File:Plasma tubes containing neon mixtures.ogv

English: Five electrodeless discharge tubes containing neon as the principal ingredient are demonstrated and discussed. A high-frequency, high-voltage power supply is used to excite the gas. Electrical breakdown in neon emits an iconic red color under the low-pressure conditions found in neon signs, but at the high pressures of interest in much plasma sculpture, it is more difficult to coax beautiful effects from this gas. Its low atomic weight means it is efficient at dissipating heat by diffusion, making it reluctant to form filamentary discharges like xenon and krypton; furthermore, its characteristic red emissions are washed out in high pressure glows. So, to produce vibrant colors and filamentary arcs, the neon is "doped" with small amounts of other gases and vapors. I show what obtains when neon is doped with (1) nitrogen; (2) oxygen and krypton; (3) 1-bromo-3-chloro-5,5-dimethylhydantoin (BCDMH); (4) iodine; and (5) xenon, nitrogen, and oxygen.