Computational Aspects of Photon Correlation Spectroscopy: The Histogram Method
Abstract
The purpose of this study was to write the computer
programs necessary to apply the Histogram Method for
analyzing correlation functions obtained from Photon
Correlation Spectroscopy and also to test how well this
method performs. The reason why The Upjohn Company was
interested in developing this technique was the ability
of the Histogram Method to extract more information from
Photon Correlation Spectroscopy than previously possible.
By analyzing correlation functions one can obtain the
radii of particles suspended in a solution. This information
can be used to characterize particles suspended in a
solution. The method currently being used to analyze
correlation functions by The Upjohn Company, the Cummulants
Method, produces only a mean radius and its standard
deviation. The Histogram Method on the other hand produces
a distribution of radii. This becomes increasingly more
important as one moves to solutions with particles of
different sizes. When one analyzes the correlation function
obtained for a solution containing two different size particles the Cummulants Method gives a radius somewhere
between the two. The Histogram Method will however will
distinguish between the two particles and produce a size
distribution which more accurately reflects the actual
sizes of the particles present.