Abstract
There is a growing class of elementary particle detectors, large-water Čerenkov detectors, that have a body of water (thousands of tons) as a sensitive medium. Particles are detected when they interact with the water and produce Čerenkov light, so detection efficiency relies on the transparency of the water. These detectors are active typically for many years, so biological activity (primarily bacterial growth) is one of the means by which the transparency of the water may be reduced. We present the results of a measurement of light scattering and absorption from a population of Escherichia coli in water, which is used as a model for bacteria in general. One can separate the scattering and absorption by varying the refractive index of the medium by using a solute of high molecular weight. We show that the results can be understood simply in terms of light scattering from small spheres (radius ≈ wavelength) with an effective refractive index, n b, plus a small amount of absorption in the ultraviolet. We compare this scattering with Rayleigh scattering in pure water.
© 1994 Optical Society of America
Full Article | PDF ArticleMore Like This
Murugesan Venkatapathi, Bartek Rajwa, Kathy Ragheb, Padmapriya P. Banada, Todd Lary, J. Paul Robinson, and E. Daniel Hirleman
Appl. Opt. 47(5) 678-686 (2008)
Willem P. Van De Merwe, Donald R. Huffman, and Burt V. Bronk
Appl. Opt. 28(23) 5052-5057 (1989)
Joanne C. Zwinkels, W. F. Davidson, and C. X. Dodd
Appl. Opt. 29(22) 3240-3248 (1990)