Multispectrum rotational states thermometry

Marangoni, Marco

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https://hdl.handle.net/2142/107611 Copy

Description

Title

Multispectrum rotational states thermometry

Author(s)

Marangoni, Marco

Contributor(s)

• Laporta, Paolo
• Kaenders, Wilhelm
• Leisching, Patrick
• Wilk, Rafal
• Rohde, Felix
• Robinson-Tait, Julian
• Mayzlin, Yuriy
• Puppe, Thomas
• Wojtewicz, Szymon
• Gatti, Davide
• Lamperti, Marco
• Gotti, Riccardo

Issue Date

2020-06-24

Keyword(s)

Mini-symposium: Precision Spectroscopy for Fundamental Physics

Abstract

We introduce Multi-spectrum Rotational States Thermometry (MRST) as a new optical method for primary thermometry that relies on the global fitting of multiple molecular absorption lines of the same band at different pressures. This allows leveraging the temperature-dependence of the Doppler width and also of the distribution of line intensities across the ro-vibrational band, provided a sufficiently accurate line-strength model is available. We give a preliminary demonstration of the method with a comb-locked frequency-swept cavity-ring-down spectrometer operated on the 3$\nu$$_{1}$+$\nu$$_{3}$ band of CO$_{2}$ located around 1577 nm, which stands out among other spectroscopic samples for the availability of several line intensity models of both experimental and theoretical origin. The spectra signal-to-noise ratio represents the main limitation to a combined uncertainty to 510 ppm, but the comparative analysis between different line-strength models shows promise to reduce the error budget to 33 ppm. As compared to Doppler-broadening-thermometry, an advantage of the approach is the reduced impact of a wrong modelling of the absorption line-shapes. In a reversed approach, MRST can be applied on a gas of known temperature to set an upper limit to the accuracy of a given line intensity model.

Publisher

International Symposium on Molecular Spectroscopy

Type of Resource

Text

Language

eng

Permalink

http://hdl.handle.net/2142/107611

Copyright and License Information

Copyright 2020 is held by the Author(s)

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