Asymmetric electron cyclotron emission from superthermal electrons in the TFR tokamak

Measurements of electron cyclotron radiation near the fundamental frequency on the high-and low-magnetic-field side of the TFR tokamak are reported. In the presence of a superthermal electron component the measured intensities are asymmetric. A theoretical explanation based on the combined effects of the electron relativistic mass variation and the $\frac{1}{R}$ variation of the tokamak magnetic field is discussed.