Vibrational relaxation of the ngr;2=1 level of ortho and para NH3

摘要

A lead salt diode laser operating in the 12 mgr;m region is used in conjunction with aQhyphen;switched CO2laser to measure relaxation rates on many different transitions in the ngr;2bands of14NH3and15NH3. The measured lifetime of the ngr;2=1 level is found to differ for ortho and para NH3transitions. This difference is shown to be caused by a relatively slow (Vndash;V) energy transfer between the ortho and para species. (Vndash;V) and (Vndash;T,R) relaxation rates are reported for NH3ndash;NH3and NH3ndash;N2collisions at 200 and 300 K. The rate of vibrational energy transfer between14NH3and15NH3is also determined.