The Effect of Bore Diameters in Two Electrodes Electrostatic Immersion Lens Design

The paper handles a new method that is utilized in determining the best bore diameter of two electrodes of the electrostatic lens design. However, the bore diameter is considered the most important geometrical parameter in any electron optical device. Accordingly, the immersion electrostatic lens have been designed and its electron optical properties were calculated for different bore diameters of the two electrodes to determine their optimum value. Also the study is concerned with the equal values of the bore diameter for the two electrodes, and the ratios of their first to the second bore diameters found including the calculated value of the optimum bore diameter. It was found that the best electron optical properties were obtained when the ratio of the bore diameters for the electrostatic lens is approximately equal (0.66).