A Numerical Method to Magnetic Field Problems of Electromagnetic Focusing System of High Resolution Project Tube

A pecular boundary element is defined in the boundary of the eletromagnetic focusing system instead of the conventional define method of BEM to boundary in this paper, which can employ less boundary elements without reducing the calculation precision. The irregular matrix elements of the matrix equation is also simplified. It takes less time to run numerical calculation than common methods. When the method is used in electron gun CAD, the period of design is shorten and the precision is improved.