BSA Flow Software Installation and User's Guide - CSI

Figure 7-45. The upper panel shows ray traces indicating the three modes
of scattering, reflection and first and second order refraction, for a water
droplet. In the lower panel, the light intensity (log scale, one decade
between each circle) for each of these modes is shown in a polar plot for
scattering angles from 0° to 180° and for two polarizations — the upper half
at 90° to the scattering plane, and the lower half parallel to the scattering
plane.
Dependence of geometrical factor on relative refractive index
Refraction by As it appears from equation (For first order refraction (Equation 7-17)) for
first order refraction, the geometrical
a droplet factor, β, for refraction depends on the relative refractive index of the
particle, n rel , in addition to the angles ϑ, ψ and ϕ. In many situations the
exact value of n rel is not known.
As shown in Figure 7-46, the geometrical factor, β, becomes less dependent
on n rel as the scattering angle ϕ increases. Clearly, however, there is a limit
to how great a scattering angle can be used, since light scattered by
refraction only exists at scattering angles less than ϕ c1 . Moreover, to get a
linear size-phase relationship regions where two or more modes of scattering
make contributions of the same order of magnitude to the intensity of the
scattered light should be avoided.
7-52 BSA Flow Software: Reference guide