Protection of materials from O-atom collision in low earth orbit using thin oxide film growth in space

宇宙の低地球軌道における酸素原子衝突から酸化物薄膜を用いた物質保護

横田 久美子*; 吉越 章隆 ; 寺岡 有殿; 神田 一浩*; 古山 雄一*; 松本 康司*; 田川 雅人*

Yokota, Kumiko*; Yoshigoe, Akitaka; Teraoka, Yuden; Kanda, Kazuhiro*; Furuyama, Yuichi*; Matsumoto, Koji*; Tagawa, Masahito*

In this study, the hydrogenated diamond-like carbon (DLC) film was tested as the candidate for the next generation space lubricant. The atomic oxygen (AO) environment in the low Earth orbit (LEO) was achieved in a laboratory by a laser-detonation AO beam source which could provide collision energy as high as 5 eV. Real-time mass-loss measurement and chemical analysis of the surfaces after the hyperthermal AO beam exposure were performed with a quartz crystal microbalance and synchrotron radiation photoelectron spectroscopy at BL23SU in the SPring-8 facilities, respectively. Hydrogen content and sp/sp ratio of the DLC were evaluated by an eleatic recoil detection analysis method and a near-edge X-ray absorption fine structure method. Although a non-dope DLC could not be survived by the AO bombardment, a thin SiO layer was formed at an Si-doped DLC surface. It protects the underneath DLC. Hydrogen in the DLC was not affected by the AO bombardment.