The Effects of Magnetic Components on the Cohesion of Lunar Soils

This paper introduces simulated experiments conducted to investigate two major issues related to luna soil behaviors. The first one is related to the electromagnetic properties of lunar soils at microwave frequency (dielectric permittivity, magnetic permeability and electrical conductivity) which aims to identify specific problem that might arise when applying electromagnetic wave based geophysics tools such as Ground Penetration Radar (GPR) for lunar subsurface survey. The second issue investigated is the orginal of cohesion in lunar soils. Measurement of electromagnetic properties is conducted using Time Domain Reflectometry (TDR), which is a guided electromagnetic wave technology. TDR utilizes the propagation of electromagnetic wave to measure material properties. It works by generating a small-magnitude electromagnetic field excitation and measures the material response. By using a fast rising pulse of a few picoseconds by the current electronics, TDR measures the broad frequency band material responses from a few megahertz to gigahertz. A detailed analyses indicated that the magnetic permeability for Ferite Oxide at TDR frequency range is around 7. Magnetic components are believed to attribute to the cohesion in lunar soils. A method to differentiate their contribution to cohesion from other sources such as molecular attractions is if mixing them randomly, the cohesion will disappear due to disturbance of the alignments of these "small magnets". The cohesion will increase, however, as Ferite grains are re-magnetized at their new locations.