Understanding Polywell

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Wenderro

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I saw that a lot of ppl are enthusiastic about a Polywell fusion reactor and now it will work maybe very soon so I tried to find more info about it. Unfortunately I couldn't find much so I'm left with gaps on understanding how it should work. Here it is what I understood about it so far:


One uses superconducting magnets positioned in a certain way to both contain the plasma and also accelerate electrons.
The basic idea is by accelerating electrons one overcomes the strong force making atoms fuse.

What I don't understand is:

Since one uses energy to produce fusion(overcome the strong force) how can the reactor break even? (since the energy released is exactly the strong force one overcame)
 
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theridane

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since the energy released is exactly the strong force one overcame

Energy != force. In case you ment the energy required to fuse two atoms is equal to the energy released during the fusion event, then no, it can't break even.

The energy released and the energy required aren't related - that's why certain reactions do yield net energy, and others don't.
 
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Wenderro

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theridane":hjdas0tb said:
Energy != force. In case you ment the energy required to fuse two atoms is equal to the energy released during the fusion event, then no, it can't break even.

Yes that what I meant.

theridane":hjdas0tb said:
The energy released and the energy required aren't related - that's why certain reactions do yield net energy, and others don't.

Can you extrapolate a bit here? As far I understand there is no gain in energy anywhere but a transformation.
Like:
Chemical reaction: H2 + O = H20 it releases X energy but if u want to divide it back u require X energy(no losses reactions).
Fission: by breaking an atom u release the energy that was needed to fuse that atom in the first place

To clarify, my knowledge is pretty small in this field, I'm not saying I'm right, I just want to understand what I'm doing wrong.
 
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Wenderro

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Well never mind my above post I think I got it, like u said certain reactions do release a net energy.

The stars wouldn't shine otherwise :p
 
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theridane

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It's similar in both nuclear and chemical reactions. You need to add some energy to start the reaction (overcome the repulsive forces between reactants) and then the reaction occurs and energy is released. If the amount of energy you add is lower than what you end up with at the end, you have gain (exothermic reaction).

In nuclear reactions the energy estimation is simple:

400px-Binding_energy_curve_-_common_isotopes.svg.png


If your reactants (say deuterium and tritium) are both lower than your products (say helium), and the difference is sufficient, then you can have energy gain. The same goes for fission, products need to be higher on the graph.
 
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