Measurement Principle
The MEFISTO (Mercury Electric Field In-Situ Tool) (Kasaba et al. 2020a; Karlsson et al. 2020) consists of two wire booms with deployment units installed on the lower deck of the spacecraft and a control unit MEFISTO-E installed on the PME chassis. Each MEFISTO-S unit consists of an extendable boom with a preamp box, a conductive short wire, and a sphere at the top. The preamp box is situated at the end of the extendable boom and is exposed to the space. Its thermal design was one of the greatest challenges of the MEFISTO-S. A short wire (length: 1.5 m) with a sphere is deployed from the preamp box. By installing a guard electrode on the preamp chassis, the MEFISTO is optimized for DC and lower frequency ranges in which the antenna is resistively coupled to the surrounding plasma. The output of the MEFISTO-preamp is sent to the EWO and SORBET receivers via MEFISTO-E inside of the PME chassis. Within the MEFISTO deployment boom on the lower deck, a current probe (AM2P-S) is installed for mutual-impedance measurement of the antenna.
Members
- Co-Principal Investigator
- Jan-Erik Wahlund (IRFU, Sweden)
- Lead Co-Investigator
- Tomas Karlsson (KTH, Sweden)