Research on the single scattering albedo of spheroids

2014 ◽  
Vol 24 (8) ◽  
pp. 1762-1768 ◽  
Author(s):  
Hong Tang ◽  
Xian-Xia Li
Keyword(s):  
Aspect Ratio ◽  
Cross Section ◽  
Complex Refractive Index ◽  
Single Scattering ◽  
Single Scattering Albedo ◽  
Scattering Cross Section ◽  
Nonspherical Particles ◽  
Incident Wavelength ◽  
Content Type ◽  
Scattering Cross

Purpose – The purpose of this paper is to discuss the light scattering of nonspherical particles that is very important for the research on the aerosol optical properties. Design/methodology/approach – In this paper, the authors use the spheroid model as the characteristic particle shape to study the single scattering albedo of real nonspherical particles. Meanwhile, the extinction and scattering cross section of spheroids are calculated with the T matrix method combined with the improved geometric optics approximation method (IGOM). Findings – Through this combination, the extinction and scattering cross section of spheroids can be obtained in the larger size range and aspect ratio range. Furthermore, the comparison of the single scattering albedo for the spheroids and their equivalent spheres is conducted in order to investigate the difference of the spherical and nonspherical particles. Originality/value – Simulation experiments indicate that the single scattering albedo of spheroids can be calculated well with this combination, and it has some obvious influence on the variation of the aspect ratio, incident wavelength, and complex refractive index of spheroid particles.

The scattering of light. I. The optical response of a finite molecular fluid

1984 ◽  
Vol 312 (1521) ◽  
pp. 251-293 ◽  
Keyword(s):  
Refractive Index ◽  
Cross Section ◽  
Complex Refractive Index ◽  
Scattered Light ◽  
Optical Response ◽  
Scattering Cross Section ◽  
Material System ◽  
Optical Extinction ◽  
Many Body Theory ◽  
Scattering Cross

We present a classical many-body theory of the optical response of a molecular fluid. The unified treatment provides mutually consistent expressions for the dielectric constant, the refractive index, the optical extinction coefficient, and the optical scattering cross section. The theory treats a finite material system and handles all surface effects associated with transmitted and scattered light. The complex refractive index and the scattering cross section will be analysed in two future papers.

scholarly journals Modeling of Scattering Cross Section for Mineral Aerosol with a Gaussian Beam

2018 ◽  
Vol 2018 ◽  
pp. 1-7 ◽  
Author(s):  
Wenbin Zheng ◽  
Hong Tang
Keyword(s):  
Gaussian Beam ◽  
Cross Section ◽  
Cross Sections ◽  
Scattering Cross Section ◽  
Nonspherical Particles ◽  
Red Clay ◽  
The Real ◽  
Scattering Cross ◽  
Mineral Aerosols ◽  
Scattering Cross Sections

Based on the generalized Lorenz Mie theory (GLMT), the scattering cross section of mineral aerosol within the Gaussian beam is investigated, and an appropriate modeling of the scattering cross sections for the real mineral aerosols including the feldspar, quartz, and red clay is proposed. In this modeling, the spheroid shape is applied to represent the real nonspherical mineral aerosol, and these nonspherical particles are randomly distributed within the Gaussian beam region. Meanwhile, the Monte Carlo statistical estimate method is used to determine the distributed positions of these random nonspherical particles. Moreover, a method for the nonspherical particles is proposed to represent the scattering cross section of the real mineral aerosols. In addition, the T matrix method is also used to calculate the scattering cross sections of the spheroid particles in order to compare the scattering properties between the plane wave and the Gaussian wave. Simulation results indicate that fairly reasonable results of the scattering cross sections for the mineral aerosols can be obtained with this proposed method, and it can provide a reliable and efficient approach to reproduce the scattering cross sections of the real randomly distributed mineral aerosols illuminated by the Gaussian beam.

scholarly journals 10-micron emission feature of nonspherical olivine particles

2021 ◽  
Author(s):  
D. V. Petrov ◽  
◽  
A. A. Savushkin ◽  
E. A. Zhuzhulina ◽  
◽  
...  
Keyword(s):  
Cross Section ◽  
Spectral Range ◽  
Circumstellar Disks ◽  
Emission Feature ◽  
Scattering Cross Section ◽  
Spherical Particles ◽  
Nonspherical Particles ◽  
Scattering Cross ◽  
Oblate Spheroids ◽  
Large Particles

Many astronomical objects, from comets to circumstellar disks, contain silicate particles. The spectrum of silicates has a set of emission features, the most characteristic of which is in the spectral range of about 10 microns, and is called a 10-micron emission feature. The 10-micron emission feature is often studied under the assumption that the scattering particles are spherical. In this work, we investigated the contribution of nonspherical particles (elongated and oblate spheroids) of olivine to the 10-micron emission feature. It is shown that enough large non-spherical particles (whose size more than 20 microns) cause a noticeable increasing of scattering cross section Csca in comparison with spheres. Thus, the observed 10-micron emission feature of large particles can be explained by the non-sphericity of the scattering particles.

scholarly journals CALCULATION AND ANALYSIS ON SCATTERING CHARACTERISTICS OF NON-SPHERICAL PARTICLES OF HAZE

2019 ◽  
Vol XLII-3/W9 ◽  
pp. 83-88
Author(s):  
W. M. Ji ◽  
F. Y. Jiang ◽  
C. X. Chu
Keyword(s):  
Aspect Ratio ◽  
Cross Section ◽  
Scattering Cross Section ◽  
Spherical Particles ◽  
Small Scale ◽  
Depolarization Ratio ◽  
Shape Factors ◽  
Equivalent Radius ◽  
Scattering Cross ◽  
The Mean

Abstract. The light scattering characteristics of sulfate, one of the main pollutant particles in haze, are calculated by T-Matrix method at a target wavelength of 550 nm. The variation between shape factors (such as effective radius and aspect ratio) and scattering phase functions with different types and shapes are analysed in small scale range. The influence of shape factors on scattering cross section and depolarization ratio of particles are also discussed. Results show that the shape of particles has great effects on the spatial distribution of scattering energy, and the scattering properties of particles are sensitive to aspect ratio. The depolarization of spherical particles is close to zero, while the difference between ellipsoidal and cylindrical particles reaches several orders of magnitude. When the equivalent radius is larger than 1.0 μm, the mean depolarization ratio of the non-spherical particles is greater than 0.2. The mean depolarization ratio and scattering cross section of non-spherical particle change continuously with a certain aspect ratio and particle size range, and the shape of some particles can be therefore distinguished under certain conditions.

Modeling of Light Scattering by Silica Nanoporous Structures

2008 ◽  
Author(s):  
Qunzhi Zhu ◽  
Yongguang Li ◽  
Dawei Chen
Keyword(s):  
Light Scattering ◽  
Cross Section ◽  
Power Law ◽  
Structural Parameters ◽  
Visible Spectrum ◽  
Silica Aerogels ◽  
Scattering Cross Section ◽  
Incident Wavelength ◽  
Differential Scattering Cross Section ◽  
Scattering Cross

Study of light scattering by nanoscale structures is essential to evaluate the radiative heat transfer in silica aerogels. For the purpose of simplification and feasibility regular structures are proposed to substitute irregular structures in silica aerogels to obtain average results of light scattering. The differential scattering cross section increases with density and decrease dramatically with wavelength in the visible spectrum. An inverse power-law relation can be observed between the differential scattering cross section and the incident wavelength. Furthermore, a power-law relation can be obtained for dimensionless scattering cross section and density. These findings are very helpful to understand the influences of structural parameters on light scattering.

Mass Determination by Direct Measurement of Electron Scattering

1975 ◽  
Vol 33 ◽  
pp. 240-241
Author(s):  
M. K. Lamvik ◽  
A. V. Crewe
Keyword(s):  
Cross Section ◽  
Electron Scattering ◽  
Mass Density ◽  
Variable Mass ◽  
Scattering Cross Section ◽  
Mass Determination ◽  
Number Density ◽  
Cross Sectional ◽  
Thin Slice ◽  
Scattering Cross

If a molecule or atom of material has molecular weight A, the number density of such units is given by n=Nρ/A, where N is Avogadro's number and ρ is the mass density of the material. The amount of scattering from each unit can be written by assigning an imaginary cross-sectional area σ to each unit. If the current I0 is incident on a thin slice of material of thickness z and the current I remains unscattered, then the scattering cross-section σ is defined by I=IOnσz. For a specimen that is not thin, the definition must be applied to each imaginary thin slice and the result I/I0 =exp(-nσz) is obtained by integrating over the whole thickness. It is useful to separate the variable mass-thickness w=ρz from the other factors to yield I/I0 =exp(-sw), where s=Nσ/A is the scattering cross-section per unit mass.

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