A high performance MM-wave electron spin resonance spectrometer

We describe a novel millimetre-wave electron spin resonance (ESR) spectrometer designed to operate in the frequency range 90-200 GHz and in the temperature range 1.5 K-270 K. The spectrometer uses a bimodal reflection cavity coupled to a circular corrugated guide and uses Gaussian quasi-optics for most of the front-end signal processing. This technique has very low insertion loss and allows a number of sophisticated measurement techniques to be employed including induction operation and illumination by both circular polarisation states.<
>