Work

Generation of seed electrons in guided ionization waves in He–O2 mixtures: The effect of negative ion cluster formation

Year: 2024

Type: article

Abstract: The kinetics of electrons and negative ions was numerically studied under the conditions, which are typical for multi-pulsed guided ionization waves in He flows ejected into ambient air. It was shown that, in He with a small admixture of O2 or air, O2− ions formed due to three-body electron attachment in the discharge afterglow are rapidly converted to O4− cluster ions in pulse off time. We suggested that seed electrons are generated at the leading edge of a pulse in two steps, and these steps are dissociation of O4− ions to form O2− ions followed by electron detachment from the O2− ions. The rate of O4− dissociation was calculated in He–O2 mixtures for various reduced electric fields on the basis of a Monte Carlo simulation. This rate, as well as the rate of electron detachment from O2− ions calculated previously, was used to simulate seed electron generation in a high-voltage nanosecond pulse in He–O2 mixtures for different gas pressures. It was shown that the formation of O4− ions drastically hinders the generation of seed electrons in multi-pulsed guided ionization waves in He–O2 and He–air mixtures.

Source: Physics of Plasmas

DOI: 10.1063/5.0222343

Authors: N. L. Aleksandrov, A. A. Ponomarev, A. A. Syssoev

Institutions: National Research University Higher School of Economics, Russian Academy of Sciences, Institute of Applied Physics, Privolzhsky Research Medical University

Language: English

Topic: Plasma Applications and Diagnostics

Subfield: Radiology, Nuclear Medicine and Imaging

Field: Medicine

Domain: Health Sciences

Open Access status: hybrid

Funder: Russian Science Foundation

Award: G170339875