The Challenge of Nuclear Fusion: Harnessing the Power of the Sun

[Mako Ruu]

I had a question after having read an article in an old Popular Science magazine I found at a children's Hospital.

These two guys apparently are building a nuclear fusion generator that's going to excite hydrogen plasma inside of a magnetic "sphere", and then they're going to use magnetic piston rods to slam the field down, simulating the containment gravity of a star.

All so they can use the the heat to boil some water and spin a turbine... ... ...


Isn't there a way to draw the power directly from the energy released during fusion? Tens of thousands of times more energy than we need is released from the sun every single day.. There has to be some way someone didn't think of. In a world of infinite possibilities I refuse to believe they'll create a miniature sun to boil water.

(I apologize if this is the wrong place to post this.)

 

[Fightfish]

All so they can use the the heat to boil some water and spin a turbine... ... ...

And that is how you get most of your electricity everyday!

Isn't there a way to draw the power directly from the energy released during fusion?

Unfortunately, most of the energy is released as heat.

 

[JaredJames]

Isn't there a way to draw the power directly from the energy released during fusion? Tens of thousands of times more energy than we need is released from the sun every single day.. There has to be some way someone didn't think of. In a world of infinite possibilities I refuse to believe they'll create a miniature sun to boil water.

1. There's not "infinite possibilities", just a hell of a lot of them.

2. This is the standard process for generating the majority of our electricity.

3. The energy released, as above, is mainly in the form of heat. How exactly do you propose to use that in its heat form in everyday life without using it to produce electricity?

 

[Mako Ruu]

3. The energy released, as above, is mainly in the form of heat. How exactly do you propose to use that in its heat form in everyday life without using it to produce electricity?

All I'm saying is that there's got to be a better conversion of the energy. I was thinking of maybe using some kind of photovaic cells, or a more sensitive medium that transfers heat into electricity. This way they can use the heat radiated from the fusion, instead of simply just putting it's heat to good use.

Wouldn't something like that work more efficiently?

 

[JaredJames]

All I'm saying is that there's got to be a better conversion of the energy. I was thinking of maybe using some kind of photovaic cells, or a more sensitive medium that transfers heat into electricity.

Photovoltaic cells react to light - not much use to you there although I suppose you could use them to get a tiny bit more out of it (assuming light is produced).

There are a number of ways to produce power from nuclear reactors, but none as efficient as turning a turbine with steam.

This way they can use the heat radiated from the fusion, instead of simply just putting it's heat to good use.

Surely that's the same thing.

 

[Mako Ruu]

Photovoltaic cells react to light - not much use to you there although I suppose you could use them to get a tiny bit more out of it (assuming light is produced).

There are a number of ways to produce power from nuclear reactors, but none as efficient as turning a turbine with steam.

I'm sorry, I was merely using photovoltaic cells to translate an idea in my head. Perhaps another type of cell or device that can draw it's power from the energy released sub-atomically when fusion occurs.

 

[JaredJames]

Perhaps another type of cell or device that can draw it's power from the energy released sub-atomically when fusion occurs.

The energy released is heat (primarily). You need to take that heat and convert it to a useful form - which is what we do when generating steam to turn turbines.

 

[mishima]

This maybe a little different than what you're saying, but have you ever studied the physics of photosynthesis? Basically a certain pigment molecule gets an excited, unstable, state when hit by sunlight, and this electron is transferred around and does different mechanical functions. One of which is turning (yes turning) a protein called ATPase, which isn't like a turbine at all, but rather creates energy in the form of spring loaded organic molecules. (The energy stored there is then passed along to make sugar.) If you study something called the Z-scheme you can see how the energy is passed along through a bunch of intermediates.

Anyways, my point was that at the first time the excited, unstable pigment passes along its energy the accepting molecule is actually stable. I'm not sure how much energy is lost during that kind of electron transfer, but could be something interesting there applicable to nuclear reactions.

 

[Pengwuino]

There has to be some way someone didn't think of. In a world of infinite possibilities I refuse to believe they'll create a miniature sun to boil water.

That's nice. When you figure out something that thousands of people spending decades of research haven't, let us know.

I, like others, don't see what your issue is. Photovoltaics are not efficient and unless you can somehow envision a "cell" that is more efficient and cheaper and simpler than steam turbines, it's silly to consider. We have the concept of running steam powered turbines figured out perfectly well. It's simple. We've been using it with astounding success for over a century.

Hell, the wheel has been around for millennia, and no one complains that some of even the most advanced transportation methods around now still use wheels.

 

[russ_watters]

More to the point, perhaps: energy conversion efficiency is not the limiting factor in successful fusion power, so discussing it is putting the cart before the horse.

 

[Drakkith]

Isn't there a way to draw the power directly from the energy released during fusion? Tens of thousands of times more energy than we need is released from the sun every single day.. There has to be some way someone didn't think of. In a world of infinite possibilities I refuse to believe they'll create a miniature sun to boil water.

If you use a tritium-deuterium fuel, or a dueterium-deuterium fuel, both of those release most of their energy in the form of high energy (high velocity) neutrons. The only way to harness this energy is to have them slam into something and convert the kinetic energy into heat energy. D-D fuel release less energy in the form of neutrons, and more in the form of charged particles, but its still a very significant portion that is released as fast neutrons.

Now, with Proton-Boron fuel, I've heard that you can use a direct conversion of the fuel to electricity. About 99% of the energy released in P-B fuel is in the form of Alpha Particles, which are charged. Supposedly you can capture these and directly convert them into electricity to reach a very high conversion efficiency.

But, like what was posted above, we need to get Fusion Power to the point of net power production before we can really get into the ways to gather the energy. (By net power production I mean the point where we have a self sustaining fusion reaction over a long period of time.)

 

[QuantumPion]

If you use a tritium-deuterium fuel, or a dueterium-deuterium fuel, both of those release most of their energy in the form of high energy (high velocity) neutrons. The only way to harness this energy is to have them slam into something and convert the kinetic energy into heat energy. D-D fuel release less energy in the form of neutrons, and more in the form of charged particles, but its still a very significant portion that is released as fast neutrons.

Now, with Proton-Boron fuel, I've heard that you can use a direct conversion of the fuel to electricity. About 99% of the energy released in P-B fuel is in the form of Alpha Particles, which are charged. Supposedly you can capture these and directly convert them into electricity to reach a very high conversion efficiency.

But, like what was posted above, we need to get Fusion Power to the point of net power production before we can really get into the ways to gather the energy. (By net power production I mean the point where we have a self sustaining fusion reaction over a long period of time.)

Also P-B fusion requires orders of magnitude higher temperatures and densities, far beyond what we are currently technically capable of. Even the easiest fusion, D-T, is barely within our grasp in the coming decades.

 

[Drakkith]

Also P-B fusion requires orders of magnitude higher temperatures and densities, far beyond what we are currently technically capable of. Even the easiest fusion, D-T, is barely within our grasp in the coming decades.

Yep. Gotta crawl before you can walk. And walk before you can run.

 

[Mako Ruu]

I've read things about some Hydrogen reactor that they can get to burn for like half a second contained inside of a magnetic field. I'm not sure how it creates energy, but I think that's what set me off on Nuclear power.

If nothing else, we've at least created an interesting discussion. - For instance, there was also a man who built a plasma generator that runs on garbage. And it's only bi-product is molten glass. I think we should build more of those and clean up some of this garbage. Cause I don't know about your towns, but mine is lousy with the stuff, and our energy prices are ridiculous.

 

[JaredJames]

I've read things about some Hydrogen reactor that they can get to burn for like half a second contained inside of a magnetic field. I'm not sure how it creates energy, but I think that's what set me off on Nuclear power.

I'm not entirely sure of the process, but in fusion you combine two Hydrogen atoms. The mass of the two 'fused' is less than the two individually. It is this mass difference that represents the energy released.

I'm not sure how accurate that is, but it's my very basic understanding of the process.

If nothing else, we've at least created an interesting discussion. - For instance, there was also a man who built a plasma generator that runs on garbage. And it's only bi-product is molten glass. I think we should build more of those and clean up some of this garbage. Cause I don't know about your towns, but mine is lousy with the stuff, and our energy prices are ridiculous.

You're going to need to cite a source for this claim before we can comment.

If it's only bi-product is molten glass, that means the only things going in are the components of glass and/or glass - so it can't run on general garbage and produce molten glass.

 

[Mako Ruu]

Sorry, I should have included a link. I read a lot of popular Science, that's where I read about the garbage generator.

http://www.popsci.com/scitech/article/2007-03/prophet-garbage

 

[uart]

Sorry, I should have included a link. I read a lot of popular Science, that's where I read about the garbage generator.

http://www.popsci.com/scitech/article/2007-03/prophet-garbage

It's fun to read poop science stuff Mako Ruu, but be honest with us, do you even understand that's there is a difference between a high temperature rubbish incinerator and a nuclear fusion?

EDIT: Whoops I meant to say "pop" science. That genuinely was a typo, but I think I'll leave it as is because it's kind of funny. Also it might just have been a "Freudian slip" after reading some of the articles on the linked site. :tongue:

 

[Mako Ruu]

Aye. Just bringing it up in conversation.

 

[Drakkith]

I've read things about some Hydrogen reactor that they can get to burn for like half a second contained inside of a magnetic field. I'm not sure how it creates energy, but I think that's what set me off on Nuclear power.

If nothing else, we've at least created an interesting discussion. - For instance, there was also a man who built a plasma generator that runs on garbage. And it's only bi-product is molten glass. I think we should build more of those and clean up some of this garbage. Cause I don't know about your towns, but mine is lousy with the stuff, and our energy prices are ridiculous.

The difficulty isn't in simply making a fusion reaction happen, it is making it happen in a way that produces more power than is required to sustain the reaction. In the case of most reactors, it takes massive amounts of energy to setup/maintain the magnetic fields and to heat the plasma to a high enough temp for fusion to occur. The half second reaction IS producing power, but not a NET power gain. In other words, it still takes MUCH more energy to get this plasma to burn for 1/2 of a second than the fusion releases in that 1/2 second.

As for your Plasma Generator, it is very easy to create a plasma. A plasma is simply a heated substance that has had its electrons stripped from its nucleons from the heat, resulting in a cloud or sea of charged particles. (Since electrons are - charge and protons are + charge.)