In this work, we study the non-radiative energy relaxation rate of methane isotopologues in the mid-infrared spectral range, at about 7.719 μm. We exploited quartz-enhanced photoacoustic spectroscopy to measure the photoacoustic signal at different pressures, exploiting several custom quartz tuning forks operating in the range from 3 to 16 kHz. For each isotopologue the relaxation time in a matrix of water vapor and nitrogen was retrieved, to evaluate the effect of water vapor as an energy relation promoter. Moreover, mixtures composed of 12CH4 and 13CH4, with concentration ratios different from the natural abundance, in a matrix of water vapor and nitrogen were analyzed.
Measurement of the methane isotopologues relaxation rate exploiting quartz-enhanced photoacoustic spectroscopy
Olivieri M.
;Sukhinets A.
;Di Gioia M.
;Elefante A.
;Zifarelli A.
;Patimisco P.
;
2022-01-01
Abstract
In this work, we study the non-radiative energy relaxation rate of methane isotopologues in the mid-infrared spectral range, at about 7.719 μm. We exploited quartz-enhanced photoacoustic spectroscopy to measure the photoacoustic signal at different pressures, exploiting several custom quartz tuning forks operating in the range from 3 to 16 kHz. For each isotopologue the relaxation time in a matrix of water vapor and nitrogen was retrieved, to evaluate the effect of water vapor as an energy relation promoter. Moreover, mixtures composed of 12CH4 and 13CH4, with concentration ratios different from the natural abundance, in a matrix of water vapor and nitrogen were analyzed.I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.
