Two-Dimensional LCIF Images of Electron Density and Temperature Within an ECR Plasma Cathode

Two-dimensional mappings of electron density and temperature within an electron cyclotron resonance (ECR) plasma cathode are presented. As electron current is extracted, a secondary plasma is formed on the upstream side of the extraction aperture, and the spatial distribution of the ECR plasma is affected. The aperture plasma is surrounded by a region of “hot” electrons, suggesting the possibility of a double layer near the aperture.