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• Inversion of physical properties of thermal insulation ceramics. • Establish a new scattering phase function. • Improve inversion speed through parallel algorithms. • Analyze the optical path of the experimental system. Accurately obtaining the radiation properties of insulating ceramic materials is essential for engineering applications. This article obtained the bidirectional transmittance and reflectance of thermal insulation ceramics, and introduced a new scattering phase function to establish a radiation transfer model based on Monte Carlo method. Combined with parallel genetic algorithm inversion, radiation properties such as extinction coefficient, scattering albedo, and scattering phase function are obtained. Firstly, the experimental optical path is simulated and analyzed, which has little effect on the measurement results due to slight deflection of strong extinction material samples and detectors. For the measurement of bidirectional transmittance, a larger spot radius and detector radius will increase the measurement bidirectional transmittance. Secondly, through parallel genetic algorithm inversion, >5 measurement points are required to obtain their radiative properties, however, the radiation properties of backscattering materials cannot be precisely obtained using bidirectional transmittance for inversion. The required inversion accuracy can be achieved when the bidirectional transmittance and reflectance ratio measurement angle step is <4 °. Finally, this study determined the radiation properties of ceramic insulating materials that show little wavelength variation, their spectral extinction coefficients are above 9000m−1, and spectral scattering albedo are greater than 0.9. It is difficult to characterize scattering features using isotropic scattering phase functions because materials have both forward and backward scattering characteristics. The scattering characteristics of insulation ceramics described using the newly proposed scattering phase function have higher accuracy. [ABSTRACT FROM AUTHOR]

This paper presents a comprehensive simulation approach for the temperature-dependent Raman spectra of CO 2 , a common product in combustion and reactive environments. Previous studies have typically been limited to isotropic scattering or a restricted number of energy levels. In contrast, our simulation incorporates both isotropic and anisotropic scattering, including all ro-vibrational O, P, Q, R, and S transitions, and extends to all energy levels contained in and up to polyad 30, which our results demonstrate is essential for accurate modeling at high temperatures. The four most prevalent isotopologues ▪ , ▪ , ▪ , and ▪ are included, collectively accounting for over 99.99 % of naturally occurring CO 2. Polarizability ratios between the v 1 and 2 v 2 modes and the isotropic/anisotropic contributions were determined by fitting them to experimental spectra at 296 K. The simulated CO 2 spectra demonstrate excellent agreement with experimental data across temperatures up to 2355 K, thereby enhancing the reliability of Raman spectroscopy in various applications involving CO 2. • Accurate and comprehensive simulation of CO 2 Raman scattering. • Simulation of four most abundant isotopologues: 12C16O 2 , 13C16O 2 , 16O12C17O, 16O12C18O. • Inclusion of energy levels up to polyad 30 necessary for accurate cross section. • Simulating anisotropic component including O, P, Q, R, and S transitions. • Excellent agreement with measurements up to 2355 K. [ABSTRACT FROM AUTHOR]