LM showing off again

[paperburn1]

n one building, Lockheed is using the world's largest gantry machine and 3-D printing to build aircraft. Across campus, Lockheed has a giant airship that could deliver cargo to remote areas, and a compact nuclear fusion reactor that could revolutionize power generation.
The whole article
http://www.reuters.com/article/2014/12/ ... 6S20141210

[ohiovr]

That's nice about the fusion reactor

They don't tell us one thing about the theory behind it's supposed practicality as an energy source, except that its high beta. That's nice. If it works as well as advertised I will take note of the fact it can make 150 million degree temperature plasma around magnets that have physical supports. How this avoids the fusor dilemma is beyond me. That plasma is going to get smacked darn hard on those supports. So I say if it does work as advertised, its miracle.

Like the F35. muahahaha

[D Tibbets]

That's nice about the fusion reactor

They don't tell us one thing about the theory behind it's supposed practicality as an energy source, except that its high beta. That's nice. If it works as well as advertised I will take note of the fact it can make 150 million degree temperature plasma around magnets that have physical supports. How this avoids the fusor dilemma is beyond me. That plasma is going to get smacked darn hard on those supports. So I say if it does work as advertised, its miracle.

This is where the Lockheed concept enters vague territory for me. If it is essentially a variation on the Polywell, then the plasma density/ containment is inside the space bordered by the three magnets (or two magnets in one illustration). The plasma (presumably mostly electrons, as these are what is escaping primary magnetic containment)in these outer regions are much lower density, by the ratio of the Wiffleball trapping factor. This 'exterior plasma' is equivalent to the recirculating electron plasma in a Polywell. The efficiency and management of this recirculation componet may be modified, perhaps profitably, but the concept is still that of the polywell.

If this is not the case, and this external plasma is as dense as the plasma inside the magnets, then the losses to the unshielded or partially shielded supports outside the magnets are presumably tremendous. There are also increased magnet surface area exposed to ExB diffusion. EMC2 has apparently reached the conclusion that even the nubs- connects between the magnets in WB6 and WB7 was major loss mechanisms. By moving the supports to greater radii past the midplane of the magnets apparently reduces the exposure, because the supports are further away from the B field lines upon which much of the escaped electrons are following, at least to the point where recirculation reversal of the electrons is possible with a positively charged magrid. The neutral magrid arrangement confounds this somewhat. I think the saving grace is that the density of electrons in this exterior area is ~ 1000 times or less than that inside the machine. Relative losses compared to external electron densities is thus much less. Such might apply to the Lockheed machine, but the description of the plasma wrapping around the magnets without the qualifier that this wrapping plasma represents only the primary containment escaped electrons leaves questions.

Also, if by plasma they mean a near neutral plasma of both ions and electrons wrapping around the magnets, then the Polywell concept of efficient ion electrostatic confinement so that electron losses dominate is absent and all of the reasoning for decoupling ion confinement from the electron magnetic confinement is abandoned.

PS: I haven't considered the MHD instabilities that I think would manifest in these exterior regions if additional layers of magnets are used. Concave B fields would be present between these layers of magnets and macro instabilities would be unavoidable. The density of this exterior plasma (primarily electrons?) being much less than the interior plasma density may mitigate this concern to an extent that other gains might offset it.


Dan Tibbets