IEEE Spectrum: Fusion on a Budget

…. it’s pretty simple, according to Paul Schatzkin, who runs Fusor.net, a Web site where amateur ”fusioneers” congregate to swap equipment and advice: ”Find two stainless steel half-spheres, seal them together around a wire grid, suck the air out of it, apply some high voltage to the grid, inject a bit of deuterium into the chamber, and sit back and count the neutrons.” Don’t expect to reach energy breakeven, Schatzkin says, but at least you’ll be failing to achieve practical fusion at only a millionth the cost of a tokamak….

Building a fusor is simple enough for amateurs to contemplate because
of the enormous global inventory of used lab equipment, says veteran
fusioneer Richard Hull. For example, fusion containers need only
achieve pressures of about one millitorr; vacuum pumps with that
capability make their way to eBay for US $10 to $100. High-voltage
feedthroughs are in the same range—or free, if you build your own from
microwave-oven salvage. The most expensive items, according to
Schatzkin, are neutron detectors, which have to be purchased new. But a
cheap workaround is available, Hull says: You can prove your fusor is
working by irradiating a piece of silver and watching the decay of the
Ag-108 and Ag-110 isotopes with a simple Geiger counter.