POLE LENGTH TAPERING HIGH-PRECISION METHOD FOR TETRODE ELECTROMAGNETIC LENS

摘要

PROBLEM TO BE SOLVED: To provide a high-precision method of a tetrode electromagnetic lens used widely for convergence of particle beam in a particle accelerator. SOLUTION: The tetrode electromagnetic lens is formed so as to have a taper in the cross section of lens axis derection and, a polar length of magnet pole in a diameter direction is optimized, a high-precision method of a tetrode electromagnetic lens is processed by a tapered magnet pole length.