chrismb wrote:Can you please just state what made-up numbers you have an issue with?
50 MW drive power on a 100 MW reactor. Where did that come from? Granted we don't yet have enough data to actually refute this number, but it's not an estimate I'd put money on, especially for a D-D plant...
Or how about 5000 MW fusion power, 750 MW net? I've never seen those numbers before. Granted that wasn't you, but still...
If you put 100MW in and get 303MW out and after converting that 301MW you get 101MW power again 100 of which goes back into the machine, then you've got a net of 1MW.
If that's not "making up numbers for the sake of argument", I don't know what is. The point is not to have something that can technically make net energy; it's to have something that works better than other ways, so somebody will actually build it. That's the answer to the original question in this thread, and I'm given to understand you don't actually disagree with this...?
Yes, you might want this for a moon base if you couldn't get anything else, but we're not talking about moon bases, and in any case you CAN get something else - fission and solar are both better options for a moon base than a polywell with a system gain of 1.01...
We can play that game if you like and you would loose
It's not a question of 'loosing'. Please, give me a bit of background. It's very hard to tell where you're coming from, why you say some of the things you do, and what I can expect you to know about. Sometimes you seem very well educated and trained, sometimes... not.
You were talking about steam-based turbines, then you went from there on to something about making up numbers
Yes, I "went on". The jump was clearly labeled; did you miss it?
None of your comments have even mentioned heat engine efficiency or employed the concept in any way, so you have no excuse for suddenly pulling out Carnot in this context.
I was the one who pointed out that Carnot (or more accurately Rankine) is where the approximate factor of 1/3 comes from. This is one of the two factors that require such high raw fusion gains in a D-D plant. The other is that steam-based conversion equipment is very expensive, and this cost is not related to the net fusion power - it's related to the gross fusion power, because a polywell requires pure electrical drive, not a combination of electrical drive and ash heating like a tokamak.
...I thought you didn't even disagree with MSimon on this. Why the sarcasm?