Electron cyclotron absorption in a high-temperature plasma revisited

The angular dependence of the electron cyclotron (EC) absorption in a high-temperature plasma (Te≳20 keV) is revisited on the basis of analytical expressions for the EC absorption coefficients of both the extraordinary and ordinary mode obtained by performing the required integration over pitch angle and energy directly. This method, hence, avoids the complexity one is faced with, when starting from Trubnikov's second formula which involves a numerical integration in which a large number of (complex) saddle points must be taken into account. In particular, the non-monotonous dependence on the angle of propagation of the absorption coefficient of the ordinary mode (which cannot be obtained from a Trubnikov-like approach without consideration of several saddle points) is covered by the analytical expression obtained.