N2, O2, H2, Ar and He broadening in the ν1 band of NH3

Abstract N 2 -, O 2 -, H 2 -, Ar- and He-broadening coefficients and pressure shifts have been measured for Q - and R -branch transitions in the ν 1 fundamental band of ammonia using a difference-frequency laser spectrometer. The J - K dependence of the broadening coefficients is much smaller than previously observed for self broadening of NH 3 . Semiclassical line broadening calculations for N 2 broadening are in reasonable quantitative agreement with the data, but they also exaggerate the J - K dependence. Dicke narrowing is observed as strong deviations from Voigt profiles at intermediate pressures and provides estimates for optical diffusion constants which correlate well with the mass diffusion constants for NH 3 in the various buffer gases.

[1]  T. Encrenaz,et al.  Ammonia: Experimental absolute linestrengths and self-broadening parameters in the 1800- to 2100-cm−1 range , 1987 .

[2]  J. Margolis.  Hydrogen broadened half-widths of ammonia , 1975 .

[3]  C. J. Tsao,et al.  Line-widths of pressure-broadened spectral lines , 1962 .

[4]  M. Broquier,et al.  An inelastic rotational transfer study of NH, colliding with H2, and He , 1987 .

[5]  A. S. Pine,et al.  N2 and air broadening in the fundamental bands of HF and HCl , 1987 .

[6]  A. S. Pine,et al.  High-resolution methane ν 3 -band spectra using a stabilized tunable difference-frequency laser system* , 1976 .

[7]  S. Weissman.  Estimation of Diffusion Coefficients from Viscosity Measurements: Polar and Polyatomic Gases , 1964 .

[8]  S. Marchetti,et al.  Self‐broadening and self‐shifting of ammonia lines in the 2ν2 band around 16 μm , 1985 .

[9]  P. Anderson.  Pressure Broadening of the Ammonia Inversion Line by Foreign Gases: Quadrupole-Induced Dipole Interactions , 1950 .

[10]  K. Rao,et al.  Fourier transform and CARS spectroscopy of the ν1 and ν3 fundamental bands of 14NH3 , 1985 .

[11]  J. Margolis,et al.  Low temperature hydrogen broadened linewidths of ammonia in the (0,1,0,0)?(0,0,0,0) band at 200 K. , 1991, Applied optics.

[12]  G. Baldacchini,et al.  A review of experiments and theory for collisional line shape effects in the rotovibrational ammonia spectrum , 1991 .

[13]  A. Pine.  Doppler-limited molecular spectroscopy by difference-frequency mixing* , 1974 .

[14]  M. Broquier,et al.  Pressure broadening and cross relaxation of ammonia perturbed by hydrogen and helium: Implications on intermolecular potentials and discussion of rotational effects , 1988 .

[15]  G. D. Billing,et al.  Fourier transform linewidths measurements in NH3 in the vibrational ground state , 1988 .

[16]  A. Picard-Bersellini,et al.  Linewidths and cross relaxation rates in the rotational inversion doublets of NH3 perturbed by H2 in the infrared , 1985 .

[17]  Koichi M. T. Yamada,et al.  Pressure broadening and lineshifts in the ν2 band of NH3 , 1988 .

[18]  A. Pine,et al.  Linear scan control of tunable lasers using a scanning fabry-perot. , 1979, Applied optics.

[19]  S. L. Srivastava,et al.  Molecular Collision Cross Section Due to Quadrupole‐Induced Dipole and Dipole‐Induced Quadrupole Interactions , 1965 .

[20]  P. Anderson.  Pressure Broadening in the Microwave and Infra-Red Regions , 1949 .

[21]  Josef Humlíček,et al.  An efficient method for evaluation of the complex probability function: The Voigt function and its derivatives , 1979 .

[22]  A. Stogryn,et al.  Molecular multipole moments , 1966 .

[23]  S. Marchetti,et al.  Experimental and theoretical investigation of self‐broadening and self‐shifting of ammonia transition lines in the ν2 band , 1982 .

[24]  P. Varanasi,et al.  Intensities and line shapes in the v2-fundamentals of 14NH3 and 15NH3☆ , 1981 .

[25]  A. Pine.  Self‐, N2, O2, H2, Ar, and He broadening in the ν3 band Q branch of CH4 , 1992 .

[26]  Alan S. Pine,et al.  Self broadening in the v1 band of NH3 , 1993 .

[27]  Giovanni Buffa,et al.  Foreign-gas pressure broadening and shift of ammonia transition lines in the ν2 vibrational bands , 1990 .

[28]  A. F. Krupnov,et al.  Study of microwave pressure lineshifts: Dynamic and isotopic dependences , 1983 .

[29]  B. Bleaney,et al.  The inversion spectrum of ammonia at centimetre wave-lengths , 1947, Proceedings of the Royal Society of London. Series A. Mathematical and Physical Sciences.

[30]  P. Hewitt.  Width and shift measurements in the microwave spectra of NH3, CH3Cl and OCS , 1977 .

[31]  William V. Smith,et al.  Microwave Collision Diameters I. Experimental , 1950 .

[32]  B. Srivastava,et al.  Studies on Mutual Diffusion of Polar‐Nonpolar Gas Mixtures , 1962 .

[33]  Robert L. Legan,et al.  Linewidths of the Microwave Inversion Spectrum of Ammonia , 1965 .

[34]  B. Bleaney,et al.  Collision Broadening of the Inversion Spectrum of Ammonia: III. The Collision Cross-sections for Self-broadening and for Mixtures with Non-polar Gases , 1948 .

[35]  L. Galatry,et al.  Simultaneous Effect of Doppler and Foreign Gas Broadening on Spectral Lines , 1961 .

[36]  Sergei G. Rautian,et al.  Reviews of Topical Problems: the Effect of Collisions on the Doppler Broadening of Spectral Lines , 1967 .

[37]  P. Varanasi.  Shapes and widths of ammonia lines collision-broadened by hydrogen. , 1972 .

[38]  T. Oka,et al.  Pressure Broadening Measurement of the ν 2 [qR − (0,0)] Transition of 15NH3 by a CO2 Laser , 1971 .

[39]  S. Marchetti,et al.  Self‐broadening and self‐shifting of ammonia lines in the 2ν2 band , 1983 .

[40]  F. Meyer,et al.  Absorption measurements using CW MIR NH3 laser , 1986 .

[41]  T. Oka,et al.  Determination of electric dipole moment for the ν2 vibrational state of 15NH3 by infrared-infrared double resonances , 1977 .

[42]  A. F. Krupnov,et al.  The study of microwave pressure lineshifts , 1982 .