Research on Certain Aspects of Laser Diffraction Particle Size Analysis Relevant to Autonomous Self-Diagnosing Instrumentation.
Abstract
The 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 areas: inverse scattering algorithms; multiple scattering; and the problems of laser beam deflections due to refractive index gradients in hostile propulsion environments. Direct integral transform techniques for the inverse problem have been formulated on a common basis and comprehensively evaluated. An error in the original derivation of the the method of Petrov has been corrected and a new integral transform solution has been developed. Concerning multiple scattering, a new synthesis of successive order and discrete ordinates models has been developed for predictions of near forward radiative transfer in optically thick media and the results have been verified with experimental data and an independent Monte Carlo simulation. Finally, a new concept involving programmable spatial filtering at the transform plane which allows annular detectors of variable geometries to be configured on line by an intelligent instrument has been proposed and proof of principle experiments have begun. The concept will permit a detector to be automatically reconfigured around the deflected beam center and also will allow adaptive grid methods to be incorporated into the inversion algorithms.
Document Details
- Document Type
- Technical Report
- Publication Date
- Nov 26, 1986
- Accession Number
- ADA176968
Entities
People
- E. D. Hirleman
- Joseph H. Koo
Organizations
- Arizona State University