“Effect of the Gap Size Between the Cathode and the Wehnelt Cylinder Bore on the Emittance of the Thermionic Electron Gun”. Iraqi Journal of Science 63, no. 8 (August 31, 2022): 3382–3389. Accessed May 4, 2024. https://ijs.uobaghdad.edu.iq/index.php/eijs/article/view/4981.