Color Fades in discharges

["Tesla list" <tesla@xxxxxxxxxx>]

Original poster: "Mike" <induction@xxxxxxxxxxx>

Hello List,
                  Several messages, like the Ozone issue, thoughts on
placing Argon in a display / discharge area, discharge behavior,
the corkscrew and great pictures Terry made available of his 811A
driven coil have merged into my thinking of a problem I've been observing
for a while now regarding color changes in discharges. You usually will not
see this problem in those "Lightning globes" as they have different gas mix
than regular air.
This problem presents with regular air mixture, a discharge of either DC or
AC, power line frequency as in a NST of 60 MA, 15 KV or line frequency AC
at 2600 volts to a few hundred at 100 MA down to 500 microamps. The greater
 the current, the faster the color fade. Also to RF frequencies, the 
current seems
 to be more important than the frequency or even if it is only DC.
Important to viewing this seems to be that the discharge must be in a confined
air volume, that the same air is in the discharge without fresh air mixing 
in any
significant quantity. I see this in a vacuum chamber but it presents at 
considerable
pressures up to 1/4 atmospheric, roughly. Above those pressures in the current
 system I run out of voltage as there is no TC here small enough to work 
this chamber.
An available hand type kicker coil will not tune to the extra large 
capacity of an
extended probe wire into the tube. I think it will present with a TC at 
full sea level
pressure as the voltages are more than high enough and as long as you have
a glass or clear plastic container large enough to place over a small TC.
Here is what happens. Under all conditions, there is an electrode at each 
end of
the 6 feet long, 2 feet wide chamber, at low pressure. In DC, there is at 
the negative
end the classic cathode blue glow, the classic dark space then ~ 75 percent 
of the
 remainder and to the positive terminal, the anode, is the red/pink glow. 
That is mostly
the 80 percent nitrogen being ionized.
Switching to AC, there is the blue/purple you see in the TC discharges through
the whole tube. Spectra taken shows up as normal.
Now, the problem. At say 20 / 60 MA within a few minutes or less, for this 
air volume,
the colors for the DC case will both fade from a blue one end, red the 
remainder,
 to a steel gray and remain that same steel gray. The same for AC, the 
Blue/purple
will fade to the same steel gray and remain as such. Leave it on all day 
and it stays
gray. Turn off the power, use the same air, start up again, remains gray.
As long as the same air is used this gray is all you get. Now let in a 
small supply of
fresh air, the colors return until that air "burns" and the gray is back.
We added electric valve, hit the button, presto, instant normal color, a 
little time,
the color is gone again with button off.
With "burned air" as we call it, the spectra is all out of sorts. The N21P 
lines are down
to half and all messed up, the H alpha, always in our spectra, is up 25 
percent. Does
the same thing if the tube is glass or plastic. The N21N and N22P are also 
jocked
compared to normal in this "burned" air.
The broadband spectral noise floor, usually clean between normal peaks, 
rises across
the board by ~15 percent from 380 nm to 780 nm, our whole range on this unit.
Spoke to another researcher in NJ, she had the same problem, she thought it was
 at her end. Not so it seems.
Also we found that the burned air will conduct and maintain visible glow, 
even if
a useless gray, down to lower currents and less voltages, than good and not 
burned
air. To the TC person, burned air, so called, would let discharges go further.
Also, 'burned air" happens in both glow discharges or arc discharges, again the
greater the current, the faster the burn, given the same air.
What I need from the TC list, who has a small coil they can cover and watch for
blue to gray changes by zapping the same air. Or, who has a larger coil 
that they
can tie a wire from the top load into a closed air container and compare your
blue streamers to the burned air color in the closed container. If you need 
to add
an air tight wire to the other end of the burned air chamber so there is a 
path through
it, that is fine.
We were going nuts with this, setup, pump down to 75 KM high, be ready to 
take the
 readings and spectra before the air burned, hit the power, purge with 
clean air, pump
 down, try again.
We ended up with a needle valve adjusting to the final pressure we wanted 
to park the
system at, keeping the 3 vacuum pumps going and kept a constant fresh air 
supply
entering the chamber to beat the problem. But honestly, we did not beat the 
problem,
we figured a work around for it.
The spectra has been shown around, nobody is sure what we have.
Is it O3, are there bindings in combinations with the N2, why is so little 
fresh
air capable of instant color restoration? Maybe a clue, there is what is
known as the "Andes Glow" (try google), mountain tops discharge to huge
areas up to 300 miles, initially many colors then with time the discharge
goes to a mono color. Is the volume so great that even that air "burns" as 
we see?
Today, one wise coiler said we really need to understand the nature of the
discharges, not so much how far in contests they go but the understanding 
of the
streamers and branches. Natural lightning is such a short event, yet the
patterns are so like the Tesla coil. Nature is quick in lightning, the TC 
person
can throw a switch and study at will.
So I am asking the help of the List here, 1000 plus strong, is any body
interested in helping find out why the chemistry seems to change with
the discharges and in confined air volumes? Thanks and regards,
Mike