Modification of emission from the X-mode at the third electron cyclotron harmonic from mode conversion and reflection

Abstract

Both absorption and emission of the X-mode in the vicinity of the third electron cyclotron harmonic (o-3 w,,) in a weakly inhomogeneous magnetic field are analyzed. The mode conversion problem is solved both without absorption and with synchrotron absorption and emission. The transmission is shown to be independent of absorption, and the emission is related to absorption exclusively through the reflection coefficient, which is calculated. The numerical values for the reflection coefficient are obtained from a sum that is exact, and quickly gives high accuracy values within its radius of convergence. The effects of reflection are shown to be generally neglectible for most laboratory plasmas, but potentially important in some space plasmas.