Hitachi scanning electron microscopy has a more obvious technical advantage
2017/3/20
Hitachi Scanning Electron Microscope is a fine electronic instrument developed in the 1960s. Using the Hitachi Scanning Electron Microscope, you can investigate the appearance of the bulk sample, and then draw the concept of the stereoscopic layout of the sample. The sunrise scanning electron microscope illumination system is similar to that in transmission electron microscopy. But not the same is the scanning electron microscope has some unique needs, such as by the condenser after the arrival of the sample at the electron beam should be very small diameter of the electron probe; electron beam can be used for scanning movement; final condenser plan should be easy to signal Collecting and so on. Hitachi scanning electron microscopy is mainly the use of secondary electronic signal imaging to observe the surface morphology of the sample, that is, with a very narrow electron beam to scan the sample, through the electron beam interaction with the sample to produce a variety of effects, which is the main sample Electron emission.
Hitachi Scanning Electron Microscope consists of three major components: a vacuum system, an electron beam system, and an imaging system.
Vacuum system - mainly including vacuum pump and vacuum column two parts. The vacuum column is a sealed cylindrical container. The vacuum pump is used to generate a vacuum in the vacuum column.
Electron beam system ---- electron beam system consists of electron gun and electromagnetic lens composed of two parts, mainly used to produce a bundle of energy distribution is very narrow, electron energy to determine the electron beam for scanning imaging. Electron guns are used to generate electrons, mainly using the field emission effect to produce electrons and use the heat emission effect to produce electrons.
Imaging system ---- electronic through a series of electromagnetic lens bundles, hit the sample and the sample interaction, will produce secondary electrons, back scattered electrons, electronic leather and X-ray and a series of signals. So different detectors such as secondary electron detectors, X-ray spectrum analyzers, etc., are needed to distinguish these signals to obtain the desired information.
Hitachi Scanning Electron Microscope Principle
Hitachi scanning electron microscopy working principle is mainly the use of secondary electronic imaging, Hitachi scanning electron microscopy working principle is this: from the electron gun filament issued by the diameter of about 20 ~ 35μm electron beam, by the anode 1 ~ 40kV high pressure accelerating mirror Tube, and by the first, dimer mirror and the convergence of the objective lens, narrowed into a diameter of about tens of angstroms of the narrow electron beam shot on the sample.
At the same time, the deflection yoke causes the electron beam to be scanned in a grating on the sample. Electron beam interaction with the sample will produce a variety of signals, the most important of which is secondary electrons. Since the circuit that controls the scanning coil of the electron beam to control the electron beam also controls the scanning of the electron beam of the picture tube on the screen. Hitachi Scanning Electron Microscope In this way, like the TV screen on the same, little by little, line up to form a like.
The image is a stereoscopic image that reflects the surface structure of the specimen. In order to make the surface of the specimen emitted secondary electrons, specimens in the fixed, dehydrated, to spray a layer of heavy metal particles, heavy metals in the electron beam under the bombardment of secondary electronic signals.
