Burner Plasma Confinement Geometry
Confinement in the burner combines magnetic mirroring with electrostatic plugging along a single straight axis.
Confining on a line
The burner confines its plasma along a straight axis rather than around a ring, which changes the whole geometry of the problem. Instead of twisting field lines to trap particles on nested surfaces, a mirror machine traps them between two regions of strong field and, in a tandem, behind two electrostatic barriers.
Two confinement mechanisms
- Magnetic mirroring: particles moving into rising field are reflected, held between the two plug throats.
- Electrostatic plugging: the plugs establish a potential that repels central-cell ions, plugging the leaks the magnetic mirror alone would allow.
- Together these confine the central-cell plasma far better than either mechanism alone.
The loss cone
A simple mirror always leaks particles whose velocity is aligned closely enough with the axis to slip through the throat, the loss cone. The tandem's electrostatic barrier narrows this loss, but confinement in any mirror is ultimately about minimizing loss-cone leakage. The escaping particles are not purely waste, though: they are the stream the direct-energy converter harvests.
Why the linear geometry pays off
The open-ended geometry that makes confinement harder is the same geometry that makes direct energy conversion easy. Particles that escape do so along the axis, straight out through the expander into the converter. The burner turns the mirror's classic weakness, end losses, into the mechanism by which it produces electricity.
In the model
The axial cutaway shows the field profile and the confined plasma column, with the loss stream continuing through the expander. See the plug throats that do the confining and the coordinate systems that frame the axis.