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Given what you’ve said, it certainly sounds like D-T radioactivity wouldn’t be an issue, and I agree that theoretical D-T breakeven would be a big achievement. But I’m not sure if it would necessarily bring in the funding bonanza, since as far as I know an FF device is unsuited to using D-T as a practical, power-generating fuel. At the very least, the current design is not set up to capture any reasonable amount of neutron energy for power production (I don’t know how easy it would be to reconfigure a basic FF design for such purpose.)

If I were a potential investor, I’d see D-T breakeven with FF as a neat trick, but that doesn’t really indicate if it can do the much harder p-B11 breakeven.

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Shielding would help with protecting the general area, but wouldn’t the actual FF device itself become radioactive? I think the main concern with doing D-T runs is practical — LPP only has enough financial resources for the one FF-1 device, and if they make it too hot to handle easily, that becomes problematic for them to work on further. (I also don’t know if such residual radiation would have any impact on the actual p-B11 reaction when they would move to that fuel.)

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JimmyT wrote: Since you can’t capture the rather large fraction of total fusion energy from a DT reaction which is imparted to the neutrons it really is merely a theoretical point.

But it’s a theoretical point that has huge implications for the validity of the FF approach.

I think the very large downside of doing a DT run is that it would make FF-1 radioactive. That’s apart from the problems of handling tritium. (Is LPP even licensed to handle a radioactive substance like tritium?)

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dennisp wrote: Or to put it another way, one box powers about 150 homes for a year.

Now that really makes clear how much energy fusion can produce! That seems so absurdly small. (It would be interesting to compare that to how much coal would be needed…)

The great thing about fusion is that its fuel costs are practically nil (even presuming a fuel as pricey as decaborane), and the great thing about aneutronic fusion is that it also doesn’t have all the costs associate with complex steam generation. It’s a win/win.

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dennisp wrote: Cool. So 5kg of fuel is 4.4 kg boron, divided by .8 for 5.5 kg natural boron. Then divide by 11% for 50 kg Borax, or 110 lbs.

And divide that by 365 for about .14 kg per day, which, given that a 2.15 kg box of 20 Mule Team sells for $6 at Amazon, works out to around 39 cents a day for fuel costs. And at 5MW, that would power about 5000 homes (I believe this is right, no?). Meaning that, if my math is right, the cost in fuel for each home per day is .0018 cents — presuming the cost of fuel is just the cost of borax, which it obviously isn’t since it needs to be made into decaborane. But, that cost is Amazon Prime delivering the box to the door of the fuel processing plant — I’m just guessing there are cheaper sources of borax, or even decaborane.

EDIT: OK, so pricing for actual decaborane can run around $50/g. That would make the actual fuel costs for a single home around 13 cents a day.

Of course, fuel is not the only cost involved in generating the power, but for fossil fuel power plants it is overwhelmingly the majority of the costs. And not only does FF have vastly cheaper fuel, it also has a much smaller physical plant (conventional or nuclear power generating stations also have large machinery and plumbing dedicated to boiling water to make steam to turn a turbine to spin a generator, something FF doesn’t have).

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I know this has been suggested before, but if machining is an issue, is 3D printing an option? There appear to be several firms that do additive manufacturing with tungsten (although I don’t know whether the properties of sintered tungsten would be appropriate for your use).

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Wow. I wonder if there is any way that LPP could access their simulation software.

It’s very interesting to me that, although they talk of “neutron sources” and “collapsing plasma”, no where in the press release do they use the word “fusion”. I realize that this work is largely targeted at producing more efficient neutron sources, but given that Z-pinch and DPF are two of the most prominent approaches to fusion power, this omission seems a bit odd to me.

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asymmetric_implosion wrote: You are correct that the largest piece is the capacitors. Super capacitor technology is advancing quickly but they are the wrong kind of capacitors. The capacitors for FoFu require low inductance, fast discharge current and high voltage. Super capacitors tend to be low voltage, slow discharge capacitors. It is challenging to reduce the size of high voltage capacitors that can discharge as needed in FoFu. Other technologies may replace capacitors but a FoFu reactor will still need shielding. I can imagine a 5 MW reactor with everything fitting in a 1 car garage but much small than that is unlikely.

So sized appropriately for use in ships, and maybe even trains, but not planes or cars. Perhaps shipping-container-sized?

Speaking of ships, it seems there is a nice confluence of the types of caps that FF needs and that the Navy will need for directed energy weapons and railguns. It looks like FF would be ideal for an electric Navy.

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JimmyT wrote: If a train wreck (powered by Focus fusion) were to occur resulting in rupture of a reactor. Would those down wind need to be worried?

Lerner wrote: I think a reasonable comparison would be what happens if 3 tons of gasoline blows up.

And, of course, we’ve just seen what tanker cars full of oil can do. These tanker cars wouldn’t be necessary in anywhere near the numbers they are now if FF were up and running. I’ll take the risk of release of a tiny bit of C11 to this petroleum-fueled devastation.

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Nice summary, zapkitty — a great accounting of why this work is so incredibly exciting. It really could be an enormous game-changer.

This is also why I find the apparent lack of funding interest in DPF to be so frustrating. It has such huge potential if it works, and the main issues seem to be engineering, not theoretical, meaning a relatively small investment could determine its potential relatively quickly. An Elon Musk, Bill Gates, or Warren Buffett could use the spare change from their sofa cushions to fund a potentially world-changing technology that could have real-world impact in less than a decade. Why aren’t smart angel investors flocking to the doors of LPP?

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Yep, my first thought when I saw this report was “Why use a thermal imaging camera? Why not just dunk it in water?”

The whole Rossi circus is embarrassing.

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Although carbon nanotubes may not be available in practical amounts currently, it appears that the metallic versions may have better thermal and electrical conductivity than most of the metals discussed. Would they be a potential replacement for the electrodes, or at least as a sheath? Would their properties at least in theory help to solve some of the evaporation issues?

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I would think the tremendous mechanical simplicity of FF would also be a huge benefit in space propulsion applications. Slough’s approach requires precise delivery of metal liners once every minute, which has to have a lot of mechanical overhead (in terms of complexity and weight), and introduces reliability issues. One of the beauties of the FF approach is how physically simple it is, with no moving parts apart from valves to deliver the fuel.

I guess that if the issue is crewed applications, with the possibility of directly addressing mechanical problems by on-board staff, then the extra thrust is worth it. But I would think that FF would be ideal for robotic deep space exploration, with its potentially high Isp and reliability.

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I agree that fusion rockets are hugely important in the long-term, but if I were trying to create an actual company, the potential revenue for any reasonable time horizon is surely in power generation.

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If they can get over-unity, it seems extremely perverse to me to focus on space propulsion rather than terrestrial power generation. The latter market is far far bigger, and the need is far far greater.

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