Slashdot and Scientific American

[Dr_Barnowl]

Slashdot has a topic on NIF

I couldn’t resist a few posts about Focus Fusion…

Someone mentioned this article in Scientific American : Fusion’s False Dawn, which is pretty negative about the engineering challenges of DT fusion (and I agree with much of it, in that context)

I liked the paragraph on DT fuel pellets for the proposed LIFE reactor ; Rochester university makes similar pellets and they cost about $1 million dollars each.. and you’d need almost 90,000 a day for a NIF-like facility.

[vansig]

i quite like the readers’ comments to that article

[Rezwan]

I like where Yvanhoe says

The summary also is funny in how it understates achievements of fusion research. I remember a physicist saying “The Sun ? Pfah ! Too cold and too inefficient ! If we were to reproduce the conditionss in the sun, we would never get anything that would interest industries !”

And then Pedestrian Crossing adds:

Indeed. From Wikipedia:

The energy production per unit time (power) produced by fusion in the core varies with distance from the solar center. At the center of the sun, fusion power is estimated by model to be about 276.5 watts/m3, a power production density which more nearly approximates reptile metabolism than a thermonuclear bomb. Peak power production in the Sun has been compared to the volumetric heats generated in an active compost heap. The tremendous power output of the Sun is not due to its high power per volume, but instead due to its large size.

[Augustine]

Dr_Barnowl wrote: Slashdot has a topic on NIF

I couldn’t resist a few posts about Focus Fusion…

Someone mentioned this article in Scientific American : Fusion’s False Dawn, which is pretty negative about the engineering challenges of DT fusion (and I agree with much of it, in that context)

I liked the paragraph on DT fuel pellets for the proposed LIFE reactor ; Rochester university makes similar pellets and they cost about $1 million dollars each.. and you’d need almost 90,000 a day for a NIF-like facility.

I also like the LIFE reactor not just because it burns the nasty nuclear waste but because it is a 3GW power plant. Yes I know that smaller is better but you have to admit that 3GW is a staggering number on the order of the Palo verde power plant. http://en.wikipedia.org/wiki/Palo_Verde_Nuclear_Generating_Station

As MSimon says at talk-polywell, it doesn’t matter if the science for tokomak fusion works if the engineering is impossible. Hopefully FF can sustain the desired rate of pinches without destroying itself.

[Dr_Barnowl]

I think the thing about LIFE is the engineering sounds pretty impossible.

They use the phrase “gatling gun” and it’s about right – in NIF at the moment you have to position absolutely pristine fuel pellets with world-class precision in terms of position AND alignment.

For LIFE you need 600 a second… you can’t afford any imperfections like magazine extractor scratches … the engineering boggles.

And then you need a factory capable of churning out 90,000 of these a day – bear in mind these are cryocooled gold-uranium alloy enclosures with a beryllium sphere containing the D-T fuel mix. So you need to make 600 of these perfect targets every second from expensive and rare materials that are also difficult to handle and toxic (the tritium being the largest fraction of the cost, but uranium and deuterium are not exactly cheap and beryllium is nasty, as we already know from assessing it’s intended use as DPF electrodes.).

Whereas the DPF essentially constructs it’s own self-compressing “fuel pellets” from nothing more than electricity and tenuous gas.

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