DEVELOPMENT OF A SELECTIVE SOLAR ABSORBER BY CONTROL OF SURFACE MICROTOPOGRAPHY
The work is divided into a number of parts: a) The development of a mathematical model to prove the theory of a pure metal absorber and to define the parameters. b) To produce test specimens by a laser photofabrication technique to test the model, and c) To explore methods that would lead to a commercially exploitable manufacturing process. To this end, some fundamental studies of electroplating were made. This model has confirmed the theory that surface topography can alone act as a solar absorber: it has described reflectivities in the visible region as a function of the amplitude of the microasperities, angle of incidence, polarization, profile shape, and metal characteristics for given values of peak-to-peak distance. The test specimens were manufactured with different peak distances in both gold and chromium, and with amplitudes determined by the exposure time during manufacture. These studies confirmed that high absorptivities in the visible region were possible and that a cut-off in absorptivity near to the ideal wavelength value (2-2.5 mum) could be obtained.
Bibliographic Reference: EUR 9847 EN (1985) MF, 52 P., BFR 150, BLOW-UP COPY BFR 260, EUROFFICE, LUXEMBOURG, POB 1003
Availability: Can be ordered online
Record Number: 1989123123000 / Last updated on: 1987-01-01
Available languages: en