Synchrotron Radiation Losses
Electrons spiralling in a strong magnetic field radiate at the cyclotron frequency; in the high-field plug region this cannot be ignored.
Radiation from gyrating electrons
Electrons circle magnetic field lines and radiate at the electron cyclotron frequency and its harmonics — synchrotron (cyclotron) radiation. The radiated power scales strongly with magnetic field (roughly B2) and with electron temperature. In the burner's plug region, where the field reaches 26.49 T, this loss channel becomes significant.
Unlike bremsstrahlung, synchrotron radiation is emitted at relatively low frequencies and is partly reabsorbed by the plasma before it escapes, so the net loss depends on plasma size and opacity. In a compact, high-field region the reabsorption helps, but the raw emission is large enough that the electron temperature and field profile must be managed to keep it in check.
Interaction with the plug
The plug is where the field is highest and the loss is worst, yet it is also where a strong confining potential is needed. This tension between field strength, radiation, and confinement is part of why the plug regime is one of the burner's honest gates.
The reabsorption that softens this loss depends on the plasma being optically thick at the cyclotron frequency, which in turn depends on size and density — so the same compactness that makes the plug's field so demanding also changes how much synchrotron energy escapes. Getting the field profile, temperature, and geometry to keep both bremsstrahlung and synchrotron in check simultaneously is part of what makes the plug regime narrow.
- Psyn rises steeply with B and Te
- Worst in the 26.49 T plug region
- Partly reabsorbed — net loss depends on size/opacity
- Couples radiation limits to plug confinement