Research On Certain Aspects of Laser Diffraction Particle Sizing Relevant to Autonomous Self-Diagnosing Instrumentation.
Abstract
The fundamental scientific deficiencies impeding the integration of laser diffraction particle sizing techniques into intelligent sensors for next generation propulsion systems have been identified. The research addressed three relevant areas: inverse scattering algorithms; multiple scattering; and the problems of laser beam deflections due to refractive index gradients in hostile propulsion environments. A generalized eigenfunction approach to the inverse Fraunhofer diffraction particle sizing problem has been developed. Based on an analysis of the eigenvalue spectrum, scaling laws for optimal configuration of the system are proposed. The results are in agreement with an independent analysis of the system based on condition number analysis of the linear system produced by numerical quadrature as reported in a previous annual report. The formulation and scaling laws provide a scheme for determining the optimal number and location of the scattering sensors and the maximum number of pieces of independent information on the particle size distribution which can be reliably extracted from the inversion. Finally, a new concept involving programmable (real time) detector configuration at the transform plane has been demonstrated. Keywords: Light scattering, Fraunhofer diffraction, Particle sizing, Optical sensors.
Document Details
- Document Type
- Technical Report
- Publication Date
- Oct 01, 1987
- Accession Number
- ADA190220
Entities
People
- E. D. Hirleman
- Joseph H. Koo
- Paul A. Dellenback
Organizations
- Arizona State University