Correlation of Direct and Remote Measurements on a Hollow Cathode Plasma Discharge

Summary form only given. Results are presented of measurements made on a hollow-cathode-generated plasma using direct and remotely located probes. Based on previous life tests where erosion was observed on hollow cathode assembly components, it is important to characterize the plasma flow field created nearby of hollow cathode discharges. Experimental data are presented of large amplitude plasma potential oscillations. These measurements were made using a floating emissive probe, and potentials ranged from 20 V to 80 V within a 35 V discharge. In addition to the emissive probe, a direct measurement triple Langmuir probe was used to study plasma potential, density, and electron temperature. Data are also presented from an electrostatic analyzer (ESA) that was placed outside of the plasma discharge and used to measure the energy of the ions falling from plasma to the ESA. A model is presented for correlation of the measurements that are made from the direct and remotely located probes.