A Farnsworth-Hirsch fusor, to be specific. Fairly cheap. Really, authentically produces hydrogen fusion... but not much of it (neutron flux is very low) and it can't run very long before the accelerator grids overheat. It's basically a spherical particle accelerator, and doesn't come anywhere close to achieving breakeven. http://en.wikipedia.org/wiki/Fusor
This is the weirdest example of pg's negative comment up-voting I have ever seen. True you are not actually nit-picking the article but the second paragraph comes close to dismisal.
A teenager built a fusion reactor FFS. I had trouble making coffee this morning.
This is the Maker top 1% - and should be celebrated, not compared poorly to other similar attempts.
Well, it depends on his budget, and what equipment he had already. If you have unlimited money, you can build a fusor straight from a Cole-Parmer catalog.
Buy a vacuum chamber, bolt a turbopump on it, connect a roughing pump to that, bolt the thermoelectric vacuum gauge on, bolt a off-the-shelf HV passthrough to the chamber, plug in the HV psu, pump it down to 1 micron, backfill it with deuterium, flip the switch, bask in the neutron radiation. Easy.
The only thing that requires actual fabrication is the grids, which a competent welder can make in 20 minutes with a MIG and some bent stainless welding rod. Everything else is pure COTS.
If he didn't have $50k, then it could have been almost arbitrarily hard. A 40 year old two-stage mechanical pump+diffusion pump can do the high vacuum required, if you don't have the money for a modern setup-- only if you keep them flawlessly maintained, (including frequent oil changes, to replace the gunk that dissolves into it) and don't mind 24 hour pumpdown times. You can build your own chamber instead of using commercial flange hardware, if you've got a week of free time. You can kludge together a 75K HV PSU by running a couple microwave oven transformers in series, in a vat of transformer oil to keep them from arcing over.
Either this fusor was high-dollar legos, or it was an epic year-long engineering job. We don't know, because the article is a lot more interested in bureaucratic trivia rather than the fusor itself.
What amazes me is that I read the original comment as just an explanation to encourage others to try. It seemed like a list of places to start if you wanted to make one yourself.
There is nothing negative in the original comment, because there is no shame in replicating a scientific experiment that has been done before.
In fact, carefully replicating other people's complicated experiments is what science is about. If you want to pretend that you're being original take up structural knitting or something.
The original comment's context was very useful because it tells us that the article isn't about some crazy and dangerous attempt to build a fission reactor by hoarding radioactive waste (see: scary link from patio11) but about an experiment that has been legitimately accomplished by high school students in the past and which is rather less dangerous (because it doesn't start irradiating nearby objects, like your body, until you throw the switch... and you don't need to leave it turned on much longer than it takes to read a Geiger counter and high-five somebody.)
I agree with these comments in support of the original comment. It was, in my opinion, informative. Which is -- to put it in the context of the current apparent meta-discussion about HN's role that I seem to see scattered about the site -- where HN started out.
It was a much smaller community, then. And it was, perhaps more so than today, supportive -- genuinely supportive.
But it was about information. And support was not about obligatory glad-handing or pats on the back. Some of it could be fairly critical, at times. Informatively critical and in the interest of improvement, for the target of criticism and for the community at large. "Constructive" criticism, I guess.
Not that I perceived the comment that started this sub-thread as being critical. (Except perhaps -- if one chose to take it that way -- of what might be a hyped news headline. Not the student.)
I really appreciate the context that comment provides. If I'd known that when I was a student, maybe I would have had another interesting thing to try out.
just a suggestion for all us geeks, if we want others to understand our meaning, we should be doubly clear in our explanations and state what may seem obvious out loud.
No idea! If so, he might have gotten a big head start by using some of his grandfather's old equipment-- the reactor vessel in the article photo appears to be new, but 50 year old diffusion pumps and HV power supplies function identically to today's equipment.
A Farnsworth-Hirsch fusor, to be specific. Fairly cheap. Really, authentically produces hydrogen fusion... but not much of it (neutron flux is very low) and it can't run very long before the accelerator grids overheat. It's basically a spherical particle accelerator, and doesn't come anywhere close to achieving breakeven. http://en.wikipedia.org/wiki/Fusor
Tom Ligon wrote an article for Analog in 1998 describing how a high school student could build one for a science fair: http://fusor.net/newbie/files/Ligon-QED-IE.pdf
Quite a few people have built operational fusors, including many high school students: http://fusor.net/board/viewtopic.php?f=7&t=13&p=512