Influence of ambient environment on dust grains detection by electric field instruments

Abstract

Dust grain impacting the spacecraft body can be either partly or totally evaporated and ionized as well as a small part of spacecraft material. A cloud of charged particles (impact cloud) generated by such impact can consequently influence the spacecraft potential and/or measurements of on-board scientific instruments. Electric field instruments are sensitive to these disturbances and typically register signals generated by dust impacts as short transient pulses. This method is commonly used for the detection of dust grains even without dedicated dust detectors. The presented study is focused on the influence of the ambient environment on dust detection for various designs of electric field instruments (probes/antennas) operating in the monopole and dipole configurations. An ambient plasma influences the spacecraft potential, which is crucial for charge separation and consequent propagation of the impact cloud. The plasma and solitary waves also affect dust detection by the presence of other pulses in the measured data. It is important to understand these effects to compare results obtained by various spacecraft in different environments.