Reply To: General thought on old coal mines.

[jamesr]

Brian,
As far as i knew the the a significant proportion of the He will be retained in the plasmoid (and needs to be if appreciable fusion is to occur). After >50ns (ie a long time), when hopefully most of the fuel as fused does the collapsing magnetic field create the strong axial electric field that accelerates the beam of ions and electrons.

If a triton or alpha is produced near the edge of the plasmoid then it might escape, but if it is generated somewhere such that the closed field lines of the plasmoid keep it trapped long enough to have the 20 or so collisions needed to deposit all its energy into the dense part of the plasma then that energy can make up for the huge losses due to bremsstrahlung radiation that is cooling the plasma.

By using all the information provided by these deuterium tests and understanding the processes going, I was suggesting that you could use the tritons to estimate how stable the plasmoid is to the production of fast ions, and so how much of their energy is transferred to the fuel ions to maintain the temperature high enough for them to fuse.