Barry Kirk wrote:The polywell has 2 major advantages over the Tokamak.
1) It is only trying to directly confine electrons not ions. Electrons are a lot easier to confine.
If I hear this nonsense one more time I'm going to pull my hair out! Any machine that can confine one species will automatically confine the other species electrostaticly.
Barry Kirk wrote:2) It is not using a Maxwellian distribution for energy.
Why the hell should that be an advantage? A non-Maxwellian distribution doesn't buy you much but it costs a lot of energy to maintain.
93143 wrote:The toroidal configuration has problems with plasma instability. One of the reasons Polywell is supposed to be better is the inherent MHD stability of the field configuration. With a wiffleball, you push outwards and the field strengthens. With a toroid, you push outwards and the field weakens.
With a torus, you lose all the advantages of the "wiffleball" configuration, since you can't run at high beta. The electrons are always on field lines, so they aren't truly 'confined'; by turning a neutral 5 keV plasma into a non-neutral 50 keV plasma, you've just taken ITER's confinement troubles and magnified them substantially. Aneutronic fusion of any description is probably out, and even if it's not, direct conversion will be a nightmare.
This comes closer to hitting the mark. The potential strengths of a polywell vis a vis a tokamak are MHD stability and high beta. (Of course, the statement that electrons on field lines "aren't truly 'confined'" doesn't make any sense.)
93143 wrote:I suppose it could work, but if EMC2 can get the transport worked out for Polywell it should be vastly superior to any toroidal system.
If EMC2 can get the polywell to work better than the tokamak then it will work better than the tokamak? I can buy that.
Art Carlson wrote:Of course, the statement that electrons on field lines "aren't truly 'confined'" doesn't make any sense.
...yeah, I was a little dubious about that. Basically I was working off an old memory of a description of how tokamaks don't "confine" the plasma, they just slow down transport to the walls. Which is a niggly point that's technically true of a Polywell too, for slightly different reasons... I probably shouldn't have left it in...
93143 wrote:I suppose it could work, but if EMC2 can get the transport worked out for Polywell it should be vastly superior to any toroidal system.
If EMC2 can get the polywell to work better than the tokamak then it will work better than the tokamak? I can buy that.
That's not quite what I said - basically Polywell has enough advantages that if it works like it's supposed to it will be a lot better than a tokamak. Even if it doesn't work like it's supposed to, the odds of it not working as well as a tokamak, but still being useful as a power producer at all, are low...
93143 wrote: the odds of it not working...as a power producer...are low...
On what basis do you come by this conclusion? On the last 25 years of research and $25M funding which has produced so much evidence that your conclusion is undeniable??
You have 3 reasons to think this - each blip on the neutron detector. That gives me about a quadrillion reasons to think it'll fall short of break-even, I guess!?
Perhaps better to say 'I believe that...', or 'in my evangelised opinion...'.
rnebel wrote:The major focus for the next generation Polywell is transport. We will be trying to take the machine from "OK" confinement to "good" confinement. Historically, this is a step that has been difficult for fusion machines. The next couple of years are going to be interesting.
I also notice that a number of people are trying to make Polywell arguments using classical collision models. The dominant mechanisms for transferring energy between the ions and the electrons are collective mechanisms, not classical binary collisions. Our experience is that you have to do full-up kinetic simulations if you want to understand these mechanisms and their effects. We've been doing that for the past 1.5 years, and we plan to be doing a lot more simulations over the next 2 years.
This is a busy thread.
Wow, so plasma simulations are a field that is going to get a lot of attention in the next few years. (Going beyond the current models.) I hope we see sim techniques develop that significantly improve our ability to model a polywell.
93143 wrote: the odds of it not working...as a power producer...are low...
On what basis do you come by this conclusion? On the last 25 years of research and $25M funding which has produced so much evidence that your conclusion is undeniable??
93143 wrote: the odds of it not working...as a power producer...are low...
On what basis do you come by this conclusion? On the last 25 years of research and $25M funding which has produced so much evidence that your conclusion is undeniable??
Go back and read the whole sentence again.
Or are you trying to be funny?
It is always possible to write in such a way as to be totally misunderstood. Sometimes you don't even have to try.
Engineering is the art of making what you want from what you can get at a profit.
chrismb wrote:On what basis do you come by this conclusion? On the last 25 years of research and $25M funding which has produced so much evidence that your conclusion is undeniable??
Go back and read the whole sentence again.
Or are you trying to be funny?
It is always possible to write in such a way as to be totally misunderstood. Sometimes you don't even have to try.
No, just that he's getting a bit surly at scientists for wanting to explore things at costs orders of magnitude less than other projects. and also at the few americans who are actually interested in science for being interested/excited in/about science.
The pursuit of knowledge is in the best of interest of all mankind.
Even if it doesn't work like it's supposed to, the odds of it not working as well as a tokamak, but still being useful as a power producer at all, are low
What? are you saying we cant read ?
Hmm. If I drop some words, and move what's left around, I come up with:
Even the odds, the tokamak, it's not working as well as being useful like it's supposed to at all.
93143 wrote: the odds of it not working...as a power producer...are low...
On what basis do you come by this conclusion? On the last 25 years of research and $25M funding which has produced so much evidence that your conclusion is undeniable??
Go back and read the whole sentence again.
Or are you trying to be funny?
The logical structure of your whole sentence DEFINITELY suggests that the odds of Polywell not working as some form of energy producer are low. That's how politicians try to get to say something - leaving themselves scope to backtrack but to still have implied something unjustifiable.
So, let's just try to rephrase, you DO think the odds of Polywell working as a net energy producer are low?
You'll argue molehills into mountains, given the tiniest chance... It's not hard to see what he means:
Even if the polywell doesn't work like it's supposed to,
the odds of it not working as well as a tokamak while still being useful as a power producer at all
are low
There's a conditional to his statement of "the odds of Polywell not working as some form of energy producer".
Betruger wrote:You'll argue molehills into mountains, given the tiniest chance... It's not hard to see what he means:
Even if the polywell doesn't work like it's supposed to,
the odds of it not working as well as a tokamak while still being useful as a power producer at all
are low
There's a conditional to his statement of "the odds of Polywell not working as some form of energy producer".
I write a LOT. On a blog. I get a lot of feedback so it helps me make my thoughts clear. Here is how I would do it:
Polywell may not work the way current theory explains it. Even so the odds are good that if it works it will work better than a tokamak when it comes to producing power.
When at all possible it is wise to get the nots out of sentence structure. Positive statements are best. You don't want sentences that have to be diagrammed to be understood.
Engineering is the art of making what you want from what you can get at a profit.
Betruger wrote:You'll argue molehills into mountains, given the tiniest chance... It's not hard to see what he means:
Even if the polywell doesn't work like it's supposed to,
the odds of it not working as well as a tokamak while still being useful as a power producer at all
are low
There's a conditional to his statement of "the odds of Polywell not working as some form of energy producer".
I write a LOT. On a blog. I get a lot of feedback so it helps me make my thoughts clear. Here is how I would do it:
Polywell may not work the way current theory explains it. Even so the odds are good that if it works it will work better than a tokamak when it comes to producing power.
When at all possible it is wise to get the nots out of sentence structure. Positive statements are best. You don't want sentences that have to be diagrammed to be understood.
Thanks. That sentence is much clearer than what 93143 originally wrote. Unfortunately the content is as fuzzy as ever. The only way I can make sense of it is that the probability is low that the cost of power from a future polywell reactor will be higher than that from a future tokamak reactor, but still lower than that from future alternatives. Considering the high projected costs of tokamak power, even in optimistic scenarios, this statement is true but not very helpful.
chrismb wrote:Patents expire after 20 years. I think the IP has now expired. It's taken too long to attempt to make polywell work. None to worry about.
The requirement is sole sourced to Energy/Matter Conversion Corporation (EMC2) who is the original developer of the plasma fusion (polywell) approach and holds the proprietary data rights.
