Question about fusion reactors

Page 3 - Seeking answers about space? Join the Space community: the premier source of space exploration, innovation, and astronomy news, chronicling (and celebrating) humanity's ongoing expansion across the final frontier.
Status
Not open for further replies.
Y

yevaud

Guest
Ultimately, it all boils down to containment. No matter how robust the magnetic containment is, the highly energetic plasma always grows chaotic, develops "hot spots," and "burns through" the containment. End fusion. And hitherto, it always occurs well before break-even, instead of the goal where more energy is collected from the system than what is required to create the plasma and contain it.
 
R

RWJ

Guest
Neutral plasma behaviour is hard to predict. Non-neutral plasma containment, penning trap, can be more easily calculated, making it less chaotic. The problem is to reduce the ions electrostatic repulsion is needed to reduce the charge/mass ratio, to compensate this is by increasing electric voltages and magnetic fields, leading to utilization of superconducting magnets and mega-volts power supplies.
I think electrostatic acceleration is the most efficient method of heating plasma, as has been demonstrated by Farnsworth-Hirsh Fusor and Bussard Polywell.
However, I appreciate some attempts of improvements combining the best of existing fusion technologies.
http://en.wikipedia.org/wiki/CrossFire_Fusion_Reactor
Using superconducting magnets, mega-volts power supplies, improving/combining existing fusion approaches in order to have new insights; in this way, maybe we can get closer of harnessing the fusion energy.
 
Y

yevaud

Guest
Cold fusion is a method whereby via a simple electrical current into a deuterium-rich medium via a Palladium electrode will purportedly cause a sort of fusion reaction in miniature. Excess heat has supposedly seen, although virtually no one has been able to reproduce this using the same methods utilized by Pons and Fleishmann.

Which, btw, is different than Sono-fusion, which is a method whereby intense focused sound is aimed into a deuterium-rich medium, which causes tiny bubble via cavitation. These tiny bubble purportedly create sufficient heat and pressure on a tiny scale, such that fusion (Hot Fusion) is initiated.

Both are highly speculative, can't generally be reproduced, and rebounded on their authors - particularly Pons et al - to their detriment.

Read all of the following:

http://en.wikipedia.org/wiki/Cold_fusion
http://en.wikipedia.org/wiki/Stanley_Pons
http://en.wikipedia.org/wiki/Martin_Fleischmann
http://en.wikipedia.org/wiki/Sonofusion
 
T

Tritium

Guest
Perhaps there is something to "Sono-Fusion",which causes the bubble cavitation at the proper frequencies.I wonder if some kind of answer lies in a hybrid reactor which uses a combination of the techniques of chemical,or low energy fusion,and the current plasma chamber techniques.What that would be is beyond me,but it just seems that often,there are clues provided by separate approaches,which lead to a eureka moment in some lab somewhere.We are so close,yet so far away...
 
R

RWJ

Guest
I think there's no magic solution. For example, deuterium-deuterium fusion reaction to produce 500MWatts (500MJ/s):
[super]2[/super]H + [super]2[/super]H + 15keV → 50%( [super]3[/super]H + [super]1[/super]H) + 50%( [super]3[/super]He + n) + 7.3MeV

Energy density:
(7.3MeV × 1.60218×10[super]-19[/super]J)/(2 protons + 2 electrons + 2 neutrons)=
(7.3MeV × 1.60218×10[super]-19[/super]J)/( (2×1.67262×10[super]-27[/super] +2×0.00091×10[super]-27[/super] + 2×1.67493×10[super]-27[/super]) = 174.64×10[super]12[/super] J/kg

Energy density to ignite:
(15keV × 1.60218×10[super]-19[/super]J)/( (2×1.67262×10[super]-27[/super] +2×0.00091×10[super]-27[/super] + 2×1.67493×10[super]-27[/super]) = 358.86×10[super]9[/super] J/kg

Fuel consumption: 500×10[super]6[/super] / 174.64×10[super]12[/super] = 2.863×10[super]-6[/super] kg/s
Energy consumption: 2.863×10[super]-6[/super] × 358.86×10[super]9[/super] = 1.027MWatts
Not taking into account steam turbine efficiency of only 30% and other losses.

In a steady state operation, if the fuel loses electrons to become ionized plasma, in another moment they should receive back their electrons, performing effectively the energy consumption.
Well, one advantage that I see in using electrostatic acceleration is that is possible to postpone the neutralization/recombination to exhausting phase of byproducts, reducing the overall consumption of energy.
I mean that to fusion takes place is needed energy, but the energy doesn’t need to be consumed instantaneously by each reaction.
In this case, I think electric and magnetic fields could play a role of induction on fusion reaction, similarly to energy of gravitational field of the sun that is not consumed promptly by fusion reaction. Taking in mind the law of conservation of energy, I think it is possible.
 
T

Tritium

Guest
RWJ":3j1o1bxz said:
I think there's no magic solution. For example, deuterium-deuterium fusion reaction to produce 500MWatts (500MJ/s):
[super]2[/super]H + [super]2[/super]H + 15keV → 50%( [super]3[/super]H + [super]1[/super]H) + 50%( [super]3[/super]He + n) + 7.3MeV

Energy density:
(7.3MeV × 1.60218×10[super]-19[/super]J)/(2 protons + 2 electrons + 2 neutrons)=
(7.3MeV × 1.60218×10[super]-19[/super]J)/( (2×1.67262×10[super]-27[/super] +2×0.00091×10[super]-27[/super] + 2×1.67493×10[super]-27[/super]) = 174.64×10[super]12[/super] J/kg

Energy density to ignite:
(15keV × 1.60218×10[super]-19[/super]J)/( (2×1.67262×10[super]-27[/super] +2×0.00091×10[super]-27[/super] + 2×1.67493×10[super]-27[/super]) = 358.86×10[super]9[/super] J/kg

Fuel consumption: 500×10[super]6[/super] / 174.64×10[super]12[/super] = 2.863×10[super]-6[/super] kg/s
Energy consumption: 2.863×10[super]-6[/super] × 358.86×10[super]9[/super] = 1.027MWatts
Not taking into account steam turbine efficiency of only 30% and other losses.

In a steady state operation, if the fuel loses electrons to become ionized plasma, in another moment they should receive back their electrons, performing effectively the energy consumption.
Well, one advantage that I see in using electrostatic acceleration is that is possible to postpone the neutralization/recombination to exhausting phase of byproducts, reducing the overall consumption of energy.
I mean that to fusion takes place is needed energy, but the energy doesn’t need to be consumed instantaneously by each reaction.
In this case, I think electric and magnetic fields could play a role of induction on fusion reaction, similarly to energy of gravitational field of the sun that is not consumed promptly by fusion reaction. Taking in mind the law of conservation of energy, I think it is possible.
Here's the math...lets do it.Build it and fire it up,and give mankind the new engine to the future goals we need to achieve! :twisted:
 
N

nimbus

Guest
EMC2 website has a few new details. A couple of pictures and this:
Fusion R&D Phase 1 - Validate and extend WB-6 results with WB-7 Device:
1.5 years / $1.8M, Successfully Completed


Fusion R&D Phase 2 - Design, build and test larger scale WB-8 Polywell Device
2 years / $7M, In Process


Fusion R&D Phase 3 - Design, build and test full scale 100 MW Fusion System:
4 years / $200M, In Design Phase
Successful Phase 3 marks the end of fossil fuels
Phase 2 should end in about a year and a half tops, which would put the end of phase 3 sometime in 5-6 years.

"Validation of WB-6 Results With Improved Diagnostics - WB-7 2008"

"Confinement Behavior With Detailed Diagnostics - WB-8 2010"
 
M

MeteorWayne

Guest
nimbus":qpd4cn42 said:
Phase 2 should end in about a year and a half tops, which would put the end of phase 3 sometime in 5-6 years.
Or 20 :lol:
 
N

nimbus

Guest
MeteorWayne":2j61exms said:
nimbus":2j61exms said:
Phase 2 should end in about a year and a half tops, which would put the end of phase 3 sometime in 5-6 years.
Or 20 :lol:
The expected physics actually say (said) it shouldn't even work as far as it has.
 
B

bdewoody

Guest
After all this discussion it still boils down to the fact that a sustainable net positive energy producing fusion reactor has yet to be built, let alone one that would bring profits to the entity that builds it. It's a shame to as this is possibly the key development needed to turn us away from burning fossil fuels to generate energy, ie. electricity.
 
N

nimbus

Guest
You could say that for many other things that did eventually work out.
 
T

Tritium

Guest
bdewoody":2t3wbws4 said:
After all this discussion it still boils down to the fact that a sustainable net positive energy producing fusion reactor has yet to be built, let alone one that would bring profits to the entity that builds it. It's a shame to as this is possibly the key development needed to turn us away from burning fossil fuels to generate energy, ie. electricity.

I totally 100% agree that fusion power is going to be a key development which will change the game for humanity by providing a new power source which will not create radioactive waste which takes 100,000 years to decay to safe levels,and requires enormous,and potentially dangerous storage vaults within the Earth's crust.There are hazards from neutrons,as a form of radiation,but these can be shielded and contained,and have no radioactive decay times.

We have to find something to replace fossil fuels relatively quickly,because we are running out of them,and even bio-fuels still produce harmful emissions,which we need to see an end to,for the long range health of our biosphere.Solar panels on every roof top,windmill generators,tidal power stations,ocean current generators, will all help reduce the load,but they are intermittent,and cannot supply the demands of our modern civilization.

Sorry,I digress into my long winded tirades...

The answer is very close.The problem is almost solved.The plasma is being generated,but it just cannot be sustained long enough to get more output than input.There is some simple,eloquent solution waiting to be found.Maybe that mind is just graduating from a college or university this year,and will plug in the final sequence to the formula in the coming year...
 
T

Tritium

Guest
MeteorWayne":nf861jup said:
Or in 20 years... :lol:
Such keen minds,ever on the alert,waiting to interject such substance into each conversation... :lol:
 
M

MeteorWayne

Guest
Sorry, but you seem to have been around as long as I have, so you should know. Fusion power has been 20 years away for 30 years now, and there is NO indication that any of the problems preventing it from being a useful power source are even close to being solved. In fact the lack of progress indicates that 20 years may be far too optimistic.

Whoopee, we dump in 14 GW and a fusion reaction occurs yielding 0.1 watt. That's progress?
 
D

dryson

Guest
Here is still another idea that would be safer than nuclear energy production

http://www.madsci.org/posts/archives/19 ... .Eg.r.html

Laser diodes with power conversion efficiencies greater than 50% are being
developed, however they currently generate only a few watts of power.
Recently our laboratory was able to generate a record 1000 watts of
continuous laser power using a large number of laser diodes to pump (excite
resonances) in a pencil sized YAG laser crystal; however, the over all
efficiency from battery power to light power for this laser is less than
30%. Also, we have to get rid of 70% of the total input power (3300 watts)
as waste heat. This waste heat might be used to preheat the water vapor
before it is injected into the cylinder to improve the over all efficiency
of a steam engine.
 
N

nimbus

Guest
MeteorWayne":24b302gc said:
Sorry, but you seem to have been around as long as I have, so you should know. Fusion power has been 20 years away for 30 years now, and there is NO indication that any of the problems preventing it from being a useful power source are even close to being solved. In fact the lack of progress indicates that 20 years may be far too optimistic.

Whoopee, we dump in 14 GW and a fusion reaction occurs yielding 0.1 watt. That's progress?
Alright seriously: There is no indication that we're near, but that's a virtue of a few things (as far as I've seen and understand). The trend that's stopped fusion almost everytime up to date is unknown unknowns. Not predictable developments and challenges. So the researchers, not seeing anything on the road ahead, say "all clear" only to walk right into some complications. +20 years (a ballpark number) to schedule. In this respect the situation is that there's no predicting whether it'll work out, not that the unpredictability means it won't.

Then there's the fact that fusion research has almost entirely been of the Tokamak variety. This is a flawed "all eggs in one basket" path, but more importantly in this discussion it means that the perpetual "20 years" prediction is mostly 20 Tokamak years. There's been a number of alternatives researched over time, but Tokamak has had the lion's share of public attention and funding.

Now there's a few different research paths, and at least one of them has a very clear short term path to figuring out if it works or not. It's credible as such because the physics and engineering are much simpler, so that the project budget is literally orders of magnitude less than ITER. It isn't an engineering and theoretical labyrinth like ITER or LHC (cf insider comments that no single person knows how LHC works) - a dozen people are enough to research it, and altogether it might hit 1 billion $ cumulative to take it from the very beginning (incl a few wrong paths that might've saved years and millions had they had their eureka moment earlier, cf Bussard's Google talk) to the very final research phase: a 100MW demo reactor which is in design right now.


So, it's not any sort of guarantee that it's going to work, but the funding is minimal and manpower required tiny (no gravy train inertia) and the physics/engineering challenges simple so that it's only going to take 5 years tops (2 more years according to research lead) to see (not just theory but experimental evidence) if it's worth pursuing or not, compared to historical fusion standards largely set by Tokamak research.

Considering all this evidence, I think it's not unfair to say that we very well may be near to finally seeing useful fusion in the decade. Just not from Tokamak. Either from Polywell or Focus Fusion or Laser Ignition or General Fusion, or another method. If e.g. Polywell had ITER's funding, it'd be a done deal. Or maybe not, if it had turned into a self-perpetuating bureaucrat and science byzantium like ITER.
 
E

EarthlingX

Guest
nimbus":23pqjr33 said:
A program to have 2,500 fusion reactors in campuses, on a short time frame.
http://www.earthtimes.org/articles/show ... 6053.shtml
Very good move. It will give food for thought to many still open minds, and since it is open source, all results will be available for further studies and examination from anyone.
When this starts, it would be nice, if all the results and experiments could be found at one place, because it will be quite interesting to follow. It might even give some results sooner that ITER ..
 
M

MeteorWayne

Guest
Please note the source of the article: Source : PRWeb

"
Such a network’s numbers are intriguing. 2,500 campuses raising $1M per year results in $2.5G of private capital. At $100 per donor, this represents at least 25 million influential donors- possibly enough to isolate and challenge any lobbying group that believes it can’t benefit from virtually free energy. "
 
E

EarthlingX

Guest
MeteorWayne":2jeflx4s said:
Please note the source of the article: Source : PRWeb

"
Such a network’s numbers are intriguing. 2,500 campuses raising $1M per year results in $2.5G of private capital. At $100 per donor, this represents at least 25 million influential donors- possibly enough to isolate and challenge any lobbying group that believes it can’t benefit from virtually free energy. "
That would be about 10 000 influential donors per campus, or 2000 x $500/donor. I don't know how probable is that, what do you think ? It does sound like a big thing, i agree.

I think that campuses will be the level, where lobbying would have strongest influence, and if it comes with resources which can be used - lovely.
Teams working on the similar technologies will, as it seams, share experience, and this might be stronger force than lobbying.

Yea, that PRWeb thing, i checked. They are a bit slimy, true, but let see if and when and what comes out of this, if anything.

I like the idea though, if nothing else, but it does look a bit dreamy - best wishes and good luck !
 
B

bdewoody

Guest
MeteorWayne":of8odydw said:
Sorry, but you seem to have been around as long as I have, so you should know. Fusion power has been 20 years away for 30 years now, and there is NO indication that any of the problems preventing it from being a useful power source are even close to being solved. In fact the lack of progress indicates that 20 years may be far too optimistic.

Whoopee, we dump in 14 GW and a fusion reaction occurs yielding 0.1 watt. That's progress?
Wayne you have hit the nail on the head as my original post basically implies the same point. All that time and money and entire careers and still no working fusion power plants. I hope it wasn't a waste.
 
M

MeteorWayne

Guest
Not sure I agree bdewoody. Your OP had to do with how to extract the energy...my post you quoted aimed at the fact that the yield has always been far less that the input energy, so there's no net energy to extract :)
Maybe in 20 years :lol:
 
Status
Not open for further replies.

ASK THE COMMUNITY

Latest posts