Stellarators with Permanent Magnets

Discuss how polywell fusion works; share theoretical questions and answers.

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Nanos
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Re: Stellarators with Permanent Magnets

Post by Nanos »

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permanent magnets have a reactive behavior so their response to reach a new equilibrium position is slower than a coiled superconductor
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I wonder if different permanent magnetic materials have different response times ?

I might also wonder if different material superconductors also have different speeds of response too.


Could this be augmented / supplemented by an additional electro-magnet to provide that fast response time without needing all of the flux to be provided by an electro-magnet alone ?


I'm also wondering, do we need fast response times because our design is inheritable unstable, and a more stable one might get away with slower response times ?

Could we also not predict in advance where we want the flux, or is our flux pattern always dictated by events that we have to respond to, like a ship and waves on the ocean ?

I kinda imagine a reactor as like water in a bottle, more predictable. :-)


Maybe there is a way to slow down what is happening, so we don't need a fast response time.

Giorgio
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Re: Stellarators with Permanent Magnets

Post by Giorgio »

Nanos wrote:
Sat Feb 25, 2023 4:21 am
Which begs a question, due to my interest in permanent magnetic gearing, how much flux energy will a permanent magnet lose over time ?
That depends on the use (and abuse) you do of the magnet.
While there is no general formula to calculate it, you might consider that a modern magnet in isolated environment can lose about 0.01% of its strength for year, and about 0.1% for year under normal use.
Again, it "highly" depend on the use you do, on the starting strength of the magnet, and so on.
But in general you can consider a permanent magnet like a capacitor for magnetic energy (or the tank of air of a compressor, or a water basin on a mountain to store water for an electric generator). Anyhow it will always require more energy to fill it than the energy you can get back from it, and it will always lose energy (or compressed air, or stored water) over time.

Nanos wrote:
Sat Feb 25, 2023 4:21 am
If permanent magnets lose their flux over time, won't superconducting ones do the same, unless recharged ?
Of course, even if it is minimal (unless under major stress) that is not normally a concern for the use we make of them so far.
The major loss mechanism is due to alternating magnetic fields that induce a voltage in the superconductor itself that destabilize the superconducting equilibrium.

It is a fascinating field of research but due to the limited use of superconductors is still highly underfunded.
A society of dogmas is a dead society.

Giorgio
Posts: 3061
Joined: Wed Oct 07, 2009 6:15 pm
Location: China, Italy

Re: Stellarators with Permanent Magnets

Post by Giorgio »

Nanos wrote:
Sat Feb 25, 2023 7:00 am
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permanent magnets have a reactive behavior so their response to reach a new equilibrium position is slower than a coiled superconductor
---

I wonder if different permanent magnetic materials have different response times ?
I might also wonder if different material superconductors also have different speeds of response too.
They do, but nowhere near to the response time of a superconductor.

Nanos wrote:
Sat Feb 25, 2023 7:00 am
I'm also wondering, do we need fast response times because our design is inheritable unstable, and a more stable one might get away with slower response times ?
]
Could we also not predict in advance where we want the flux, or is our flux pattern always dictated by events that we have to respond to, like a ship and waves on the ocean ?

I kinda imagine a reactor as like water in a bottle, more predictable. :-)

Maybe there is a way to slow down what is happening, so we don't need a fast response time.
It is hard to predict what we might be able to do in the next 200 years, after all we are still in our technological infancy, but I personally doubt that it might happen. What we learned from nature so far is that to control any reaction you need to have a faster response time of the reaction itself.
This has been proven true in every field so far, i do not see why it should not be the same also for fusion.
A society of dogmas is a dead society.

Nanos
Posts: 363
Joined: Thu Jul 05, 2007 8:57 pm
Location: Treasure Island

Re: Stellarators with Permanent Magnets

Post by Nanos »

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What we learned from nature so far is that to control any reaction you need to have a faster response time of the reaction itself.
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I wonder how the sun manages that trick ?

Or is gravity helping out ?

Does gravity have a fast response time I wonder ?

I wonder if material choices effect the speed of gravity ?

Suddenly I'm reminded of Cavorite. :-)
https://en.wiktionary.org/wiki/cavorite


I thought nature was all about the conservation of energy ?

Do leaves have fast response times to harvest sunlight into energy ?

Nanos
Posts: 363
Joined: Thu Jul 05, 2007 8:57 pm
Location: Treasure Island

Re: Stellarators with Permanent Magnets

Post by Nanos »

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nowhere near to the response time of a superconductor.
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I wonder if there is any theoretical limit of the speed we might expect, if we test all the material choices ?


But isn't a permanent magnet simply a type of room temperature superconductor to start with ?


Now I'm wondering if there are materials that when cooled, suddenly become permanent magnets ?

Since, permanent magnets all ( ? ) lose their magnetic qualities if heated high enough don't they ?


If they are stored energy, I wonder then how much energy you can store in a permanent magnet, and could you make a battery out of heating and cooling it ?

Can you have a reverse magnet, eg. a material that sucks up energy to become magnetic, is that a fast reaction, or a slow one ?

Nanos
Posts: 363
Joined: Thu Jul 05, 2007 8:57 pm
Location: Treasure Island

Re: Stellarators with Permanent Magnets

Post by Nanos »

Talking of magnets:

https://www.youtube.com/watch?v=drD416THU7Y
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CMR Demos Its Printed Polarity Magnets
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Nanos
Posts: 363
Joined: Thu Jul 05, 2007 8:57 pm
Location: Treasure Island

Re: Stellarators with Permanent Magnets

Post by Nanos »

https://bigthink.com/hard-science/nucle ... 1683877074

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Hard Science — March 20, 2020

New nuclear fusion reactor design may be a breakthrough

Using permanent magnets may help to make nuclear fusion reactors simpler and more affordable.

However, researcher Michael Zarnstorff in New Jersey may have recently made a significant breakthrough while helping his son with a science project. In a new paper, Zarnstorff, a chief scientist at the Max Planck Princeton Research Center for Plasma Physics in New Jersey, and his colleagues describe a simpler design for a stellarator, one of the most promising types of nuclear fusion reactors.
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I wonder what the current rate of progress is using permanent magnets ?

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