Measurement of Plasma Resistivity at ELF

Abstract

The mutual-impedance (MI) technique can be used to used to measure the resistivity of space plasmas down to frequencies of a few hundred hertz. We outline the physics and technology of an MI probe designed for this purpose, and present the results from a rocket experiment in the auroral ionosphere. Though certain features of the data are hard to interpret, most of the results are consistent with normal resistivity, not modified by plasma turbulence. They suggest, however, that jointly with accurate instruments for electron density and temperature and for ion composition, a probe of this kind would be able to detect anomalous resistivity.