So we have sodium and mercury lamps. Which heat up a vaporize said metals to form plasma arcs.

What is stopping us from upping the heat and vaporizing say... copper, iron, tin, maybe even uranium, gold, lead, Into a plasma arc?

What colors would be produced by such vaporized metals?

I am sure there is alot of fundamental knowledge I am missing. But from my understanding with a thick enough quartz wall and large enough electrodes or electromagnet, it maybe possible to vaporize anything into a plasma state for atleast a short while yes?

I am assuming this has been done somewhere. But I am having trouble finding examples on the web. And finding pictures of said discharges is hard because alot of the search engines also pull up pictures from movies/news articles/market listings for unrelated stuff.

Mercury and sodium have higher vapor pressure and low vaporizing temperatures. Other metals have lower vapor pressure and higher vaporizing temperatures.

I know for a fact that we can get to at least the boiling point of thallium metal (in Tl spectral lamps), which is 1500C at atmospheric pressure. But even metals like tin and lead have higher boiling points than that, 2600C and 1750C respectively. Zinc has been used in spectral lamps, and you would think that it's boiling point would be higher than tin and lead but it is only 900C. Even gallium has a boiling point of around 2400C. Anything higher than 1600C will soften quartz, anything above 1750C will soften alumina (so lead is probably excluded). Making the metals into iodides makes them boil at lower temperatures, but that's just a MH lamp, not very original. But:

What I would love to see is a potassium SOX lamp (POX?). The boiling point of potassium is a little lower than sodium, and the same two-ply glass would probably be able to work for it. Maybe even having a mixture of potassium and sodium in the lamp, because potassium makes purple and sodium makes yellow and yellow+purple might equal white-ish. Or maybe you can just add a small amount to increase CRI a little. I think this would be very interesting to see.

As to the colors produced by the metals, I have had an okay amount of luck using ChatGPT to generate HEX codes for different metal plasmas, but I doubt that is very accurate. I really don't know how else you would tell, because just looking at a spectrum distribution is not so easy.

As to electromagnetic arc confinement, I would think it would still rely on the coldest spot temperature of the arc tube, but I am unfamiliar with that concept so I don't really know. I would think that for a few seconds you can vaporize almost anything (before the arc tube explodes), but I could be wrong.

My understanding is that not a lot of substances are suitable for arc lamps, and we tried most of them. The only seemingly practical idea that I have come up with has been potassium, but I can't say I have been trying super hard to come up with one. I am sure there are some things that we haven't tried yet. Look into it more, I would like to hear more ideas. I might make them into drawings if they are very unique.

You can get an idea of the spectrum of different materials by burning them in fire. That's how it's been done in spectral sources for centuries before electrical lighting became a thing



Arc confinement does not equal vapor confinement. The vapor will still be all over the place :

 - You got to have enough supply of the material so there is enough of it where the arc is supposed to go, despite the material continually getting away from there. That's basically how a carbon arc lamp as well as several welding processes work - There is no confinement at all, the arc medium is a consumable

 - If there is confinement, you got to do something with the material (especially metals) which will tend to concentrate and condense in the colder areas, so it doesn't coat the insides of the confinement and obstruct the light, drown and short circuit the electrodes, do unwanted chemical reactions and so on



The thick quartz wall proposed in itself is a problem. The quartz will expand. If it is thick enough, there will be significant differences in expansion between the inside and outside regions of the quartz block, which will build very high strain

It will probably be able to explode through even massive solid blocks of quartz (in a similar way to how huge rocks are blown up with fairly small explosives placed in a small drilled hole). I wonder if the end result (when such massive block explodes) will have enough force to obliterate lanterns completely

If not, then at some point i think it will start cracking and breaking parts of the quartz wall inside the arc volume, creating a network of new cracks and voids which essentially become the new arc volume. The new volume may deviate enough from the electrodes to make the arc extinguish, but if it doesnt, it will continue the same process from the new position (and probably faster, with radial cracks propagating to the depth of the quartz from where it happened)