Radiation effects on dielectric multilayer coatings on optics
- Paper number
IAC-05-C2.5.02
- Author
Dr. Kazuhisa Fujita, Japan Aerospace Exploration Agency (ISTA/JAXA), Japan
- Coauthor
Dr. Kazuyuki Suzuki, Japan
- Year
2005
- Abstract
Radiation damage on dielectric thin-layer was studied. The dielectric multilayer coating is a promising technology for the use of solar light collection mirrors in Space Solar Power System (SSPS), requiring removal of too long and short wavelength components for efficient energy conversion and long life of the converter. Radiation effects on the dielectric coatings on the mirror are quite important because the mirrors will be exposed without any protection from the radiations. Protons, electrons, and UV light dominate the radiation environment on the geostationary orbit. We estimated numbers of displacement atoms using a Kinchin-Pease model for the proton incidence, and Frenkel pairs created via self-trapped-exciton process initiated by electron excitation in the target for the proton and electron incidences. Energy spectra of the incidence, and tangential incidence are taken into account. Proton incidence gives damages near the surface of the target due to low energy protons dominating its energy spectrum. Electron gives an almost uniform damage profile due to the small stopping power in the thin target. Silica and titania are treated as target materials in this estimate. Some of irradiation experiments including UV light now being performed will be also discussed.
- Abstract document
- Manuscript document
IAC-05-C2.5.02.pdf (🔒 authorized access only).
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