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Nuclear physicist explains why fusion ignition is hailed as a major breakthrough

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Re: Nuclear physicist explains why fusion ignition is hailed as a major breakthrough

#31

Post by rgmerk »

fallingknife wrote: post #14
a3w wrote: post #2

Fusion bombs soon with a laser primer instead of fission for heat generation? Not yet I guess. Clean power? Perhaps never.

Actually, the tech that you are hinting at would guarantee clean fusion power. If you could generate clean fusion explosions, detonate underground and use the heat to generate power. Nuclear bombs are currently the only net energy positive fusion devices we have.

It might guarantee clean fusion power, but there's no guarantee it would be in any way economic.

Edward Teller proposed something along these lines with conventional two-stage nuclear explosives back in the 1970s, but it was rapidly abandoned as horribly inefficient and costly:

https://en.wikipedia.org/wiki/Project_PACER

I know this stuff is fun to speculate about but the boring and unsexy option of more solar panels, wind turbines, and transmission lines is likely to be both cheaper and more politically saleable.

Re: Nuclear physicist explains why fusion ignition is hailed as a major breakthrough

#32

Post by chongli »

garyclarke27 wrote: post #9

Most interesting fact from the article. At the system level it took 300 million Joules to produce 3 Million a 1% return - so still a very long way to go! With this kind of approach I can’t see how fusion can ever be cheap, the capital costs are enormous. Better to focus on standardised production lines for small fission reactors.

That's not the only big challenge. The fuel pellets are 1mm diameter hollow spheres machined out of diamond to extreme precision and filled with a tiny amount of deuterium-tritium gas inside. The pellets need to be carefully cooled to cryogenic temperatures so that the gas condenses evenly around the inside of the pellet, in order to maintain the near-perfect geometry needed for ignition. Once the pellet is hit with the x-rays produced by the lasers striking the interior of the chamber (hohlraum), it compresses and the fuel undergoes fusion, vaporizing the whole package.

So it takes an incredible amount of precision engineering to produce these tiny diamond pellets of fuel which then produce an even tinier amount of energy while being destroyed in the process. There is no indication whatsoever that the pellets can be scaled up due to the incredible difficulty of scaling the precision geometry involved.

So I remain incredibly skeptical that this is anything more than hype for a project that's really about maintaining nuclear weapons stockpiles. I sincerely doubt this approach will lead to a real production power plant without some major research into how to overcome the requirement for extreme precision geometry and a similar effort to scale up the size of the reaction. Then throw the laser efficiency issue into the mix!

Re: Nuclear physicist explains why fusion ignition is hailed as a major breakthrough

#33

Post by fragmede »

ThePhysicist wrote: post #21
garyclarke27 wrote: post #9

Most interesting fact from the article. At the system level it took 300 million Joules to produce 3 Million a 1% return - so still a very long way to go! With this kind of approach I can’t see how fusion can ever be cheap, the capital costs are enormous. Better to focus on standardised production lines for small fission reactors.

Well, early transistors were 3-5 orders of magnitude larger, slower and more dissipative than those we have today. So by the same argument, the computer revolution would have seemed impossible just 50 years ago.

Transistors? Computers before them used vacuum tubes. In 1943 Thomas Watson, chairman of IBM, said, "I think there's a world market for maybe five computers." Now, it would be easy for us to laugh at him, thanks to us being almost 80 years in the future, but on the topic of "what does the future hold for us", put yourself in Watson's place. You're reasonably smart and knowledgeable, and understand what goes into a computer, and thus you'd make the same claim.

Fusion is similarly incomprehensible to us here and now. There are untold advancements in materials sciences and engineering technologies that need to happen before it's possible so we have to invest in trying to so we can make those advancements in order to make it possible.

Re: Nuclear physicist explains why fusion ignition is hailed as a major breakthrough

#34

Post by xbmcuser »

garyclarke27 wrote: post #9

Most interesting fact from the article. At the system level it took 300 million Joules to produce 3 Million a 1% return - so still a very long way to go! With this kind of approach I can’t see how fusion can ever be cheap, the capital costs are enormous. Better to focus on standardised production lines for small fission reactors.

Solar panel and power cost were 100s of times more than they are today. Costs will come down that is actually not the problem having a sustainable fusion reaction is. How would you know how efficiently you can build something when you don't know what to build in the first place. If we can get sustainable fusion reaction then only should peope worry about how to bring down the costs.

Re: Nuclear physicist explains why fusion ignition is hailed as a major breakthrough

#35

Post by _joel »

graderjs wrote: post #30
d4mi3n wrote: post #6

Earlier quoted context omitted.

Cheap power enables a lot of things, like synthesis of fertilizers or the ability to cheaply desalinate water. It won’t fix these crisis directly, but it would reduce or remove a lot of the contributing factors.

Sure, it's complex interaction. But where should our focus priorities be, what task should we do first...what should we publish most about??? Maybe my priorities are wrong...what are you saying?

It's possible to do 2 things at once.

Re: Nuclear physicist explains why fusion ignition is hailed as a major breakthrough

#37

Post by pavlov »

fragmede wrote: post #33
ThePhysicist wrote: post #21

Earlier quoted context omitted.

Well, early transistors were 3-5 orders of magnitude larger, slower and more dissipative than those we have today. So by the same argument, the computer revolution would have seemed impossible just 50 years ago.

Transistors? Computers before them used vacuum tubes. In 1943 Thomas Watson, chairman of IBM, said, "I think there's a world market for maybe five computers." Now, it would be easy for us to laugh at him, thanks to us being almost 80 years in the future, but on the topic of "what does the future hold for us", put yourself in Watson's place. You're reasonably smart and knowledgeable, and understand what goes into a co…

Just 75 years after Thomas Watson said that, we were already doing EUV lithography, a process whose description and commercial incentives would have been totally incomprehensible to him:

"In our laser-produced plasma (LPP) source, molten tin droplets of around 25 microns in diameter are ejected from a generator at 70 meters per second. As they fall, the droplets are hit first by a low-intensity laser pulse that flattens them into a pancake shape. Then a more powerful laser pulse vaporizes the flattened droplet to create a plasma that emits EUV light. To produce enough light to manufacture microchips, this process is repeated 50,000 times every second."

https://www.asml.com/en/technology/lithography-principles/li...

Transistors, microchips and lasers were not invented yet in 1943. How would one even guess that it could soon be a viable business to build a giant machine that shoots molten tin droplets at 50,000 Hz to produce a particular bandwidth of light so that you could create billions of tiny computers out of sand?

Hopefully fusion is on a similar path where the description of 2100's commercial reactor will sound similarly incomprehensible to us.

Re: Nuclear physicist explains why fusion ignition is hailed as a major breakthrough

#38

Post by moloch-hai »

xbmcuser wrote: post #34
garyclarke27 wrote: post #9

Most interesting fact from the article. At the system level it took 300 million Joules to produce 3 Million a 1% return - so still a very long way to go! With this kind of approach I can’t see how fusion can ever be cheap, the capital costs are enormous. Better to focus on standardised production lines for small fission reactors.

Solar panel and power cost were 100s of times more than they are today. Costs will come down that is actually not the problem having a sustainable fusion reaction is. How would you know how efficiently you can build something when you don't know what to build in the first place. If we can get sustainable fusion reaction then only should peope worry about how to bring down the costs.

Even if heat from fusion could be extracted at exactly zero cost, thermal fusion would still be uncompetitive. There is no way around it, wish as you might.

Aneutronic fusion could possibly have a future, but hardly anybody is working on that.

Re: Nuclear physicist explains why fusion ignition is hailed as a major breakthrough

#39

Post by bawolff »

Everything i have heard about this makes it sound more like a milestone than a breakthrough. I.e. its great it happened and an important step, but its not shocking that we eventually did it.

When i hear breakthrough i think of something more unexpected. I.e. figuring out how to solve a problem we had no idea how to solve.

Re: Nuclear physicist explains why fusion ignition is hailed as a major breakthrough

#40

Post by bawolff »

graderjs wrote: post #26
voldacar wrote: post #16

Earlier quoted context omitted.

Energy is the ability to transform matter from one state to another. Food is a particular form of matter. Therefore...

Brilliant! YOur semantics have solved the wolrd food crisis. Advance to next stagel

You don't think having a cheap way to power artificial light sources might be relavent to the food crisis in places not suitable to growing food the natural way?
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