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Joeviocoe wrote: As of today, where is LPP in this list?

1) The “teeth that chew the sheath” tungsten crown to regularize the filaments – 10-100x yield
2) Full power output of Capacitors and to ‘Imitate’ the heavier mixuture of pB11 by using Deuterium/Nitrogen.
3) Shorter Electrodes, slower run down, more fill gas.
4) New Raytheon switches for more Current from capacitors – 10x yield.
5) Switch to pB11 (incrementally higher percentage from the D/N mix) – 15x yield.

I think it is the first point. They would have told us otherwise.

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Joeviocoe wrote: Has the new Tungsten crown regularized the filaments, and yielded any higher gains?

Two options:

1st: There weren’t new shots until now.
2nd: The results don’t look good.

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asymmetric_implosion wrote: Anode erosion does not have to be a show stopper.

Thank you for your backround information. It makes hope again… 🙂

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asymmetric_implosion wrote: Pinch/plasmoid break up is being neglected. The e-beam can escape the pinch during breakup of the plasmoid. The damage can be substantial and it might be even worse if the electrons are high energy. You can superheat a larger volume of metal and erode more mass. It might be possible to reduce the beam current but eliminating it will be a problem. I believe the e-beam confinement by the LPP model is due to extremely large magnetic fields in a toroidal geometry. This works well until the plasmoid falls apart. Then you have hot electrons running around everywhere.

200 Hz operation is problematic for many reasons. We are finding that operating above 5 Hz is not intuitive as it was up to 5 Hz. We are thermally managing a Mo anode to control the temperature, but temperature control alone is not enough. The e-beam erosion can do two things: release gases trapped in the metal like hydrogen, oxygen and other common gases, erode the anode material into a vapor that cannot plate out before the next shot. High Z vapor like tungsten or Molybdenum seems to help the neutron yield as was reported for high Z inert gas/deuterium mixes. The current thinking on our experiment is at high repetition rate the vapor density is beyond the optimum mixing ratio which depresses the fusion yield. LPP might be able to push beyond 5 Hz if the e-beam is suppressed but plasma erosion will eventually supply enough material corrupt the gas and spoil the fusion gain. Flowing the gas a modest rates is not enough to maintain a clean environment. Even the lithography folks operating at 80 Hz had some problems with this. The solution they found was to increase the anode size above the optimum and operate with reduced yield. If I understand LPP’s operating regime, it relies on small anode diameters and high pressure. Increasing the anode size for a fixed current requires operating at lower pressure. The problem is somewhat constrained due to the PF physics.

Relying on governments to get this working is a joke. Resources are key and private resources would be better suited to drive this forward. I don’t know if a global collaboration will come to pass if successful, but the problems are materials limited. All fusion concepts have materials problems and they are not addressed because most fusion folks have a plasma background rather than a materials background. I agree that more can be done but materials are going to be a limiting factor in any fusion device. I’ve done a small materials survey and no material I’ve run across can withstand the e-beam and/or plasma erosion without sacrificing grams of material for the 1E7 shot operation at 100 Hz and 60 kA.

So electrode erosion is a show stopper…

The question is: how long can one electrode be used? How many shots? 200 Hz -> 120 * 10⁶ shots per week. So one electrode needs to last at last 120 Million shots!

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Joeviocoe wrote:

And the other two are…?

1) Several MW of waste heat

2) Very high efficiency of Ion Beam energy conversion. Roughly 80%

3) Energy extraction from X-rays using the photoelectric effect. The science is WELL known, but I don’t think engineers ever had reason to build such a thing. X-rays are usually produced from other power sources because X-rays are desirable. This, I believe, would be the first device that is the other way around. LPP wants greater than 80% efficiency with this as well.

http://www.youtube.com/watch?v=FSYOIayQ7bI

@ 4:02

Thanks 😉

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And the other two are…?

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Joeviocoe wrote: governments will focus all efforts to get that anode erosion problem taken care of.

But even goverments can’t do magic. Exspecially goverments can’t do magic!

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I don’t no, becouse I don’t know much about DPFs (I am still an undergraduate). But isn’t said there is a problem with anode/cathode erosion? Maybe I mixed anode an cathode up…

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Is there any prove EMC2 have got a new contract? Any serious source? Or only rumors?

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Tulse wrote:

we will see…

I am sceptical…

What facts have been reported that make you skeptical? Or are you doubtful of the whole approach in general?

I would think that the continued involvement of the US Navy suggests at least that there have been no obvious show-stoppers found to this point, which surely would be good news.

I am not skeptical in the sense that i am thinking it isn’t serious sience. Of course it is not pseudo sience. I don’t say it is like Rossi’s eCat, so “skeptical” is a hard word regarding to polywell.

PS: If something is wrong with my english, please tell me. I have to learn still…

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we will see…

I am sceptical…

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zapkitty wrote: More important is the rate of wear and the minimum time of a maintenance cycle.

Per current LPP estimates an electrode assembly might last a month.

Also per LPP estimates it will take about 9 hours for an FF unit to “cool down” to less than background radiation levels. So that’s ~9 hours cooldown, plus a couple of hours for unbolting and replacing prefabricated solid metal components. (And any other maintenance that might be needed by that unit.) Close it up and start it up.

So, given currently available information, unless actual electrode life turns out to be measured in hours and not weeks then erosion isn’t going to be a show-stopper for FF plants.

These are good news.

But what about the cost of the cathodes? If all the energy of the earth is secured by “Focus Fusion”, then what about the supply with cathodes. Could there be problems with the resources? Can you recycle the used cathodes somehow?

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