Centering Devices for Electron Microscopes

Abstract

The invention discloses a centering device for an electric microscope. The centering device comprises a first connecting seat, a second connecting seat and a connecting structure. The first connecting seat is fixedly connected with an emission source component of the electric microscope, the second connecting seat is connected with a lens cone component and the connecting structure is used for tightly connecting the first connecting seat and the second connecting seat. First arc grooves arranged concentrically with a first through hole are formed on the first connecting seat, and second arc grooves arranged concentrically with a second through hole are formed on the second connecting seat. Geometric center lines of inner arcs and outer arcs of the arc grooves are faced oppositely. Deformation-resistant and insulating supporting pieces are arranged between the first arc grooves and the second arc grooves. Each supporting piece comprises a first cambered surface for being embedded in each first arc groove and a second cambered surface for being embedded in each second arc groove. The chord length of the cambered surfaces is no smaller than the groove width of the corresponding arc grooves. Round grooves formed in the prior art are replaced by the arc grooves formed on the end surfaces of the upper connecting seat and the lower connecting seat, so that centering accuracy required by the electric microscope is reached.

Description

technical field [0001] The invention relates to a centering device applied to an electron microscope, in particular to an insulating parallel centering device in which an emission source part and a lens barrel part are connected in an ultra-high vacuum, belongs to the field of instruments and meters, and specifically relates to electron microscope technology. Background technique [0002] The emission source component (electron gun) is a tiny high-brightness electron source, usually working at an accelerating voltage of 30kV, and is a key component in the electron optical system. Its function is to provide a stable electron source for the entire lens system to form an electron beam. Due to the small diameter of the electron beam, the path in the lens system is very long, and the requirements for insulation, parallelism, and coaxial precision are relatively high. Therefore, a special centering device is required, which can be connected to the emission source component at one e...

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Problems solved by technology

[0005] For this reason, the technical problem to be solved by the present invention is that the upper and lower connecting seats of the centering device in the prior art produce large size errors and shape errors during the processing of the circular holes in the circumferential direction, which cannot meet the requirements of the electron microscope. The problem of centering accuracy, so as to provide a way to ensure the centering accuracy by forming arc grooves on the end faces of the upper and lower connecting seats, so that the insulating spherical surface is embedded in the arc grooves, instead of forming round holes on the end faces of the upper and lower connecting seats in the prior art , so that the spherical surface of the insulating ball is embedded in the round hole for centering, so as to meet the centering accuracy required by the electron microscope, and the centering device meets the requirements between the emission source part and the lens barrel part of the electron microscope. insulation requirements

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