Mixer and beamforming advances in millimeter-wave imaging

Millimeter-wave imaging diagnostics have been developed in the 50∼150 GHz region which provide 2D localized measurements of electron temperature and electron density fluctuations inside magnetic fusion plasma devices. New mixer and antenna geometries are being developed to extend these techniques to THz frequencies. Also under investigation are beam shaping techniques which offer the possibility of matching the illumination and receive beams in real time to density profile changes as the plasma evolves.