A radiofrequency heating method that uses high-power microwave beams to heat electrons at the electron cyclotron frequency — providing precise, localized heating and current drive in fusion plasmas.
ECRH uses high-power microwave beams (gyrotrons) at frequencies matching the electron cyclotron frequency or its harmonics. At the resonance location, electrons absorb the wave energy efficiently, heating the plasma. Because the cyclotron frequency depends on the local magnetic field strength, the heating location can be precisely controlled by adjusting the beam frequency or injection angle.[1]
ECRH offers unique capabilities: (1) localized deposition — power can be deposited at specific radial locations, enabling control of temperature and current profiles; (2) neoclassical tearing mode (NTM) stabilization — by driving current at the location of magnetic islands; (3) no particle fueling — unlike NBI, ECRH does not add particles, giving independent control of temperature and density.[2]
Electron Cyclotron Current Drive (ECCD) can replace inductively driven current for steady-state tokamak operation, though the efficiency is modest compared to other methods.[3]