Using radio astronomical receivers for molecular spectroscopic characterization in astrochemical laboratory simulations: A proof of concept

TL;DR

This paper demonstrates a novel laboratory setup coupling radio astronomical receivers with chemical reactors to perform molecular spectroscopy and chemical simulations, enabling rapid detection of low-pressure chemical species.

Contribution

It introduces a new method integrating radio telescope technology with laboratory astrochemistry experiments, allowing sensitive and fast spectroscopic analysis of chemical reactions.

Findings

Detected low-pressure chemical species within seconds.

Achieved kinetic measurements of chemical reactions.

Maintained high abundance of reactive species during experiments.

Abstract

We present a proof of concept on the coupling of radio astronomical receivers and spectrometers with chemical reactorsand the performances of the resulting setup for spectroscopy and chemical simulations in laboratory astrophysics. Several experiments including cold plasma generation and UV photochemistry were performed in a 40\,cm long gas cell placed in the beam path of the Aries 40\,m radio telescope receivers operating in the 41-49 GHz frequency range interfaced with fast Fourier transform spectrometers providing 2 GHz bandwidth and 38 kHz resolution. The impedance matching of the cell windows has been studied using different materials. The choice of the material and its thickness was critical to obtain a sensitivity identical to that of standard radio astronomical observations. Spectroscopic signals arising from very low partial pressures of CH3OH, CH3CH2OH, HCOOH, OCS,CS, SO2 (<1E-03 mbar) were detected in a few seconds. Fast data acquisition was achieved allowing for kinetic measurements in fragmentation experiments using electron impact or UV irradiation. Time evolution of chemical reactions involving OCS, O2 and CS2 was also observed demonstrating that reactive species, such as CS, can be maintained with high abundance in the gas phase during these experiments.