Influence of the gas-flow Reynolds number on a plasma column in a glass tube

Atmospheric-plasma generation inside a glass tube is influenced by gas stream behavior as described by the Reynolds number (Rn). In experiments with He, Ne, and Ar, the plasma column length increases with an increase in the gas flow rate under laminar flow characterized by Rn   4000, the length of the plasma column is short in front of the electrode, eventually leading to a shutdown.