Photoabsorption Spectra of Ammonia in 1050 to 2250 Å Region

ABSTRACT Photo absorption spectrum of ammonia was investigated in the 1050 to 2250 A region using synchrotron radiation from the Indian synchrotron light source, Indus-1. Photophysics beamline coupled to a gas phase experimental station was used to record ammonia spectrum. Experiments were carried out at different static pressures (0.02 to 20 mbar) of ammonia and its mixtures with inert gases. Extensive progressions of bands of Rydberg nature converging to the first ionization potential of ammonia, X2A2″ have been observed. Addition of rare gas enhanced the Rydberg band absorption intensities especially in the 1050 to 1600 A region. The 6sa1′ (F′″)- ← X and 5pe′(F″) ← 1a″2 Rydberg series, not reported earlier by VUV absorption spectroscopy, is observed in the present studies and are presented along with their vibrational assignments. The G state reported to be a 6de″ Rydberg state, is more likely a 7sa1′ Rydberg state, verified from the quantum defect calculations. Details of the analysis and results obta...