Electron-cyclotron heating of a tokamak reactor at down-shifted frequencies

The absorption of electron cyclotron waves in a hot, dense tokamak plasma is investigated for the case of the extraordinary mode for outside launching. It is shown that, for electron temperatures Te≥5 keV, strong absorption occurs for oblique propagation at frequencies significantly below the electron gyrofrequency at the plasma center. A new density dependence of the wave absorption is found which is more favorable for plasma heating than the familiar n−1e scaling.