Looks as though the National Ignition Facilty (NIF) near San Francisco is making headway with its energy fusion project. Objective being to deliver clean energy as a source of renewable energy to large cities. Friedman from NY Times interviewed NIF Director Edward Moses:
http://www.nytimes.com/2009/03/15/opinion/15friedman.html?_r=1
| Quote: |
Last Monday at 3 a.m., for the first time, all 192 lasers were fired at high energy precisely at once — no small feat — at the target chamber’s empty core. That was a major step toward “ignition” — turning that hydrogen pellet into a miniature sun on earth. The next step — which the N.I.F. expects to achieve some time in the next two to three years — is to prove that it can, under lab conditions, repeatedly fire its 192 lasers at multiple hydrogen pellets and produce more energy from the pellets than the laser energy that is injected. That’s called “energy gain.”
“That,” explained Moses, “is what Einstein meant when he declared that E=mc2. By using lasers, we can unleash tremendous amounts of energy from tiny amounts of mass.”
Once the lab proves that it can get energy gain from this laser-driven process, the next step (if it can secure government and private funding) would be to set up a pilot fusion energy power plant that would prove that any local power utility could have its own miniature sun — on a commercial basis. A pilot would cost about $10 billion — the same as a new nuclear power plant.
I don’t know if they can pull this off; some scientists are skeptical. Laboratory-scale nuclear fusion and energy gain is really hard. But here’s what I do know: President Obama’s stimulus package has given a terrific boost to renewable energy. It will pay lasting benefits. And we need to keep working on all forms of solar, geothermal and wind power. They work. And the more they get deployed, the more their costs will go down.
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Clean energy? Wouldn't fusion still produce radioactive waste?
| ocalhoun wrote: |
| Clean energy? Wouldn't fusion still produce radioactive waste? |
Very small amounts and not the same type as fission (much lower half-life - tens of years rather than millenia)..Good stuff then... I hope they finally manage it. How long have 'they' been trying?
| ocalhoun wrote: |
| Good stuff then... I hope they finally manage it. How long have 'they' been trying? |
Well, the idea has been around since the early 20th century. Uncontrolled fusion has been around since the mid 1950s (the hydrogen bomb is basically a fusion device, for example). Scientists have been working to contain the reaction seriously for about 50 years and progress is being made.
http://en.wikipedia.org/wiki/Nuclear_fusionIn 1920 or something Rutherford (was it?) I think got an alpha particle (He) and Nitrogen to combine to form Oxygen and Hydrogen. I'm not sure about this.
What kind of reaction is this called? Is it artificially transmuted fusion?
This is really interesting. There must be massive amounts of energy released from the hydrogen if it can somehow be more than the energy used by all 192 lasers. I thought at first that this was supposed be another attempt at cold fusion but upon reading the article I see that the lasers bring it up to an extremely high heat. If this is made available on a commercial scale it would be great. Hopefully its not another dead end when it comes to clean energy.
| Magicman wrote: |
| This is really interesting. There must be massive amounts of energy released from the hydrogen if it can somehow be more than the energy used by all 192 lasers. I thought at first that this was supposed be another attempt at cold fusion but upon reading the article I see that the lasers bring it up to an extremely high heat. If this is made available on a commercial scale it would be great. Hopefully its not another dead end when it comes to clean energy. |
Well, all you have to do is look at Einstein's famous e=mc^2
A very tiny amount of mass converts to a huge amount of energy.
Cold fusion is widely regarded by the scientific community as a dud. Most physicists think that the original 1989 experiments, which claimed to show the effect, were in fact showing experimental error. Attempts to reproduce the claimed effect have failed repeatedly.
To achieve fusion you need massive energies - you essentially need to slam hydrogen atoms together hard enough to make them fuse into helium. How that could possibly happen in a test tube has never been explained and, to my mind, it simply doesn't happen. | Bikerman wrote: |
| How that could possibly happen in a test tube has never been explained and, to my mind, it simply doesn't happen. |
Extremely high opposite electric charges? In a vacuum to prevent electrical discharge as much as possible...
You could get two groups of hydrogen atoms to rush at each other quite quickly that way, and have a nice, hot spark just as they meet as a bonus.
Just a (probably wrong) thought. | ocalhoun wrote: |
| Bikerman wrote: | | How that could possibly happen in a test tube has never been explained and, to my mind, it simply doesn't happen. |
Extremely high opposite electric charges? In a vacuum to prevent electrical discharge as much as possible...
You could get two groups of hydrogen atoms to rush at each other quite quickly that way, and have a nice, hot spark just as they meet as a bonus.
Just a (probably wrong) thought. |
Then it's probably more likely that they would just form H2 instead of Helium. (not that I'm sure you could even get Hydrogen to a very high opposite charge since it only has one proton 
) Fusion takes more energy than that... To accomplish cold fusion we would need to know a lot more about the atom's structure.Yes, I have to agree with Aredon. You can form negative ions of hydrogen (anions) by forcing more electrons onto the atom but you wouldn't be able to generate anything like enough force to fuse anions and protons.
The positive charge doesn't have to be large, if the opposite charge is... in fact, they could both be negative...
If the charge of one was -5 and the other -5,000,000 then it would still work... maybe...
I guess that would depend on just how much of a charge you can apply to a few gaseous atoms... Is there a theoretical limit to that, or just a practical one?
| ocalhoun wrote: |
The positive charge doesn't have to be large, if the opposite charge is... in fact, they could both be negative...
If the charge of one was -5 and the other -5,000,000 then it would still work... maybe...
I guess that would depend on just how much of a charge you can apply to a few gaseous atoms... Is there a theoretical limit to that, or just a practical one? |
Well the problem is there's only one proton (simplistically we say it has a charge of +1), and that proton can't "hold on", realistically, to more than a handful of electrons. Even if you were able to shove 5,000,000 electrons into it's orbitals you'd likely reach a point were as you added each electron some were flying off. So in this way there's a sort of dynamic cap. You'd eventually reach a point were the speed at which you're adding electrons is canceled out by the speed of the electrons freeing themselves of the single proton's "grip". That said, if we ever figure out exactly how these particles have charges. It could be possible to change the strength of the charge of one proton. Pretty unlikely, granted, but then again we don't know all that much. If something like that were to happen we may see some form of cold fusion in the future, but again, pretty unlikely. As we start getting smaller and smaller things start getting less and less concrete, and harder to understand. | ocalhoun wrote: |
| The positive charge doesn't have to be large, if the opposite charge is... in fact, they could both be negative... |
I think not... | Quote: |
| If the charge of one was -5 and the other -5,000,000 then it would still work... maybe... |
I can't see how. Surely there would be no electrostatic attraction between two such atoms - rather a repulsion...hmmm....unless the large negative charge produced a repulsive charge induction in the other atom....that would require someone with greater knowledge of electrostatics than me.... | Bikerman wrote: |
| ocalhoun wrote: | | The positive charge doesn't have to be large, if the opposite charge is... in fact, they could both be negative... |
I think not... | Quote: | | If the charge of one was -5 and the other -5,000,000 then it would still work... maybe... |
I can't see how. Surely there would be no electrostatic attraction between two such atoms - rather a repulsion...hmmm....unless the large negative charge produced a repulsive charge induction in the other atom....that would require someone with greater knowledge of electrostatics than me.... |
I figured that the charges are all relative anyway, and that a charge of 0 is simply an arbitrary reference point, and what we call 0 in one place might be +6 in another, where the reference point is more negative.
Or perhaps that doesn't work that way in static electricity... | ocalhoun wrote: |
| Bikerman wrote: | | ocalhoun wrote: | | The positive charge doesn't have to be large, if the opposite charge is... in fact, they could both be negative... |
I think not... | Quote: | | If the charge of one was -5 and the other -5,000,000 then it would still work... maybe... |
I can't see how. Surely there would be no electrostatic attraction between two such atoms - rather a repulsion...hmmm....unless the large negative charge produced a repulsive charge induction in the other atom....that would require someone with greater knowledge of electrostatics than me.... |
I figured that the charges are all relative anyway, and that a charge of 0 is simply an arbitrary reference point, and what we call 0 in one place might be +6 in another, where the reference point is more negative.
Or perhaps that doesn't work that way in static electricity... |
No it doesn't. Charge is an absolute. Of course we can quibble about the units, but the zero point is an absolute, in the sense that -1+1=0. (If you simply said that -1 was (for example) 1 and +1 was therefore 3, then you would get a summative result of 4, which is not what happens).There are two very difficult problems that must be solved for nuclear fusion to be commercially viable.
1. Since fusion occurs at extremely high temperatures, a major problem is the containment of the actual fusion process. Since most containing material melt at such high temperatures strong magnetic fields are usually used today to contain the reactions.
2. To be viable source of energy, there must be a net gain in energy ...i..e you must extract more energy that you supply the to the fusion apparatus. The energy needed to create the conditions for fusion, including magnetic containment, is enormous!
This will all take some time.
