Computational Model of Light Scattering by Irregular Particles: Approximation to Polarization Measurements of Cometary Dust

We present a computational model to obtain the scattering properties of a distribution of non-spherical particles at visible wavelengths and its application to cometary dust and to laboratory scattering measurements of cometary dust analogue. We have calculated the size-shape-averaged scattering matrix elements for both regular and irregular compact shapes and the size-averaged scattering matrix elements for the same irregular porous shape. We have also done calculations for two compositions. The mixture of silicate plus carbon is more appropriate to reproduce the cometary measurements. We have also found that it is possible to approximate the linear polarization curve of cometary dust by using a rectangular prisms distribution in which the most elongated shape prevails and by averaging in sizes for a irregular porous shape. We have also obtained that the irregular compact particles approximates better the laboratory measurements of cometary analogue.