Quasi optical resonant cavity gyrotron for millimetre waves - has auxiliary resonant cavity in which interfering electromagnetic wave is generated and suppressed by two opposing attenuating mirrors.

摘要

An electron beam (2) cross the principal e.m. wave beam (FP) in a principal resonant cavity (10) between two highly reflective mirrors (MP1,MP2) with as low a loss as possible. The auxiliary resonant cavity in which the auxiliary e.m. wave (FA) appears when the interfering e.m. wave is generated has a length equal to a whole number of wavelengths between the two attenuating mirrors (MA1,MA2). The distance between the attenuating mirrors is a submultiple of a power of two of the distance between the principal mirrors. The auxiliary beam intersects the electron beam at the same point as the principal beam and it may be deviated along its length between and the electron beam and each mirror by a pair of highly reflective mirrors so that it runs partly parallel to the principal beam. ADVANTAGE - Reduced manufacturing costs, easier to start oscillations; does not affect principal cavity operation.