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Patrick

Thu Apr 14 2016, 06:36AM

Registered Member #2431 Joined: Tue Oct 13 2009, 09:47PM
Location: Chico, CA. USA
Posts: 5639

I'm conducting some experiments, and will post some already completed here shortly, based on corona and entrained air.

But in my effort to explain the specific math, physics and chemistry at work, ive run into the complication of generating the corona itself.

So, lets say the atmosphere is 78% N, 21% O, and 1% Ar. And then we have a HV point near a grounded sphere, we generated a corona, but no arc or sparking.

What percentage of these gases would be in there first ionization energy ? And then their 2nd energy ? Do they all, or almost all have to be ionized to the first level before they can go to the second? or would it be possible for there to be a fractional "zoo" of this species flying about ?

-TY

Ill explain this test stand shortly.

Sulaiman

Thu Apr 14 2016, 07:16AM

Registered Member #162 Joined: Mon Feb 13 2006, 10:25AM
Location: United Kingdom
Posts: 3140

I believe that humidity and pressure also are involved so should be considered

I think that you will need a high speed microscopic video capture and more realistically,
a spectrometer, with some kind of microscopic focus.

Nik

Thu Apr 14 2016, 11:05AM

Registered Member #53 Joined: Thu Feb 09 2006, 04:31AM
Location: Ontario, Canada
Posts: 638

If you have a diffraction grating it might be possible to record the spectrum and try to identify the ions present by that spectrum. You would have to have some light source, or sources with a known spectrum to callibrate against but it is doable by on a hobbies level.

Proud Mary

Thu Apr 14 2016, 06:24PM

Registered Member #543 Joined: Tue Feb 20 2007, 04:26PM
Location: UK
Posts: 4992

Patrick

Fri Apr 15 2016, 06:42PM

Registered Member #2431 Joined: Tue Oct 13 2009, 09:47PM
Location: Chico, CA. USA
Posts: 5639

I cant get that PDF to open, but am I basically asking about singlets and doublets ?

I just wonder how ill get sensitivity at the hobby or college level, to sort out a population, unless its singlet common, and doublet/triplet uncommon.

Oxygen Ionization energies.
1st: 1313.9 kJ/mol
2nd: 3388.3 kJ/mol
3rd: 5300.5 kJ/mol

the first Ionazation energy is just 39% of the second. so if the population of doublets is high, it needs to be accounted for, but if rare, like 0.000001% then it wouldn't matter much in my calculations.

Sulaiman

Fri Apr 15 2016, 07:37PM

Registered Member #162 Joined: Mon Feb 13 2006, 10:25AM
Location: United Kingdom
Posts: 3140

AFAIK ionisation, oxidation etc. proceeds in stages,
e.g. to get to 'level 2' you go ground, step1, step2 ...
so maybe if you can remove the first ionisation level species quickly you should get much less level2 etc.
e.g. a very thin stream of high speed air such that only a small fraction of the molecules are ionised,
then analysis MAY be easier.

Patrick

Fri Apr 15 2016, 08:26PM

Registered Member #2431 Joined: Tue Oct 13 2009, 09:47PM
Location: Chico, CA. USA
Posts: 5639

Sulaiman wrote ...

. . .
e.g. to get to 'level 2' you go ground, step1, step2 ...
so maybe if you can remove the first ionisation level species quickly you should get much less level2 etc.
. . .

I'm wanting to produce as much corona possible in singlet, from a high speed moving airstream. so I hope this works as a whole solution, not just for the spectrum analysis.
Hopefully this will heap.

My camera is recording things excessively yellow, so I don't know why that is. But ive chosen oil here as its easy to visualize, but my real interest is in air flow.

Bored Chemist

Sat Apr 16 2016, 12:10PM

Registered Member #193 Joined: Fri Feb 17 2006, 07:04AM
Location: sheffield
Posts: 1022

Patrick wrote ...

I cant get that PDF to open, but am I basically asking about singlets and doublets ?

I just wonder how ill get sensitivity at the hobby or college level, to sort out a population, unless its singlet common, and doublet/triplet uncommon.

Oxygen Ionization energies.
1st: 1313.9 kJ/mol
2nd: 3388.3 kJ/mol
3rd: 5300.5 kJ/mol

the first Ionazation energy is just 39% of the second. so if the population of doublets is high, it needs to be accounted for, but if rare, like 0.000001% then it wouldn't matter much in my calculations.

AFAIK those are the ionisation potentials for the atoms and air is composed of O2 molecules.

The only hope you have of working out what is going on is via spectroscopy and that's going to be difficult.

Patrick

Mon Apr 18 2016, 04:16AM

Registered Member #2431 Joined: Tue Oct 13 2009, 09:47PM
Location: Chico, CA. USA
Posts: 5639

more pics . . .

DekuTree64

Mon Apr 18 2016, 06:53PM

Registered Member #54596 Joined: Fri Mar 06 2015, 11:31AM
Location:
Posts: 19

Patrick wrote ...

I cant get that PDF to open,

It works for me (Windows XP, Adobe reader 11). Page title is "An Investigation of Ionic Wind Propulsion". It's pretty basic, though. I don't see anything about percentages of ion species.

I think you can safely ignore double ions in negative corona. Since the electrons moving away from the electrode have to slow down before they can stick to anything, and would be repelled by any negative ions in the area, I'm not sure you'd get any double ions at all.

But in positive corona, the electrons rushing toward the electrode would be attracted to any positive ions in the area, so more likely to run into them and knock off a second electron. I have no idea what the actual percentage would be, but probably worth investigating further before ignoring it.

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