Computing root mean square radius of electrostatic imaging tubes and evaluating imaging quality

Aim: To research on a method for evaluating of imaging quality in electron optics imaging sys tems. Methods: Based on the theory of root mean square, computing a large number of dropping points by tracing space electron trajectories and the system's root mean square radius. Based on these, computing the modulation transfer function of imaging syst e m, and utilizing the traditional computation method to check it. Results: With practical imaging tubes, the computation results of root mean square radius and the point diagram were offered, and it was confirmed that computing the modulation transfer func tion has higher precision utilizing the root mean square radius. Conclusion: Evaluating the system imaging quality by the root mean square radius can be applied in practical imaging systems.