Accession Number : AD0616892

Title :   AN EXPLORATORY STUDY OF RADIANT ENERGY TRANSPORT IN BEO.

Descriptive Note : Final rept.,

Corporate Author : NAVAL RESEARCH LAB WASHINGTON D C

Personal Author(s) : Chapin,E. J. ; Howe,D. G.

Report Date : 22 MAR 1965

Pagination or Media Count : 73

Abstract : Current hypotheses were reviewed relative to the contribution of radiant energy to heat transfer in BeO. The problem of radiant energy transmission in BeO was explored by exposing simultaneously, two types of BeO sample materials heated from 1000 to 2000 C, to pulses of radiant energy of known intensity. The effects were monitored with potentiometer and oscilloscope instruments from emf signals obtained from thermocouple detectors. Translucent thin-walled BeO tube material, heated from 1000 to 2000 C, exhibited no sustained transmission of radiant energy when exposed to radiant energy pulses of high intensity. An initial effect from the applied incident radiant energy was detected, however, which was interpreted to be due to the exposed surface of the BeO reaching a high temperature so rapidly that, momentarily, little heat was generated in the mass of the material and no immediate temperature rise occurred in the heated BeO. It was postulated that during this short interval incident radiant energy was transferred in the BeO by a process involving simultaneous emission and absorption of radiant energy in depth. As soon as the BeO temperature began to rise, this process of radiant energy transfer appeared to be replaced by the normal process of radiant energy absorption, conversion to heat, and reradiation. BeO heated above 1800C exhibited no tendency toward an initial rapid transfer of radiant energy. (Author)

Descriptors :   (*BERYLLIUM COMPOUNDS, OXIDES), (*HEAT TRANSFER, BERYLLIUM COMPOUNDS), (*THERMAL CONDUCTIVITY, BERYLLIUM COMPOUNDS), VAPOR PRESSURE, EMISSIVITY, PHONONS, PHOTONS, HIGH TEMPERATURE, LOW PRESSURE

Distribution Statement : APPROVED FOR PUBLIC RELEASE