Giorgio wrote: ↑Mon Mar 29, 2021 7:35 am
Yes, I was mentioning in the other thread that I agree that the 2 Hz pulses operation is an advantage to limit impurities, but this will not solve the D-D fusion chain issue because anyhow 50% of the fusion products will take the Tritium route regardless of length of fusion (compression) time.
I think you misunderstood me. The goal is to fuse D+D and make He3 and T. The T and He3 get separated and the He3 is fed back into the system for the next pulse. There won't be any T left in the reactor to fuse with a D in the next shot. That is at least what I understand to be the goal.
Now there is of course a possibility that the T will fuse with a D right after it was produced in the same shot. I think that largely depends on the fuel mix. If they run it He3 rich, the chances are lower, though that might cause the problem that you consume more He3 from He3 + He3 and D+He3 reactions than you produce from D+D reactions. I am not entirely sure how high the chances for these D+T reactions are but from what I know and understand I would put the likelihood of this in Helion's reactor at around 5%, most likely a lot less. That is because the Tritium will be very energetic (1 MeV), in a 40keV plasma. AFAIK, it would have to slow down considerably before it can fuse with a D. So we would first have to produce a T from a D+D reaction (50% chance). That T then has to hit a D, rather than a He3, or a p and both are present in the plasma 50% * 0.333 and then it has to slow down significantly before the pulse is over. Not sure about that chance, but I would be surprised if it was more than 30%. Ah and let's not forget that the 50% chance of a tritium being produced is a relatively high estimate, since there are also D+He3 reactions (though again those depend on the fuel mix).
But don't take my word for it. I am not a plasma physicist and may be off in my estimate somewhere.
Now the T is an interesting thing actually. You could store it until it decays into more He3, or you could sell it and make a lot of money. Tritium is (at least right now) more than an order of magnitude more expensive than He3. So one could sell the T and buy more He3 and still have money left in the bank. Question is how long that will go before the market is saturated with T and higher demand drives up prices for He3.