Pressure broadening of rotational bands. I - A statistical theory

Absorption of electromagnetic waves by rotational transitions of molecules is formulated for the case in which the wave frequency is displaced from resonance by an amount large compared to the reciprocal duration of a typical binary collision, and also large compared to the differences between frequencies of the strong resonances of the gas. In this far‐wing limit, Fano’s relaxation operator is reduced to a scalar parameter which depends on the frequency displacement. This relaxation parameter is not symmetric with respect to reflection about resonance, but becomes symmetric when multiplied by the factor exp(ℏωd/2kT) where ωd is the frequency displacement. The theory applies to dipolar molecules of any shape, in collisions with either dipolar or quadrupolar molecules.

[1]  H. Kuhn.  XCIII. Pressure shift and broadening of spectral lines , 1934 .

[2]  Long Range Interactions Between Dipole Molecules , 1937 .

[3]  H. Margenau.  Pressure Broadening in the Inversion Spectrum of Ammonia , 1949 .

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

[5]  G. Herzberg,et al.  Spectra of diatomic molecules , 1950 .

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

[7]  Shang-yi Ch'en,et al.  Broadening and Shift of Spectral Lines Due to the Presence of Foreign Gases , 1957 .

[8]  H. Griem,et al.  Theory of Line Broadening in Multiplet Spectra , 1958 .

[9]  M. Baranger.  GENERAL IMPACT THEORY OF PRESSURE BROADENING , 1958 .

[10]  H. Margenau,et al.  Structure of Spectral Lines from Plasmas , 1959 .

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

[12]  Raymond J. Seeger,et al.  Lectures in Theoretical Physics , 1962 .

[13]  U. Fano.  Pressure Broadening as a Prototype of Relaxation , 1963 .

[14]  M. Strandberg,et al.  Statistical Theory of Spin-Spin Interactions in Solids , 1964 .

[15]  A. Ben-Reuven.  Impact Broadening of Microwave Spectra , 1966 .

[16]  D. L. Huber,et al.  THE ROLE OF BOLTZMANN FACTORS IN LINE SHAPE , 1966 .

[17]  J. E. Boggs,et al.  Collision Broadening of Rotational Absorption Lines. I. Theoretical Formulation , 1967 .

[18]  S. D. Tvorogov,et al.  Formation of the Far Wings Contour of Spectral Lines Broadened by a Foreign Gas; Analysis of Exponential Decrease of Continuous Absorption Beyond the Band Head of the 4.3-micro Band of CO(2). , 1973, Applied optics.

[19]  W. E. Baylis,et al.  Unified Franck-Condon treatment of pressure broadening of spectral lines , 1975 .

[20]  K. Lam.  Application of pressure broadening theory to the calculation of atmospheric oxygen and water vapor microwave absorption , 1977 .

[21]  L. Bonamy,et al.  Far infrared absorption of diatomic polar molecules in simple liquids and statistical properties of the interactions. I. Spectral theory , 1977 .

[22]  George Birnbaum,et al.  The shape of collision broadened lines from resonance to the far wings , 1979 .

[23]  Thomas D. Wilkerson,et al.  Atmospheric Water Vapor , 1980 .

[24]  R. Ballagh,et al.  Collisional redistribution of radiation. I. The density matrix , 1980 .

[25]  R. G. Breene,et al.  Theories of Spectral Line Shape , 1981 .

[26]  R. Nordstrom,et al.  The N2-broadened water vapor absorption line shape and infrared continuum absorption. I - Theoretical development. II - Implementation of the line shape , 1982 .

[27]  C. Boulet,et al.  Short time behavior of the dipole autocorrelation function and molecular gases absorption spectrum , 1982 .

[28]  J. Roberts,et al.  Pressure broadening theory of assymmetric-top molecules using the methods of irreducible tensor operators , 1983 .