Spectral entropy of the microturbulence induced by the electron-drift instability in a Hall thruster with different propellants
- Paper number
IAC-20,C4,IP,4,x56988
- Author
Mr. Rodrigo Alkimim Faria Alves, Brazil, University of Brasilia
- Coauthor
Dr. Rodrigo Andrés Miranda, Brazil, University of Brasilia
- Year
2020
- Abstract
In this work we perform numerical simulations of a SPT-100 Hall thruster with argon and xenon gases as propellants. The simulations were developed using the particle-in-cell method and the Monte-Carlo method for the discretization of particle collisions. The device is represented using two-dimensional cylindrical coordinates by keeping the axial and azimuthal directions and neglecting the radial direction. We identify the growth of a large-amplitude wave in the azimuth electric field and in the density of the ions. These waves are formed due to the $E\times B$ electron drift instability (EDI). The characterization of the frequency and wavelength was made by means of a spectral analysis. We quantify the degree of disorder due to the microturbulence induced by the $E\times B$ EDI by computing the power spectral entropy. Our results demonstrate that the plasma in a Hall propellant exhibits a turbulent behavior with a cascade of energy induced by the EDI instability, and that this turbulence is characterized by an inertial subrange that extends to scales smaller than 1 mm. The power spectral entropy computed using the azimuthal component of the electric field at the end of the acceleration region indicates that the degree of disorder is similar for argon and xenon. Our results show that the power spectral entropy can be a useful tool to characterize the microturbulence observed in Hall thrusters.
- Abstract document
- Manuscript document
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