Development of 3D charged particle trajectory calculation software and its application to X-ray tube design

摘要

3D charged particle trajectory calculation software was developed, which properly takes into account "the space charge effect" and makes it possible to simulate charged particle trajectories within vacuum tubes operated with comparatively high current, such as medical X-ray tubes. The software can also estimate automatically the current density on the cathode surface in either the temperature or space charge limited condition. The calculation is performed combining several "module programs". The data file flow is made as clear as possible so that the software users can understand, without any difficulty, how the calculation is done. The developed program has been applied to the analysis of a medical X-ray tube and was found to produce the calculation results consistent with the experimental observation. The simulation capability of viewing directly electron trajectories themselves has made it a lot easier to optimize the electron gun design of the tubes.