Optical properties and equilibrium temperatures of titanium-nitride-and graphite-coated Langmuir probes for space application
| Autor: | M. Veszelei, Eugen Veszelei |
|---|---|
| Rok vydání: | 1993 |
| Předmět: |
Materials science
business.industry Metals and Alloys Analytical chemistry chemistry.chemical_element Surfaces and Interfaces engineering.material Titanium nitride Surfaces Coatings and Films Electronic Optical and Magnetic Materials symbols.namesake chemistry.chemical_compound Optics chemistry Coating Aluminium Materials Chemistry symbols engineering Langmuir probe Graphite Tin business Nitriding Titanium |
| Zdroj: | Thin Solid Films. 236:46-50 |
| ISSN: | 0040-6090 |
| DOI: | 10.1016/0040-6090(93)90640-b |
| Popis: | The equilibrium temperature of a coated Langmuir probe in space is determined by the optical properties of the coating and the geometry of the probe. In this investigation we report on the optical properties of graphite- and TiN-coated aluminium and titanium. Earlier results have shown that a TiN-coated sphere is preffered as a Langmuir probe for the Cassini satellite bound to Saturn owing to the hardness, chemical inertness and photoelectric stability of the TiN coating. The TiN coatings were prepared by high temperature nitriding of a titanium alloy in pure nitrogen gas. An epoxy-based graphite dispersion (DAG 213) was used to apply the graphite coating. The integrated total solar absorptance αs was calculated, for a spherical and a cylindrical probe, using measured total reflectance. Total hemispherical emittance ϵH(T) of spherical samples was measured using a calorimetric method and compared with infrared reflectance measurements from 2 to 30 μm. The ratio αsϵH for graphite was determined to be 0.95−1.11 for spherical and cylindrical probes in the temperature interval 90−380 K. For TiN the ratio αsϵH is 2.64−4.64 for temperatures between 130 and 490 K. Equilibrium temperatures for spherical and cylindrical probes were estimated for solar constants at Venus, Earth and Saturn. |
| Databáze: | OpenAIRE |
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