Measurements of the Ultraviolet Fluorescence Cross Sections and Spectra of Bacillus Anthracis Simulants.
Final rept. Jun 95-Sep 98
LOS ALAMOS NATIONAL LAB NM
Pagination or Media Count:
Measurements of the ultraviolet autofluorescence spectra and absolute cross sections of the Bacillus anthracis Ba simulants Bacillus globigii Bg, Bacillus megaterium Bm, Bacillus subtilis Bs, and Bacillus cereus Bc were measured. Fluorescence spectra and cross sections of pine pollen Pins echinata were measured for comparison. Both dried vegetative cells and spores separated from the sporulated vegetative material were studied. The spectra were obtained by suspending a small number 10 of particles in air in our Single Particle Spectroscopy Apparatus SPSA, illuminating the particles with light from a spectrally filtered arc lamp and measuring the fluorescence spectra of the particles. The illumination was 230 nm 20 nm FWHM and the fluorescence spectra was measured between 300 and 450 nm. The fluorescence cross section of vegetative Bg peaks at 320 nm with a maximum cross section of 5 X 10-14 cm2sr-nm- particle, whereas the Bg spore fluorescence peaks at 310 nm with peak fluorescence of 8 X 10-15 cm2sr-nm-particle. Pine pollen particles showed a higher fluorescence peaking at 353 nm with a cross section of 1.7 X 10-13 cm2sr-nm-particle. Integrated cross sections ranged from 3.0 X 10-13 cm2sr-particle for the Bg spores to 2.25 X 10-12 cm2sr-particle for the vegetative cells.