File:23 Nixie tube.jpg

"''We still have an old Nixie tube driven event counter in the lab. Love these things. Alot.

Howsitwork? Each vacuum tube is filled with neon and mercury, and has ten cathodes: one for each number 0-9. High voltage may be applied indepedently to each cathode, causing electrons to accelerate toward the grounded grid. On their way they kick gas atoms causing them to emit a photon. So the right number glows. ''"

from, used on S23 with kind permission of the photographer, fatllama