Role of gas flow on plasma stream dynamics in a pulsed plasma accelerator

• Published in: Fusion engineering and design 2021-07, Vol.168, p.112400, Article 112400
• Main Authors: Borthakur, S., Ahmed, A., Singha, S., Neog, N.K., Borthakur, T.K.
• Format: Article
• Language: English
• Subjects: Argon; Electromagnetic gas injection valve; Flux density; Gas flow; Gas injection; Gases; Mass flow rate; Plasma; Plasma stream energy density; Plasma stream velocity; Pressure sensors; Pulsed plasma accelerator; Substrates
• ISSN: 0920-3796; 1873-7196
• DOI: 10.1016/j.fusengdes.2021.112400

•Effect of gas flow due to gas injection valve on the plasma stream velocity and energy density in Pulsed Plasma Accelerator.•Analytical study to understand the relation between plasma parameters and the mechanism of gas flow.•Plasma stream of velocity seems to increase beyond the electrode region.•The fraction of gas particles ionised by the system has various effects on the flow velocity.•A range of energy density of the plasma stream are estimated for different gases. The effect of gas injection on the plasma in a pulsed plasma accelerator is important to determine the plasma stream velocity. Thereafter, the Plasma Surface Interaction and related issues during transient heat loading to a substrate depends on the mass flow rate and subsequent plasma stream velocity. In this work, the dependence of plasma stream velocity with the gas injection are analysed numerically in different gases such as Argon, Nitrogen, Helium and Hydrogen. The mass flow rates of the gases and their Alfven velocities with respect to the plasma-inherent magnetic field are determined. The quantity of gas inserted determines the working pressure of the system which, is dynamic in nature due to the prolonged insertion of gas throughout the discharge. The gas distribution profile of the injected gas obtained experimentally, using a piezo-resistive pressure probe, has been used in this analysis to obtain a plasma stream profile. Finally, the plasma stream energy density is calculated to relate the plasma parameters with that of Type-I Edge Localised Modes of ITER (International Thermonuclear Experimental Reactor) like tokamak.