Study on Influence of Temperature on Field Emission Performance of Metals

Abstract

The electrons escaping from metal surfaces driven by an external electric field are invariably associated with radio-frequency breakdown of microwave systems, seriously limiting the physical performance of accelerators and electronic devices. In this paper, the influence of temperature on the field emission characteristics of metals has been investigated. It is experimentally revealed that the field emission performance of titanium and oxygen-free copper is greatly improved when the temperature is increased within 100 degrees centigrade. The field-emission current of oxygen-free copper at 105℃ increases to 4.0 times its value at room temperature as the intensity of the applied electric field remains 140 kV/cm, while the field-emission current of titanium at 150℃ is 14.6 times that at room temperature under an electric field strength of 190 kV/cm. These experimental phenomena are not consistent with the traditional metal model. Afterwards, the thermal-field emission theory of dielectric microdot is introduced to reasonably explain the promotion of temperature on the field-emission characteristics of these two metals, indicating that the dielectric microdots on the surface dominate the thermal-field emission of metals. The new discovery can provide theoretical guidance for suppressing vacuum breakdown in microwave devices and accelerators.

Keywords: field electron emission, Electron Beam