Table 8.
Performance of Test Models for Particles Classified as Overall Absorbing or Scattering: Asymmetry Parameter
| Absolute Deviation in <cos θ> From Reference Models |
||||||||
|---|---|---|---|---|---|---|---|---|
| Homogeneous Spatial Modelc | Heterogeneous Geometric Model |
Homogeneous Geometric Models |
||||||
| Absorber or Scatterer as Dominant Phasea | Particles | Type | Sphere | Cube | Tetrahedron | |||
| Absorber dominant | BC; k = 0.39 to 0.48 | LA1 and LA2 | 0.0307 (n = 2) | Core/shell | 0.0337 (n = 2) | 0.0116 (n = 2) | 0.0315 (n = 2) | 0.0253 (n = 2) |
| Graphite; k = 0.72 to 0.87 | LA1 and LA2 | 0.0250 (n = 2) | 0.0679 (n = 2) | 0.0219 (n = 2) | 0.0927 (n = 2) | 0.0673 (n = 2) | ||
| Hematite; k = 0.072 | LA3 | 0.0119 | two spheres | 0.0152 | 0.0392 | 0.0271 | 0.0441 | |
| Goethite; k = 0.06 to 0.09 | LA3 and S1 | 0.0099 (n = 2) | two spheres (LA3) | 0.0419 (LA3) | 0.0390 (n = 2) | 0.0568 (n = 2) | 0.0503 (n = 2) | |
| Wustite; k = 0.038 | S2 | 0.0103 | 0.0242 | 0.0221 | 0.0256 | |||
| Average Absolute Deviation ± s | 0.014 ± 0.01 (n = 8) | 0.043 ± 0.022 (n = 6) | 0.026 ± 0.013 (n = 8) | 0.051 ± 0.032 (n = 8) | 0.044 ± 0.022 (n = 8) | |||
| Goethite; k = 0.016b | S3 | 0.0909 | four spheres | 0.218 | 0.0467 | 0.108 | 0.0966 | |
| Wustite; k = 0.112b | S3 | 0.188 | four spheres | 0.216 | 0.223 | 0.216 | 0.197 | |
| Scatterer dominant | Limonite; k = 0.0032 to 0.0042 | LA3 and S1 | 0.0137 (n = 2) | two spheres | 0.223 (LA3) | 0.174 (n=2) | 0.163 (n = 2) | 0.158 (n = 2) |
| Albite/Gypsum; k = 0.00073 | S2 | 0.001 | 0.0787 | 0.0564 | 0.107 | |||
| Albite/Almandine/Pyrope/Quartz; k = 0.00014 | LA4 | 0.0629 | three spheres | 0.269 | 0.195 | 0.0262 | 0.0882 | |
| Albite/Illite/Kaolinite/Quartz k = 0.00433 to 0.00047 | LA4 | 0.0312 (n = 3) | 0.141 (n = 3) | 0.123 (n = 3) | 0.0757 (n = 3) | 0.0522 (n = 3) | ||
| Average Absolute Deviation ± s | 0.026 ± 0.02 (n = 7) | 0.18 ± 0.06 (n = 5) | 0.14 ± 0.07 (n = 7) | 0.091 ± 0.083 (n = 7) | 0.095 ± 0.053 (n = 7) | |||
| Calcite/Anorthite/Gypsum; k = 0.00073b | S3 | 0.171 | four spheres | 0.233 | 0.0068 | 0.0720 | 0.283 | |
a
Absorber is dominant if the imaginary part of complex refractive index, k, for the whole particle is >0.01. Scatterer is dominant if k for whole particle is <0.01.
b
Treatments for particle S3 (italics) are not included in determinations of the average absolute deviation as explained in text.
c
Model includes particle shape, surface features, and voids.