Elusive fusion reactors to be commercialised by 2025-2030... Or so they say

Angilion said:
I vaguely recally reading that the temperature gradient in a working fusion reactor is the steepest temperature gradient in the known universe. I think that might be true.
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Well it's hotter than a stars surface and as you can only measure temperature of "something" not a vacuum.

So I think you're right simply because even the sun to space all you're measuring is difference between a star and the stuff that's thrown off it?

Although in wonder what the difference between say an ecreation disk and a singularity and how far apart they actually are


I mean we're talking a meter or so from millions to minus 150+ (-?)
 
ChroniC said:
Anyone care to ELI5 how something that is the hottest thing in the solar system by x10 @ 120million degrees doesn't melt the very thing containing it. I understand powerful magnets contain the plasma but does that mean that there is little to no radiated heat? If that's the case how do they actually get the energy out?
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I am not a lawyer physicist, but I'll have a go at saying how I think it works...

The amount of heat energy in some stuff is determined by both its temperature and its mass. The plasma in a fusion reactor has an enormous temperature but a low mass - at any given time there's not much fuel in the reactor. So the amount of heat energy in the plasma is far, far lower than the mind-boggling temperature of it might lead a person to expect. It's still a lot, but nothing unusual for a power station. Business as usual for a power station - use the heat to boil water, use the steam to turn a turbine, use the turbine to spin magnets around a wire, electricity results.

It makes more sense on a more comprehensible scale. Imagine a room with a large radiator and a tea light candle. The water in the radiator is at maybe 60C, the candle flame is at maybe 1000C. But the radiator will have a lot more heat energy than the candle flame.

Continuing the analogy...the candle flame will set fire to stuff touching it, but it won't turn the room into an 800C oven that will kill you. For the candle flame and for the fusing plasma, as long as you keep it away from stuff things are OK. The fusing plasma would actually be less dangerous than the candle flame if it touches stuff. A plasma containment failure in a fusion reactor won't set fire to the place and burn it down. As long as the reactor has been built at least somewhat sensibly, containment failure won't be particularly dangerous. It won't do the reactor chamber much good, but the rest of the facility should be undamaged and outside it will be fine. It wouldn't be like a meltdown in a fission reactor.
 
Angilion said:
I vaguely recally reading that the temperature gradient in a working fusion reactor is the steepest temperature gradient in the known universe. I think that might be true.
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The temperature of deep space is 2-3k. Liquid helium starts at 4.2k (for the cheap stuff, which is what they are probably using). Depending on the temperature of the plasma itself in comparison to a star, your statement would be correct.

Note: For those who do not know, K is kelvin and is an offset of the degrees C scale. E.G. 0 k is -273.15 deg C, 0 deg C is 273.15K, 100c is 373.15k ...
 
snibmiu.gif

In August a new breakthrough was made using laser based fusion, so no magnetic confinement needed for the plasma even though MIT a couple months previously successfully demonstrated new magnets that are smaller and more powerful and capable of stable confinement in tests.

The laser one appears to be on the right tracks faster still though.

https://www.imperial.ac.uk/news/228373/major-nuclear-fusion-milestone-reached-ignition/

However, this process has never been fully realised before – until now. The results from the experiment on 8 August indicate an energy output of over one mega-joule, which marks one of the agreed thresholds for the onset of ignition and is six times the previous highest energy achieved.
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With all these different types of reactors being worked on with a new breakthrough every other month now things feel more legit than ever before.

Gut feeling remains the same as before, in our lifetime we will see commercial ignition of fusion power if this rate of progress continues. Getting my head around it all has been and still is tough, but been reading and watching all I can to understand it all for ages now. Find it fascinating!
 
mrk said:
snibmiu.gif

In August a new breakthrough was made using laser based fusion, so no magnetic confinement needed for the plasma even though MIT a couple months previously successfully demonstrated new magnets that are smaller and more powerful and capable of stable confinement in tests.

The laser one appears to be on the right tracks faster still though.

https://www.imperial.ac.uk/news/228373/major-nuclear-fusion-milestone-reached-ignition/




With all these different types of reactors being worked on with a new breakthrough every other month now things feel more legit than ever before.

Gut feeling remains the same as before, in our lifetime we will see commercial ignition of fusion power if this rate of progress continues. Getting my head around it all has been and still is tough, but been reading and watching all I can to understand it all for ages now. Find it fascinating!
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Read a good article on the nation ignition laboratory and the laser fusion will try to find it later.

But th main point was this latest "big leap" is more hyping for publicity/funding it was much much further from equaling energy in to out in real numbers than what's stated (headlines comparing laser power to energy released, but the laser generation is not very efficient so the actual energy in is much more) as well as the optics not being designed for prolonged use.


The machines actual use is for nuclear weapons research after the test ban, not power so even so often they do one of these pr cycles trying to portray something else
 
So far the most viable "reactor" is the original from the 60s-70s.


Drill a big hole, drop a H-bomb down it and set it off, drill a few more holes and pump water down and run a geothermal plant off it :p
 
Source of said article? Whilst no doubt many of these will include an element of weapons research, I can't believe for a moment that it's all hush hush given that many of these are being researched in educational institutes etc.

Source needed. until then I'm taking any such near conspiracy like claims with a pinch of salt :p

Many of these researchers have even published their papers into scientific journals that you can read so it's not just a PR cycle really but actual data and continued research. The only reason for recent breakthroughs is thanks to advances in technology that simply was not possible years ago.
 
mrk said:
Source of said article? Whilst no doubt many of these will include an element of weapons research, I can't believe for a moment that it's all hush hush given that many of these are being researched in educational institutes etc.

Source needed. until then I'm taking any such near conspiracy like claims with a pinch of salt :p

Many of these researchers have even published their papers into scientific journals that you can read so it's not just a PR cycle really but actual data and continued research. The only reason for recent breakthroughs is thanks to advances in technology that simply was not possible years ago.
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National ignition laboratory isn't at all hush about being a weapons maintainence facility it's what it does.

Also it is reported it is the energy of the laser not the energy to make the laser.

Trying to find it now it was a recommended thing on my feed ages ago so hard to Google for was an interview with a fusion physicist
 
Ah lovely, I'll see if I can find a job there. If it's not too far I can commute in my flying car, hopefully the fuel crisis has sorted itself out by then, can't find Thorium anywhere :mad:
 
Deuterium is a hydrogen isotope which is common in the universe and extracted from sea water so no problem with supply there. Tritium is the other isotope of hydrogen but is more rare so needs to be produced for the deuterium-tritium fusion reaction to happen in the reactor. Tritium can be mined from the Earth's core and from sand which I did not know :o

Tefal said:
This isn't the article but it explains. Bit about the discrepancy in numbers


https://bigthink.com/hard-science/nif-fusion-power-breakthrough/

Personally I like general fusions method atm.

Just boarding plane will google more later, the ignition lab seems one of the poorest methods so far though vs tomak and liquid metal
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Hmm it does pose some interesting questions I guess - Mostly though no matter what the military will always be hot on the trail of anything that could give them an energy edge over another nation I guess. Kind of unavoidable in a way?
 
mrk said:
Deuterium is a hydrogen isotope which is common in the universe and extracted from sea water so no problem with supply there. Tritium is the other isotope of hydrogen but is more rare so needs to be produced for the deuterium-tritium fusion reaction to happen in the reactor. Tritium can be mined from the Earth's core and from sand which I did not know :o [..]
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I didn't know that either. Is it practical? Or is it one of those "well, it could be done but it would cost a million dollars per microgram" kind of things?

AFAIK it's not a problem anyway partly because it's possible to have a fusion reactor make more tritium than it uses and partly because so little fuel is needed for a fusion power station.
 
The Tritium is produced by introducing Lithium into the reactor stages - Lithium is what can be mined from the core and sand is what I should have worded above, just read my post back and realised that bit was missing :o

So yeah, Lithium is what's needed to get Tritium produced in the reactor.

Edit* Correction, crust not core and salt desserts not specifically sand! Too much reading frazzling the mind lately.

Tritium is a radioactive isotope that decays relatively quickly (it has a 12-year half-life) and is rare in nature. Fortunately, exposing the more abundant element of lithium to energetic neutrons in a fusion reactor can generate tritium. A working fusion power plant could potentially use lithium to breed the tritium it needs to close the deuterium-tritium fuel cycle since lithium can be obtained from the Earth’s crust via ore mining and from salt deserts.
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mrk said:
The Tritium is produced by introducing Lithium into the reactor stages - Lithium is what can be mined from the core and sand is what I should have worded above, just read my post back and realised that bit was missing :o

So yeah, Lithium is what's needed to get Tritium produced in the reactor.
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I was interested when you said tritium could be mined from sand because I didn't know that was possible. No wonder I couldn't find anything about it when I had a quick look :)

I did find out that it's possible (though not practical, at least not yet) to make tritium from deuterium, which I didn't know before. So I learned something. Which also means that it's possible (though not practical) to fuel a nuclear fusion power station solely with urine, since urine contains deuterium.

Then I got sidetracked into some interesting reading about why deuterium-deuterium fusion is also possible but not practical. I knew that was the case, but not why. Shame, as it would be better in some ways. Which lead me into the origin of the unit "barn" to describe a detail of collisions between particles. It was originally intended to be wartime obfuscation, from the phrase "couldn't hit the broad side of a barn". That was an interesting snippet.
 
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