Incoherent Thomson scattering measurements of electron properties in a conventional and magnetically-shielded Hall thruster

Abstract

Abstract Reliable measurements of electron properties are key for the validation of simulations of Hall thrusters and similar plasma sources. In this paper, a recently-developed incoherent Thomson scattering diagnostic is successfully applied to electron property measurement in a low-power Hall thruster discharge. Investigations of electron properties along radial and azimuthal directions in both conventional and magnetically-shielded architectures are performed. The high diagnostic sensitivity gives access to electron property measurements in a plasma environment with densities as low as <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" overflow="scroll"> <mml:msup> <mml:mrow> <mml:mn>10</mml:mn> </mml:mrow> <mml:mrow> <mml:mn>16</mml:mn> </mml:mrow> </mml:msup> <mml:mspace width="0.25em"/> <mml:msup> <mml:mrow> <mml:mi mathvariant="normal">m</mml:mi> </mml:mrow> <mml:mrow> <mml:mo>−</mml:mo> <mml:mn>3</mml:mn> </mml:mrow> </mml:msup> </mml:math> . Electron temperatures reaching several tens of eV and drift velocities on the order of <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" overflow="scroll"> <mml:mrow> <mml:msup> <mml:mrow> <mml:mn>10</mml:mn> </mml:mrow> <mml:mrow> <mml:mn>6</mml:mn> </mml:mrow> </mml:msup> <mml:mspace width="0.25em"/> <mml:msup> <mml:mrow> <mml:mrow> <mml:mi mathvariant="normal">m</mml:mi> </mml:mrow> <mml:mspace width="0.25em"/> <mml:mrow> <mml:mi mathvariant="normal">s</mml:mi> </mml:mrow> </mml:mrow> <mml:mrow> <mml:mo>−</mml:mo> <mml:mn>3</mml:mn> </mml:mrow> </mml:msup> </mml:mrow> </mml:math> are measured in the exit plane region. The impact of the magnetic field (intensity and direction) and discharge voltage are investigated.