AAAR 35th Annual Conference October 17 - October 21, 2016 Oregon Convention Center Portland, Oregon, USA
Abstract View
A General Method for Calculating the Rayleigh Scattering by an Arbitrary Shape
JUSTIN MAUGHAN, Chris Sorensen, Amit Chakrabarti, Kansas State University
Abstract Number: 467 Working Group: Aerosol Physics
Abstract A general method for calculating the Rayleigh scattering by a particle of arbitrary shape is introduced. Although analytical solutions for Rayleigh scattering exist for spheres and ellipsoids, analytical solutions for more complicated shapes don’t exist. We find that in general the Rayleigh differential cross section goes as k$^(4)R$^(6)|alpha(m)|$^(2) where k=2pi/lambda and lambda is the wavelength, V is the volume of the particle and alpha(m) is the average volume polarizability, which is dependent on the shape and the complex index of refraction m. We use existing computational techniques, such as the discreet dipole approximation (DDA), to calculate the differential scattering cross section divided by k$^4 and plot it vs V$^2 to determine alpha(m). We show that once alpha(m) is known it can be used to calculate the Rayleigh scattering for any combination of and volume within the Rayleigh limit for a given shape and index m. Furthermore, we show that this leads to a general description of the internal coupling parameter rho'=2piV/A|alpha(m)| where A is the cross sectional area of the particle in the direction of incident light.