Mie scattering computation of spherical particles with very large size parameters using an improved program with variable speed and accuracy

Abstract

The electromagnetic radiation scattering patterns were computed using an improved C program to study variations in the patterns with changes in the size distribution, size parameters and refractive index of small particles in a volume element. The particle size distributions considered were gamma, normal and lognormal. The program is stable for computation of the theoretical values of the non-zero elements of the scattering matrix, efficiency factors, single scattering albedo, radiation pressure and asymmetry parameter for particles ranging from very small to very large size parameters. One of the significant features of the program is that it incorporates two methods for the determination of the optimal number of terms required for the computation of Mie series with the added benefit of having the option of either going for computational speed or accuracy. After a comparison of the C program with other reported benchmark results, it has been found that the program is very accurate and reliable for electromagnetic scattering computations.

Keywords:

• electromagnetic radiation
• Mie scattering
• scattering matrix
• size distribution

Acknowledgement

The work has been supported by the Council of Scientific and Industrial Research, India through financial grant (vide sanction no: 09/796/(0013)/2009/EMR-I.) under the Senior Research Fellow scheme.