Hydrogen CARS (Coherent Antistokes Raman Spectroscopy) Spectra from CH(4)/N(2)O and Nitramine Composite Flames

摘要

The hydrogen spectra from the CH(4)/N(2)O and nitramine composite flames allow use of each of the concurrent capabilities of CARS: (1) rovibrational state resolution better than a wavenumber, (2) time resolution better than 10 nrs, and (3) spatial resolution better than 100 micrometers. The rovibrational state resolution results in direct observation of previously unobserved higher J transitions in the Q branch v = 0 and v = 1 and S branch v = 0 transitions. These transitions are in accord with transitions calculated from ab initio results and with transitions indirectly obtained from electronic emission spectra. The ab initio results give a compact set of constants that give results within experimental accuracy of the CARS experimental results. The experimental transition energies were used to construct Boltzmann plots that allow discrimination among the various spectra used to determine temperature. CARS provides the spectral resolution and intensity to allow direct observation of previously unobserved hydrogen higher J and v rotational transitions. Keywords: Propellants, Lova, Hydrogen, Coherent Antistokes, Raman Spectroscopy.