Only about a week ago have I come across the Polywell fusion idea and I have to say that I am almost without words on how elegant this machine is.
I mean 6 rounded EM coils, 2 electron guns, 4 ion injectors, electrostatic fields, a little DT fuel and then *BAM* you got workable fusion. I know I'm oversimplifying the device, but COME ON, this is just genius. Forget those doughnut shaped machines, go Polywell!!
I've tried to find another "complements" thread but hey even if there is, another one can't hurt.
I will be dumbfounded by this simple design for quite sometime. WTG Bussard, may he rest in peace.
What is inelegant about just a smooth, hot doughnut of plasma?
All ideas are simple, but getting most of them to work with multiple ancillary parts is the fiddly bit and all the extra systems to make up for all the complexities that always seem to crop up in 'simple' systems.
I could show you under the bonnet of my car - it's a mass of technology that appears physically squashed into a substatial volume, yet all for just a set of simple pistons moving backwards and forwards with two valves venting to each!
The Sun looks like a very elegant solution - from 93Mmiles away. Get up close and you see it's a seething mass of chaos that even gravity and extreme magnetism fail to contain from mass ejections.
Bussard's great contribution, to my thinking, is his single-minded commitment to progressing the project. That act in itself, and while competing with so much autocratic self-accolade by tokamak proponents, sets a standard.
Both a Polywell and Tokamak torus look simple and eligant from a distance. In a sense the Tokamak is simpler as it only depends on magnetic confinement vs the Polywell's combined magnetic and electrostatic (or rather electrodynamic) approach. The ugliness comes into play once various subsystems, and tradoffs, and workarounds come into play.
The Polywell is more eligant in the sinse that ignition conditions are not nessisary.
Also, the predicted ability of the Polywell to do fusion without the costs and complexities of generating tritium in situ is a really big advantage.
The RFC machines may be the most elegant, though expectaions are more modest (in terms of Q).
D Tibbets wrote:
The Polywell is more eligant in the sinse that ignition conditions are not nessisary.
Some tokamak researchers I have spoken to openly think that tokamak won't run steaty state anyway and will be a pulsed (viz. not ignited) system. It can still be argued on viability.
In reality, ALL new technologies go through phases of complexity - first the concept is simple but needs endless tweaking and adjustments, which may be complex, clunky, systems if automatic control is required. Then there is a phase of engineering refinement of all that complexity as designers realise what really is, or is not, needed and at some point soon after you get a 'bare-bones' system. Then it goes back into an upward trend of complexity as the designers begin to master the subtleties of the machine and start overlaying refinements that tweak to optimum efficiency and functionality. Just consider motor cars, computers, mobile phones. Whatever you like....
Once we have several viable fusion systems operations that have evolved a little beyond the start-of-production model, then and only then would I suggest we might be able to tell which is actually the most elegant.
But still, if someone had the money, they can get most of the parts from radio shack and other online vendors and build a unit in their garage.
The only specialty items they would need to get is the fusion fuel, vacuum chamber, and shielding against the radiation soup this puppy will produce.
As far as the doughnut tokamak goes, it looks neat especially when it's operating. But I could not understand how it would attain the particle density it would need to be at to make usable power. Not to mention the whole HOST of safety checks that have to be verified before each and every use. Plus having to have liquefied lithium to protect the magnets from "hot" neutrons produced in the reaction.
OTOH, the Polywell configuration likes to "squeeze" the ions/electrons into a small space which seems to provide for a better plasma density.
Not to mention the Polywell is smaller, safer, and cheaper to build once it's (near) perfected. Just got to love those aspects in a device like this.
