Since the mid-20th century, electron-beam technology has provided the basis for a variety of novel and specialized applications in semiconductor manufacturing, microelectromechanical systems, nanoelectromechanical systems, and microscopy.
Free electrons in a vacuum can be manipulated by electric and magnetic fields to form a fine beam. Where the beam collides with solid-state matter, electrons are converted into heat or kinetic energy. This concentration of energy in a small volume of matter can be precisely controlled electronically, which brings many advantages.
The rapid increase of temperature at the location of impact can quickly melt a target material. In extreme working conditions, the rapid temperature increase can even lead to evaporation, making an electron beam an excellent tool in heating applications, such as welding. Electron beam technology is used in cable-isolation treatment, in electron lithography of sub-micrometer and nano-dimensional images, in microelectronics for electron-beam curing of color printing and for the fabrication and modification of polymers, including liquid-crystal films, among many other applications.
Electron-beam furnace
In a vacuum, the electron beam provides a source of heat that can melt or modify any material. This source of heat or phase transformation is absolutely sterile due to the vacuum and scull of solidified metal around the cold copper crucible walls. This ensures that the purest materials can be produced and refined in electron-beam vacuum furnaces. Rare and refractory metals can be produced or refined in small-volume vacuum furnaces. For mass production of steels, large furnaces with capacity measured in metric tons and electron-beam power in megawatts exist in industrialized countries.
Electron-beam welding
Since the beginning of electron-beam welding on an industrial scale at the end of the 1950s, countless electron-beam welders have been designed and are being used worldwide. These welders feature working vacuum chambers ranging from a few liters up to hundreds of cubic meters, with electron guns carrying power of up to 100 kW.
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A cold cathode is a cathode that is not electrically heated by a filament. A cathode may be considered "cold" if it emits more electrons than can be supplied by thermionic emission alone. It is used in gas-discharge lamps, such as neon lamps, discharge tubes, and some types of vacuum tube. The other type of cathode is a hot cathode, which is heated by electric current passing through a filament. A cold cathode does not necessarily operate at a low temperature: it is often heated to its operating temperature by other methods, such as the current passing from the cathode into the gas.
Transmission electron microscopy (TEM) is a microscopy technique in which a beam of electrons is transmitted through a specimen to form an image. The specimen is most often an ultrathin section less than 100 nm thick or a suspension on a grid. An image is formed from the interaction of the electrons with the sample as the beam is transmitted through the specimen. The image is then magnified and focused onto an imaging device, such as a fluorescent screen, a layer of photographic film, or a sensor such as a scintillator attached to a charge-coupled device.
Thermionic emission (also known as thermal electron emission or the Edison effect) is the liberation of electrons from an electrode by virtue of its temperature (releasing of energy supplied by heat). This occurs because the thermal energy given to the charge carrier overcomes the work function of the material. The charge carriers can be electrons or ions, and in older literature are sometimes referred to as thermions. After emission, a charge that is equal in magnitude and opposite in sign to the total charge emitted is initially left behind in the emitting region.
Ce cours d'introduction à la microscopie a pour but de donner un apperçu des différentes techniques d'analyse de la microstructure et de la composition des matériaux, en particulier celles liées aux m
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Histology, also known as microscopic anatomy or microanatomy, is the branch of biology that studies the microscopic anatomy of biological tissues. Histology is the microscopic counterpart to gross anatomy, which looks at larger structures visible without a microscope. Although one may divide microscopic anatomy into organology, the study of organs, histology, the study of tissues, and cytology, the study of cells, modern usage places all of these topics under the field of histology.
Solid-state physics is the study of rigid matter, or solids, through methods such as solid-state chemistry, quantum mechanics, crystallography, electromagnetism, and metallurgy. It is the largest branch of condensed matter physics. Solid-state physics studies how the large-scale properties of solid materials result from their atomic-scale properties. Thus, solid-state physics forms a theoretical basis of materials science. Along with solid-state chemistry, it also has direct applications in the technology of transistors and semiconductors.
A vacuum tube, electron tube, valve (British usage), or tube (North America), is a device that controls electric current flow in a high vacuum between electrodes to which an electric potential difference has been applied. The type known as a thermionic tube or thermionic valve utilizes thermionic emission of electrons from a hot cathode for fundamental electronic functions such as signal amplification and current rectification.
Learn about the fundamentals of transmission electron microscopy in materials sciences: you will be able to understand papers where TEM has been used and have the necessary theoretical basis for takin
Learn about the fundamentals of transmission electron microscopy in materials sciences: you will be able to understand papers where TEM has been used and have the necessary theoretical basis for takin
Active in robotic solutions, nanometer scale and semiconductor industry. Imina Technologies Sàrl offers high-precision robotic solutions for interacting with and characterizing samples at the nanometer scale under light and electron microscopes, trusted by leading semiconductor companies and research institutes globally.
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