@Article{CarlessoVieiBernSavo:2021:DeImCh,
               author = "Carlesso, Franciele and Vieira, Luis Eduardo Antunes and Berni, 
                         Luiz Angelo and Savonov, Graziela da Silva",
          affiliation = "{Instituto Nacional de Pesquisas Espaciais (INPE)} and {Instituto 
                         Nacional de Pesquisas Espaciais (INPE)} and {Instituto Nacional de 
                         Pesquisas Espaciais (INPE)} and {Instituto Nacional de Pesquisas 
                         Espaciais (INPE)}",
                title = "Design, Implementation and Characterization of Cavity for Absolute 
                         Radiometer",
              journal = "Frontiers in Physics",
                 year = "2021",
               volume = "9",
                pages = "e598490",
                month = "Mar.",
             keywords = "total solar irradiance, electrical substitution radiometers, 
                         reflectance map, bidirectional reflectance distribution function, 
                         ultra-black Ni-P, ray-tracing.",
             abstract = "Absolute radiometers are based on electrical substitution 
                         radiometers, which compare optical and electrical power. The same 
                         physical principle applies to standard reference detectors 
                         operating at cryogenic temperatures and room temperature 
                         radiometers for total solar irradiance (TSI) measurements. Both 
                         types rely on the cavity with an internal low-reflectance coating 
                         to absorb incident radiation similar to a black body. The cavity 
                         shape design requires an analysis of the coating reflection 
                         properties. Like many materials, ultra-black Ni-P exhibits a 
                         mixture of diffuse and specular reflection that depends on the 
                         angle of incidence of light in the pores. We employed ray-tracing 
                         software to study the impact of the geometry on the absorptivity 
                         and distribution of the scattered rays. We describe the scattering 
                         model of the black coating in terms of the bidirectional 
                         reflectance distribution function. Also, we examined the 
                         difficulties of Ni-P electroless deposition and blackening inside 
                         the cavity. The measured absorptance of the cavity showed some 
                         discrepancies of the simulated absorptance mostly probably due to 
                         Ni-P non-uniformity coating.",
                  doi = "10.3389/fphy.2021.598490",
                  url = "http://dx.doi.org/10.3389/fphy.2021.598490",
                 issn = "2296-424X",
             language = "en",
           targetfile = "carlesso_design_2021.pdf",
        urlaccessdate = "09 maio 2024"
}