Improving The Sensitivity Of Chirped-pulse Fourier Transform Mm-wave Detection In Uniform Supersonic Flows

Abdelkader Khedaoui, Omar

Permalink

https://hdl.handle.net/2142/111304 Copy

Description

Title

Improving The Sensitivity Of Chirped-pulse Fourier Transform Mm-wave Detection In Uniform Supersonic Flows

Author(s)

Abdelkader Khedaoui, Omar

Contributor(s)

• Sims, Ian R.
• Drissi, Myriam
• Gupta, Divita
• Guillaume, Theo
• Hearne, Thomas Sandow
• Cooke, Ilsa Rose
• Hays, Brian M

Issue Date

2021-06-22

Keyword(s)

Instrument/Technique Demonstration

Abstract

The CPUF (Chirped Pulse in Uniform supersonic Flow) technique is a combination of the CRESU (Cinétique de Réaction en Ecoulement Supersonique Uniforme, or Reaction Kinetics in Uniform Supersonic Flow) technique to provide a very low temperature (down to 5 K) gas-phase collisional environment with chirped pulse Fourier transform mm-wave/microwave (CPFTMW) spectroscopic detection. The goal of the current CRESUCHIRP project is to determine branching ratios of astrochemically relevant bimolecular reactions at low temperatures using the CPUF technique. Two new CPFTMW spectrometers have been built and characterized in the Ka band (26.5-40 GHz) and the E-band (60-90 GHz). While reaction products have been successfully detected at temperatures down to 10 K in continuous CRESU flows in Rennes, the sensitivity of the CPFTMW technique is reduced by collisional broadening in the relatively high pressure CRESU flows. Reducing the collisional frequency rate is critical, and one of the methods that have been developed to achieve this aim is molecular beam sampling of the uniform flow via a skimmer to create an expansion into a much higher vacuum environment where both the temperature and pressure of the gas will be lowered, creating favorable conditions for the detection of the molecular signal. The latest results from these experiments will be presented.

Publisher

International Symposium on Molecular Spectroscopy

Type of Resource

Text

Language

eng

Permalink

http://hdl.handle.net/2142/111304

DOI

10.15278/isms.2021.TI09

Owning Collections