Duration: 12 months
The comprehensive mitigation of dust in space missions such as those on the Moon and Mars is a tremendously complicated problem. Dust sticking on surfaces has been recognized by ESA as one of the Critical Technologies in its Global Exploration Roadmap 2022 [1]. What makes this problem so complicated? First it is the physical aspect: dust is irregular in shape, size and surface morphology. Dust particles size can range from tens of nanometers to hundreds of microns. Their shape is far from being spherical and their surface can be smooth, porous etc. When dealing with these differences, some spanning several orders of magnitude, it is clear that a comprehensive solution is problematic. Also, to make matters worse the chemical composition can be different from grain to grain and therefore their density is not uniform. Their electrostatic properties can vary, from dielectric to conductor and so is the electron secondary emission which significantly affects the charging state of dust. This last feature can also modify dust adherence to surfaces. The scope of this project is to provide a proof of concept for a new type of technology for removing dust off surfaces based on the use of a pulsed electron beam “pencil”. A focused beam of electrons with a spot size ~10 mm, with energy in the KeV range and total current of ~ mA per pulse will be employed to clean surfaces made of a variety of materials such as glass, metals, fabric and rubbers. The frequency of the pulsed beam can be tuned (10’s Hz), while the pulse duration is 40 us. Our approach is based on the momentum imparted by the energetic electrons to the dust particles rather than on their charging and lofting above the surface. This a completely new approach for cleaning surfaces which is decoupled from the charging state of dust particles. Most of the known cleaning methods presented in the literature, including some employing electron beams with lower energy (i.e., ~100 eV) rely on the induced charging of dust.
