부산대학교 도서관

New equations of motion to describe the coupling phenomena between the transverse and longitudinal coordinates in the accelerators are derived from D’Alembert’s principle. To consider the longitudinal motion, the new coordinate system comoving with the ideal particle is suggested. The newly derived coupled equations of motion with the new coordinate system is useful in investigating the coupling not only in the storage ring but also in steady-state microbunching (SSMB) and in X-ray free-electron laser (XFEL).