Re: Fluorescent Lamps

["Jim Lux" <jimlux-at-jpl.nasa.gov> (by way of Terry Fritz <twftesla-at-uswest-dot-net>)]

> Good question....    and now for some more since i read the other replies
 ;)
> 
> is the tube being lit solely by RF ??

More by the electric field, but it happens to be an RF field.  It's just
the field though, not something like the tube acting as an antenna and
capturing energy at a distance.

> 
> I seem to get really good lighting from direct strikes to the tube ( one
end
> grounded) but this is to be expected ;)
> 
> if the tube is not grounded is it RF or EMI that makes the tube glow (
non
> grounded = even glow thru-out tube)

RF == EMI  but you don't necessarily get an even glow, because the field
isn't even.  Once glowing, the contents of the tube move around somewhat
changing it's properties, though, so the glow could start in one place and
extend as the plasma inside gets bigger.

> 
> has anyone ever tried to see if the phosphoresenct coating inside the
tube is
> the main contributing factor to the glow?    ( seeing if a tube that is
broken
> still lites up ???  )

Nope.. it's the mercury vapor being excited/ionized, which makes UV, which
makes the phosphor glow.  The phosphor isn't sensitive to electric fields.
If  the loose phosphor (which is somewhat toxic by the way, not to mention
the mercury, so don't breath it or eat it) does glow, it's due to being
excited by high energy photons or particles (i.e. UV from a spark,
electrons, xrays, etc.)
>