Effects of vertical stress, temperature and density on the dielectric properties of lunar samples 72441,12, 15301,38 and a terrestrial basalt

Abstract

The dielectric properties of lunar soil samples 72441,12 and 15301,38 have been measured as a function of vertical stress to 2 bars, temperature to 200°C and density, in vacuum, over the frequency range 200–10 5 Hz. It was found that the dielectric constant varies not only with density, but also with stress at constant sample density. The loss tangent was found to be insensitive, within experimental limits, to both stress and density variations over the ranges measured. A solid terrestrial basalt sample has been ground and the dielectric properties of the powder and a remaining portion of the solid sample have been measured in vacuum. The measured dielectric constants for the basalt soil at different densities are compared with calculated values using the solid sample data in conjunction with the Lichtenecker, Rayleigh and Krotikov-Troitskiy mixing formulas. Qualitative behavior of the dielectric properties of the lunar regolith with depth is discussed.