Measurement of photoelectron emission by vacuum ultraviolet ray irradiation

Recently, the satellite plays many roles depending on the purpose, including communication, weather observation, astronomy observation and space development. The satellite is requisitioned long life and high reliability in such situation. However, around an altitude of several 100 km, there is Atomic Oxygen (AO) which is a main ingredient agents. AO has high reactivity and its density is about 10(exp 15) atoms/cu m. Because the satellite collides with AO, surface materials of the satellite are deteriorated. As a result, it leads unevenness and oxidation. Accordingly, it is necessary to monitor the surface condition. In this study, photoemission characteristics of several materials, such as metals, glasses and polymers are measured by use of the deuterium lamp and the band path filters. From the measurement the threshold energy for photoemission and the quantum efficiency was evaluated. As a result, the thresholds of samples are 4.9 to 5.7 eV. The quantum efficiency of metals is about 100 times higher than other samples. The quantum efficiency of PS (PolyStyrene) which includes benzene ring is several times higher compared with PP (PolyPropylene) and PTFE (PolyTetraFluoroEthylene). From these results, it is deduced that deteriorated materials may emit large amount of photoelectron.
資料番号: AA0063997015
レポート番号: JAXA-SP-07-030