154. Total hemispherical emittance of graphite and pyrolytic graphite at elevated temperatures

✍ Scribed by R.J Champetier; J.D McClelland

• Publisher: Elsevier Science
• Year: 1969
• Tongue: English
• Weight: 126 KB
• Volume: 7
• Category: Article
• ISSN: 0008-6223
• DOI: 10.1016/0008-6223(69)90683-6

✦ Synopsis

integrated intensities and diffuse X-ray scattering were measured from highly oriented pyrolytic graphite to characterize the thermal displacement parameters. Values of the mean square displacements (uz) of the carbon atoms perpendicular to the basal planes are large, whereas, the displacements are small in the basal planes.

154. Total hemispherical emittance of graphite and pyrolytic graphite at elevated temperatures R. J. Champetier and J. D. McClelland (Aerospace Corporation, El Segundo, Calz~ornia). The total hemispherical emittance of ATJ graphite and 'as deposited' pyrolytic graphite layers on ATJ graphite cylinders has been measured from 1200" to about 2800°C using a high temperature calorimeter technique. The emittance of ATJ is about O-8 over the entire range. A value of 0.6 was obtained for PG up to 2600 were irreversible changes in surface finish increased cH to progressively higher values. Data is also presented on measurements of the normal emittance, the electrical resistivity and thermal conductivity which are obtained as part of the experimental technique.