Abstract book - Prof. Per Jensen, Ph.D. - Bergische Universität ...

88 Poster session, D41New progress in spectroscopy of ammonia in the infrared 1.5 µm rangeusing evolution of spectra from 300K down to 122KPatrice Cacciani 1 , Peter Cermak 1 , Jean Cosléou 1 , Mohamed Khelkhal 1 , XavierMichaut 2 , Pascal Jeseck 21PhLAM, UMR CNRS 8523, France, Patrice.Cacciani@univ-lille1.fr;2LPMAA, UMR 7092 CNRS France, Xavier.Michaut@upmc.fr;Cacciani P.Cermak P.Cosleau J.Khelkhal M.Michaut X.Jeseck P.Analysis of the temperature dependence of the ratio of the intensity of two assigned andunassigned lines enables the determination of the most probable energy of the lowerstate of the unassigned transition. Such a new procedure has been applied to transitionsof ammonia in the range 6626.0–6802.7 cm-1 between 122K and 300K. Informationsderived are complemented by Ground State Combination Difference technique. Thecomparison to a line list obtained from variational calculation using optimized potentialsurface allows to tentatively assign the band head of a new combination band 2ν 2+3ν 4.This work represents a step in the considerable task of the assignment of the complete1.5 µm infrared spectral range. Results will also be compared with recent resultsobtained with Fourier Transformed spectroscopy in a wider 6300 to 7000 cm -1 energyrange 1 .Fig. 1: .Evolution of a spectrum of NH 3 in the energy range 6660.4 - 6662.1 cm -1 atdecreasing temperatures. Bullets are published assigned transitions confirmed by ouranalysis. The doublet in the middle of the spectra is an example where our techniquehas allowed to derive the lower state of the transitions.Acknoledgment: This work is supported by the French National Research Agency(Project ANR GASOSPIN number 09-BLAN-0066-01).References[1] Sung Keyoon et al JQSRT 2012, http://dx.doi.org/10.1016/j.jqsrt.2012.02.026