Investigating the Effectiveness of the Proposed Algorithms to Reduce the Simulation Time of the EBAC FEM Gun Code

This paper presents the results of a newly developed 2-D electron beam analyzing code (EBAC) and its capabilities. This finite element cylindrical axis-symmetric code tracks particles by the fourth-order Runge-Kutta method in the local coordinate of elements and calculates steady-state results for both particle trajectories and the emitted current under space-charge limited condition. Two analytical test cases, along with an experimental case are presented to validate the EBAC results. Some techniques have also been developed to augment the basic algorithm of gun codes, dealing with computation of both the emitted current and particle trajectories. These proposed techniques in EBAC have proven to be efficient for reducing convergence time of the basic steady-state algorithm in Pierce-type structures for producing rectilinear electron beam.