Field emission and electron beam transmission characteristics of microtips array on the (100) plane of single-crystal Gadolinium hexaboride ceramic

A field-emission microtips array with a radius of curvature, height, and separation distance of 0.5, 5, and 4 mu m, respectively, was processed on the single-crystal Gadolinium hexaboride ceramic (GdB6) (100) plane using a femtosecond laser. The height and morphology of the microtips array were uniform, and the crystal structure and phase composition of GdB6 did not change after the processing. According to the field-emission performance test of a GdB6 microtips array, the turn-on electric field intensity was 1.9 V/mu m, and the field-emission current density reached 0.49 A/cm(2) when the applied electric field strength was 6.7 V/mu m; meanwhile, it had outstanding field-emission stability. Subsequently, the transmission process of the field-emission current of the GdB6 between the cathode and the anode was simulated using COMSOL Multiphysics 5.6 software. The transmission process of the electron beam from emitters to the anode surface was divided into three stages due to the interaction between emission electrons and a magnetic field generated by its motion, including divergence, pinch, and drift. The increase of electric field strength reduced the radial displacement of the electron beam while moving the beam waist further away from the anode surface. The simulation results provide theoretical guidance for regulating the shape of the field-emission electron beam, size, and energy.