Lockheed Martin has obtained a patent for a compact fusion reactor

Re:Lockheed Martin has obtained a patent for a compact fusio... by luke0016 on Tuesday March 27, 2018 @10:36AM (#16688792)

It's the opposite of fission. Fission produces energy by "destroying" matter (splitting it into smaller parts). Fusion produces energy by creating it (combining it into larger parts). The difference in mass between the inputs and outputs manifests as energy. In simple mathematical terms, thanks to Einstein, E=mc^2

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Re:Lockheed Martin has obtained a patent for a compact fusio... by slavik81 on Tuesday March 27, 2018 @02:35PM (#16691461)

I don't quite understand what mass is lost. I thought fusion involved overcoming the electrostatic forces to get two protons close enough that they are pulled together by a nuclear force, thus releasing the nuclear potential energy. But, you start with two protons, and you end with two protons, so what's the mass that's converted to energy?

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Re:Lockheed Martin has obtained a patent for a compact fusio... by slavik81 on Tuesday March 27, 2018 @05:21PM (#16692835)

Apparently I was mistaken. They don't just make a weird hydrogen isotope. They make plain-old hydrogen. 4 protons become 2 protons and 2 neutrons. The difference in mass between a proton and a neutron is 2.3×10^-30 kg. So, naively, you'd generate 4.1×10^-13 J per helium atom. Or, roughly 11 GJ (3 Mwh) per litre of helium at STP.

Seems a little low, though I suppose 1L is only 1/5th of a gram of helium. I still might be missing something, too.

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