Shifts and broadening in the CN A 2Π− X 2Σ+ (2-0) band induced by argon collisions

Lockhart, James

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https://hdl.handle.net/2142/100526 Copy

Description

Title

Shifts and broadening in the CN A 2Π− X 2Σ+ (2-0) band induced by argon collisions

Author(s)

Lockhart, James

Contributor(s)

• Hall, Gregory
• Sears, Trevor

Issue Date

2018-06-18

Keyword(s)

Linelists, Lineshapes, Collisions

Abstract

Selected P-and R-branch transitions of the CN A 2Π−X 2Σ + (2-0) band have been recorded at room temperature as a function of argon pressure, using frequency modulation spectroscopy. The experimental line shapes have been successfully fit using a Quadratic Speed-Dependent Voigt (QSDV) model at total pressures ranging from 1 - 160 Torr. The pressure broadening coefficients derived from the QSDV analysis are nearly independent of the rotational quantum state and rotational branch. The pressure-dependence of the line shifts, in contrast, displays a distinctive variation with rotational state and branch, with larger and strongly J-dependent shifts for P-branch lines, compared to smaller and more J-independent shifts for R-branch lines. The pressure-induced shifts provide a challenge to first principles scattering calculations on validated potential energy surfaces. Previously puzzling measurements on fewer lines in the (1-0) band are confirmed and extended by the present measurements. Work at Brookhaven National Laboratory was carried out under Contract No. DE-SC0012704 with the U.S. Department of Energy, Office of Science, and supported by its Division of Chemical Sciences, Geosciences and Biosciences within the Office of Basic Energy Sciences.

Publisher

International Symposium on Molecular Spectroscopy

Type of Resource

text

Language

eng

Permalink

http://hdl.handle.net/2142/100526

DOI

10.15278/isms.2018.MI10

Copyright and License Information

Copyright 2018 James Lockhart

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