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by 1958325146 2310 days ago
I am just learning about this reaction, but can anyone explain what is wrong with the following naive idea?

- Fire a stream of hydrogen ions with a particle accelerator at a chunk of Boron 11. - The hydrogen and boron combine and release heat and helium. - Use the heat from that to run a turbine and keep running your particle accelerator.

It seems like you would be ending up with lower-energy collection of atoms. Does that work but it is just not efficient enough to keep running the accelerator, or what?

2 comments

The problem with firing a stream of hydrogen ions at a chunk of Boron 11 is that most of the collisions between the hydrogen and the Boron are glancing blows that will dissipate the energy very quickly. Only a small fraction of the collisions result in a fusion reaction.

This is the reason why most fusion approaches rely on thermal systems. In a thermal system, the ions have a bell-shaped distribution of energies and undergo many collisions before they leave the region in which they are confined and their energy leaves the system.

To achieve net gain, the temperature, density and energy confinement time must be above a certain threshold. If the system is non thermal, like a stream of hydrogen ions where the distribution of energies is a spike, the energy in the hydrogen ions that are deflected by glancing blows must be recaptured somehow.

Thank you!
>fire a stream of hydrogen ions with a particle accelerator at a chunk of Boron 11.

This is what's wrong. The energy required to accelerate the ions is much higher than the energy which can be harvested this way.

The concept under discussion substitutes a simpler setup that accelerates particles using laser induced plasmas from a very small table top laser. The thing could "almost" be battery powered.