Multispectrum fitting measurements of line parameters for 5-μm cold bands of acetylene

Abstract Using FT spectra (unapodized FWHM: 0.002 cm −1 ) of acetylene 12 C 2 H 2 , absolute line positions have been measured (average accuracy: ±0.0002 cm −1 ) between 1860 and 2180 cm −1 in the 3ν51, (2ν4+ν5)1I, and (2ν4+ν5)1II cold bands, improving the wavenumbers previously published by Pliva under a resolution of about 0.03 cm −1 . Absolute intensities have been obtained for more than 130 lines, with a mean accuracy of ±5%, the accuracy of the amount of 12 C 2 H 2 in the sample being estimated to be better than 2%. For each band, the vibrational transition dipole moment squared has been determined, as well as empirical Herman–Wallis coefficients. Self-broadening coefficients have been measured at room temperature for more than 120 lines. No striking vibrational dependence has been observed for the self-broadening coefficients, and a polynomial expansion describing the rotational dependence is given. Furthermore, self-shifting coefficients have been measured for 89 lines, together with more than 150 absolute line positions. A multispectrum fitting procedure has been used to retrieve the line parameters from the spectra, and cross comparisons have been performed on a few lines between two different codings of this procedure.

[1]  D. Hurtmans,et al.  Laser spectroscopy of the ν1+3ν3 absorption band in 12C2H2. I. Pressure broadening and absolute line intensity measurements , 1999 .

[2]  G. Blanquet,et al.  On the Speed-Dependent Hard Collision Lineshape Models: Application to C2H2 Perturbed by Xe , 1997, Journal of molecular spectroscopy.

[3]  G. Blanquet,et al.  Line-Mixing Effects in He- and N2-Broadened Σ ← Π Infrared Q Branches of C2H2 , 2000 .

[4]  T. Gabard,et al.  Speed-dependent broadening and line mixing in CH4 perturbed by Ar and N2 from multispectrum fits , 2000 .

[5]  H. Valipour,et al.  Investigation of J dependence of line shift, line broadening, and line narrowing coefficients in the ν1+3ν3 absorption band of acetylene , 2001 .

[6]  Laurence S. Rothman,et al.  Total internal partition sums for molecules in the terrestrial atmosphere , 2000 .

[7]  R. Cahill,et al.  Mass Spectrometric Measurement of Diffusion Coefficients , 1964 .

[8]  G. Blanquet,et al.  Diode laser measurements of collisional broadening in the ν5 band of C2H2 perturbed by O2 and N2 , 1989 .

[9]  V. Dana,et al.  New improvements in the determination of line parameters from FTS data , 1992 .

[10]  J. Plíva.  Molecular constants for the bending modes of acetylene 12C2H2 , 1972 .

[11]  J. Vander Auwera,et al.  Absolute Intensities Measurements in the ν4 + ν5 Band of 12C2H2: Analysis of Herman-Wallis Effects and Forbidden Transitions , 2000 .

[12]  P. Varanasi,et al.  Diode laser line strength measurements of the (ν4 + ν5)0 band of 12C2H2 , 1984 .

[13]  J. S. Wong.  Pressure broadening of single vibrational-rotational transitions of acetylene at ν = 5 , 1980 .

[14]  Francisco P. J. Valero,et al.  Measurements of nitrogen-broadened line widths of acetylene at low temperatures , 1983 .

[15]  J.-Y. Mandin,et al.  Line intensities in the ? 5 band of acetylene 12C 2H 2 , 2000 .

[16]  P. Varanasi.  Intensity and linewidth measurements in the 13.7 μm fundamental bands of 12C2H2 and 12C13CH2 at planetary atmospheric temperatures , 1992 .

[17]  P L Varghese,et al.  Collisional narrowing effects on spectral line shapes measured at high resolution. , 1984, Applied optics.

[18]  Laurence S. Rothman,et al.  Total internal partition sums in the temperature range 70–3000 K: Atmospheric linear molecules , 1990 .

[19]  Yoshihisa Sakai,et al.  Frequency stabilization of laser diodes using 1.51-1.55 mu m absorption lines of /sup 12/C/sub 2/H/sub 2/ and /sup 13/C/sub 2/ , 1992 .

[20]  B. Lemoine,et al.  Line frequency shifting in the ν5 band of C2H2 , 1998 .

[21]  J.-Y. Mandin,et al.  Line intensities of hot bands in the spectral region of acetylene 12C2H2 , 2001 .

[22]  G. Guelachvili,et al.  The absorption spectrum of C2H2 around ν1 + ν3: energy standards in the 1.5 μm region and vibrational clustering , 1994 .

[23]  V. Chin,et al.  Hydrogen and nitrogen broadening of the lines of C2H2 at 14 μm , 1987 .

[24]  P. Varanasi,et al.  Intensity and half-width measurements in the 1·525 μm band of acetylene☆ , 1975 .

[25]  Laurence S. Rothman,et al.  Reprint of: The HITRAN molecular spectroscopic database and HAWKS (HITRAN Atmospheric Workstation): 1996 edition , 1998 .

[26]  J. Plíva.  Spectrum of acetylene in the 5-micron region , 1972 .

[27]  Alain Barbe,et al.  REIMS HIGH RESOLUTION FOURIER TRANSFORM SPECTROMETER. DATA REDUCTION FOR OZONE , 1995 .

[28]  C. Boulet,et al.  Lineshapes and broadening coefficients in the v5 band of C2H2 in collision with Kr and He , 1991 .

[29]  T. A. Wiggins,et al.  Shapes and Breadths of Some Molecular Rotation‐Vibration Band Lines Perturbed by Rare Gases , 1960 .

[30]  V. Malathy Devi,et al.  Tunable diode laser measurements of N2- and air-broadened halfwidths: lines in the (ν4+ν5)0 band of 12C2H2 near 7.4 μm , 1985 .

[31]  William C. Swann,et al.  Pressure-induced shift and broadening of 1510–1540-nm acetylene wavelength calibration lines , 2000 .

[32]  G. Blanquet,et al.  N2- and O2-broadening coefficients of C2H2 IR lines , 1990 .

[33]  C. F. Curtiss,et al.  Molecular Theory Of Gases And Liquids , 1954 .

[34]  L. Régalia-Jarlot.  Mesures a l'aide d'un spectrometre par transformation de fourier, des intensites et coefficients d'elargissement de molecules d'interet atmospherique. Etude des precisions : application a n#2o, h#2o, o#3 , 1996 .

[35]  Bouanich,et al.  Nitrogen Broadening of Acetylene Lines in the nu5 Band at Low Temperature. , 1998, Journal of molecular spectroscopy.

[36]  B. Lutz,et al.  Pressure broadening and shift coefficients for H2, He and N2 in the 3ν2 band of 12CH3D retrieved by a multispectrum fitting technique , 1999 .

[37]  Toth,et al.  Water Vapor Measurements between 590 and 2582 cm-1: Line Positions and Strengths. , 1998, Journal of molecular spectroscopy.

[38]  N. Ohashi,et al.  0.85-μm Diode laser spectroscopy of 12C2H2 , 1988 .

[39]  Herman,et al.  Ar and Self-Pressure Broadening Coefficient of the R(11), 5;gn3 Line of 12C2H2 , 1997, Journal of molecular spectroscopy.

[40]  F. Pavone,et al.  Sensitive detection of acetylene absorption in the visible by using a stabilized AlGaAs diode laser. , 1993, Applied optics.

[41]  Nathalie Picqué,et al.  A multispectrum fitting procedure to deduce molecular line parameters: Application to the 3-0 band of 12C16O , 2001 .

[42]  V. M. Devi,et al.  A multispectrum nonlinear least squares fitting technique , 1995 .

[43]  A. Barbe,et al.  Multispectrum fitting technique for data recorded by Fourier transform spectrometer: application to N2O and CH3D , 2001 .

[44]  Perevalov,et al.  Application of the Effective Operator Approach to the Calculation of 12C16O2 Line Intensities , 1998, Journal of molecular spectroscopy.

[45]  Anup Sharma,et al.  Pressure-induced self-broadening and frequency shift measurements of absorption lines of acetylene using tunable diode laser absorption spectroscopy , 2001 .

[46]  Yoshihisa Sakai,et al.  Frequency stabilization of laser diodes using 1.51-1.55 μm absorption lines of 12C2H2 and 13C2H2 , 1991 .

[47]  Bouanich,et al.  Inhomogeneous Lineshape Profiles of C(2)H(2) Perturbed by Xe. , 1999, Journal of molecular spectroscopy.

[48]  Daniel Hurtmans,et al.  Laser Spectroscopy of the ν1+3ν3 Absorption Band in 12C2H2(II): Self-Collisional Lineshift Measurements , 1999 .

[49]  Francisco P. J. Valero,et al.  Infrared absorption by acetylene in the 12-14 μm region at low temperatures , 1983 .