Laboratory investigations into the electromagnetic properties of magnetite/silica mixtures as Martian soil simulants

Abstract

In this paper a set of frequency domain (500 Hz to 1 MHz) experimental data on electrical and magnetic parameters of magnetite/silica mixtures as Martian soil simulants is presented. Complex permittivity was obtained by measuring the magnitude and phase of the electrical impedance of a capacitive cell filled with the tested material. Complex magnetic permeability was obtained by measuring the impedance of a toroid fully embedded in the mixtures. Both the permittivity and magnetic permeability exhibited an appreciable increase with the magnetite volume fraction and a complex behavior with grain size and origin. Furthermore, to assess the possibility of extending the data acquired at 1 MHz to higher frequencies (tens to hundreds of MHz), some comparisons were made between these data and Time Domain Reflectometry measurements. Finally, the attenuation versus magnetite volume fraction and frequency (in a band consistent with the MARSIS and SHARAD sounders) was computed for various types of magnetite/silica mixtures. The results indicate that in a dry soil which contains a significant fraction of magnetic material both the wave velocity and the attenuation are a combination of different factors, including the dimension, shape, and origin of the magnetic material.