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Build A Fusion Reactor

Build A Fusion Reactor
Yes, you can build your very own nuclear fusion reactor in your house! But first, a few warnings:

-This project includes lethal voltage levels. Make sure you know your high voltage safety or have a qualified electrical advisor.
-Potentially hazardous levels of x-rays will be produced. Lead shielding of viewports is a must!
-Deuterium, an explosive gas, will be used. Make sure to check for fuel leaks.
-All the other inherent dangers of a home engineering project of this degree (a wide gamut of potential injuries, damage to the checking account, and the loss of general sanity)



Here are the minimum required materials:

-A vacuum chamber, preferably in a spherical shape
-A roughing vacuum pump capable of reaching at least 75 microns vacuum
-A secondary high vacuum pump, either a turbo pump or oil diffusion pump
-A high voltage supply, preferably capable of at least 40kv 10ma - Must be negative polarity
-A high voltage divider probe for use with a digital multimeter
-A thermocouple or baratron (of appropriate scale) vacuum gauge
-A neutron radiation detector, either a proportional He-3 or BF3 tube with counting instrumentation, or a bubble dosimeter
-A Geiger counter, preferably a scintillator type, for x-ray detection and safety
-Deuterium gas (can be purchased as a gas or extracted from D2O through electrolysis - it is much easier and more effective to use compressed gas)
-A large ballast resistor in the range of 50-100k and at least a foot long
-A camera and TV display for viewing the inside of the reactor
-Lead to shield the camera viewport
-General engineering tools, a machine shop if at all possible (although 90% of mine was built with nothing but a dremel and cordless drill, the only thing you really can't build without a shop is scratch building the vacuum chamber)
 
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Step 1Assemble The Vacuum Chamber

Assemble The Vacuum Chamber
A quality high vacuum chamber is required for the fusor to operate. Sometimes an appropriate chamber can be found on eBay, but generally it is best to make one. Parts can be scrounged for several hundred dollars, or purchased new for $500+.

Get two stainless steel hemispheres, purchase two corresponding conflat-flanges (8" flanges in my case), bore out holes for accessory flanges, and then TIG weld it all together. Flanges are typically either of the KF or the conflat style. Conflat can be seen in the image below as the flanges with bolts, and KF (kwik-flange) are seen as those with only clamps holding an o-ring on the mating surface. Only weld on the inside, never on the outside (since virtual leaks can be formed if both inside and outside are welded). If you've never TIG welded before, it would be wise to have someone with experience do it as the welds must be flawless with no pin-sized holes or porous areas to hold a vacuum.

After machining, thoroughly clean the chamber and avoid getting fingerprints in it since these will outgas, which means at vacuum pressure molecules in the oil of finger prints or machining oil will become vapor and make it hard to maintain plasma stability or reach a good ultimate vacuum level.
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329 comments
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Dec 2, 2011. 8:11 PMpunkhead58 says:
Was this a freelance project at home? Because, if so, you will need to obtain a Radioactive Materials License from the NRC.
May 13, 2012. 7:35 PMsciencetor2 says:
But would he? None of the materials used, including the deuterium, are radioactive except during fusion, in addition, the only radiation produced is x-rays and neutron radiation. Various vaccum tube high voltage devices may produce x-rays, and these items do not require licensing as far as I am aware
May 12, 2012. 2:27 AMPREM1Z says:
can i use this to power my pc? :)
Jun 29, 2011. 8:55 AMlaserpoint2.0 says:
I love your fission reactor in wich it is 100% correctly designed to be perfect i have studied this for over a year now and it is great to see you pull it off with just everyday household things. congradgulations to you man!
Aug 26, 2011. 9:35 PMkgoogins says:
Uh, fusion. We don't want to die from radiation now do we?

May 8, 2012. 3:55 PMsciencetor2 says:
Well, technically it still produces radiation, but neutron and X-ray radiation, rather than the really nasty stuff present in fission reactors
Feb 5, 2012. 8:35 PMjinnd319 says:
How much power does your FISSION reactor make?
P.S. impressive
May 8, 2012. 1:49 PMsciencetor2 says:
I'm pretty sure this is a fusion reactor... A fission reactor is powered by uranium rods, and IS an efficient(if dangerous) way of producing power on a large scale. A Fusion reactor runs on deuterium, and what this instructable fails to mention is that they don't usually generate enough power to be self-sustaining. They DO however make an excellent science project, and can be built on rather a smaller scale from much safer (and less illegal) substances.
May 7, 2012. 11:19 AMTemennigru says:
Could you please tell me what vacuum pumps and chambers you would reccomend?
Apr 28, 2012. 4:39 AMtfitz19 says:
Hi there, just wondering is the power supply shown in this instructable:
http://www.instructables.com/id/Build-a-Variable-High-Voltage-Power-Supply/
powerful enough to run a fusor? From what I can tell, 50,000 volts is plenty but does it have enough current?
Thanks
May 4, 2012. 5:14 PMtfitz19 says:
Do you think this would be powerful enough to run it?
May 3, 2012. 8:05 PMbarrywilliams says:
Did you achieve fusion?
Apr 19, 2012. 1:01 PMpwnag3 says:
Would Hydrogen obtained via electrolysis work in this?
Jan 2, 2011. 4:16 PMM4industries says:
Where is deuterium bought?
Apr 15, 2012. 12:06 PMgaragegenius says:
i was looking at airgas and one of the required field was a company affiliation. i was wondering what i should put in.
Apr 13, 2012. 6:35 PMgaragegenius says:
simply out of curiosity, wouldnt a nickel or palladium grid be more effective at producing fusion, or would if fail to create neutrons as in the fleischman-pons experiment
Apr 5, 2012. 4:24 PMTgrock says:
How much deuterium gas is required? Would one ampoule be sufficient?
Mar 25, 2012. 5:38 PMmatt_and_nick says:
a couple things.
1: could you use this to power your house, and
2: you do realize each of us is carrying an unlicensed nuclear accelerator on our backs?
Feb 27, 2012. 6:25 AMgaragegenius says:
I'm going to try building one of these so any advice or tips would go a long way
Feb 25, 2012. 7:39 AMgaragegenius says:
so i am assuming this is the infamous cold fusion
Feb 15, 2012. 1:22 PMhowler6 says:
what temperature would you say it reaches inside the reactor?
Jan 2, 2012. 10:44 AMfmenne says:
Hi, im trying to build a fusion reactor from houshold stuff.
But is it possible to use nitrogen to fuel the reaction instead of Deuterium gas?
Dec 2, 2011. 11:00 PMrkeyzer says:
"American make nuclear fusion device in a garage" should be the head line in every news paper in the world followed by "Man says he was bored and wanted to do something fun" USA USA USA
Dec 2, 2011. 8:16 PMbig65mopar says:
Curious as to your comment that tig welding is the only vacuum tight welding option. Shielded metal arc welding is used in pipe welding applications such as oil pipe lines and nuclear coolant piping both of which require zero imperfections in the weld beads. I work with all three processes on various flavors of carbon steel and stainless steel in the defence industry and shielded metal arc is used in critical pressure related applications.
Dec 2, 2011. 2:06 PMsq9nip says:
Nice Project I would like to give it a try myself
Nov 6, 2011. 1:33 AMscarrillo says:
GOOD JOB SIR!
Sep 6, 2011. 12:08 AMaeternusjunk says:
Congrats on your matriculation to MIT! I wish I had discovered my love of physics as early as you did. Just how much current on the 40kV line are we talking about here? The voltage is needed to rip electrons off the deuterium and send the nucleus hurling to the center, but are there really enough particles flying around to need current on the order of milliamps? I'm a Tesla coil aficionado and curious if I could detune my SGTC to around 40kV and rectify it. That would give me something like uA. My SSTC likes to melt solder unlike the SGTC, maybe that would work better.

I've read that one problem with Farnsworth type fusors is that the central wires have small radius ergo a high voltage gradient ergo much of the 2H is ionized near the center of the chamber (which is bad). I wonder if this problem could be lessened by inducing large gradients on the interior of the vacuum chamber with, say, a bunch of steel pins welded on?
Aug 27, 2011. 1:10 AMinfinity11 says:
Does this have to be DC or AC
Aug 1, 2011. 5:43 PMcarlchipsanders says:
If I licked this device frequently, would I get super powers?
Aug 25, 2011. 7:05 AMdmartin13 says:
probly
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