Plasma Colors
alan sailer, Sat Feb 24 2018, 11:06PMI though t that I would throw out this kind of random question to see if anyone has promising ideas.
I have been doing a lot of plasma tube work and have had a lot of great results. I was wondering if
putting metal salts in a tube would cause color changes ie like a flame test. I know the temperature
inside a plasma tube is much lower but hey, why not try.
Today I tried my first experiment with sodium specifically NaOH. I decided on sodium since it
give such dramatic colors in flame tests. The result (in a neon/nitrogen/krypton mix) was null. Which
isn't surprising.
Can anyone here think of a metal compound that might work in this application? Strontium, sodium
and copper are all salt that give good bright colors.
Cheers.
Re: Plasma Colors
ShieldExperiments, Sun Feb 25 2018, 09:05PM
From what I know about gas discharge lights, salts and metals are unlikely to be useful in a plasma globe due to their melting points.
Take for example a typical metal halide streetlight. When if first lights up, a small amount of argon (?) has a plasma glow as you are working with. Then, a small amount of mercury evaporates, then after that the various salts that make the characteristic glow. The thing at play here is temperature; in order for the salts to emit light, they must evaporate first. Thus, salts aren't going to be much use in a plasma tube.
That said, if you're willing to do some playing around, you might try using a low melting alloy of whatever elements you want to try out, or play with lowering tube pressures to lower the melting point of your salts. The other answer is the risky one; you might try adding a bit of mercury and working from there, but that would require the utmost of caution.
Keep us updated!
ShieldExperiments, Sun Feb 25 2018, 09:05PM
From what I know about gas discharge lights, salts and metals are unlikely to be useful in a plasma globe due to their melting points.
Take for example a typical metal halide streetlight. When if first lights up, a small amount of argon (?) has a plasma glow as you are working with. Then, a small amount of mercury evaporates, then after that the various salts that make the characteristic glow. The thing at play here is temperature; in order for the salts to emit light, they must evaporate first. Thus, salts aren't going to be much use in a plasma tube.
That said, if you're willing to do some playing around, you might try using a low melting alloy of whatever elements you want to try out, or play with lowering tube pressures to lower the melting point of your salts. The other answer is the risky one; you might try adding a bit of mercury and working from there, but that would require the utmost of caution.
Keep us updated!
Re: Plasma Colors
alan sailer, Sun Feb 25 2018, 09:17PM
Yes I agree. the only examples I can think of use heaters to vaporize the salts (?)
with some sort of heater then establish the arc.
I am afraid enough of mercury that it's a no-go. I have a nice vacuum system and
would hate to turn it into a SuperFund site
Your alloy idea is interesting. I'll think about and search to see if I can find any with
a high vapor pressure.
Cheers.
alan sailer, Sun Feb 25 2018, 09:17PM
Yes I agree. the only examples I can think of use heaters to vaporize the salts (?)
with some sort of heater then establish the arc.
I am afraid enough of mercury that it's a no-go. I have a nice vacuum system and
would hate to turn it into a SuperFund site
Your alloy idea is interesting. I'll think about and search to see if I can find any with
a high vapor pressure.
Cheers.
Re: Plasma Colors
Conundrum, Sat Mar 03 2018, 08:58AM
maybe worth trying an alloy of GaInx where x is the alkali metal.
Conundrum, Sat Mar 03 2018, 08:58AM
maybe worth trying an alloy of GaInx where x is the alkali metal.
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