Ambient gas properties of field emission devices

In order to study whether the ambient gases affect the emission current stability of the cathode, the cathode should be the same one. In addition, the working condition should be kept constant except the ambient gas condition, so that other factors, which may also lead to the emission current degradation of the cathode, can be avoided. Only the influence from the residual gases will be concerned. For this consideration, an experimental system was set up, as shown in Fig. 1. It consisted of a vacuum system with a quadrupole mass spectrometer (QMS) and FE device opening set to introduce the residual gases inside the FE device into the analysis system.