Accession Number : AD0815911

Title :   REFLECTIVITY MEASUREMENTS OF SELECTED THERMAL CONTROL COATINGS IRRADIATED IN HIGH VACUUM.

Descriptive Note : Technical rept. 1 Oct 64-1 Dec 66,

Corporate Author : GENERAL DYNAMICS FORT WORTH TX NUCLEAR AEROSPACE RESEARCH FACILITY

Personal Author(s) : McDaniel, R. H. ; Bell, J. R. ; Wattier, J. B.

Report Date : JUN 1967

Pagination or Media Count : 124

Abstract : Several specimens of each of the following types of thermal-control coatings were irradiated for 200 hrs at a power level of 3 Mw by the Ground Test Reactor: Acrylic TiO2, Silicon alkyd TiO2, 3M White Velvet, MgO acrylic, Fe2O3, M-polyvinyl butyrol TiO2, ZnO/K2O SiO2, YO2/K2O SiO2, Anodized aluminum, and PV 100. Reflectance values for each of the above types were determined in the 0.3- to 26.4-micro range. The specimens were irradiated at the west position of the GTR irradiation cell while in a high-vacuum (.000001 torr) environment. The integrated neutron and gamma doses incident on the specimens were 10 to the 17th power nvt (E>10 kev) and 2 x 10 to the 11th power ergs/gm(C), respectively. After the apparatus containing the specimens had decayed sufficiently for safe handling, reflectance measurements were made. In the 0.3- to 2.2-micron range, the reflectance was measured in high vacuum (.000001 torr) by use of a MgO reference, a MgO-coated integrating sphere, a tungsten source, a fused-silica prism, and photomultiplier and lead sulphide detectors. In the 2.2- to 26.4- micron range, the reflectance was measured by use of a hohlraum, a gold reference, KBr, and CaF2 prisms, and a high-sensitivity thermocouple detector. The reflectance data obtained in this experiment indicated that all the thermal-control coatings except Fe2O3 were damaged to some extent by the reactor radiation. The MgO acrylic coating displayed the most change throughout the complete spectral range (0.3-26.4 microns). (Author)

Descriptors :   (*REFRACTORY COATINGS, REFLECTION), VACUUM, DAMAGE, RADIATION EFFECTS, SPACE ENVIRONMENTS, TITANIUM COMPOUNDS, DIOXIDES, MAGNESIUM COMPOUNDS, IRON COMPOUNDS, SILICONES, SILICATES, OXIDES, SILICON DIOXIDE, ACRYLIC RESINS, SPECTROPHOTOMETERS, DOSIMETERS, HIGH ORBIT TRAJECTORIES, SPACECRAFT, THERMAL RADIATION, BLACKBODY RADIATION, HEAT TRANSFER, EMISSIVITY, SOLAR RADIATION.

Subject Categories : Coatings, Colorants and Finishes

Distribution Statement : APPROVED FOR PUBLIC RELEASE