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Nuclear Fusion - the truth

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BlueJay Flag UK 09 Feb 22 6.06pm

Major breakthrough on nuclear fusion energy - [Link]

Quote European scientists say they have made a major breakthrough in their quest to develop practical nuclear fusion - the energy process that powers the stars.

The UK-based JET laboratory has smashed its own world record for the amount of energy it can extract by squeezing together two forms of hydrogen.

If nuclear fusion can be successfully recreated on Earth it holds out the potential of virtually unlimited supplies of low-carbon, low-radiation energy.

The experiments produced 59 megajoules of energy over five seconds (11 megawatts of power).

This is more than double what was achieved in similar tests back in 1997.

It's not a massive energy output - only enough to boil about 60 kettles' worth of water. But the significance is that it validates design choices that have been made for an even bigger fusion reactor now being constructed in France.

"The JET experiments put us a step closer to fusion power," said Dr Joe Milnes, the head of operations at the reactor lab. "We've demonstrated that we can create a mini star inside of our machine and hold it there for five seconds and get high performance, which really takes us into a new realm."

 

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YT Flag Oxford 09 Feb 22 7.45pm Send a Private Message to YT Add YT as a friend

Mr Thicky question coming...

The Oxford lab reportedly created a temperature of 150 million degrees celsius, which is "far hotter than the core of the Sun", according to BBC News. What is the chamber (or whatever it's called) made of and why doesn't it vaporise?

 


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Stirlingsays Flag 09 Feb 22 9.05pm Send a Private Message to Stirlingsays Holmesdale Online Elite Member Add Stirlingsays as a friend

Originally posted by YT

Mr Thicky question coming...

The Oxford lab reportedly created a temperature of 150 million degrees celsius, which is "far hotter than the core of the Sun", according to BBC News. What is the chamber (or whatever it's called) made of and why doesn't it vaporise?

I haven't seen the article because it won't load for some reason.

I think those temperatures are only created for very small time periods and I think it does vaporise. The temperatures at the core of the sun are maintained by huge gravity and hence atom pressure while on earth we have to use other methods.

 


'Who are you and how did you get in here? I'm a locksmith. And, I'm a locksmith.' (Leslie Nielsen)

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davenotamonkey Flag 10 Feb 22 4.36pm Send a Private Message to davenotamonkey Add davenotamonkey as a friend

Originally posted by YT

Mr Thicky question coming...

The Oxford lab reportedly created a temperature of 150 million degrees celsius, which is "far hotter than the core of the Sun", according to BBC News. What is the chamber (or whatever it's called) made of and why doesn't it vaporise?

Magnetic containment. The plasma never touches anything in the chamber (well... that's the initial simple answer).

Basically, the JET is a Toroid (Joint European Torus). Think of it as a doughnut with a hole. The chamber itself (inside the ring) is a vacuum, and there are extremely strong magnets aligned around the ring. These act to produce a very tight magnetic field.

Gas is superheated and pumped into the chamber. It is so hot, that the electrons are stripped from the nucleus - this is a plasma. The plasma has a charge (an electromagnetic charge), so it can be constrained by the magnetic field. The huge magnetic force constraining the plasma pushes the particles close enough together to fuse. The more force, the more fusion, the more energy.

If the containment fails, or the plasma escapes, the drop in pressure (from not being squeezed) / contact with the torus will cool the plasma rapidly, and fusion stops. If the plasma touches the walls, then it is contaminated and the whole chamber needs to be evacuated.

I can go into the challenges in a bit more detail if wanted, but the main problems over the past 30+ years have been in what is called MHD - MagnetoHydroDynamics - namely the behaviour of fluids (as a plasma is) under magnetic fields.

The chamber, incidentally, are metallic plates. They become irradiated by the radiation produced by fusion products, but these do not stay radioactive for very long. These plates are actually the "power station" part of the machine - they are bombarded (by neutrons) and this generates heat, which then heats water, turns a turbine etc.

Source: me. I do science things.

...also: I was lucky enough to stick my head into an older (not running) Tokamak at JET - much smaller than their primary, but cool nevertheless.


 

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davenotamonkey Flag 10 Feb 22 4.43pm Send a Private Message to davenotamonkey Add davenotamonkey as a friend

Originally posted by jeeagles

Fair enough. Having had a brief look, the purpose of the research is currently to see how much energy they can produce from firing two atoms together. To do that, they need to superheated them and turn them into plasma to give them the energy to overcome the repellant magnetic force between the neutrons.

Whilst she's right to point out the papers don't provide details on how much energy is used to produce the plasma in the first place, this is not what the tests are looking at. The production process of the plasma is a separate issue. The assumption that's probably accepted is once the process is scaled up, then there would be considerable scope to make this more efficient.

Seems like a two stage process.

Stage 1) Work out how to produce energy from Fusion.
Stage 2) Work out how to turn Fusion into a large scale industrial process.

We are still on stage 1. No point working on stage 2 until stage 1 is sorted. Although, stage 2 seems more straight forward.

Examples used in the video are probably clear they are only looking at the theory, not the industrial process, but that's Edited out as it doesn't make a good story.

We already know how to do this. I've not seen the videos, but I'm surprised at the statement on how much energy is used to produce the plasma. The science is immensely well understood in terms of how fusion works, energy yields, reaction pathways etc. We have been generating energy from fusion devices for decades, the issue is to get beta > 1.

As to stage 2: it turns out that the primary issue (cascading instabilities in the plasma resulting in loss of containment) becomes much more manageable as the Torus volume increases. We already see this as Tokamaks have grown from early prototypes to Japanese and European efforts. ITER (the prototype reactor) has a design specification exactly because at the proposed volumes much of the plasma issues are damped down and a sustained "burn" can occur.

 

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Stirlingsays Flag 10 Feb 22 4.47pm Send a Private Message to Stirlingsays Holmesdale Online Elite Member Add Stirlingsays as a friend

Originally posted by davenotamonkey

Magnetic containment. The plasma never touches anything in the chamber (well... that's the initial simple answer).

Basically, the JET is a Toroid (Joint European Torus). Think of it as a doughnut with a hole. The chamber itself (inside the ring) is a vacuum, and there are extremely strong magnets aligned around the ring. These act to produce a very tight magnetic field.

Gas is superheated and pumped into the chamber. It is so hot, that the electrons are stripped from the nucleus - this is a plasma. The plasma has a charge (an electromagnetic charge), so it can be constrained by the magnetic field. The huge magnetic force constraining the plasma pushes the particles close enough together to fuse. The more force, the more fusion, the more energy.

If the containment fails, or the plasma escapes, the drop in pressure (from not being squeezed) / contact with the torus will cool the plasma rapidly, and fusion stops. If the plasma touches the walls, then it is contaminated and the whole chamber needs to be evacuated.

I can go into the challenges in a bit more detail if wanted, but the main problems over the past 30+ years have been in what is called MHD - MagnetoHydroDynamics - namely the behaviour of fluids (as a plasma is) under magnetic fields.

The chamber, incidentally, are metallic plates. They become irradiated by the radiation produced by fusion products, but these do not stay radioactive for very long. These plates are actually the "power station" part of the machine - they are bombarded (by neutrons) and this generates heat, which then heats water, turns a turbine etc.

Source: me. I do science things.

...also: I was lucky enough to stick my head into an older (not running) Tokamak at JET - much smaller than their primary, but cool nevertheless.


Thanks for that, very interesting.

The push continues....it feels like a race similar to the space race of the fifties and sixties.

 


'Who are you and how did you get in here? I'm a locksmith. And, I'm a locksmith.' (Leslie Nielsen)

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Forest Hillbilly Flag in a hidey-hole 11 Feb 22 5.10am Send a Private Message to Forest Hillbilly Add Forest Hillbilly as a friend

I was reading The Sun's take on the possibilities of nuclear fusion. Helpfully, they explained in comprehensive detail, the technical issues surrounding development of the process, for their special readership.

"It mirrors the Fusion generator that powers Marty McFly’s flying DeLorean time-machine in the Back To The Future movies, though that one was fuelled by garbage." (The Sun)


[Link]

Edited by Forest Hillbilly (11 Feb 2022 5.10am)

 


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