A Digital Tellurium Atlas For Spectral Calibration, 19000 - 24000 Cm−1

Ross, Amanda J.

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https://hdl.handle.net/2142/116540 Copy

Description

Title

A Digital Tellurium Atlas For Spectral Calibration, 19000 - 24000 Cm−1

Author(s)

Ross, Amanda J.

Contributor(s)

• Clouthier, Dennis
• Smith, Tony
• Cardon, Joseph M.

Issue Date

2022-06-21

Keyword(s)

Linelists

Abstract

We propose a digital record of the absorption spectrum of $^{130}$Te$_2$ vapour as an aid to calibration of laboratory spectra currently referenced to the paper atlas of Cariou and Luc\footnote{Atlas du spectre d'absorption de la mol\'ecule de t\'ellure, Luc \& Cariou, Laboratoire Aim\'e Cotton, CNRS publications, (1980)}. The strong and crowded $A$0${_u^+}$~--$X$0${_g^+}$ bands of Te$_2$ have long provided useful benchmarks for calibration beyond 20000 cm$^{-1}$, where room-temperature $B$~--$X$ I$_2$ absorption cuts off. Molecular tellurium offers more lines per wavenumber than atomic uranium, whose atlas is also useful in this region.\footnote{A uranium atlas, from 365 to 505 nm; Ross $et ~al.$ J Mol Spectrosc \underline{369} 111270 (2020)}. Absorption spectra were recorded through the emission port of a Fourier transform spectrometer, using an external sample and light source. The sample was a sealed, evacuated 10-cm cell containing a small quantity of $^{130}$Te$_2$. The cell was heated to temperatures between 600 and 640 $^{\circ}$C, generating tellurium vapour pressures 8-11 Torr, to produce strong absorption without saturation. Optical filters were used to select 2000 cm$^{-1}$ spectral sections; interferograms were taken at nominal apodized resolution of 0.02 to 0.033 cm$^{-1}$. The pieces were spliced together to cover the range 19000~--~24000 cm$^{-1}$. The wavenumber scale was fine-tuned to match earlier (and sometimes absolute) reference data$^{a}$\footnote{Absolute wavelength determinations in molecular tellurium: new reference lines for precision laser spectroscopy, Gillaspy and Sansonetti, J. Opt. Soc. Am. B 8, 2414 (1991)}$\footnote{Absolute wavenumber measurements in $^{130}$Te$_2$: reference lines in the 420.9 to 464.6-nm region, Scholl $et~al$ J. Opt. Soc. Am. B 22(5), 1128 (2005)}$\footnote{Cavity dispersion tuning spectroscopy of tellurium near 444.4 nm, Coker $et~al$ J. Opt. Soc. Am. B 28 (12), 2934 (2011)}. Measured linewidths of isolated peaks vary from 0.04 to 0.09 cm$^{-1}$, \textit{i.e.} broader than expected from Doppler broadening and instrumental resolution considerations, but we believe the wavenumber scale to be good to $\pm$ 0.005 cm$^{-1}$ . Ascii data files with Te$_2$ transmittance and absorbance data are freely available for download from J. Mol. Spectrosc.,\footnote {Te$_2$ absorption spectrum from 19000 to 24000 cm$^{-1}$, Ross and Cardon, J. Mol. Spectrosc. \underline{384} (2022) 111589} and from the Mendeley database, at https://data.mendeley.com/datasets/kmkbwtjhd3/1.

Publisher

International Symposium on Molecular Spectroscopy

Type of Resource

text

Language

eng

Handle URL

https://hdl.handle.net/2142/116540

DOI

https://doi.org/10.15278/isms.2022.TC11

Copyright and License Information

Copyright 2022 held by the authors

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