Carbon/graphene foils: a critical subsystem for plasma instruments in space

Abstract:

Thin carbon foils play a critical role in the time-of-flight (TOF) and charge conversion subsystems used in many of the plasma sensors developed for space. These instruments take advantage of properties of the particle-foil interaction: charge conversion of neutral atoms and/or secondary electron emission. This interaction also creates several adverse effects for the projectile exiting the foil, such as angular scattering and energy straggling, that usually act to reduce the sensitivity and overall performance of an instrument. The magnitude of these effects varies with the incident angle, energy, and mass of the incoming projectile and the foil thickness. The thinnest foils flown typically have a nominal thickness (as specified by the manufacturer) of ~0.5 – 1 µg cm^-2. In this presentation, we will summarize several studies that have quantified the properties of ions exiting the thin carbon foil and discuss recent work on graphene foils, a promising new technology that may be capable of mitigating the undesirable effects associated with these interactions.