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U.S. Department of Energy
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Calorimeter to measure the 10. 6-micrometer absorption of metal-substrate mirrors. Final report

Technical Report ·
OSTI ID:6180450

An instrument was designed, constructed, and tested to calorimetrically measure the 10.6-micrometer absorption coefficient, alpha, of high-reflectivity metal-substrate mirrors. Optical, electrical, and thermal design considerations are discussed. The techniques of absorption measurement presented include the in-situ heat capacities, the reflected and absorbed laser light energies to an accuracy of + or - 4%, and the simplified data-reduction technique. Detailed operating instructions, data-reduction methods, and other information (e.g., electrical schematics) required for an operational understanding of the measurement system are included. This report may also serve as an instruction manual. An error analysis indicates that the accuracy is + or - 0.1 alpha and the precision is 0.0005 alpha. Comparative measurements on the same mirrors by different reflectivity and absorption devices and extensive absorption data on state-of-the-art 10.6-micrometer metal-substrate mirrors are presented. The smallest absorption that was measured is 0.0010 for a gold-coated multi-dielectric enhanced mirror.

Research Organization:
Air Force Weapons Lab., Kirtland AFB, NM (USA)
OSTI ID:
6180450
Report Number(s):
AD-B-031757/8/XAB; AFWL-TR-76-63
Country of Publication:
United States
Language:
English