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So is the scaling of individual units primarily limited by heat? I presume there must be some limits beyond that relating to the plasmoid formation and/or other basic aspects of DPF.

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Aeronaut wrote: have they any idea how to capture and use all that glorious heat? If so, is that part of the 3.5 to 5G$ already budgeted?

The real purpose of the NIF is to test models for thermonuclear warheads to ensure the reliability of the US nuclear stockpile without actually blowing up the occasional warhead. To do that, you need to be able to produce fusion on a regular basis.

The NIF is emphatically not designed to produce a practical source of fusion energy, or even to provide a path for designing a practical fusion generator. While I have no doubt that very useful information about the basics of the D-T fusion process will come from their research, I think the NIF is being rather misleading to suggest the facility is a major step in the road to practical fusion energy. It’s really a weapons lab that (at some point) happens to produce fusion.

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Rezwan wrote: Unfortnately, this is the kind of thinking that makes them conservative.

I don’t see how one can argue that spending tens of billions and decades on one approach is “conservative”, when other options would take orders of magnitude less money and time to test (and possibly rule out). Researching all of the “alt-fusion” approaches to the point of determining their viability would likely take less than $100 million and five years’ time. It is hardly “conservative” to go all-in on one unproven technology that won’t show definitive results for years.

Of course, the NIF is a special case, since its main purpose is really for nuclear weapon research — any fusion power applications are incidental (and any practical uses are very far down the road, even if they are successful).

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I think it is safe to say that, when there is something to report, it will be reported. Research generally can’t adhere to a rigid schedule.

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jamesr, which technologies are you thinking of that would limit actual creation of a DPF device? Again, I’m not thinking of what would be needed to hook it up to the grid, or even to monitor/test it properly, but what technologies are needed to build it?

Or, put another way, if one had the appropriate knowledge and were sent back in time, how far back could one go and still make a working DPF using readily-available materials and techniques?

(I think a very interesting steampunk world would be one in which DPF were discovered in the Victorian Era — such discovery would offer at least some justification for the kinds of devices typically seen in the genre.)

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ExpressionEngine (the CMS used here) has an RSS module as well.

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I’ve played with it, and to be honest it is rather clunky to install, and doesn’t give the user much feedback as to what it is prior to installation. If I didn’t know if came from someone trustworthy on these boards, I wouldn’t have gone through with the install process (even though it is just a web app).

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Rezwan wrote: success in one fusion endeavor would breed it everywhere.

I very much doubt that’s true for Big Fusion if LPP or EMC2 or Tri-Alpha or General Fusion or any of the other low-cost “alt-fusion” approaches succeed. Who is going to pay tens of billions for a huge facility to do what someone has accomplished for a few million in the equivalent of a garage?

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I have to imagine that regulators are not going to be at all happy with an untended nuclear device running as it is driving across the country. Just sayin’.

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Wrestling with wording like this is always hard 🙁

If the FFS doesn’t want to limit itself to aneutronic fusion advocacy specifically, then I’d suggest that simply prioritizing/emphasizing “clean” and “safe” would be sufficient. (I’m presuming that the reason the FFS would want to advocate for aneutronic is precisely because it has those qualities, and not just because it is aneutronic.) If you want to advocate for fusion in general, I think it would be a mistake to explicitly mention aneutronic in the bylaws, as that would immediate raise the hackles of those pursuing other methods. I think that everyone, regardless of technological preference, wants the cleanest and safest alternative (all things being equal), and so emphasizing those would be a “neutral” way of promoting aneutronic.

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The traditional Big Fusion approaches already have well-heeled advocates, as evidenced by the billions (and billions and billions) poured into ITER, NIF, and prior projects. I’m not sure that a grassroots effort is needed to promote these forms of fusion. It seems to me that aneutronic and other “alt-fusion” approaches are in far greater need of champions, especially as they are often dismissed by Big Fusion supporters.

If ITER ultimately produces something that can be turned into practical fusion power, it won’t need a non-profit society to help. So I don’t think advocacy for “fusion in general” in needed, so much as assistance to those approaches that aren’t supported by massive research funds.

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vansig wrote: probably not, unless we can force a situation where secondary electrons have exactly the right energy

If not, then would a thermal approach be better than photo-voltaic, especially since the latter is unproven?

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vansig wrote: the only point to doing it this way is IF it can achieve better efficiency than a heat engine.

Is there a maximum theoretical efficiency for photo-voltaic solutions? As I understand it, current commercial photo-voltaic solar panels are rather inefficient (~15-20%). Can we reasonably expect to get significantly better out of the onion?

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Rezwan wrote: Was that in the DVD extras, or did you have to do some book learning for it?

It’s pretty much from the original series and the film. (There is an “official” list of planets and their locales, but that is basically a retcon for the film, as the original series was not terribly clear about the relationships among the various named locations.)

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which is about the surface area of a sphere at 4.4m radius

Does the onion really need to be a sphere? Creating a multi-layer sphere seems like a fairly daunting engineering task compared to creating flat panels. Is it necessary for the x-rays to hit the surface at a normal angle? If not, I would think that simply six panels, put together as a cube, would be a much simpler design — the panels themselves could be mass-produced far more easily. Presumably one wouldn’t even need to join the panels, as long as there was no space for the x-rays to leak through externally — just ensure that the panels overlap sufficiently that there are no through gaps.

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