1994 Volume 78 Issue 10 Pages 497-503
Relative density distributions of particles at excited levels are estimated in fluorescent lamps having oblate cross sections (aspect ratios of 0.4-1.0).
Since the plasma in such a fluorescent lamp does not have cylidrical symmetry, a new computed tomo graphic (CT) technique, which is applicable to a spatially non symmetrical shape, is used to measure emission intensities from optically thin levels. Reflection and refraction at the surface of the tube are calibrated by their first order components.
From the measured values of electric field strength, electron energy distributions and density distributions of particles at excited levels including optically thick levels are calculated.
On the major axis, the distributions of excited levels emitting visible lines sag under the Jo distribution, and on the minor axis, they are bullet shaped.
These distributions depend heavily on its tube aspect ratio and not on its current.