Quasi-optical antennas for plasma scattering

Abstract

Two types or quasi-optical antennas are examined for their suitability as a means of directing the radiation from a tunable gyrotron millimetre-wave source into a plasma for scattering. The first type of antenna has a single parabolic reflector. The second has two reflectors; the first elliptical, the second parabolic. This combination has the advantage of focusing the beam into a spot at the centre of the plasma.