference to minimize the risk of X-Rays. The grids were made out of various materials which we obtained locally and at the school. The outer grid was constructed from fine copper tubing with a steel music wire core for structure. The inner grid was constructed from stainless steel wire obtained from our welding department at peninsula, along with a high temperature ceramic bead, which I constructed by hand with a dremel. I cut a piece of ceramic into an equilateral triangle from some high temperature ceramic that the welding guys gave us. I then drilled three cross wise holes through it from each point on the triangle to the center of the opposite side. This was fairly tricky and required several attempts, but in the end yielded a bead for the top of the grid to organize the wires. The outer grid just involved measuring the tubing and wires correctly, then fitting it all together and soldering it with silver solder.

2 X 25 kV DC power supplies from amazing1.com, which we then frankensteined into our power supplies. I, or Chris, can supply plans as per request for how we altered the power supplies using only what was included with the ones we ordered.

10 X 8" by 10" lexan sheets obtained from Home Depot. You can find these at Home Depot, but I'm not sure about other hardware stores. These can be found in the back by the window glass, or with the help of a mostly helpful Home Depot employee.

2 X 12 volt fan, which Chris obtained one from Radio Shack and we got the other from a computer power supply that I had.

1 X package of 1/8" by .025" by 12" copper tubing, which I obtained from my local hardware store, but comes from a company called K&S Engineering out of Chicago. This is the same company that produces the other size of copper tubing that I used, as well as the music wire. I used this to create the main equitorial band that both halves of the outer grid attached to.

2 X packages of 1/16" by .014" by 12" copper tubing, also from K&S engineering. I used this to create all of the lateral lines on the outer grid, as well as loops to form the poles of the grid.

1 X package of .012" steel music wire, which can also be obtained from K&S engineering. I used this to tie the pieces of the outer grid together and give it stability. Without this wire the pieces were incredibly difficult to solder together.

3 X about 7-8 inch sections of steel wire for the inner grid, which I obtained from the PC welding department.

4 X ceramic pieces(the number of which was due to mistakes), which I also obtained from the PC welding department.

4 X ceramic tubes, obtained from the PC chemistry department. These I used to insulate the wires coming from the feedthrough and going to the grids, as well as to facilitate the connection from the grids to the feedthrough.

Other than what I have already listed, the only things we used were the shielding, which was designed by Devon and Sarah, and constructed from parafin wax and boxes of borax, and our neutron detector(bubble detector), which was obtain from Dr. Francesco d'Errico at Yale University. I cannot say how much it would cost an unaffiliated individual to purchase a bubble detector from Yale or if it would even be possible, but we obtained ours for $80 plus shipping. The parafin ended up costing about $80 also, and the borax about $20. The shielding was a 3 inch thick layer of parafin backed by the boxes of Borax to first slow neutrons(the parafin), and then capture them (the borax).

So there it is. Sorry it took so long to get this up. I started in with a summer job that worked me a lot harder than I though it would, and I lost track of how much time had gone by since the end of the year. This was really an incredible project to be a part of. I guess next year Chris, Derek, and I will be working on a particle accelerator for Peninsula College. That should be really fun . Thanks for all the help from everyone here at fusor.net!


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Re: Long belated parts list

Post by DaveC » Tue Aug 05, 2008 5:52 am

Aaron -

Thank you for great description and parts list. It should help many to have a better idea of all that's involved in putting the fusor system together.

Glad your project team had a good time doing the Fusor. Your final result was very impressive.

The upcoming accelerator project sounds quite challenging. There's probably more than few on this board who'd like to have a link to it, when you get under way.

All the best to each of you in your studies.

Dave Cooper

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Re: Long belated parts list

Post by Nanos » Tue Aug 05, 2008 8:07 am

If I might add, that pictures of the various parts and stages would be most useful if they are available.

Also with descriptions of said parts and associated bits & pieces is most useful to those of us learning just what all the bits do.

Sadly our UK version of Home depo stores are not quite as well stocked as yours.

(Mumbles something about how hard it is to just buy one way plumbing valves..)

Chris Roberts
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Re: Long belated parts list

Post by Chris Roberts » Mon Aug 11, 2008 8:34 pm

Thank you for posting this parts list, it helped clarify a few questions I had been mulling over. I especially liked your gas delivery system, very simple and straightforward.

I have a couple of questions about your setup if you do not mind; first, what did you use for a viewport? The ones I see for sale online look pretty expensive, so did you somehow make one or if not, where did you buy yours? Also, from what I can see in your pictures from an earlier post you had just the rotary vacuum pump for your vacuum system. Is this true, or did you have a diffusion pump in there as well?


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