为了研制CO2探测仪定标漫反射板, 采用物理研磨和化学腐蚀相结合的工艺方法制作了铝漫反射板试验样块, 搭建了相对双向反射分布函数和半球反射率的测试装置。在0°和45°入射光的情况下, 对可见近红外波段的测试结果表明: 表面粗糙度影响铝漫反射板的朗伯特性, 240#研磨砂制作的漫射板的朗伯特性最佳; 化学腐蚀不仅能提高铝漫反射板的朗伯特性, 也能提高铝漫反射板的半球反射率。当选取碱蚀温度为室温20 ℃、NaOH溶液浓度为526 g/L时, 最佳腐蚀时间约为4 min; 镀膜使铝漫反射板的半球反射率平均提高20%, 但会使其朗伯特性稍变差; 不同波长处铝漫反射板的相对双向反射分布函数略有不同, 但变化趋势相同。实验确定了影响漫反射板漫反射特性的关键参数, 并定量优化了这些工艺参数, 为进一步研制CO2探测仪星上定标漫反射板提供了依据。

To develop a diffuser for CO2 detector calibration, the process of physical grinding and chemical etching was used to produce the test specimens of the aluminum diffuser for the CO2 detector calibration, and their test devices for relative Bidirectional Reflectance Distribution Function(BRDF) and hemispherical reflectance were built. In the case of 0° and 45° of the incident lights, the test results for visible to near-infrared band, show that the surface roughness affects Lambert characteristics of the aluminum diffuser and the Lambert characteristics of the diffuser made of 240# abrasive grit is the best. Chemical corrosion can not only improve Lambert characteristics of the aluminum diffuser, but also can improve the hemispherical reflectance. When etching temperature is selected at 20 ℃ and the concentration of NaOH solution is in 526 g/L, the optimal time of corrosion is about 4 min. Aluminizing makes hemispherical reflectance of aluminum diffuser to be improved by 20% on average, but it makes Lambert characteristics deteriorated. Furthermore, the relative BRDF of aluminum diffuser is slightly different at different wavelengths, but shows the same trend. The experiments in this paper determine the key parameters affecting the diffuse reflection characteristics of the diffuser, quantitatively optimize process parameters, and provide a basis for the further development of the diffuser for CO2 detector calibration on orbit.