Burner Plug Magnet Control
A tandem mirror confines plasma between strong end plugs, so controlling the high-field plug coils is central to the burner's operation.
How a mirror confines
A magnetic mirror uses regions of strong field at each end of a straight central cell. Charged particles moving toward a strong-field region feel a force that can reflect them back, trapping most of the plasma between the two mirrors. A tandem mirror adds electrostatic potential plugs at the ends to plug the loss of particles that a simple mirror would leak.
The plug coils
The end-plug coils produce the high magnetic field that forms the mirror and shapes the confining potential. These are the strongest coils in the machine, so their current control, protection, and cryogenics are demanding. Holding the plug field steady and symmetric is what keeps the central plasma confined, so plug-coil control has the same priority that toroidal-field control has in a tokamak.
What is controlled
Control regulates the plug-coil currents to set the mirror ratio and the plug field, coordinates them with the central-cell field, and holds the whole magnetic geometry steady during operation. Because the coils store large energy at high field, quench detection and protection are integral, as is temperature-margin monitoring under the machine's heat loads.
- Strong end fields reflect and trap particles
- Electrostatic plugs reduce end losses
- Plug coils are the highest-field coils in the machine
- Control holds plug field steady and symmetric
Kronos burner context
The Kronos burner is a D-3He tandem-mirror generator with a modeled plug field of 26.49 T and a throat field of 17 T; these high fields make plug-magnet control and protection a central engineering task. The machine is deployed conceptually as fixed Aegis defense installations and MetroVolt data-center units. It is a design and simulation case, not built hardware, and no net-gain claim precedes its first-of-a-kind demonstration.
The plugs are the burner's confinement, so their coils get the most careful control the machine offers.