MIT advance helps remove contaminants that slow fusion react

[Nik]

MIT advance helps remove contaminants that slow fusion reactions

http://www.physorg.com/news/2010-12-fus ... nants.html

"The new experiments have revealed a set of operating parameters for the reactor — a so-called “mode” of operation — that may provide a solution to a longstanding operational problem: How to keep heat tightly confined within the hot charged gas (called plasma) inside the reactor, while allowing contaminating particles, which can interfere with the fusion reaction, to escape and be removed from the chamber."
/quote

Nik-note: Not strictly relevant to polywell, but...

[Tom Ligon]

We know nothing about the mechanism, but Polywells almost certainly will suffer from contamination, both from hydrogen evolved from the walls and probably also sputtered material. After high reaction rates are achieved (assuming Dr. Bussard's basic calculations are correct), this could wind up being the biggest obstacle to building commercially-useful continuous-running powerplants.

I'd love to see what they figure out, to see if it suggests a similar route on other reactors. Anything that confines plasma for any significant length of time may benefit.

[mdeminico]

We know nothing about the mechanism, but Polywells almost certainly will suffer from contamination, both from hydrogen evolved from the walls and probably also sputtered material. After high reaction rates are achieved (assuming Dr. Bussard's basic calculations are correct), this could wind up being the biggest obstacle to building commercially-useful continuous-running powerplants.

I'd love to see what they figure out, to see if it suggests a similar route on other reactors. Anything that confines plasma for any significant length of time may benefit.

Eh, if contaminants are a problem, it would seem to me that starting a polywell wouldn't take *that* much effort, so if contaminant buildup would become sufficiently problematic, just shut it down, flush it, and restart every so often.

So in a commercial application, a series of polywells could be built, only running say 4 out of 5 at a time, maybe switch that one that's being flushed every 15 minutes or something. Power output would remain steady enough, and contaminants could be flushed.

[MITlurker]

Eh, if contaminants are a problem, it would seem to me that starting a polywell wouldn't take *that* much effort, so if contaminant buildup would become sufficiently problematic, just shut it down, flush it, and restart every so often.

So in a commercial application, a series of polywells could be built, only running say 4 out of 5 at a time, maybe switch that one that's being flushed every 15 minutes or something. Power output would remain steady enough, and contaminants could be flushed.

"shutting" down a polywell, or any fusion reactor for that matter after ignition begins is extremely wasteful (when considering energy).

The fewer contaminants the more profitable the reactor.

[D Tibbets]

Ignition is a moot point in the Polywell. It is a power amplifier, not an ignition machine.

What I believe may be important about this so called I mode operation with reversed magnets, is not that it might have some benefit for diverters, but that it may provide a means to control edge instabilities that otherwise is probably a show stopper for Tokamaks.

For that matter, does flipping some of the magnets create something like a Field reversed configuration. (FRC). Does this behave like a toroidal FRC?

Speculation based on ignorance is unlimited

Dan Tibbets

[mdeminico]

Eh, if contaminants are a problem, it would seem to me that starting a polywell wouldn't take *that* much effort, so if contaminant buildup would become sufficiently problematic, just shut it down, flush it, and restart every so often.

So in a commercial application, a series of polywells could be built, only running say 4 out of 5 at a time, maybe switch that one that's being flushed every 15 minutes or something. Power output would remain steady enough, and contaminants could be flushed.

"shutting" down a polywell, or any fusion reactor for that matter after ignition begins is extremely wasteful (when considering energy).

The fewer contaminants the more profitable the reactor.

That's true, the fewer contaminants the better. But it depends on if the method for reducing those contaminants hinders the operation of the reactor, if the net effect is a lessening of the lifespan, or any other number of factors.

Shutting it down and restarting could also cause those same problems I mentioned.