Results and prospects of oblique ECE measurements

Electron cyclotron emission spectrum is a rich source of information about thermonuclear plasmas. Perpendicular low field side detection of X mode second harmonic is commonly used to measure electron temperature in toroidal devices. Measurements at different angles, and over a wider range of harmonics, sample different regions of the electron momentum space and can, in principle, give information on it. This is extremely interesting in view of burning plasma experiments, where energy transfer from non-thermal population to thermal particles is expected to be significant.