A Suggested Mechanism for the 337µ CN Maser

Abstract

STIMULATED emission at a wave-length of 337µ has been observed¹ from pulsed discharges in volatile cyanides in the pressure range 0.1–1.0 mm. No other stimulated emission lines from such sources have been observed so far in our experiments. This is a surprising result when we consider how many transitions are possible in a molecular system. In view of the known high dissociation energy of CN it is plausible to assume that either CN or CN⁺ is the emitter. We have now recorded the ultra-violet and visible spectra of the discharge using a Hilger large quartz spectrograph. No sign of the band at 3263 Å [f′Σ→a′Σ] characterstic of the CN⁺ molecule was observed although the ‘Melinex’ windows of the maser are transparent at this wave-length. In fact all the observed bands belonged to the well-known violet and red systems of CN.