Talk-Polywell.org

a discussion forum for Polywell fusion
It is currently Sat Nov 22, 2014 8:36 am

All times are UTC




Post new topic Reply to topic  [ 42 posts ]  Go to page 1, 2, 3  Next
Author Message
 Post subject: Magneto-Inertial Fusion
PostPosted: Fri Dec 11, 2009 4:59 am 
Offline

Joined: Mon Jul 16, 2007 7:37 pm
Posts: 13713
Location: Rockford, Illinois
*

http://www.iop.org/EJ/article/1742-6596 ... bc9f48301d

*

Quote:
The intense magnetic field suppresses cross-field thermal diffusivity in the plasma during the compression, and thus facilitates the heating of the plasma to thermonuclear fusion temperatures. The extremely high magnetic field created in the hot spot or the target plasma also enhances alpha-particle energy deposition in the plasma when fusion reactions occur.

_________________
Engineering is the art of making what you want from what you can get at a profit.


Top
 Profile  
 
 Post subject:
PostPosted: Fri Dec 11, 2009 6:24 am 
Offline

Joined: Mon Apr 14, 2008 2:43 pm
Posts: 991
very exciting stuff. good find.

Quote:
...
The strategy could potentially eliminate altogether the very challenging practical problem of high
rep-rate fabrication of precision cryogenic solid targets
...US$4.7M in FY 2008


looks like they need to get to Mach 15 (for fusion), and are trying for Mach 10 over the next couple of years (presently somewher around half of that, if i read right).

some related 2009 experiments here - http://scitation.aip.org/getabs/servlet ... s&gifs=yes

and some further background here - http://www.sc.doe.gov/ofes/HEDLP-Thio/M ... ina_v1.pdf (Rostocker, Slough and others aknowledged)


Top
 Profile  
 
 Post subject:
PostPosted: Fri Dec 11, 2009 7:59 am 
Offline

Joined: Sat Dec 13, 2008 6:00 pm
Posts: 3161
Useful fresh detail. It's still one already on my list, though. Will anyone come up with a new idea sometime?


Top
 Profile  
 
 Post subject:
PostPosted: Fri Dec 11, 2009 10:55 am 
Offline

Joined: Thu Mar 12, 2009 3:51 pm
Posts: 686
Gravitic containment. Use Hiem's theory to build a "gravitron" to contain the plasma, rather than a magnetic field. :P

_________________
Evil is evil, no matter how small


Top
 Profile  
 
 Post subject:
PostPosted: Fri Dec 11, 2009 12:35 pm 
Offline

Joined: Sun Jun 28, 2009 9:24 pm
Posts: 154
kunkmiester wrote:
Gravitic containment. Use Hiem's theory to build a "gravitron" to contain the plasma, rather than a magnetic field. :P


And make everything around it fall into the reactor? Not very practical. :mrgreen:

_________________
Because we can.


Top
 Profile  
 
 Post subject:
PostPosted: Fri Dec 11, 2009 5:33 pm 
Offline

Joined: Sat Dec 13, 2008 6:00 pm
Posts: 3161
Stoney3K wrote:
kunkmiester wrote:
Gravitic containment. Use Hiem's theory to build a "gravitron" to contain the plasma, rather than a magnetic field. :P


And make everything around it fall into the reactor? Not very practical. :mrgreen:

I'm sure gravity shields would be viable, if we can manipulate gravity in that way.

It is a pure fantasy (in my theory of things) to begin to contemplate being able to control gravity forces but, blimey, wouldn't it be amazing!

Back to fusion, actually I don't think it would make for a viable fusion reactor, if we could control gravity, because there is a balance needed between reaction rate (viz temperature and the rate it tries to expand) and the gravity (the rate it tries to contract/compress). Whether or not we could generate the gravity of the Sun itself, we'd only get a fusion reactor as powerful as the Sun - which is crap (in specific output) and would be useless for terrestrial humans.

We'd need to be able to control and generate gravitational fields several orders of magnitude greater than that of the Sun.

The common media bull about "making a star on earth" is just non-sense because that'd be useless (and is wrong anyway - different fuels and different rates), but it sounds better than "making an h-bomb in a bottle" which is much closer to what we're trying for.


Top
 Profile  
 
 Post subject:
PostPosted: Fri Dec 11, 2009 6:26 pm 
Offline

Joined: Wed Oct 07, 2009 6:15 pm
Posts: 2263
Location: China, Italy
Before anything else we need to understand what gravity is exactly and how is generated. I believe that when we will have that knowledge it will be the start of a new era for the Human race.

I would not dismiss Heim theory also. I am still trying to grasp the fundamental concept and main logic passages in it (it's tough due to my zero knowledge of German, and scarce material available in English), but it is something that we might be able to test in few years, and LHC might even give us more clues about is soundness or silliness.


Top
 Profile  
 
 Post subject:
PostPosted: Sat Dec 12, 2009 6:34 am 
Offline

Joined: Mon Oct 12, 2009 5:05 am
Posts: 1970
chrismb wrote:
Will anyone come up with a new idea sometime?

How about a fusion centrifuge (my washing machine was just spinning up)? You'd have an outer layer of heavier B11 and an inner layer of lighter H nuclei. Then apply a radial E field for fusion. I'm only half joking. The tangential velocity needed would probably be a sizeable fraction of c.


Top
 Profile  
 
 Post subject:
PostPosted: Sat Dec 12, 2009 10:22 am 
Offline

Joined: Sat Dec 13, 2008 6:00 pm
Posts: 3161
DeltaV wrote:
How about a fusion centrifuge (my washing machine was just spinning up)? You'd have an outer layer of heavier B11 and an inner layer of lighter H nuclei. Then apply a radial E field for fusion. I'm only half joking. The tangential velocity needed would probably be a sizeable fraction of c.

Excellent idea! Outstanding!

Well, I would say that, wouldn't I... because that's kinda what I'm building.

I would call the principle "electro-centripetal magnetic" ion confinement, were I to add it to my own list.

The only issue is that my list is strictly those ideas taken through to published experimentation.

So, in point of fact, there are actually several patents already covering this idea in different ways, it's just that no-one's built one yet. My list had to cover only experimental works, because the total number of hair-brained fusion ideas I could list that have appeared in patents would multiply that list by a few times. I am planning on such a list one day, but bigger fish to fry right now...

On to your technical observation - it seems to be a misconception people have that you need ions to go as fast as possible to make the best fusion. This is erroneous. Once you get collisions in the MeV range you end up with Oppenheimer-Phillips stripping of the nucleus (the whole thing just falls apart) and you get a mass of neutrons and 'bits-of-old-nucleus' and it is all very endothermic. In fact, early ["professional" (read:institutionalised!)] observers of fusors commented that the neutrons observed weren't fusion neutrons but were 'just' O-P neutron products. They were wrong on this, of course.

However, clearly, too low and you get no chance of fusion. Fusion is one of those 'on the fence' kinda probabilistic processes for which there is a surprisingly tiny window of opportunity.

(If you get to consider all the facts, it rather looks like someone has made the whole of physics in this way rather intentionally just as an intellectual puzzle. I don't believe in there being a sentient 'God', but if someone were to try to persuade me by revisiting all the odd 'windows of opportunity' in physics that mean the universe a reality, like the fine structure constant and the molecular basis for life itself, then they could take me pretty close!! This work isn't a vocation or even a hobby for me, it is a frustrating, beguiling puzzle because I can see the window of possibility is soooo small it seems impossibly unlikely that it is not "an intentional" puzzle for which there is a solution planned!)

Anyhows... on the subject of how fast ions need to go for fusion - the range is quite small - the minimum collision velocity is around the 1Mm/s, which is for deuterium at 10keV, and the highest is around 10Mm/s for proton-based fusions at the 600keV range. So 'velocity' is spread only within a single order of magnitude for fusion, and represents no more than a table-top sized device operating at 1 to 5MHz rotation. Seems like it would be a very useful option, to me, even if it turns out not to be 'the best' or 'most powerful' of several future solutions to fusion.


Top
 Profile  
 
 Post subject:
PostPosted: Sat Dec 12, 2009 12:45 pm 
Offline

Joined: Thu Nov 13, 2008 4:03 pm
Posts: 769
Location: UK
chrismb wrote:
DeltaV wrote:
How about a fusion centrifuge (my washing machine was just spinning up)? You'd have an outer layer of heavier B11 and an inner layer of lighter H nuclei. Then apply a radial E field for fusion. I'm only half joking. The tangential velocity needed would probably be a sizeable fraction of c.

Excellent idea! Outstanding!

Well, I would say that, wouldn't I... because that's kinda what I'm building.

Let's hope you've over-engineered the containment structure...

_________________
Ars artis est celare artem.


Top
 Profile  
 
 Post subject:
PostPosted: Sat Dec 12, 2009 1:42 pm 
Offline

Joined: Sat Dec 13, 2008 6:00 pm
Posts: 3161
alexjrgreen wrote:
Let's hope you've over-engineered the containment structure...
It'll be for nature to 'decide'! Whether various pheonomena add up constructively, or destructively. This seems to always be the case in fusion - like tokamaks 'discovering' an H-mode behaviour, quite unpredicted.

This is also potentially true of Polywell - just maybe some odd things add up to something that works. I'm an old grumpy windbag sometimes[!], for which I apologise, but my expressed doubts are challenges to see what solutions come out in the wash. To be frank, I think the view that people on this forum have of Polywell since I landed is now more 'objective' than it was. I might still disagree on much of it, but most of the tech talk seems to have gone from having warm and fuzzy feelings about what is likely to happen and has moved to 'this' or 'that' with more concrete thinking behind it all. Right or wrong, doesn't matter, but at least clearer thoughts. May or may not be due to some part I play, but it seems that way to me.

For my efforts, I have no doubt the containment method will work, because it is a half way between a cyclotron a Penning trap and a magnetron, and all of those work. What is in serious question is what the magnitude of the contained ion currents could be; whether it will run in microamps like a cyclotron, in which case it'll make for an amusing but potentially irrelevant mass spectrometer, or whether it can run higher currents like a magnetron.


Top
 Profile  
 
 Post subject:
PostPosted: Sat Dec 12, 2009 2:13 pm 
Offline

Joined: Thu Jun 26, 2008 6:52 am
Posts: 2418
If you can control gravity, you can forget about fusion. Merely by shifting weights with the gravity varied will generate all the energy you need. Lift water under reduced gravity to a water tower, then incresae the gravity and let the water fall through a turbine, or to produce heat. And, if you can scale your magnetic fields high enough, you can easily obtain far more energy than you can through fusion. Have your convient gravity reactor in your back yard genertating a gradiant similar to massive black hole and your energy conversion efficiency can approach that of matter- antimatter reactions- 100% conversion, rather than a measly fraction of 1%. Thats the approach used by the Romulens. This assumes that the input power to run the machine is not higher than the resultant output power.

Dan Tibbets

_________________
To error is human... and I'm very human.


Top
 Profile  
 
 Post subject:
PostPosted: Sat Dec 12, 2009 2:20 pm 
Offline

Joined: Sat Dec 13, 2008 6:00 pm
Posts: 3161
D Tibbets wrote:
If you can control gravity, you can forget about fusion. Merely by shifting weights with the gravity varied will generate all the energy you need.

Youu're thinking about the 'truly' impossible. Think of a future gravity control machine more as a magnet. It takes energy to turn it on or off, even if it's a permanent magnet it takes energy to start to make it. If you have a 'permanent grvity magnet' then, clearly, it will require an input of energy to move it in the presence of a mass, just as moving a permanent magnet in the presence of a ferric metal does. There is nothing 'mathematically' contradictory about an anti-gravity machine and, therefore, there are obvious consequences and the physics of the thing are predictable, even if making it isn't!

Similarly, you can also anticipate that, like a magnet, it will only be able to attract a given quantity of mass. It cannot carry on attracting yet more mass. In the same way that if you create a magnet with 10's of joules BH energy, it won't attract EVERY metallic object in the universe - if it did then you'd have the same nonsence machine as you're describing. Instead it can attract a given quantitiy of paramagnetic material at wich point it becomes 'screened' from the RoU. SO whatever a gravity machine is, there are some predicable properties for it and what you're suggesting is ruled out.


Top
 Profile  
 
 Post subject:
PostPosted: Sat Dec 12, 2009 2:27 pm 
Offline

Joined: Thu Nov 13, 2008 4:03 pm
Posts: 769
Location: UK
chrismb wrote:
What is in serious question is what the magnitude of the contained ion currents could be; whether it will run in microamps like a cyclotron, in which case it'll make for an amusing but potentially irrelevant mass spectrometer, or whether it can run higher currents like a magnetron.

Good Luck!

The Rosetta mission had an ion trap mass spectrometer, so your skills might be in demand either way.

_________________
Ars artis est celare artem.


Top
 Profile  
 
PostPosted: Sat Dec 12, 2009 4:37 pm 
Offline

Joined: Thu Mar 12, 2009 8:14 pm
Posts: 181
Location: UK
Gravity control ? Hmm...

My SF tales invoke a 'Relativisitically Spun Plasma Micro-Pile'. Laterally, it is bigger and faster on the inside, so products emerge along the axis. Good trick is to modulate, and feed result to close-coupled laser pair. That gives an Ice Slicer capable of chopping a comet into pieces sized for canning...

Following sabotage, and with the disk of 'Autumn' growing ahead of their crippled Scout craft...
:
Tony stripped the last Field Modules, sat to think. Greg brought food and drink in zero-g pots, crouched nearby. "Thoughts?"

"Um. Yes. I've got a couple of intact Tertiary Modulators. They're the 'Phased Arrays of Ambient Super-Conducting Distributed Tunnel Diodes', the actual Poles that set up the Field to do the graviton shielding and space-bending. I just can't find enough support circuitry to activate and control them. All of this modern stuff is so sophisticated, you must have the full set. You can't play mix & match with different stages and brands...

"Anyway, the first, crude Poles -- the original 'Skyhooks' -- were self-modulating. I'm wondering if I can rig one. And, if it works, if there's any way I can tweak the phasing to control it."
/


Top
 Profile  
 
Display posts from previous:  Sort by  
Post new topic Reply to topic  [ 42 posts ]  Go to page 1, 2, 3  Next

All times are UTC


Who is online

Users browsing this forum: Bing [Bot], vnbt4 and 1 guest


You cannot post new topics in this forum
You cannot reply to topics in this forum
You cannot edit your posts in this forum
You cannot delete your posts in this forum
You cannot post attachments in this forum

Search for:
Jump to:  
Powered by phpBB® Forum Software © phpBB Group