The Fusioneers, who build nuclear reactors in their back yards

https://www.washingtonpost.com/news/style/wp/2016/05/26/fusioneers/

by Fjolsvith • 10 years ago

168 54 10 years ago

riprowan• 10 years ago

Nice bios. Would rather read about what they're building.

Farnseworth Fusors it sounds like. So EIC fusion, fortunately it's pretty tough to get a strong enough vacuum and proper backfill of deuterium to produce actual fusion which would stream neutrons out and actually be dangerous beyond the dangers of dealing with high voltage, high pressure, and x-rays. They do usually ionize the gas in the confined center which looks pretty cool.

djaychela• 10 years ago

Exactly - this was just the opening page to the article I would have like to have read; that may be because I did my apprenticeship in the UK Atomic industry and long for my 20s, but maybe it's because it would be really interesting to read about this stuff - I had no idea people were doing this sort of thing as a hobby. I feel an evening's search-and-read activity coming on!

snarfy5• 10 years ago

I have a hack project like this going in my garage.

I'm trying to build a resonant tuned polywell device. The tldr is polywell + tesla coil power source + microwave oven = fusion? I have no idea if it will work but is something I wanted to try.

The original polywell is a steady state device, where this is meant to create a dynamic system in tune with the power source.

https://en.wikipedia.org/wiki/Polywell

http://2.bp.blogspot.com/-3BPtWiGxd3c/Vj7ecWEoXuI/AAAAAAAAGc...

adaml_623• 10 years ago

How do you measure your fusion events? Does a geiger counter work?

FiatLuxDave3• 10 years ago

Not the above poster, but typically people will test first with hydrogen to make sure they have good plasma characteristics and containment, then switch to deuterium and use a neutron counter to measure the 2.45 MeV neutrons that come off of the D + D -> n + He3 branch reaction.

A Geiger counter is a good idea, though. Many people don't know until they work with it that high voltages (above 30 kV or so) will cause a fair amount of X-rays from stray electrons being accelerated. So, even when you aren't actually doing fusion, just having a device turned on will cause some X-rays, and its helpful to know that your dose rate is low enough to be safe. There are some failure modes that can cause large amounts of X-rays and you'd want to be aware if that was going on.

mh-cx2• 10 years ago

I'm trying to build a resonant tuned polywell device. The tldr is polywell + tesla coil power source + microwave oven = fusion? I have no idea if it will work but is something I wanted to try.

I hope you thought about all the consequences this may have. See Primer.[1]

[1]https://en.wikipedia.org/wiki/Primer_(film)

Hortinstein• 10 years ago

excellent documentary

pdabbadabba2• 10 years ago

The sequel is a let down though. Oh well.

FiatLuxDave3• 10 years ago

I'm interested in why you would want to try a resonant Polywell. Are you willing to share your thoughts on why you'd want to go that route? Regardless of whether you want to discuss it, good luck with your project.

snarfy5• 10 years ago

It's a combination of ideas. I liked the idea of the polywell, but there was another project that also peaked my interest, plasma focus. One of the researchers described why their idea was better than the others, and it was quite convincing. Plasma is a dynamic system and their design works with the plasma dynamics instead of against it. This led me to the idea of a dynamic polywell, where the negative potential in the center could be tuned to oscillate. Maybe there is a sweet spot or harmonic that will cause fusion.

I have no idea if it will work, but is an interesting project and something attainable in the garage. If nothing else hopefully it will at least be a fancy plasma ball lamp.

More on focus fusion:

http://www.extremetech.com/extreme/184280-focus-fusion-has-c...

snarfy5• 10 years ago

Here are some of my pics (sorry couldn't edit the original post after work):

http://imgur.com/a/Tsg40

jd3• 10 years ago

that's awesome! this would be a sort of dream project for me (I am not classically trained in physics; just a computer scientist)

paulsutter2• 10 years ago

These are Farnswoth Fusors[1], first developed by Philo T Farnsworth, one of the inventors of television.

The devices use about 100,000x more energy than they produce FROM FUSION (edit, thanks), but some fusion does occur. An individual ion can be heated by 11,000 kelvins with a single electron volt, so 15,000ev is enough to reach fusion temperature. The statistical challenge is getting ions to collide - overcome the (repelling) coulomb force - and fuse.

There are discusson groups online for this topic [2] and there's even a high school in the Seattle area that has a fusor [3].

[1] https://en.wikipedia.org/wiki/Fusor

[2] http://www.fusor.net/board/

[3] http://www.industrytap.com/overview-polywell/31940

Retric3• 10 years ago

IMO, produces energy is a poor way of describing at this. They produce ~1,000 parts light:99,001 parts heat per 100,000 units of electricity and 1 units of fusion. In other words 100,000 units of electricity liberates 1 unit of fusion power.

https://en.wikipedia.org/wiki/Fusion_energy_gain_factor is meaningful, but it's talking about inputs not outputs.

PS: Ok, heat is a poor description. 1,000 pars light, 99,000.9 units of heat, and 0.1 unit high energy particle radiation.

paulsutter2• 10 years ago

Isn't that like saying a lightbulb doesn't use any energy because its output of heat and light equals the energy input? Or that I didn't use any money shopping because the cash all stayed in the economy?

kale• 10 years ago

I looked at building one a couple of years ago before deciding I couldn't afford the equipment to make sure it was safe, but I always had this in the back of my mind: Don't all nuclear reactors use heat as the main output? To drive steam generators (like a conventional plant) or solid-state devices like a peltier-based battery used in satellites?

If you put a bounding box around a Farnsworth Fusor, and put in 100W of energy, would you not get a little more than 100W output from the fusion reaction?

Obviously still not viable as self-sustaining, since 100W of electric energy in would be lower entropy than the 100W+ coming out, but it would be a method of producing some energy as long as it's fed from another source.

Obviously, using a heat pump would be a much better way of turning 100W of electricity in to >100W heat, but still, a Fusor isn't net energy negative (although it is terrible with conversion of entropy).

usefulcat• 10 years ago

"These are Farnswoth Fusors[1], first developed by Philo T Farnsworth, one of the inventors of television."

Wow, I've been a Futurama fan since the show first came out and just now got that reference. Well done, Matt and David.

cyanoacry• 10 years ago

I've built a fusor[1], and in its simplified form, it's just a large, negatively charged grid in a vacuum chamber with some hydrogen sitting around. Nothing to be afraid of!

You're absolutely right that these devices don't produce net energy. I built mine because I wanted to learn more about all the tech involved (high vacuum, high voltage, some nuclear physics). They're really good teaching projects for folks going into experimental physics, since there's a neat outcome without too much danger.

I assembled a coffee table book with some pretty pictures about it, PDF copy here: http://shia.wsyntax.com/stuff/fusion/fusor_book_web.pdf

[1] http://fusion.wsyntax.com/ , http://fusion.wsyntax.com/setup/

steve19• 10 years ago

I really enjoyed reading that, thanks!

lakkal2• 10 years ago

Very interesting. Thanks for that.

lawpoop• 10 years ago

How much would it cost, roughly, to manufacture helium from one of these?

From what I understand, we are running out of our natural stock.

pdkl95• 10 years ago

Philo T Farnsworth, one of the inventors of television

The (very) old game show "I've Got A Secret" had Farnsworth on as a guest, with his invention of television as the "secret".

    Player:     "Do doctors use this object?"
    Farnsworth: "Yes, it's been used in surgery."
    Player:     "Is this some kind of machine that
                 is painful when it is used?"
    Farnsworth: "Yes, sometimes it's most painful!"

https://www.youtube.com/watch?v=pKM4MNrB25o

zem• 10 years ago

These are Farnswoth Fusors, first developed by Philo T Farnsworth, one of the inventors of television.

that sounds like something straight out of a heinlein book!

Aelinsaar• 10 years ago

Impressive people, but I don't feel that I got a sense of what they were actually doing. I understand that it's a challenge for a writer who probably doesn't understand the subject well, to talk to the average read who doesn't understand it at all. Still, this feels like a wasted opportunity to teach, and to inform others with more knowledge about what these interesting people are doing.

jdc0589• 10 years ago

bingo. I have no idea what they were building based on that article. The first "quote" about uranium was especially misleading.

josefresco• 10 years ago

Felt like we read just the beginning to a very thorough article. Instead we just got introduced...

jloughry• 10 years ago

This feels like the introduction to a book. It sounds like an interesting one.

andrey_utkin• 10 years ago

This listing won't be full without David Hahn aka "Nuclear Boy Scout". https://en.wikipedia.org/wiki/David_Hahn

codezero• 10 years ago

Wow totally forgot about this. Wiki linked to an article about what he's been up to recently: http://www.dailymail.co.uk/news/article-2506549/Uh-oh-Radioa...

He's been through a lot but still has a hunger for learning.

deepnet• 10 years ago

Hahn was working with fission not fusion , he was not a 'fusioneer' but splitting the atom.

Hahn produced amazing amateur nuclear work nonetheless, ( somewhat out of control when his reactor went critical ).

arethuza• 10 years ago

I wonder if you could use a Farnswoth Fusor as a neutron source to do some fissioning?

lakkal2• 10 years ago

I read his story a while back and was shocked that I used live nearby and may have (as a paperboy) delivered newspapers to his house. I left the area a few years before his experiments, though.

cm3• 10 years ago

While we're at it, are safety considerations the only problem that prevented nuclear powered automotive engines? I've always wondered why.

brandmeyer• 10 years ago

Mostly its about size. There is effectively a minimum viable size for a fission reactor. There are a pinch more than 2 neutrons born from each fission event. In order to operate at criticality, exactly one of them must go on to produce another fission. Leakage of neutron radiation from the effective surface of the core is a major way that neutrons don't make it to cause another fission event. As the ratio of surface area to volume goes up (because the core got smaller) it becomes harder and harder to design a core that doesn't lose neutrons to the other loss mechanisms to keep up with the increasing loss out the core's surface.

Animats• 10 years ago

Lockheed-Martin's Skunk Works is trying to build a useful fusion reactor using a somewhat similar approach.[1] They announced this a few years ago, and last fall, their people gave a talk at the Princeton Plasma Physics Laboratory. (There's video, but it won't play in Firefox on Linux.[2])

It's striking that a very capable organization is working on this.

[1] http://www.pppl.gov/events/colloquium-lockheed-martin-compac... [2] https://mediacentral.princeton.edu/media/Thursday+Colloquium...

nickpsecurity• 10 years ago

Let's not forget Doug Coulter:

http://sploid.gizmodo.com/this-chain-smoking-gun-loving-guy-...

He has a forum dedicated to all kinds of stuff. He occasionally stopped by Schneier's blog to deliver insightful posts. I particularly liked his calling out the Anarchist Cookbook's many ways of killing people... that try to do what it says. ;)

The Fusioneers, who build nuclear reactors in their back yards

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