Antenna Impedance Measures in a Magnetized Plasma. Part 1. Spherical Antenna

摘要

The input impedance of a metal sphere immersed in a magnetized plasma is measured with a network analyzer at frequencies up to 1 GHz. The experiments were done in the Space Physics Simulation Chamber at the Naval Research Laboratory. The hot-filament argon plasma was varied between weakly (omega sub pe) and strongly (omega sub ce > omega sub pe) magnetized plasma with electron densities in the range 10 sup 7 - 10 sup 10 cm sup -3. It is observed that the lower-frequency resonance of the impedance characteristic previously associated with series sheath resonance omega sub sh in the unmagnetized plasma occurs at a hybrid sheath frequency of omega sub r squared = omega sub sh squared + k omega sub ce squared, with k a constant 0.5.