Posted: Thu Feb 08, 2007 4:10 am Post subject: Re: Polywell Fusion Reactor
EnergyUnlimited wrote:
I suspect, there are some deep engineering problems there, likely related to handling of high voltages/currents in relatively "congested" space of his fusor....
I have in mind intractable combination of giant arcs, sparks, coronary discharges, stray electron/ion beams etc, which can make our $200 million fuser working as one time use, "disposable" device, or at best, as something, what will need expensive general overhaul every few weeks or so.
NB. You will have to produce at least 2 X more of thermal energy, than thermal breakeven point, if you want to send some excess into the grid.
The photograph at the top of the thread shows prototype WB-6 (the sixth prototype in this series). At the time it ceased to function due to a capacitor accident, but more importantly, due to lack of further Navy funding for Dr Bussard's 12-strong team, WB-6 had performed about 150 full-up test runs using a variety of gases, including D-D, and it performed fusion with a recorded neutron count of 10^9 neutrons per second. Not much for a power plant, but hugely significant for an IEC device. Note that this was being funded by the DoD, but under a 'small projects' mandate, as anything larger would have drawn congressional attention to them. The tokamak is the currently mandated best approach to fusion power (think ITER), and in Dr Bussard's own words, there are a huge number of scientists who want to hold onto their rice bowls - tokamak fusion may never be power producing, but it's really good science!
In terms of extracting power, the aim isn't do do anything as draconian as using fusion to boil water to drive turbines, though this might be used to retrofit existing power plants. The intention, I believe, is to catch the high energy alpha particles escaping the chamber via a grid system, in order to create a direct conversion to (very) high voltage current. This is also more efficient than having lots of heat wasted in a steam-based system, inefficiencies in the turbines, and all the other associated losses in power generation and transmission.
Inertial Electrostatic Containment has been around many years, and has been doing fusion for many years, but not many scientists are willing to countenance the idea that IEC fusion concepts can be net-power producing, and so while not denigrating the project, treat it with some scepticism.
Posted: Thu Feb 08, 2007 5:32 am Post subject: Re: Polywell Fusion Reactor
Jbat001 wrote:
The photograph at the top of the thread shows prototype WB-6 (the sixth prototype in this series). At the time it ceased to function due to a capacitor accident, but more importantly, due to lack of further Navy funding for Dr Bussard's 12-strong team, WB-6 had performed about 150 full-up test runs using a variety of gases, including D-D, and it performed fusion with a recorded neutron count of 10^9 neutrons per second.
It is far more important to investigate, how "nicely" pilot plant, eg net energy winner plant would operate.
Quote:
Not much for a power plant, but hugely significant for an IEC device. Note that this was being funded by the DoD, but under a 'small projects' mandate, as anything larger would have drawn congressional attention to them.
As now US government concluded, that there is nothing interesting enough there too keep it secret (and stopped funding), why not to ask Cambodian or Mexican authorities (or few rich freaks) for help?
Quote:
The tokamak is the currently mandated best approach to fusion power (think ITER), and in Dr Bussard's own words, there are a huge number of scientists who want to hold onto their rice bowls - tokamak fusion may never be power producing, but it's really good science!
Dr Bussard had also said, that every night he can see several thousands of fusion reactors and no single one of those is toroidal...
Quote:
In terms of extracting power, the aim isn't do do anything as draconian as using fusion to boil water to drive turbines, though this might be used to retrofit existing power plants. The intention, I believe, is to catch the high energy alpha particles escaping the chamber via a grid system, in order to create a direct conversion to (very) high voltage current. This is also more efficient than having lots of heat wasted in a steam-based system, inefficiencies in the turbines, and all the other associated losses in power generation and transmission.
I do appreciate this point very much.
Yet you have to show p-11B or p-3He fusion working to succed...
Quote:
Inertial Electrostatic Containment has been around many years, and has been doing fusion for many years, but not many scientists are willing to countenance the idea that IEC fusion concepts can be net-power producing, and so while not denigrating the project, treat it with some scepticism.
I bet, it can give net power, but the cost is an issue.
Quote:
You need to make your own minds up!
I did.
It looks like that:
Our civlliztion's FUTURE is either nuclear (fusion), electric (fission - I hope you can work out, what I mean), or there is no future (means the future is to go back to agrarian/feudal society from which we came).
My bet is last option as the most likely one...peoples are too stupid to do anything better than that and there is plenty of evidence of it.
What is your bet?
Posted: Tue Feb 27, 2007 7:10 am Post subject: Re: Polywell Fusion Reactor
EnergyUnlimited wrote:
I bet, it can give net power, but the cost is an issue.
It looks like that:
Our civlliztion's FUTURE is either nuclear (fusion), electric (fission - I hope you can work out, what I mean), or there is no future (means the future is to go back to agrarian/feudal society from which we came).
My bet is last option as the most likely one...peoples are too stupid to do anything better than that and there is plenty of evidence of it.
What is your bet?
The beauty of this device seems to be that we're not dealing with molten lithium blankets, office-block sized magnets and monstrous currents. The entire assembly (which can fit inside a sphere 3m diameter) can be pulled out and replaced as soon as the materials become activated by neutron flux, buried in a nice deep hole, and simply replaced like a lightbulb. Not so easy to do with a tokamak!
We're also not talking about exotic materials either - only nickel coil cans, with water-cooled copper cabling. The most exotic elements are the fuel and electron injection systems, but even this could be shielded so that it didn't become radioactive. If, of course, you managed to do aneutronic (p + B11) rather than D +T or D + D fusion, the neutron count would almost entirely disappear (not entirely, but almost).
Expense can be looked at in a number of ways:
1) Cost of materials
2) Cost of expertise, handling, building and maintaining
3) Disposal costs
In Polywell's case, point number one is fairly mundane - a decently equipped university physics department could fabricate one. There are no exotic materials involved. Points two and three are likely to be comparable to conventional nuclear power plants, which we know can be both profitable and reasonably safe, but the half-lives of the fusion ash materials are vastly better than those for fission (11 years for tritium versus thousands of years for fission products). You can't just extract a live core from a clicking hot fission reactor and bury it in a disused mine either - there is too much activated material in there, and it's too risky to transport. With a polywell vacuum chamber, you could pump out the remaining gases, fill the chamber with polystyrene foam or concrete, and put it somewhere deep, dark and safe.
I know there are many difficulties to be overcome, but I really am optimistic about the real potential of this machine to make not only electricity, but money too.
Posted: Wed Mar 28, 2007 2:10 am Post subject: Re: Polywell Fusion Reactor
ElijahJones wrote:
Listen confinement using magnetic fields is probably a waste of time. The cold fusion approach of packing a solid material full of the right type of helium atoms is probably better but not much. Yes the notion of keeping the hellium atoms nearby each other often enough and long enough for a reaction to happen is right. But the sun is run by gravity, it is an inward pulling force, you know that. The basic idea is similar but the way the sun succeeds in fusing atomes is very different. The best thing you can do is approximate it by seeing if you can mixing exotic matter in there or something. You have to get it so that there is a gravity proxy force in your system somewhere. You are never going to get a confinement fusion machine to be successful and economically competitive with other alternatives. Investors like us. Like me. You mean people who are inquisitive enough to ask why the physics community does not want to invest in this thing?
I have thought about the field geometry issues myself, the problem is you are trying to contain a reaction that in the sun is caused by the inward pull of gravity, not a containment. Create a magnetic field that has that approximates that and you are getting warm. But those types of configurations can be examined using mathematical software and some PDE's, you don;t need to build a 200 million dollar reactor to see if you can construct the right type of magentic field geometries. That is my problem with this. This whole damn thing should be able to be modeled using simulations at a cost so much less than building it.
Forgive my terse response at first, but you seem to really believe in this. I think it is waste of money, evidence by the fact that nobody in the fusion community is willing to invest in it themselves. I agree there could be culture problems getting in the way of a good idea, but I see enough stuff that gives me red flags to think it otherwise. Especially the geometry of his machine (the field of which I could analyze on ten sheets of paper with a pencil and my intro to EM fields book by my side.)
Dollars to donuts carl this crap.
The polywell is not precisely a magnetic confinement machine. A summary:
The grids are positively charged, which attract electrons, but the grids are magnetically shielded, so the electrons orbit around the grids instead of hitting them. Ion guns inject postively charged fuel ions, which are attracted to, and confined, by the electron cloud in the center of the machine.
tl;dr: The grids confine the electrons, and the electrons confine the ions.
Also: The machine turns out to be very difficult to simulate, since the electron cloud interacts and signifigantly deforms the magnetic field. It's not nearly as simple as an IXL machine, or even a tokamak.
If you want to criticize Dr. Bussard's results, then attack the weak points of his paper, rather than the bits that have been expirimentally confirmed. 3 counts over 15 microseconds is not what I would call hard data, for example.
Seriously, read the paper before you start mouthing off.
Jbat001 wrote:
We're also not talking about exotic materials either - only nickel coil cans, with water-cooled copper cabling.
The power plant is going to be using Inconel cans with liquid nitrogen cooled cuparate coils, which is also why it has to be so large, since it's difficult to form smaller coils out of high Tc ceramics.
Posted: Wed Mar 28, 2007 2:17 am Post subject: Re: Polywell Fusion Reactor
Quote:
In terms of extracting power, the aim isn't do do anything as draconian as using fusion to boil water to drive turbines, though this might be used to retrofit existing power plants. The intention, I believe, is to catch the high energy alpha particles escaping the chamber via a grid system, in order to create a direct conversion to (very) high voltage current. This is also more efficient than having lots of heat wasted in a steam-based system, inefficiencies in the turbines, and all the other associated losses in power generation and transmission.
Inertial Electrostatic Containment has been around many years, and has been doing fusion for many years, but not many scientists are willing to countenance the idea that IEC fusion concepts can be net-power producing, and so while not denigrating the project, treat it with some scepticism.
Dr. Bussard tends to frame most of his work in terms of space exploration, for good reason. Here he is such a big proponent of QED alpha particle collection because thermodynamic energy conversion requires a big heat sink in order to work at all, which reduces your mass fraction greatly.
Also: IXL fusion really is a dead end. It has been rigiously proven that the grids intercept too much of the fuel ions to reach breakeven. Most of the problems Dr. Bussard is encountering are because people are assuming that the Polywell is another IXL machine. It isn't.
Posted: Sat Mar 31, 2007 9:04 am Post subject: Re: Polywell Fusion Reactor
This is such a good solution to long term energy needs for earth and for space exploration... if only it could be made to work on a practical level. I saw the Google presentation and Dr Bussard is so convincing. Fusion has been put forward as the panacea that solves all humanity's energy worries ever since I was a lad in the '60s and we never seemed to get any closer to a working system. His approach is radical enough and elegant enough to be able to do the trick.
This has to be worth the peanuts (in budgetary terms) he says is needed to fund the next stage. His funding ended a year ago now and we're wasting time while he searches for more. Let's hope this is resolved soon.
Posted: Wed May 30, 2007 2:00 pm Post subject: Re: Polywell Fusion Reactor
bbot wrote:
The polywell is not precisely a magnetic confinement machine. A summary:
The grids are positively charged, which attract electrons, but the grids are magnetically shielded, so the electrons orbit around the grids instead of hitting them. Ion guns inject postively charged fuel ions, which are attracted to, and confined, by the electron cloud in the center of the machine.
tl;dr: The grids confine the electrons, and the electrons confine the ions.
Also: The machine turns out to be very difficult to simulate, since the electron cloud interacts and signifigantly deforms the magnetic field. It's not nearly as simple as an IXL machine, or even a tokamak.
Are you sure? I thought that the magnetic fields were designed to confine a mass of electrons in the core of the machine, not cause them to perform orbits of the coil cans. Of course, electrical forces will tend to cause the electrons to repulse each other, and some wil be lost through the field cusps, but not many (hopefully) with Bussard's 'wiffleball' configuration through proper setup of the fields. It's the confined mass of electrons that creates the gridless potential well, after all. The ions fall into this potential well created by the electrons, and virtually all of them just shoot straight through the core and out the other side, but a few fuse. The ions recirculate and eventually, they end up resulting in fusion events.
If I've got my head around this wrong, please tell me - I'm very excited about this machine, and I don't want to misunderstand it!
Posted: Wed Jun 20, 2007 4:38 pm Post subject: Re: Polywell Fusion Reactor
Quote-In terms of extracting power, the aim isn't do do anything as draconian as using fusion to boil water to drive turbines, though this might be used to retrofit existing power plants. The intention, I believe, is to catch the high energy alpha particles escaping the chamber via a grid system, in order to create a direct conversion to (very) high voltage current. This is also more efficient than having lots of heat wasted in a steam-based system, inefficiencies in the turbines, and all the other associated losses in power generation and transmission.-Quote
Why stop the alpha particles? This system will make a great nucular ash rocket.
Joined: Apr 06, 2006 Posts: 3386 Location: 3 miles NW of Champoeg, Republic of Cascadia
Posted: Thu Jun 21, 2007 9:14 am Post subject: Re: Polywell Fusion Reactor
This piqued my interest, although what Bussard is talking about is way beyond me. The above posts explain it for laymen pretty well though. Should Google Go Nuclear?
He does address Energy depletion issues about an hour into the Google video, suggesting that Brazil could use his plants to cheaply brew ethanol, the Saudis could desalanize water, the Venezuelans could cook their heavy oil. Probably not what a lot of people want to hear on this forum...Bussard's comment about ideology being one thing but money talks is spot on. Hell, four Latin American countries could do their own mini-ITER no problem.
He also mentions using his plants to bombard fission waste products for cleanup. Hmmm. _________________ Cogito, ergo non satis bibivi
I will not abide another toe.
Joined: Jun 25, 2005 Posts: 257 Location: British Columbia, Canada
Posted: Thu Jun 21, 2007 10:39 pm Post subject: Re: Polywell Fusion Reactor
I know nothing about this fusion reactor, (beyond what's in this thread) nor do I have time to learn, but I am amazed (and amused) by how closely the external appearance of this thing matches my memories of pictures (artists' renderings of what a fusion reactor would look like) in a popular mechanics magazine from the late fifties that I read as a boy.
Limitless free, or nearly free, power within twenty years I believe the article claimed.
I'm afraid my faith is shattered.
I have enjoyed Bussard's contribution to sci. fi. over the years though. Larry Niven in particular has made good use of the Bussard Ramjet.
Posted: Fri Jun 22, 2007 11:39 am Post subject: Re: Polywell Fusion Reactor
oiless wrote:
I know nothing about this fusion reactor, (beyond what's in this thread) nor do I have time to learn, but I am amazed (and amused) by how closely the external appearance of this thing matches my memories of pictures (artists' renderings of what a fusion reactor would look like) in a popular mechanics magazine from the late fifties that I read as a boy.
Limitless free, or nearly free, power within twenty years I believe the article claimed.
I'm afraid my faith is shattered.
I agree it does look a bit like those old fifties ideas about how fusion reactors would look. We could have read the same mags when growing up.
But this is an entirely different approach to fusion power that deserves to be investigated further. A small fraction of the amount spent on current fusion research using very large tokamaks would be worth putting into this idea Bussard backs. The electrostatic confinement method has lots of advantages over the tokamak method ... if it can be made to work and I'm not underestimating the problems. We should pursue both avenues particularly as the tokamak research seems to be floundering and has for decades.
Bussard's system seems much more viable than any Tokamak style reactor. You have much more control over your fusion system if you have an open reactor than a closed one. Bussard also points out that in any "box" style design, you will have surfaces near the corners that will have "funny cusps" in its magnetic B field and thus will be practically unshielded, furthering his open design hypothesis. He is of the same mind as most people around here, Tokamak reactors will NEVER work as a power source. His system may, but we don't know that yet.
His reactor design looks very different than a Tokamak, as the picture above shows. I recommend reading up on it if you want to be more fully informed about fusion technology. _________________ EntropyFails
"Little prigs and three-quarter madmen may have the conceit that the laws of nature are constantly broken for their sakes." -- Friedrich Nietzsche
I understand that as of 27-AUG-2007 Dr. Bussard has received funding from the U.S. Navy to complete the WB-7 experimental Polywell reactor. This news is several days old, but reportedly comes from a source close to Bussard.
Regards,
M.R.F. _________________ "... coal and oil were depleted... increased demands for food cut off conversion of the agricultural surplus into fuel alcohol... solar power... as much a dream as atomic energy..." - Jack Williamson, "The Crucible of Power" (1939)
I don't see why it wouldn't be funded. It's a perfectly elegant approach. All he was asking for was $200 mil to continue on the next phase of research and development.
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I agree it does look a bit like those old fifties ideas about how fusion reactors would look. We could have read the same mags when growing up.
