Near ultra-violet emission bands of benzene

Abstract

In the course of a study of the high-frequency discharge in benzene vapour, a set of bands in the spectral region 3000-2475 A. is obtained using oscillations in the frequency range 1765-1200 kc./sec. to excite the flowing vapour of benzene (pressure ~0.1 mm mercury). These oscillations were produced in a modified Hartley circuit using a Mullard PM4DX valve. A Hilger medium quartz spectrograph was used as the resolving instrument to photograph the spectrum. The bands, which are degraded towards longer wave-lengths, occur in several distinct groups, six such being obtained in the present experiments. Measurements of the wave-lengths of the band heads show that they are identical with the bands obtained in the Tesla discharge in benzene vapour.