A new instrument for kinetics and branching ratio studies of gas phase collisional processes at very low temperatures

A new instrument dedicated to the kinetic study of low-temperature gas phase neutral-neutral reactions, including clustering processes, is presented. It combines a supersonic flow reactor with vacuum ultra-violet synchrotron photoionization time-of-flight mass spectrometry. A photoion-photoelectron coincidence detection scheme has been adopted to optimize the particle counting efficiency. The characteristics of the instrument are detailed along with its capabilities illustrated through a few results obtained at low temperatures (<100 K) including a photoionization spectrum of n-butane, the detection of formic acid dimer formation, and the observation of diacetylene molecules formed by the reaction between the C2H radical and C2H2.

Automated summary

A new instrument dedicated to studying low-temperature gas phase neutral-neutral reactions has been introduced, combining a supersonic flow reactor with vacuum ultra-violet synchrotron photoionization time-of-flight mass spectrometry. The instrument utilizes a photoion-photoelectron coincidence detection scheme to optimize particle counting efficiency, and its capabilities have been demonstrated through a variety of results obtained at low temperatures, such as the photoionization spectrum of n-butane, detection of formic acid dimer formation, and observation of diacetylene molecules formed by specific reactions.