asymmetric_implosion wrote: Hmmmm. Lets do the math.

PF reactor will produce a net of 66 kJ per shot according to Sankey diagram on LPP website. With 8.7 MeV/reaction, that requires, 4.75E16 reactions per shot to produce the fusion energy. Each reaction produces 3 helium atoms so 1.4E17 atoms per shot. You fire 200 shots per second giving you 2.8E19 atoms per second. For reference, your average helium tank in party store for balloons holds 300 cubic feet or 8.5 cubic meters of helium at standard pressure and temperature. The standard pressure and temperature density of helium is 2.7E25 atoms/m^3. The total number of atoms to fill the bottle is 2.3E26 atoms. Using the production rate, it will take more than 90 days to fill a single bottle from a 5 MW PF reactor as proposed by LPP. I can’t speak for anyone else but we use a helium bottle every month and we are a very small lab. You would probably be able to produce the world’s total electricity needs many times over before you could produce enough helium to sustain the current demand.

Yeah, without having done the math myself, I ballparked this problem this way. Nuclear reactions are just beyond our natural comprehension directly in the ratio of mass to energy. That leaves the question: where CAN we get helium? It seems like prices are naturally going to drive birthday balloons out of business in a few decades, and recycling refrigerants is a natural choice. What else can we do?

Fracking solved the natural gas problem for a few decades, but I believe fracking doesn’t get much helium like traditional natural gas wells do. What can we actually do about one of the least renewable elements on earth?