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'''Transmission Electron Microscopy''' (TEM) is a microscopy technique in which a thin beam of rapidly moving electrons is transmitted through an ultra-thin specimen, interfering with the specimen placed in the tube and producing a black-and-white resulting image at very high resolution. The electron microscope consists of a cylindrical tube, which is devoid of air. The electrons are emitted by the cathode at the top of the tube and then accelerated by the anode. They then pass through a small aperture (metallic plate), which forms them into the beam in the vacuum inside the tube. The part of the microscope that generates the beam is sometimes called the electron gun. The beam is maintained along the tube by means of electromagnetic lenses. These are coils that surround the tube at given intervals. The electromagnetic field emitted by the coils focuses the beam at the center of the tube. Electromagnetic lenses are used to deflect the path of the electrons. Two condenser lenses control the "illumination" of the sample (how bright and how large the area illuminated) followed by the objective lens, which combines the scattered with unscattered electrons to give a contrasted image. After the objective lens follow a number of intermediate imaging lenses paired with apertures that are used to change the magnification from 50x to 400,000x. The image can be observed on a phosphorous screen or on a monitor.
'''Transmission Electron Microscopy''' (TEM) is a microscopy technique in which a thin beam of rapidly moving electrons is transmitted through an ultra-thin specimen, interfering with the specimen placed in the tube and producing a black-and-white resulting image at very high resolution. The electron microscope consists of a cylindrical tube, which is devoid of air. The electrons are emitted by the cathode at the top of the tube and then accelerated by the anode. They then pass through a small aperture (metallic plate), which forms them into the beam in the vacuum inside the tube. The part of the microscope that generates the beam is sometimes called the electron gun. The beam is maintained along the tube by means of electromagnetic lenses. These are coils that surround the tube at given intervals. The electromagnetic field emitted by the coils focuses the beam at the center of the tube. Electromagnetic lenses are used to deflect the path of the electrons. Two condenser lenses control the "illumination" of the sample (how bright and how large the area illuminated) followed by the objective lens, which combines the scattered with unscattered electrons to give a contrasted image. After the objective lens follow a number of intermediate imaging lenses paired with apertures that are used to change the magnification from 50x to 400,000x. The image can be observed on a phosphorous screen or on a monitor.