Electron transport across a magnetic filter: Magnetic field gradient effects on plasma properties

Abstract

Electron filtering via an external magnetic field barrier is an important issue for volume negative ion production. In this work, we study the plasma properties in an inductively coupled plasma source in the presence of a magnetic filter. Our investigation, conducted through a Langmuir probe, reveals that the magnetic field gradient, i.e., magnetic mirror effect, significantly affects the electron transport. Indeed, our results show that the electron density decreases locally in the tightened magnetic field line region, while the electron temperature is more or less unaffected by the gradient of magnetic field. Moreover, the measurements of plasma potential reveal a nonzero electric field component perpendicular to the magnetic field lines.