High-speed particle analysis using forward and backward two-dimensional angular optical scattering

Area of Science:

• Optical Physics
• Particle Characterization
• Fluid Dynamics

Background:

• Accurate detection and characterization of micron-sized, high-speed flying particles are crucial in various scientific and industrial applications.
• Traditional methods often face limitations in speed, resolution, or the range of particle properties they can assess.

Purpose of the Study:

• To demonstrate the efficacy of two-dimensional angle-resolved optical scattering (TAOS) for real-time analysis of airborne particles.
• To investigate the relationship between scattering patterns and particle morphology, size, and velocity.

Main Methods:

• Utilized an ellipsoidal reflector and a high-speed CCD camera to capture elastic-scattering patterns.
• Employed a continuous-wave (CW) laser as the illumination source.
• Resolved scattering patterns over a wide angular range (θ: 12°–168°, φ: 0°–360°).

Main Results:

• Successfully detected and resolved scattering patterns from individual spherical particles (amorphous silica, borosilicate glass) at speeds of 20–30 m/s.
• Demonstrated that the angular scattering intensity pattern provides detailed information on particle morphology.
• Showcased the potential to infer particle size, clustering, roughness, and velocity from the scattering data.

Conclusions:

• TAOS is a powerful, non-invasive technique for characterizing high-speed microparticles.
• The detailed scattering patterns offer rich insights into particle properties, enabling advanced particle analysis.
• This method holds promise for applications requiring rapid and precise airborne particle assessment.