Analysis of the absorption profiles of the collision-induced fundamental band of H₂ in H₂-Xe, H₂-Kr and H₂-Ar mixtures

Ghosh, Sambhunath (1971) Analysis of the absorption profiles of the collision-induced fundamental band of H₂ in H₂-Xe, H₂-Kr and H₂-Ar mixtures. Masters thesis, Memorial University of Newfoundland.

[English] PDF (Migrated (PDF/A Conversion) from original format: (application/pdf)) - Accepted Version Available under License - The author retains copyright ownership and moral rights in this thesis. Neither the thesis nor substantial extracts from it may be printed or otherwise reproduced without the author's permission. Download (2MB) [English] PDF - Accepted Version Available under License - The author retains copyright ownership and moral rights in this thesis. Neither the thesis nor substantial extracts from it may be printed or otherwise reproduced without the author's permission. (Original Version)

Abstract

The collision-induced fundamental infrared absorpbion band of H₂ was studied at room temperature with an absorption cell of sample path length 105.2 cm in binary mixtures of para H₂ as well as normal H₂ with Xe, Kr, and Ar. The base density of H₂ (para or normal) was in the range 4-10 amagat, and the densities of Xe, Kr, and Ar were in the ranges 10 - 70 amagat, 10 - 135 amagat and 10 - 100 amagat, respectively. The prominent feature of the Q branch of the band observed in binary mixtures of pH₂ with all the three perturbing gases is that two dips occur at the Raman frequencies of Q(0) and Q(2) of the low pressure hydrogen gas. The Q branch of pH₂-Xe and that of nH₂-Xe exhibit anomalous intensity distribution, namely, that the Qp and QR peaks show equal intensities. -- Profiles for the enhancement of absorption were analyzed by a computational procedure. The quadrupolar components, obtained with para as well as normal H₂, were assumed to have a Boltzmann-modified dispersion line form. The characteristic half-widths δ of the quadrupolar lines in each of the binary mixtures were obtained from the analysis. The present profile analysis reveals that the quadrupolar components show shifts of 9 cm⁻¹ in p(or n)H₂-Xe and 6 cm⁻¹ in p(or n)H₂-Kr toward lower frequency from the corresponding Raman frequencies of the low pressure gas; it also shows that there is no shift of the quadrupolar components in p(or n)H₂-Ar. The contributions of the quadrupolar and overlap interactions to the total intensity of the band were derived from the analysis of the profiles in each of the binary mixtures, nH₂-Xe, nH₂-Kr, and nH₂-Ar. -- The overlap profiles obtained from the analysis of the experimental profiles of nH₂-foreign gas mixtures were analyzed by a new computational procedure. The line-shape assumed for each of the overlap components consists of two functions; one, the Fourier transform of the intercollisional correlation function given by Van Kranendonk (1968) and the other, the Fourier transform of the intracollisional correlation function given by Levine and Birnbaum (1967). The values of the characteristic inter- and intra-collisional width parameters, δD and δW, respectively, were derived from the analysis. -- The binary and ternary absorption coefficients of the band for nH₂-Ar, nH₂-Kr, and nH₂-Xe were derived. The binary absorption coefficients of the S(0) quadrupolar line, obtained from the profile analysis, were used to calculate the Lennard-Jones molecular diameters a for H₂-Kr and H₂-Xe molecular pairs.

Actions (login required)

View Item