Second condenser lens for electron microscope

Abstract

The invention discloses a second condenser lens for an electron microscope, and belongs to the field of electron microscopes. The second condenser lens comprises a shell, a lower cover plate, a magnet ring, a magnetic path coil, a water jacket space ring assembly, a gasket, a pole shoe assembly, a fixed diaphragm assembly and an anastigmatic assembly, wherein the shell is an annular cylindrical cavity of which both ends are provided with an opening; the lower cover plate is used for covering an opening at the lower end of the shell; the magnetic path coil is sleeved outside the magnet ring, and the magnetic path coil and the magnet ring are arranged in the shell; the water jacket space ring assembly is arranged below the magnetic path coil; the lower cover plate is arranged below the water jacket space ring assembly; through holes are formed on the middle parts of the lower cover plate, the magnet ring and the water jacket space ring assembly, the three through holes are communicated with one another, and the gasket and the pole shoe assembly are arranged in the communicated through holes sequentially from top to bottom; through holes are formed in the gasket and the pole shoe assembly, and are communicated mutually; and the fixed diaphragm assembly and the anastigmatic assembly are arranged in the communicated through holes sequentially from top to bottom. By the second condenser lens, beam spots, which are shrunken by a first condenser lens, of cross points of an electron gun can be amplified appropriately, so that the sizes of electron beam spots are changed, the beam spots of different sizes can be provided for different samples, and the performance of the electron microscope is improved.

Description

technical field [0001] The invention relates to the technical field of electron microscopes, in particular to a second condenser lens of an electron microscope. Background technique [0002] The electron microscope is an important instrument that can observe tiny substances, and can observe substances below 0.25nm. Electron microscopes use electron beams as illumination sources, and magnetic lenses or electrostatic lenses as devices for deflecting electrons to achieve optical magnification. Electron microscopes have very broad application prospects in military and civilian fields such as physics, chemistry, materials, scientific research, life sciences, geology, prospecting, machinery industry, and electronics industry. [0003] The electron microscope irradiates the sample through the electron beam to realize the observation of the sample. The electron gun and the condenser lens are the illumination system of the electron microscope. The electron microscope requires that ...

AI Technical Summary

Problems solved by technology

For a high-performance electron microscope, different beam spot sizes should be provided for different samples. In the early electron microscopes, a single condenser was generally set up, which could only provide a fixed beam spot diameter, and could not change the electron beam spot size. Different samples provide different beam spot sizes

Images