AAAR 31st Annual Conference
October 8-12, 2012
Hyatt Regency Minneapolis
Minneapolis, Minnesota, USA
Abstract View
Scattering Phase Function Measurements of PSLs and Ammonium Sulfate Particles
PAUL KEBABIAN, Timothy Onasch, Joda Wormhoudt, Andrew Freedman, Aerodyne Research, Inc.
Abstract Number: 143 Working Group: Instrumentation and Methods
Abstract We present detailed measurements of the scattering phase function and the resultant particle asymmetry factor, g, for four sizes of polystyrene latex particles (200nm, 350 nm, 600 nm, and 800 nm) using a newly developed instrument which measures scattering from all angles simultaneously. The agreement with Mie scattering calculations for the asymmetry parameter (which varies between ~0.3 and 0.7 in this size range) agreed to within ±0.03 . We also present results from a polydisperse distribution of ammonium sulfate. Measurement of the size distribution of the ammonium sulfate at diameters greater than 1 micron was necessary to achieve proper closure with the measured value of 0.68. A discussion of the upgrades required to achieve sufficient sensitivity to measure g at scattering intensity levels found in the ambient environment will be presented.