3 ms·

With all these fusion companies popping up... The energy in - energy out might not work out (yet?) but why can't they supply helium? I assume the reason is econ

• CamperBob2 5y ago
  If you think about it, the quantities of helium that will be produced by fusion reactors are necessarily extremely small. E=mc^2 and all that. The beamline at the LHC is "powered" by a hydrogen bottle the size of a small fire extinguisher, as an example of the scales involved.
  • version_five 5y ago
    My (layman's) understanding of nuclear reactions is that the m in the equation is the difference in mass before and after the reaction, so if two 2H make one 4He, somehow there is a small change in the total mass that gets converted to energy. Depending on how small this mass actually is, you may still make a fair amount of helium. Do I have the idea right, and its just that there is so much energy in the mass difference that it really ends up making very little? Or am I way off base somehow?
    • sseagull 5y ago
      Yes, you have the right idea: https://en.wikipedia.org/wiki/Nuclear_binding_energy#Fission_and_fusion https://en.wikipedia.org/wiki/Nuclear_binding_energy#Fission...