Ahmad, alaa, A. I. M. Alabdullah, and M. A. Hussein. “the Optimization of the Third Electrode Design in Electrostatic Einzel Lenses”. Jordan Journal of Physics, vol. 18, no. 3, Aug. 2025, pp. 309-17, https://jjp.yu.edu.jo/index.php/jjp/article/view/146.