To reduce the impact of charging effects on satellites, cheap and lightweight
conductive coatings are desirable. We mimic space-like charging environments in
ultra-high vacuum (UHV) chambers during deposition of charges via the electron
beam of a scanning electron microscope (SEM). We use the charge induced
signatures in SEM images of a thin ionic liquid (IL) film on insulating
surfaces such as glass, to assess the general performance of such coatings. In
order to get a reference structure in SEM, the samples were structured by
nanosphere lithography and coated with IL. The IL film (we choose BMP DCA, due
to its beneficial physical properties) was applied ex situ and a thickness of
10 to 30 nm was determined by reflectometry. Such an IL film is stable under
vacuum conditions. It would also only lead to additional mass of below 20
mg/m2. At about 5 A/m2β3β 1019 e/(sβ m2), a typical
sample charging rate in SEM, imaging is possible with no noticeable contrast
changes over many hours; this electron current density is already 6 orders of
magnitudes higher than "worst case geosynchronous environments" of
3β 10β6 A/m2. Measurements of the surface potential are used for
further insights in the reaction of IL films to the electron beam of a SEM.
Participating mechanisms such as polarization or reorientation will are
discussed.Comment: Submitted to Proceedings of the 14th IAA Symposium on Small
Satellites for Earth System Observatio