MULTIPOLAR LENS, OBSERVATION DEVICE PROVIDED WITH THE MULTIPOLAR LENS AND MANUFACTURING METHOD FOR THE MULTIPOLAR LENS

摘要

PROBLEM TO BE SOLVED: To provide a multipolar lens with little magnetic field fluctuation and an observation device provided with the multipolar lenses. SOLUTION: This multipolar lens 4a has a plurality of pole elements 23 having held parts 22c, a circular holding member 25 holding the held parts 22c of the pole elements 23 and a circular yoke 29 arranged outside the holding member 25 and magnetically combined with base end parts of the pole elements 23. The yoke 29 is provided with an opening formed long in its peripheral direction, and the base end parts of the pole elements 23 are arranged in the opening 29a. COPYRIGHT: (C)2005,JPO&NCIPI