Plasma diagnosis of an unclosed E × B drift thruster with a visible ionization zone

Abstract

Traditional annular closed-loop E×B drifting Hall thruster is limited by the compact structure. Two-dimensional (2D) distribution of the plasma parameters inside the discharge channel cannot be accurately measured directly hindering further understanding of discharge process. In this paper, it is proposed to employed the Unclosed E×B Drift Thruster with visible ionization zone (UDTv) to conduct research about effect of the crossed electric field and magnetic field on the plasma distribution inside the discharge channel. Experiment showed UDTv presented discharge similar to Hall thruster, especially the low-frequency oscillation related to discharge voltage. A 2D symmetrically crescent-shaped distribution of plasma inside the channel with a hollow zone located near the maximum of the magnetic field was clearly captured by optical imaging and emission spectrometer. Correlation between the location of maximal magnetic gradient and the 2D ionization zone configuration was verified. Decreased magnetic mirror effect at the location of maximum magnetic field enhanced electron-wall interaction inducing near-wall conduction and secondary electrons emission. Electron temperature presented a canyon distribution resulting in a bimodal configuration of the plasma density. Increased flowrate lowered the ionization inside the channel and transformed the plasma distribution into unimodal structure because of enhanced electron conduction and lower electron temperature. Generally, the feasibility to capture the correlation between 2D plasma distribution and magnetic field inside the discharge channel was successfully demonstrated proposing new ideas for further research about internal plasma of Hall thruster.

A wearable nanoscale heart sound sensor based on P(VDF-TrFE)/ZnO/GR and its application in cardiac disease detection

“…The piezoelectric coefficient ( d 33 ) is a crucial parameter for assessing the performance of piezoelectric devices. A higher value of the piezoelectric coefficient signifies superior device performance [ 34 ]. In the context of energy harvesting from piezoelectric films, Equation 2 defines the relationship between the relative charge ( Q ) generated on the surface of the piezoelectric material, with an area ( S ), and the applied mechanical stress (Δ F ) [ 35 ]:…”