Monday, June 27, 2022

Fusion Physics - Part 2

 Fission is having a big uranium atom break apart, releasing heat.  This is ten times easier to handle than fusion, which requires high compression and heat to fuse two tritium atoms together.  The problem is the relationship between heat and pressure.  For as long as I have been around, controlled fusion has always been '30 years away', and it still is.  

Right now, all the hype has been to get the confinement and heat right, to have fusion.  Many efforts have shown some success in that.  Does that mean they are getting close?  No.  Even on the atomic scale, we are having an explosion, and useful energy requires much larger explosions involving a lot of atoms.

We can get useful work out of controlled explosions -- think of the standard gasoline engine.  There is an explosion, but within strong steel which handles the flash, and then slowly expands for a turn of the crank.  It's an amazing thing.  However, with fusion, there is no material that can hold it, so the confinement is done with lasers, and electric fields with or without magnets.  

You just can't do this, and I cannot see how it can be done in the future.  It takes all your effort to produce confinement for fusion, but you need a huge margin to handle the explosions.  That means it has to be 'easy' to handle the fusion, because then you have to handle the heat expansion.  It will take a long time of development to get that margin.  

So, if you are pinching a plasma down to a near solid to get fusion, you have to handle ten times more pressure to keep the plasma moving to the next stage where it can exchange heat energy.  That's the definition of 'continuous and controlled'.  The fusion cannot upset the apple cart.  With laser confinement, you have to sweep away all the effects of the previous explosion to set up for next.  No amount of steel can handle this.

It just means that physics conspires against a successful result.  It's just a horrible way to generate electrical power.  When they finally announce single atomic fusion in a plasma, you know they have ten times more effort to be useful.

End.

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