LARGE-SCALE SIMULATIONS OF ELASTIC LIGHT-SCATTERING BY A FAST DISCRETE DIPOLE APPROXIMATION

Simulation of Elastic Light Scattering from arbitrary shaped particles in the resonance region (i.e., with a dimension of several wavelength s of the incident light) is a long standing challenge. By employing th e combination of a simulation kernel with low computational complexity , implemented on powerful High Performance Computing systems, we are n ow able to push the limits of simulation of scattering of visible ligh t towards particles with dimensions up to 10 micrometers. This allows for the first time the simulation of realistic and highly relevant lig ht scattering experiments, such as scattering from human red - or whit e blood cells, or scattering from large soot - or dust particles. We u se the Discrete Dipole Approximation to simulate the light scattering process. In this paper we report on a parallel Fast Discrete Dipole Ap proximation, and we will show the performance of the resulting code, r unning under PVM on a 32-node Parsytec CC. Furthermore, as an example we present results of a simulation of scattering from human white bloo d cells. In a first approximation the Lymphocyte is modeled as a spher e with a spherical inclusion. We investigate the influence of the posi tion of the inner sphere, modeling the nucleus of a Lymphocyte, on the light scattering signals.