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China's Fusion Reactor Reaches 100 Million Degrees Celsius (abc.net.au)
hackingbear shares a report from the Australian Broadcasting Corporation: The team of scientists from China's Institute of Plasma Physics announced this week that plasma in their Experimental Advanced Superconducting Tokamak (EAST) -- dubbed the 'artificial sun' -- reached a whopping 100 million degrees Celsius which is six times hotter than the core of the Sun. This temperature is the minimum required to maintain a fusion reaction that produces more power than it takes to run. The Chinese research team said they were able to achieve the record temperature through the use of various new techniques in heating and controlling the plasma, but could only maintain the state for around 10 seconds. The latest breakthrough provided experimental evidence that reaching the 100 million degrees Celsius mark is possible, according to China's Institute of Plasma Physics. "While the U.S. is putting new restrictions on nuclear technology exports to China, inventions and findings of EAST will be important contributions to the development of the International Thermonuclear Experimental Reactor (ITER)," writes Slashdot reader hackingbear. The reactor is currently being built in southern France with collaboration from 35 nations. According to the Australian Broadcasting Corporation, it is expected to be "the first device to consistently produce net energy, producing 500 megawatts of clean and sustainable power."
after which time the facility and everything within about 8 miles surrounding it ceased to exist
Some of the researchers still felt it was too cold in the office and would prefer to bump up the thermostat a little more
Also I'm pretty sure the Sun, which is considerably cooler than this, is producing more power than it absorbs.
"Nine times out of ten, starting a fire is not the best way to solve the problem." - my wife
Great! So soon I can get my Chinese takeout much faster, right?
I'm thinking a really fast pizza oven. Why settle for dirty old coal-fired pizza, when you can have fusion pizza!
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DRM is like antifreeze, to the MPAA/RIAA it's sweet, to the consumers it's poison.
The protons in the core of the sun are in a temperature distribution, like a bell curve, and the average of this bell curve is way to cold for fusion. The only reason fusion happens is there are so many protons, a very few have freakishly high temperature way up the high end of the bell curve. Only those statistical outliers are fusing.
So serious question: how many oceans will that boil? It's one thing to have the moon that hot, it's another to have the head of a pin that hot. Or are the just going after temperature quantity rather than size/mass?
You're on the right track. Temperature != Heat. The plasma in the outer magnetosphere of the earth has a temperature of thousands of degrees kelvin, but it doesn't melt a spacecraft that's in it. Why? It's sparse. The average kinetic energy of particles in the plasma is high (i.e., high temperature) but the power per unit area that strikes the spacecraft is very low.
That being said, the plasma inside a Tokomak can certainly melt something. That's (part of) why there is so much effort put into magnetic confinement.
If it weren't for deadlines, nothing would be late.
That is 212 million degrees in Fahrenheit. If they did it in America it would have been much hotter.
Not just instabilities, but lack of a mechanism to capture and feed the excess energy back into the device, which was not a goal of the experiment.
When all you have is a hammer, every problem starts to look like a thumb.
While the U.S. is putting new restrictions on nuclear technology exports to China
How about instead, saying "While China is repeatedly caught attempting to steal nuclear technology from the United States"...
OK, and a linked article bashing Trump admin policies based on testimony of officials who briefed New York Times journalists under condition of anonymity? Yep, this is without question legit and unbiased.
China's Fusion Reactor Reaches 100 Million Degrees Celsius
Plasma energy sounds really large when you express it in temperature. But a more convenient gauge may be the voltage needed to accelerate the particles to velocity magnitudes correspondng to that sort of energy. This is also directly applicable to fusion systems, such as the Farnsworth-Hirsch or Bussard's Polywell, which use electric fields to accelerate the particles into the reaction volume.
Both electrons and hydrogen nuclei have a charge magnitude of 1, so dropping them across a potential difference of N volts adds N electron volts of energy to each particle. Then, if you let the plasma thermalize to a Maxwellâ"Boltzmann distribution, the electron temperature will be (by definition) the temperature of the distribution is about 2/3 that corresponding to the average electron energy.
So to go from degrees Celsius degrees (of a thermalized plasma) to electron volts: .003% drop in the bucket. (Kelvin step sizes are the same but Celsius starts at 273.15 Kelvin.)
- Subtract 273.15 - a
- Divide by 11,605 to get electron volts.
- Multiply by 2/3 to get the average energy of the electrons and ions.
That's an acceleration voltage of 6,025 volts (or 9,037 if you're going to react them before they thermalize). That's right in the ballpark for high-end vacuum tube technology - like the second anode on a CRT. (Those ran about 3000 to 6000 V in the 1940s, and about 25,000 V when modern color tubes were being replaced by flat panels.)
You can see why we all had high hopes for things like Polywell, where (if it worked as expected) a "gassy vacuum tube" that would fit in a strip-mall store's back room, with all supporting equipment (mostly mid-20th-century style electronics), and provide 100 MW of DC at cross-country power line voltages.
Of course many of the other methods for directly heating plasma heat the electrons much more than the ions. So the average energy of the plasma may be substantially lower.
Bantam Dominique roosters crow a four-note song. Once you've heard it as "Happy BIRTHday" you can't NOT hear it that way
The Sun can be cooler because it has a couple of things going for it: it's optically dense and gravitationally confined. That is, the core is SO big and SO dense that radiation doesn't just leak heat out into space. So the plasma doesn't cool down immediately. Also, the plasma density is maintained by the weight of all the mass of the rest of the star.
Lab experiments, and in fact any plasma on earth, have neither of these advantages going for them.
That is why the Sun can maintain its fusion reaction and why it is so hard to create fusion on earth.
Proton-boron fusion requires temperatures 10x higher than D-T.
What's more, because of the higher atomic number for boron, Bremsstrahlung radiation will cool the plasma (if it's thermal) faster than the fusion reactions heat it.
If the plasma isn't thermal, it's actually really hard to keep it nonthermal (entropy tends to win very quickly.) So it seems to me that aneutronic fusion reactions are hopeless for a plasma where losses due to Bremsstrahlung are larger than the fusion power will be.
--PeterM
By neutron activation of lithium-6. There are a number of proposed ways to do this.
It will run at 400 - 600 seconds and will produce more energy than it consumes, that is all. There is no power plant attached nor will there ever be: https://www.iter.org/sci/Goals
And the power production is not clean as long as we use deuterium + tritium, the reactor vessel will have to be replaced around every 10 years and discarded as highly radioactive waste.
Regarding sustainability: ITER will attempt to breed tritium ... lets see how good that works. Otherwise we had to farm tritium from the sea, which is energy intensive and causes another spot in the chain to work with an radioactive element.
Cost free eBook I read (by iBook/Kobo/Amazon/ObookO/Gutenberg etc.): "The Green Odyssey" by Philip Jose Farmer.
You Frenchies and Chinese... Clean Coal 4Ever.
Advice: don't study science. With your deep, keen insight you'll a be natural for sanitary management.
When all you have is a hammer, every problem starts to look like a thumb.
My understanding is that the energy output, per cubic meter, is about the same as the human body, 50-100 watts or whatever. Just that there are a lot of cubic meters in the core of the Sun, so it adds up. As the AC says, proton-proton fusion is slow, even at the pressures and temperatures at the core.
https://en.wikipedia.org/wiki/Inverted_totalitarianism
My understanding is that the energy output, per cubic meter, is about the same as the human body, 50-100 watts or whatever.
Humans output around 100 watts abut are somewhat less than a meter cubed (we'd weigh about a ton at that size). Human power density is more like 1000-1500W/m^3, so we have about 10x the power density of the sun.
SJW n. One who posts facts.
Sigh.
It's to do with the bonds between the parts of the nucleus, and the conversion of mass to energy.
If you take a bunch of 1 proton (Hydrogen) atoms which have
one or two extra neutrons (Deuterium, Triterium) and smash them together you will form an atom with more protons (Helium) and no neutrons, and get a bunch of "spare" neutrons which are either a) obliterated or b) ejected.
E=mc^2. A neutron worth of mass converted to energy is an awful lot.
In fission, you do something different. You take U235, fire another neutron at it, and it splits into two lighter elements, a bunch more neutrons get ejected (which keep the chain reaction going) and some of those get obliterated by the forces involved.
E=mc^2 again.
It's not about "you changed two things between two identical states and got free energy by doing so". It's "you used two different way of smashing things together, which results in one of the neutrons involved being obliterated and changed from mass to energy, and give you a bunch of waste products that you can't just recombine to get what you started with because some of it is now energy.
Fusion is also harder because you have MUCH tinier things that you need to smash together, and they don't want to do it naturally, whereas with fission the U235 becomes U236 quite easily, which is inherently unstable and will explode of its own accord very quickly anyway.
It's about "binding energy" of the start and end products. The binding energy (literally the energy used in the bonds that hold the thing together) of what you get out HAS TO BE LESS than the binding energy of what you put in. That's true for both fission of big atoms and fusion of tiny ones, but almost nothing in-between.
Which is why it's REALLY HARD to make the things in the middle which only really occur in stars because they have so much energy being given out that they can end up literally forging elements that wouldn't exist in any smaller reaction, just by chance.
Honestly, guys... a two second Google.
> The Chinese research team said they were able to achieve the record temperature through the use of various new techniques in heating and controlling the plasma, but could only maintain the state for around 10 seconds. The latest breakthrough provided experimental evidence that reaching the 100 million degrees Celsius mark is possible
100 million degrees is a record for plasma, perhaps. If it proved that reaching 100mK was possible, it's only in the tokomak design, because the Z Pulsed Power Facility achieved 1 billion K in 2006!
They keep running into problems. I've read a few papers, and they would hit problems such as the metals used weren't strong enough to withstand the magnetic fields they were generating. That was fixed. Then the plasma rings would start to twist, buckle, warp and pinch into singularities. Stellerators fixed that problem by putting some torsion into the plasma rings. Tokamaks fixed that problem by adding extra magnetic field randomness or something to break up the standing waves. That fixed that problem. Then the neutron bombardment started poking holes in the metal structure, which weakens it over time. Maybe that has been fixed, but it keeps going round and round.
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To sustain enough steam to power the world you would need, not unsurprisingly, the entire world's current supply of oil, gas, nuclear fission, solar, wind, hydro, etc. Because... that's pretty much what we use it to do (I'm excluding all losses here, for simplicity).
One you achieve fusion, you can literally power the entire world from 867 tonnes of hydrogen per year. That's maybe a shipping container full of hydrogen. Something we can pull out of the ocean.
For reference, we would need to burn 12 billion tonnes of oil, 10.4 billion tonnes of gas or even 7000 tonnes of uranium to do the same.
Pretty much the only thing more powerful is complete utilisation of E=mc^2 - merging antimatter and matter and capturing the blast. You'd only need 3 tonnes of antimatter to power the world in that instance.
https://www.forbes.com/sites/s...
Fusion, if it can be made to work, could power the entire world from one power station. Of course, that's not what would happen - we'd just end up USING UP all that energy and every country would have half a dozen of them. We'd end up synthesising rare materials and doing all the things we can't currently do because of the sheer amount of energy they require, rather than actually just settle on current usage coming from one place.
But it literally is an order of magnitude more energy than the nuclear reactors we have now, which are orders of magnitude more energy than even coal and oil, which are orders of magnitude more energy than anything else.
And it looks like we could viably do it inside the next century or so.
With that amount of energy, you could easily obliterate the planet, or fire things into space like they were paper planes.
Generally when people are talking about the Sun's power density, they are talking about the region where fusion actually occurs, in the core, not the entire visible sphere, which is the number you are using. That would be a bit like talking about the energy density in a tokamak by averaging the power output over the volume of the entire tokamak structure rather than just the actual fuel confined in the magnetic field.
The Solar core is 19% of the Solar radius, and thus the energy density in the core, where fuel is burned, is 150 times higher - 40 W/m^3.
Starships were meant to fly, Hands up and touch the sky - Nicky Minaj
It isn't going "round and round" it is going forward, step by step. Each issue that is solved is one less issue. There have been at least 226 tokamaks built to date, and each one advances knowledge about some aspect of design and operation. That is how extremely complex systems are developed. There is a lot of work to be done to build and operate the first true break-even tokamak -- about 20 years and $20 billion worth.
Starships were meant to fly, Hands up and touch the sky - Nicky Minaj
Also you are rating the human metabolic rate about a factor of 3 too high, is is about 1000 W/m^3, so the ratio of heat output per unit volume is 25 times higher for humans. But the density of the solar core is 160 g/cm^3, so the energy output per unit mass in the Sun is 6 times higher than in humans.
Starships were meant to fly, Hands up and touch the sky - Nicky Minaj
Correct. Temperature != Heat Capacity. Thanks for the improvement.
If it weren't for deadlines, nothing would be late.
Myself, if I had to make a guess, I'd pick something like the Polywell design: https://en.wikipedia.org/wiki/...
But then, I was largely persuaded by some snark from Bussard: https://www.youtube.com/watch?...
Paraphrasing from memory, his line goes something like: "We've spent billions of dollars researching Tokamaks and what we've learned is that Tokamaks are no damn good. Even the people working on them will tell you that they're never going to work, but they say the physics is really good. They're like superconducting cathedrals. But fusion works, we know it works, if you look up in the sky you see fusion reactors everywhere, and not a single one of them is torroidal."
More reasonably, he makes the point that even with minimal funding, they were able to get within something like a factor of 10- "not a factor of 100 or 1000, but a factor of 10".
What about H3? I've been hearing for years that we can get that from the moon. Where the stuff is supposed to be just laying around by the truck load tor the taking?
I read at +2. If your post doesn't reach that level I will not see or respond to it.