Plasma round dance

The round dance is the discharge breaking into beads: a chain of evenly spaced luminous clumps standing in the ring like pearls on a thread. Textbooks call them standing striations, ionization waves that stopped moving; here they hold formation and drift along the ring, hence the name. The effect is not tied to one gas, the same dance shows up white, red, blue and cyan across different fills.

Periodic Table of Plasma