表面電荷法によるショットキー陰極の電界解析

Abstract

Electric field of the ZrO/W Schoｔｔky cathode has been analyzed with the surface charge method. Numerical model consists of the Schottky cathode with the faceted tip，the Schotty shield electrode (suppressor)，the frrst anode (extractor) and the second anode. The field distribution on the tip surface was obtained from the charge density distribution. The dependence of the field strength on the tip radius was examined using the cathode models with different tip radii of 0.2 -1μm. An expression for the field factor was derived from the numerical results. Dependences of the field strength on the cathode tip position and the distance from the shield to frrst anode were also described.