Photoelectron emission from a polymer surface irradiated by oxygen ions

A satellite is required to have a long life and high reliability. However, a lot of atomic oxygen (AO), an erosive agent, is present at an altitude of several 100 km. Accordingly, it is necessary to monitor the degradation degree of the materials used on the satellite surface. In this study, to characterize the surface properties, photoelectron emission characteristics of several polymers were measured using a deuterium lamp and the band path filters. In addition, PE (Polyethylene) irradiated by oxygen ions was measured. From the measurement, the threshold energy for electron emission and its quantum efficiency were evaluated. As a result, the threshold energy of polymers was about 6 eV. The magnitude of PE irradiated by oxygen ions was not remarkably changed, but irradiation did increase its quantum efficiency. To clarify the mechanism of the phenomenon, an XPS (X-ray Photoelectron Spectroscope) and an AFM (Atomic Force Microscope) were used to analyze chemical bonds at the surface introduced by ion irradiation and surface roughness. The result shows that chemical bonds including oxygen atoms play an important role.