Development of Method of Calculating UV Dose Distributions Using Dye Microcapsules and Applying Lognormal Distributions to Their UV-Sensitive Properties

Abstract

As a basic study of the application of dye microcapsules (DMC) to Lagrangian actinometry, collimated beam tests were conducted using a DMC-Lagrangian actinometer (DMC-LA) , and a new method of calculating the UV dose distributions was developed. It was statistically confirmed that the distributions of the fluorescence intensity of DMC-LA well fitted lognormal distributions. By applying the lognormal distributions, the UV dose distributions could be calculated directly from the flow cytometer measurement results of each DMC particle without the complicated deconvolution operation required in previous studies using dyed microspheres. The obtained UV dose distributions showed that the variances were kept sufficiently narrow that the log survival rates did not deviate from the initial slope line, at least when the average UV dose was less than 150 mJ cm^-2. This result strongly suggested that the tailing phenomenon of log survival rates in biodosimetry is due to causes other than the UV dose distributions.