Hi guys, i bought a 1979 barium lamp, can anyone tell me what it was used for, and how to burn it? It has an e27 and an e14 base. I love it, never seen one before, but i could use some info. Thanks! 

That's a fascinating looking device, it looks somewhat like an early form of flood-beam cathode ray tube.  Is there a phosphor coating on the end of the bulb?

The only reference I can remember to a Barium lamp was in a paper at the 1997 International Conference on Plasma Science, where I delivered a paper on sodium lamps for GE and the lady after me presented her research on low pressure barium discharge lamps.  That was from a university research department and the lamps were not commercialised, because the performance was not commercially interesting but the technology certainly was.  Are you sure your lamp was made in 1979 or could it be later?  Could it be possible that your lamp is from the 1990s?  This weekend when I have a moment I will dig out the paper and see if there are more details, or perhaps a link to other previous papers on barium lamps.

I remember seeing such a thing, related to demonstration of field emission microscope principle, of whatever it called. If I remember correctly, they prepared the needle with coating of evaporated barium atoms, then if done correctly, you can see individual atom images (!) on the fluorescent screen when high voltage is applied.

Note mentioning of FEM in the tube description. Here is the tube manual attached.

more info https://www.ld-didactic.de/documents/de-DE/GA/GA/5/554/554605d.pdf

   
http://dodo.fb06.fh-muenchen.de/lab_didaktik/at-1-4.htm
https://www.experimente.physik.uni-freiburg.de/H_Atom_und_Kernphysik/versuchemitelektronenundmateriestrahlen/feldelemissionsmikroskop
https://vorsam.uni-ulm.de/vs/Versuche/EM/pdf/EM015V00.pdf
https://physik-phsg.de/Feldemissionsmikroskopie/aufbau6.html


[Admin edit - combined links into single post]

Superbly identified, and what a fascinating device.  There is another example and still more info on the website of Giorgio Basile, http://lampes-et-tubes.info/dt/dt024.php?l=e