Discharge Characteristics in Hollow Cathode Filled with Helium/Argon Mixture:A Simulation Study

The discharge in He/Ar hollow cathode was mathematically modeled, theoretically analyzed in fluid dynamics and numerically simulated to deepen the understanding of discharge mechanisms.The “cathode potential rapid dropping” and “negative glow” zones were found to coexist, where the plasma displays significant different properties, including the density and average energy of electron and ion.The simulated results show that the 5% Ar and voltage have a major impact.To be specific, the densities of ion and metastable atom of Ar are higher than those of He, possibly because of a lower ionization energy and a stronger impact of Ar atom on secondary electron emission.As the voltage increases, the ionization rate, ion density and electron density increased, simply due to the increases of electric field strength and electron energy.