I know Arc Specialties in Houston Texas has a torch and has used it on some projects, but to say it's an uncommon process is an understatement. I think it was a coatings/overlay application, but don't hold me to that.
A shop down in Texas I believe it was, they were making anchor chain with 4 inch rod back in mid nineties. Just bent the "rod" to form the link and put pressure while the atomic arc was held and the butt weld formed a flash and it was fully welded.
I have an old welding handbook from the 1930s, full of info about how to run and setup AHW and what its good for.
It acted like a mix of tig and ox-act from the descriptions, and back then it was cleaner than ox-act due to the lack of flux.
TIG didn’t really exist yet back then, stick was for big and brutal things and carbon arc filled out the rest.
The torch was 2 tungsten’s in holders with a spring clip that held them together, you squeezed the torch to open the gap between them and start the arc. Depending on how far apart you held them and how much current and gas flow you were running you either ended up with a soft quiet arc at low temp or a large "singing" arc that would handle 1/4" material. I have to look up the applications again... cant remember and I have to run...