Line by line calculation of spectra from diatomic molecules and atoms assuming a voigt line profile

Abstract A computer program is described that predicts the spectra resulting from electronic transitions of diatomic molecules and atoms. The program produces a spectrum by accounting for the contributions from all the individual rotational and atomic lines considered in the calculations. The integrated intensity of each line is distributed in the spectrum by an approximate Voigt profile. The program can produce spectra for either optically thin gases or for cases where simultaneous emission and absorption occur. The method allows calculations ranging from the absorption of incident radiation by a column of cold gas to the high temperature self-absorbed emission spectrum from a nonisothermal gas. The computed spectrum can be output directly and, if desired, the predicted output of a grating spectrograph or a fixed wavelength radiometer can be generated, including instrumental broadening and sensitivity. Several examples illustrating the versatility of the program are presented. Information is given which will enable the reader to acquire a copy of the program and a paper containing instructions for its usage.

[1]  R. Landshoff,et al.  Quantitative Molecular Spectroscopy and Gas Emissivities , 1959 .

[2]  R. W. Nicholls,et al.  A study of emissivities and transition probabilities of diatomic molecules in optically thick hot gases with applications to the B1∑−X1∑transition of BeO , 1967 .

[3]  A. Schadee.  The relation between the electronic oscillator strength and the wavelength for diatomic molecules , 1967 .

[4]  D. Ramsay,et al.  An Extension of the Phillips System of C_{2} and a Survey of C_{2} States. , 1963 .

[5]  T. Teichmann,et al.  Introduction to physical gas dynamics , 1965 .

[6]  A. Douglas,et al.  The Spectrum of the CN Molecule. , 1955 .

[7]  J. G. Phillips,et al.  The red system (A2Π-X2Σ) of the CN molecule , 1963 .

[8]  Wolfgang L. Wiese,et al.  ATOMIC TRANSITION PROBABILITIES. VOLUME 1. HYDROGEN THROUGH NEON , 1966 .

[9]  G. Herzberg,et al.  Molecular Spectra and Molecular Structure: I. Spectra of Diatomic Molecules , 1944 .

[10]  Lester T. Earls.  Intensities inΠ2−Σ2Transitions in Diatomic Molecules , 1935 .

[11]  L. Wallace.  Band-Head Wavelengths of C_{2}, ch, cn, co, nh, no, 02, oh, and Their Ions. , 1962 .

[12]  Ellis E. Whiting,et al.  An empirical approximation to the Voigt profile , 1968 .

[13]  G. Poletto,et al.  TheA2Π andX2Σ states of the CN molecule from the berkeley analysis of the CN red system , 1965 .

[14]  A. Fairbairn.  Self-absorption in molecular spectra: Curves of growth for C2 and CN , 1966 .

[15]  R. J. Spindler,et al.  Franck-Condon factors based on RKR potentials with applications to radiative absorption coefficients , 1965 .