0000000000315364
AUTHOR
H. Berger
Study of Collisional Effects on Band Shapes of the v1/2v2 Fermi Dyad in CO2 Gas with Stimulated Raman-Spectroscopy .1. Rotational and Vibrational-Relaxation in the 2v2 Band
0021-9606
Measurements of Collisional Line Widths in the Stimulated Raman Q-Branch of the v1 Band of Silane
0377-0486; Self-broadened widths of 28SiH4 in the v1 Q-branch have been measured at room temperature (295 K) using high-resolution stimulated Raman spectroscopy. These collisional widths have been obtained by fitting a superposition of Voigt profiles to the experimental spectra in the pressure range 28-154 Torr. No evidence for line mixing within the tetrahedral components of a Q(J) line has been found. The line broadening coefficients for J up to 13 depend weakly on the rotational quantum number. The mean value is 103.7 x 10(-3) cm-1 atm-1.
Accurate Spectroscopic Constants of Nitrogen Determined from Stimulated Raman Spectra of the Fundamental and 1st Hot Bands
0377-0486; Nitrogen specta of the Q-branch of the fundamental and the first hot bands were recorded with a high-resolution stimulated Raman spectrometer at atmospheric pressure and ca. 1300 K. The absolute frequencies of the Raman lines were measured with high accuracy, leading to a refinement of spectroscopic constants. A temperature estimation was also performed from the Raman intensities.
Collisional Line Broadening and Line Shifting in N2-CO2 Mixture Studied by Inverse Raman-Spectroscopy
0301-0104
CARS methane spectroscopy for temperature measurements in rocket engines
International audience
High-Resolution Nonlinear Raman-Spectroscopy of Small Molecules
0022-2860
Study of the Density and Temperature Dependences of the Vibrational Raman Transition in Compressed Liquid N2
0021-9606; Accurate values of linewidth and line shift in the isotropic vibrational Raman spectrum of compressed liquid N2 have been obtained by using inverse Raman spectroscopy. Experiments have been performed for eight isotherms, from the normal boiling point to the critical point temperatures of N2, the number density varying between the value on the coexistence line, and the maximum value of 2.1 x 10^22 cm-3. Minima of the linewidth have been observed above 86 K, showing the increasing influence of vibration-rotation coupling (motional narrowing) competing with the broadening due to pure vibrational dephasing. Moreover, for the first time, maxima of the red line shifts have been found, …
Rotational Relaxation of Nitrogen in Ternary Mixtures N2-CO2-H2O - Consequences in Coherent Anti-Stokes-Raman Spectroscopy Thermometry
0021-9606; The influence of CO2 and H2O on the rotational relaxation processes of N2 in ternary mixtures N2-CO2-H2O is investigated. The efficiency of these perturbers is responsible for significant modifications of the state-to-state relaxation rates and broadening coefficients. Flame data are well reproduced by taking into account these modifications. The role of these minor species in the determination of temperatures in premixed flames is analyzed. The present relaxation model allows us to understand why the discrepancy between observed and calculated coherent anti-Stokes Raman spectroscopy (CARS) spectra in flames is sometimes resolved by empirically adding a dephasing component to pur…
Enhancement of Sensitivity in High-Resolution Stimulated Raman-Spectroscopy of Gases - Application to the 2v2 (1285 cm-1) Band of CO2
0377-0486