Reply To: General Fusion Inc

[zapkitty]

nemmart wrote: If the onion and ion beam capture hit the 80-90% targets then everything will be just peachy.

The high efficiency estimates are a result of the known physics.

nemmart wrote: It’s not too difficult to imagine a scenario where the fusion works, but the engineering to hit the 80-90% conversion efficiencies fails.

The efficiencies could be lower by 5-10% each, depending on how each side sorts out, and FF would still be a viable electrical power source.

nemmart wrote: To me, this seems like a significant risk to the project.

Not really. I’m not saying it’ll all be smooth sailing but the physics of both the ion beam and the x-rays are known quantities. It’s just that we are used to converting electricity into ion beams and x-rays rather than tapping them for power.

nemmart wrote: So why not have a plan B in place?

That would be fine… as long as the plan B doesn’t involve thermal-electric conversion.

nemmart wrote: I would advocate that someone on the LPP team or who knows what parameters can be tweaked should be looked to see if there is an alternative configuration that produces more fusion power per shot.

This seems to be a fairly common misconception… the power output of an FF unit is primarily determined by its pulse rate. Any increase in individual shot power can be approximated by increasing the pulse rate.

And the maximum pulse rate is governed by anode cooling. The thermal output of an FF unit operating at 200 Hz has been estimated at ~7 MW thermal… doable, but pushing things a bit.

A substantial increase in either shot power or pulse rate would both end up with the same result: a corresponding rise in temperature and a slagged core.

nemmart wrote: We know that a heat engine can achieve 40% efficiency

… errrrrrrrrrr… not quite. Those kinds of thermal efficiencies are achieved at the expense of very high operating temperatures. Temperatures in the thousands of degrees C.

The most anyone has ever postulated for the output of an FF cooling stream is at ~700-800 degC… i.e. maybe 20-25% thermal-to-electrical conversion efficiency. That’s game over for a thermo-electric FF, I’m afraid.

… still would be a great x-ray source, though.