Sub-millimetre Maser Amplification and Continuous Wave Emission

Abstract

IN our investigations of molecular stimulated emission, we have recently observed amplification by direct current discharges in CN at a wave-length of 0.337 mm. We have also constructed continuous wave oscillator sources of the same wave-length using similar direct current discharges in an apparatus with a plane mirror resonant cavity and beam-splitter coupler as was described earlier¹. The oscillator discharge tubes were 90 cm long and 5 cm in diameter and were operated under flow conditions, as with pulsed CN masers, at an equilibrium pressure of about 0.1 mm. Typically, the potential drop across the tube carrying a current of 1 amp was 800 V and output powers of the order of 0.1 W have been recorded. Similar results have been obtained using discharges run at 50 c/s. Amplification was observed by means of a similar discharge tube of length 60 cm in the resonant cavity of an independent pulsed CN maser. When a direct current discharge is used in this way, increases of up to a factor of two have been observed in the output power of the pulsed maser.