The Focus Fusion Society › Forums › Lawrenceville Plasma Physics Experiment (LPPX) › Conversion efficiency › Reply To: General Fusion Inc
nemmart wrote:
The thermal output of an FF unit operating at 200 Hz has been estimated at ~7 MW thermal… doable, but pushing things a bit.
Initiating each shot requires 100 KJ from the capacitors. If the conversion efficiency is low (say 40%) then you won’t get enough energy from each shot to recharge the capacitors for the next shot. And the shots/sec is irrelevant.
The question is core temperature and so the results will be the same whether you increase the shot rate or the energy per shot.
The final set of beryllium electrodes will be quite a bit smaller than the old copper and current tungsten designs. Less mass and closer to the plasmoid. Increase the temperature too much [em]and the anode is going to be slag.[/em]
nemmart wrote: A plan B designed around a lower conversion efficiency would require far more energy from the fusion reactions, something like 400 KJ per shot instead of the planned 66 KJ.
That would, of course, mean switching from an aneutronic to a neutronic process. Switching from pB11 fuel to D-T fuel… from hydrogen-boron to deuterium-tritium .
And that just means that the anode will not only be slag but the entire FF core will be highly radioactive for centuries to come. Not very good for the FF project.
The temptation of D-T… the low-hanging but extremely radioactive fruit of the fusion fuel tree.
Interesting aside: EMC2’s Polywell project recently seems to be trying to use the prospect of D-T fuel to lure in investors… which seems odd since D-T’s intense high-energy neutron flux would quench the HTSC coils a Polywell power generator would need to function.