An Improved Ghost-Point Technique for the Electrostatic Equation with Curved Boundaries and Discontinuous Permittivity in ECR Ion Source PIC Simulations. Commun. Comput. Phys. [Internet]. 2026 Jan. 3 [cited 2026 Feb. 26];39(3):713-46. Available from: https://global-sci.com/index.php/cicp/article/view/23488