Dust removal from a variety of surface materials with multiple electron beams

Abstract

Dust mitigation is one of the technical challenges to overcome for future lunar surface exploration. In our previous work, a new electron beam (e-beam) mitigation technology was introduced to remove dust particles from protected surfaces through an electrostatic mechanism developed based on a Patched Charge Model. This model shows that the emission and re-absorption of e-beam induced secondary electrons inside microcavities between dust particles can result in large charges on the particles and their subsequent ejections from the surface due to strong repulsive forces. It was shown that, due to random orientations of microcavities, varying the e-beam incident angle by rotating the sample surface can cause more microcavities to be exposed, thereby improving the cleaning effectiveness. In this paper, we present and test a new configuration to implement varying the beam angle. Here multiple e-beam sources are aimed at different angles simultaneously at a sample surface that is fixed in place. A large variety of surface material samples are tested to demonstrate the e-beam technology's application scenarios, including both insulating samples (spacesuit, glass, a photovoltaic (PV) panel, Kapton tape, thermal blanket and anodized aluminum) and a conducting sample (aluminum). It is shown that the multiple e-beam source configuration improves cleaning effectiveness by 10–30% in comparison to a single fixed beam and sample. Most of the insulating samples achieve 80–90% cleanliness after only the 2–3 min beam exposure, except for the PV panel that shows 50% cleanliness. The conducting aluminum sample shows relatively low cleanliness at 35–45% likely due to the attractive Coulomb mirror force between the charged dust and aluminum surface. Finally, various e-beam configurations are suggested depending on application scenarios.