Caractérisation électromagnétique de matériaux non usinables. Application a l'étude d'éclats de météorites

National audienceRadiometric measurements in microwave frequency range and submillimeter have been performed on an asteroid, S. Gulkis (JPL) and the team MIRO (Microwave Instrument on the orbiter of the spacecraft Rosetta comet), will study the physicochemical characteristics of this asteroid. However, this requires a good understanding of the complex dielectric constant of these objects. It could be specified by microwave measurements in laboratory. The team recently received meteoritic samples (Antarctica), whose composition is similar to that of an asteroid crossed by "Rosetta" in September 2008. Dielectric measurements are performed by the team CEMT (electromagnetic characterization and Remote Sensing) IMS Laboratory (UMR 5218). The samples of meteorites are very rare and can not be machined. A measurement method has been developed at IMS laboratory. The work that we describe in this paper deal with a new measurement method using a resonant cavity that we apply at L and S band. It allows measurements on samples of any shape wich can have a high permittivity