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Chinese Tokamak reaches over 100M degrees

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Re: Chinese Tokamak reaches over 100M degrees

#191

Post by jeffreyrogers »

dbingham wrote: post #186
w323898 wrote: post #182

Fusion was, and for the foreseeable future will be, a boondoggle. In the US it was a cold-war-era arms race program intended to scare the USSR and have them overextend, and now the Chinese are using it for propaganda and scientific Keyensianism. The fact is, fusion generates neutron radiation that destroys the reaction vessel, making it an unviable technology. Nobody takes it seriously as a source of energy, aside fr…

I dunno, my buddy who just got a degree in high energy plasma physics working on fusion reactors might disagree with you. And really, you just sound like every crank ever who thought X technology was totally unfeasible and always would be -- until it wasn't. So currently attempts haven't found a solution to the reaction vessel destruction problem. That does not mean someone in the future couldn't figure that one out.

OP at least gave a reason: neutron radiation destroys the reaction vessel. No one who's responded has given any evidence for why this is false.

Re: Chinese Tokamak reaches over 100M degrees

#192

Post by w323898 »

dbingham wrote: post #186
w323898 wrote: post #182

Fusion was, and for the foreseeable future will be, a boondoggle. In the US it was a cold-war-era arms race program intended to scare the USSR and have them overextend, and now the Chinese are using it for propaganda and scientific Keyensianism. The fact is, fusion generates neutron radiation that destroys the reaction vessel, making it an unviable technology. Nobody takes it seriously as a source of energy, aside fr…

I dunno, my buddy who just got a degree in high energy plasma physics working on fusion reactors might disagree with you. And really, you just sound like every crank ever who thought X technology was totally unfeasible and always would be -- until it wasn't. So currently attempts haven't found a solution to the reaction vessel destruction problem. That does not mean someone in the future couldn't figure that one out.

https://en.m.wikipedia.org/wiki/Aneutronic_fusion Nothing is impossible, but some things are highly improbable. I'm all for research, but we should be realistic in our expectations.

Re: Chinese Tokamak reaches over 100M degrees

#193

Post by eutropia »

jeffreyrogers wrote: post #191
dbingham wrote: post #186

Earlier quoted context omitted.

I dunno, my buddy who just got a degree in high energy plasma physics working on fusion reactors might disagree with you. And really, you just sound like every crank ever who thought X technology was totally unfeasible and always would be -- until it wasn't. So currently attempts haven't found a solution to the reaction vessel destruction problem. That does not mean someone in the future couldn't figure that one out.

OP at least gave a reason: neutron radiation destroys the reaction vessel. No one who's responded has given any evidence for why this is false.

It's not false. But it's also not a universal constant like the speed of light or something, absent a reason why it couldn't be planned for and dealt with, I'm inclined to treat it as an as-yet-unsolved engineering challenge.

Re: Chinese Tokamak reaches over 100M degrees

#194

Post by DennisP »

ryanmercer wrote: post #133
fyfy18 wrote: post #114

Earlier quoted context omitted.

Why is it so underfunded? The first country to build one will be taking a big step to reducing their dependence on other countries for energy. I can understand big oil exporters not wanting to push it too much (although it's unlikely to come into fruition for the current generation of politians), but for others isn't it a no brainer?

>Why is it so underfunded? - Oil/coal/natural gas lobbyists and interests which hinder tax payer funded research. - The fact that there is no guarantee we will ever figure it out and no idea whatsoever as to how much it will cost to figure it out. Investors like returns, in their lifetime, leaving largely tax payer funded research as the greatest source of funds... see above. And then with government-funded research.…

Given climate change, giving it to other nations is exactly the right thing to do, even from a purely self-interested perspective. Nobody wins if coal plants in China tip us into runaway warming.

Re: Chinese Tokamak reaches over 100M degrees

#195

Post by DennisP »

phkahler wrote: post #147
i_am_proteus wrote: post #3

A tokamak is a kind of fusion reactor, and basically the most prevalent. "100M degrees" (Kelvin) corresponds to 10 KeV (kilo electron volts), which is an important figure to exceed for D-T fusion. D-T fusion which is the kind of fusion the ITER Tokamak (a forthcoming fusion reactor and international megaproject) intends to demonstrate. An older fusion experiment, JET (Joint European Torus) reached these levels, so th…

Didn't old-school CRT televisions "heat" electrons to more than 10KeV?

Fusion is easily achievable in your garage. The hard part is getting out more power than you put into it.

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

Re: Chinese Tokamak reaches over 100M degrees

#196

Post by godelski »

ravar wrote: post #148
muhbags wrote: post #136

Earlier quoted context omitted.

Never. It's either no units (theoretical physics), eV (particle physics) or Kelvin/Celsius for experimental physics.

Technically there is Rankine if you want to do thermo in imperial units.

I've only known engineers to use Rankine and they hate it. I've never known a scientist to use it.

Re: Chinese Tokamak reaches over 100M degrees

#197

Post by DennisP »

tim333 wrote: post #157
majewsky wrote: post #79

Earlier quoted context omitted.

Wendelstein 7-X in Germany is a stellarator-type reactor: https://en.wikipedia.org/wiki/Wendelstein_7-X

And YC is invested in Helion Energy using pulsed inertial fusion. Though the tokamak seems closest to being functional. The MIT ARC design is theoretically supposed to be able to work, at least on paper: >The ARC design aims to achieve an engineering gain of three (to produce three times the electricity required to operate the machine) while being about half the diameter of the ITER reactor and cheaper to construct.…

ARC has some funding now. They spun off a startup called Commonwealth Fusion Systems, which has $50M so far, from an Italian oil/gas company.

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

Re: Chinese Tokamak reaches over 100M degrees

#198

Post by DennisP »

gwbas1c wrote: post #161

I know very little about fusion. Did the reactor produce more energy then was put into it? I just don't understand enough about the field to figure that out by reading the article.

No, they've just reached fusion temperatures. It's a step along the way but we're not at net power yet.

Re: Chinese Tokamak reaches over 100M degrees

#199

Post by DennisP »

argc wrote: post #14

100M seems insanely high, beyond what anything man made would be able to contain. Is it extremely short lived? Or over a very small area? Very interesting.

In inertial confinement fusion, it's a very small volume for a very short time. But this is magnetic confinement, which means it's a pretty large volume (probably cubic meters in this one), and they want to keep it going as long as possible (I think 30 seconds is the record so far). But the plasma is very thin; the atoms move really fast but there aren't many of them, so the actual amount of heat isn't remarkable.

Re: Chinese Tokamak reaches over 100M degrees

#200

Post by thinkcontext »

Santosh83 wrote: post #73

Let me ask a different question to the knowledgeable folk here. It has been noted that producing the temperature is not the hardest part but confining the plasma for long periods of time is. On this note, do we have any reason to be particularly confident that magnetic confinement will ever break even and produce surplus energy? In nature fusion seems to occur through gravitational compression, so what makes us sure…

ITER is designed to address exactly what you have asked.

"The ITER thermonuclear fusion reactor has been designed to produce a fusion plasma equivalent to 500 megawatts (MW) of thermal output power for around twenty minutes while 50 megawatts of thermal power are injected into the tokamak, resulting in a ten-fold gain of plasma heating power."

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

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