2003 年 18 巻 4 号 p. 272-277
A light-scattering instrument which measures the scattering patterns from an axisymmetric particle irradiated by monochromatic light was developed. The size and orientation of particles were determined through the comparison of measured patterns and those calculated by the computation program developed by Barber et al.1) . Barium sulfate of axisymmetric particle was generated by a spray method and introduced into the scattering instrument. An argon laser was used as the light source. The detector of instrument was further improved so as to measure the scattered light of parallel and perpendicular polarizations in the observation plane simultaneously.
As a result, it was found that the particles were spheroids with major axis of 0.74 ∼ 0.75 μm and minor axis of 0.57 ∼ 0.58 μm, with orientation (Θp,Φp) = (45°, 40°) . Although the conventional scattering theory for spheroid was not sufficient, the instrument developed in the present work was confirmed to be useful for the simultaneous measurement of size and orientation of axisymmetric particles.