Thanks for the discussion, guys. Those few color lines were so bold and
bright compared to everything else, I figured those lines were most of
the light being emitted. Maybe not.
I don't think my sister in law took the spectrometer back yet. If it's
still here this weekend, I might look at it again.

Steve


Dave Gillingham wrote:
Oops! Meet you half way, Ray. You're dead right about the excited vapour atoms
emitting uv which causes the phosphor to fluoresce. It's the electrons of the
discharge which boot those atoms up to the excited states from which they relax,
emitting uv. But still, the lines to which Steve was referring are from the gas
discharge, which is incidental to the illumination function of the tube. That
comes from the continuous spectrum emitted by the phosphor.

On Mon, 23 Jan 2006 18:25:24 -0500, "Ray" wrote:


I don't know that I agree with that, Dave.

It is my understanding that the energized gas in the tube (typically a small
amount of mercury in an inert gas like argon) emits photon energy in the
ultraviolet part of the spectrum as the ions "collapse" to a lower energy
state. It is the UV that excites the phosphors, and they are solely
responsible for the visible light emitted. That phosphor composition is
varied to give different spectral " blends."

Neon would be a terrible gas to use in a fluorescent light, as the red color
of neon emission shows it to be insufficiently energetic for causing
anything to fluoresce.

Dave Gillingham
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