10:45 AM - 11:00 AM
[PEM10-01] Spacecraft charging simulations of probe B1 of Comet Interceptor - implications for plasma measurements
Keywords:Spacecraft charging, Comet Interceptor, SPIS, Comet, Ion measurements
Spacecraft charging is problematic for low-energy plasma measurements. The charged particles are attracted to, or repelled from, the charged spacecraft surface, resulting in an energy shift and a distortion of the effective field of view of the instrument. In 2019, Comet Interceptor was selected by ESA as a new F-class mission. This mission will visit a dynamically new comet that is yet-to-be-discovered. For the first time, multipoint measurements will be made in the cometary environment using three spacecraft: spacecraft A (ESA), probe B1 (JAXA) and probe B2 (ESA). This will give a new, unique, opportunity to make a three-dimensional study of the plasma environment. The plasma measurements are, however, expected to be affected by the spacecraft potential.
In this study, we use the Spacecraft Plasma Interaction Software (SPIS) to make Particle-In-Cell (PIC) simulations of the expected spacecraft potential of probe B1 of Comet Interceptor. We study the spacecraft potential both in the solar wind and in different regions of the cometary plasma environment during the cometary flyby. This is done for different activity levels of the target comet and at different flyby velocities. At low flyby velocities, the electron current and/or the photoelectron current are dominating the currents to or from the spacecraft surface. However, when the flyby velocity is high, impacts by neutral gas particles cause secondary electron and ion emissions which, in many of the studied environments, result in currents dominating all other currents.
Finally, we use particle tracing to study the expected influence of the spacecraft potential on ion measurements to be made by the Cometary Ion Mass Spectrometer (CIMS) on probe B1.
In this study, we use the Spacecraft Plasma Interaction Software (SPIS) to make Particle-In-Cell (PIC) simulations of the expected spacecraft potential of probe B1 of Comet Interceptor. We study the spacecraft potential both in the solar wind and in different regions of the cometary plasma environment during the cometary flyby. This is done for different activity levels of the target comet and at different flyby velocities. At low flyby velocities, the electron current and/or the photoelectron current are dominating the currents to or from the spacecraft surface. However, when the flyby velocity is high, impacts by neutral gas particles cause secondary electron and ion emissions which, in many of the studied environments, result in currents dominating all other currents.
Finally, we use particle tracing to study the expected influence of the spacecraft potential on ion measurements to be made by the Cometary Ion Mass Spectrometer (CIMS) on probe B1.