Modeling of the Influence of Thermal-Field Electron Emission from the Cathode with a Thin Insulating Film on its Heating in Glow Discharge

A model of glow gas discharge in the presence of a thin insulating film on the cathode is formulated. It takes into account, along with ion-induced secondary electron emission from the cathode surface, also the thermal-field emission of electrons from the cathode metal substrate into the film under a strong electric field generated in the insulator when the current flows in the discharge. The electric-field strength in the film in the steady-state discharge mode is determined from the condition of equality of the discharge current density and the current density of thermal-field electron emission from the cathode metal substrate into the film. The dependences of the film-emission efficiency, the cathode effective ion-electron emission yield and the discharge characteristics on its burning time are calculated. It is shown that already at a cathode temperature exceeding room temperature by several hundred degrees, the thermal-field mechanism of electron emission from the metal substrate into the film can have a noticeable influence on the emission properties of the cathode, the discharge current density and the intensity of its heating in the discharge.

Automated summary

A model of glow gas discharge in the presence of a thin insulating film on the cathode is proposed, taking into account ion-induced secondary electron emission and thermal-field emission of electrons. The study shows that the thermal-field mechanism can significantly influence the emission properties and discharge characteristics at high cathode temperatures.