Files in this item

FilesDescriptionFormat

application/vnd.openxmlformats-officedocument.presentationml.presentation

application/vnd.openxmlformats-officedocument.presentationml.presentation1265049.pptx (10MB)
PresentationMicrosoft PowerPoint 2007

application/pdf

application/pdf3447.pdf (22kB)
AbstractPDF

Description

Title:PRIMARY THERMOMETRY FROM A CO2 OVERTONE LINE VIA COMB-ASSISTED CAVITY-RING-DOWN SPECTROSCOPY
Author(s):Gotti, Riccardo
Contributor(s):Marangoni, Marco; Gianfrani, Livio; Laporta, Paolo; Galzerano, Gianluca; Castrillo, Antonio; Gatti, Davide; Moretti, Luigi
Subject(s):Mini-symposium: Frequency-Comb Spectroscopy
Abstract:We provide the most accurate absolute temperature measurement ever performed on an atomic or molecular sample with a Doppler-Broadening-Thermometry approach. Specifically, the absorption profile of the P$_e$(12) line of the (30012) - (00001) band of a \chem{CO_2} sample at thermodynamic equilibrium is accurately measured at 1.578 $\mu$m by a comb-assisted cavity-ring-down spectrometer that combines an extremely dense frequency axis (3000 points over 4.2 GHz) with an acquisition time as low as a few seconds. The Doppler width is extracted from a refined multi-spectrum fitting procedure accounting for the speed dependence of the relaxation rates, which were found to play a role even at the very low pressures explored, from 1 to 7 Pa. The thermodynamic gas temperature is retrieved with relative uncertainties of 8·10$^{-6}$ (type A) and 11 ·10$^{-6}$ (type B), which rank the system at the first place among optical methods. Thanks to a measurement time of only ~5 h, the technique represents a promising pathway towards the optical determination of the thermodynamic temperature with a global uncertainty at the 10$^{-6}$ level \footnote{Gotti R., Moretti L., Gatti D., Galzerano G., Castrillo A., Laporta P., Gianfrani L., and Marangoni M., Phys. Rev. A 97, 12512 (2018)}. An additional element of interest derives from the forthcoming redefinition of the unit Kelvin \footnote{J. Fischer, Phil. Trans. R. Soc. A 374, 20150038 (2016)}, in 2018, which calls for primary thermometers that are capable to operate over a large part of the temperature scale with very high accuracy.
Issue Date:06/20/18
Publisher:International Symposium on Molecular Spectroscopy
Citation Info:APS
Genre:Conference Paper / Presentation
Type:Text
Language:English
URI:http://hdl.handle.net/2142/100454
DOI:10.15278/isms.2018.WG05
Other Identifier(s):WG05
Date Available in IDEALS:2018-08-17
2018-12-12


This item appears in the following Collection(s)

Item Statistics