Nuclear fusion

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Summary
Would this make nuclear fusion work?
If the gas in the fusion reactor was compressed as much as possible wouldn't that increase the efficiency of the reactor and therefore make nuclear fusion possible. It would significantly increase the chances of hydrogen atoms colliding with each other and therefore creating much more power.
 

berkeman

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Are you familiar with the Lawson Criterion? The pressures are much higher than you can achieve by just "compressing the hydrogen gas"... :smile:

 

Astronuc

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If the gas in the fusion reactor was compressed as much as possible
Therein lies the challenge, to compress a heated gas as much as possible. One has to look at the stresses within the structural components to see that a confined pressure is limited by the maximum stress a system can achieve without failure. Magnetic confinement is used to keep a plasma from contacting the walls of the vacuum chamber that would otherwise quench the plasma through rapid conduction of the heat, not to mention the atoms of the structural material contaminating the plasma and causing substantial radiation losses.

Magnetic materials cannot withstand much stress, so they are supported by structural alloys that bear the loads/stresses, and those stresses must be below the yield stress of the material.
 
Also currently LASERS are being utilized to increase pressures, also with limited success.
 
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So, the issue is the strength of the structure? Surely if you could build a structure strong enough then, you could increase the pressure significantly and there create more power.
 
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What about if you increased the volume of hydrogen?
 
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What about if you increased the volume of hydrogen?
That doesn't help unless you have a way of compressing even more hydrogen to sufficient pressures. Having more hydrogen actually makes the issues that @Astronuc mentioned even worse.

Also, when you look at the rate at which you would actually have to burn hydrogen in a fusion reactor to give an output comparable to other commercial power reactors (roughly a gigawatt), the amount that needs to be in the reactor at any given time is very small. So increasing the volume wouldn't really gain anything since there is no need to burn very much of it at a time.
 
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Summary: Would this make nuclear fusion work?

If the gas in the fusion reactor was compressed as much as possible wouldn't that increase the efficiency of the reactor and therefore make nuclear fusion possible. It would significantly increase the chances of hydrogen atoms colliding with each other and therefore creating much more power.
Sure. If a hydrogen atom collides 1000 times with another hydrogen atom before colliding with the reactor wall, then there is a good chance that it fuses before reaching the wall. So there should be as many hydrogen atoms as possible between some random hydrogen atom and the wall.


If we talking about tokamaks, then we don't know yet how to increase the number of fuel atoms without causing instabilities. See page 91 here: (I mean chapter 10 or page numbered 81 in the text )
 
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If we talking about tokamaks, then we don't know yet how to increase the number of fuel atoms without causing instabilities.
We don't know, but we are guessing that stronger magnets would help. But there are problems with stronger magnets, as explained by other posters.
 
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"If we talking about tokamaks, then we don't know yet how to increase the number of fuel atoms without causing instabilities"

What if there was some sort of stabiliser. What if there was some sort of inert gas which could help stabalise the reaction
 

berkeman

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What if there was some sort of stabiliser. What if there was some sort of inert gas which could help stabalise the reaction
It seems like the inert gas would just cool down the plasma. Here is an interesting PF thread about other approaches to stabilization:


:smile:
 

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