A Ceramic Surface Charging Model for Accurate Prediction of E-Beam Trajectory in Field Emission Digital X-Ray Sources

In a digital x-ray source based on a field-emitted electron beam (e-beam), it is important to control the position and size of the focused e-beam at the anode surface, to achieve required performances. For this purpose, e-beam trajectory prediction is performed using a charged particle optical simulation in the geometries of the designed x-ray tube. In this study, to more accurately predict the e-beam trajectory inside a vacuum-sealed digital x-ray tube whose electrodes are insulated with a ceramic material, we newly introduce a ceramic surface charging (CSC) model into the e-beam trajectory simulation. The obtained e-beam characteristics with the CSC model have been compared with the experimental results, and we found that the proposed CSC model successfully led appropriate to calculation well matched with the experimental tendencies compared to the conventional model.