Plasma chemical reactions initiation in supersonic jets by a high-voltage electron beam

Abstract

The results of the study of processes occurring in supersonic flows of gas mixtures under the influence of high voltage electron beam are presented. The research was performed on the gas-dynamic complex of experimental installations located in the Department of Applied Physics of Novosibirsk State University. Spectral methods and molecular beam mass spectrometry were used to diagnose the processes. A significant difference in the clustered argon mass spectra was found in comparison of spectrum recorded during ionization by a quadrupole mass spectrometer own ionizer and spectrum obtained with the transport of ions formed by an electron beam in the jet through a skimmer to the mass spectrometer detector (without using an ionizer of spectrometer). The second variant of gas flow ionization presents the possibility of registering the mass spectrum of a hydrocarbon series with features indicating the occurrence of heavier hydrocarbons in the jet. The mechanism of intracluster energy exchange with the transfer of excitation initiated by electrons with subsequent intense radiation at certain wavelengths of a neutral argon atom was detected and identified.

Generation of a low-temperature plasma in a nozzle to initiate ion-cluster reactions in jets of mixtures of methane with a buffer gas

“…Experimental studies were carried out on the setup LEMPUS-2 of the Applied Physics Department by the Novosibirsk State University [5]. To detect ions formed in a supersonic flow by a well-focused high-voltage electron beam crossing the jet at a selected distance from the nozzle exit, a diagnostic system was developed and implemented at the facility with the transport of the formed ions to the quadrupole detector of the molecularbeam system by focusing with electrostatic lenses, which are used as a skimmer and collimator [3]. In the present work, this system is adapted for use in the regimes of gas or gas mixture ionization in the diffuser part of a supersonic nozzle.…”

“…Depending on the outflowing gas or gas mixture, the gas-dynamic parameters of the outflow, and the geometrical parameters of the sonic or supersonic nozzle, the proportion of condensate can reach 20-30% of the total volume of the outflowing gas, and the cluster size can vary from two to thousands of particles. This method of cluster generation was used by us in [3] to search for conditions for the initiation of ionmolecular reactions in clusters, as well as in [4] in the formation of cluster ions in supersonic jets of methane and its mixtures with inert gases using a high-voltage electron beam crossing the supersonic jet in the selected section. Thus, we tried to implement a variant of the process in the form: first, the formation of clusters, and then their excitation and ionization to initiate the mechanisms of intracluster energy exchange.…”