Patent ID: 7655891
Filing Date: 2010-02-02
Classification: H01J

Abstract:
1. A charged-particle detecting apparatus, comprising: a micro channel plate, arranged on a plane crossing a predetermined reference axis, emitting secondary electrons multiplied therein in response to incidence of charged particles, said micro channel plate having an incidence surface on which the charged particles are made incident and an exit surface which faces said incidence surface and emits the secondary electrons; a first electrode arranged so as to cover said incidence surface of said micro channel plate while crossing the reference shaft, said first electrode having an opening through which the charged particles going toward said micro channel plate pass; a second electrode arranged so as to sandwich said micro channel plate together with said first electrode while crossing the reference axis, said second electrode having an opening through which the secondary electrons outgoing from said exit surface of said micro channel plate pass; a third electrode arranged so as to sandwich said second electrode together with said micro channel plate while crossing the reference axis; a signal output part including a signal line electrically connected to said third electrode; and a rear cover arranged in a state that the reference axis penetrates its internal space so that said rear cover is positioned on the opposite side of said micro channel plate with respect to said third electrode, wherein the surface of said first electrode, excluding a region that faces said micro channel plate, is exposed so as to function as a part of the outer surface of said charged-particle detecting apparatus, and wherein at least said micro channel plate, said second electrode, and said third electrode, which are arranged between said first electrode and said rear cover along the reference axis, have contours whose section sizes are equal to or smaller than that of the contour of said first electrode when viewed from said first electrode side toward said rear cover.