The increasing demand for powerful reliable and efficient gyrotron oscillators for Electron
Cyclotron Resonance Heating (ECRH) in fusion plasma experiments requires a close look at the
various factors in gyrotrons that determine gyrotron performance. In this frame the influence
of emitter surface roughness emission inhomogeneity and secondary electron generation on
gyrotron operation is presented with focus on Low Frequency Oscillations (LFOs) and Electron
Beam Halo (EBH) generation.
