Plasma and Fusion Research

Volume 20, 1406032 (2025)

Regular Articles

Investigation of the Compositional Effect of Mixed Gas of Heavy and Light Gas Species on the Parameters of Mixed Plasma Driven by Pulsed Power Discharge
L. Malith M. De SILVA1), Taichi TAKEZAKI2), Kazumasa TAKAHASHI1), Takashi KIKUCHI1), Toru SASAKI1)
1)
Nagaoka University of Technology, Nagaoka, Niigata 940-2137, Japan
2)
University of Toyama, Gofuku, Toyama 930-8555, Japan
(Received 4 October 2024 / Accepted 22 April 2025 / Published 24 June 2025)

Abstract

A pulsed power discharge experiment was conducted to investigate the compositional effect on plasma parameters of a mixed gas plasma of argon (Ar) and helium (He) gases as the heavy and light species, respectively. As the plasma parameters, electron temperature, drift velocity, and ion density were estimated for different compositions of Ar and He. Electron temperature and drift velocity were estimated by line-pair and time-of-flight methods, respectively. Ion density was estimated by Faraday cup method. Line-pair method results obtained by Ar lines and He lines at each composition show that Ar and He are in different partial local thermal equilibrium (PLTE) states in the mixed gas. Different relaxation times between different atomic species confirm the deviation of LTE. Similar drift velocity estimated by Ar and He lines separately at each composition shows that the plasma is a homogenous mixture. Drift velocity decreases as the increment of the Ar percentage in the mixture since the average mass of the mixture increases.

Keywords

pulsed power discharge, solar wind, mixed gas plasma, partial local thermal equilibrium, relaxation time of elastic collisions

DOI: 10.1585/pfr.20.1406032

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