electro-, electr-, electri-
(Greek > Latin: electric, electricity; from amber, resembling amber, generated from amber which when rubbed vigorously [as by friction], produced the effect of static electricity)
Electronics in our lives consists of numerous tools
Equipment which we use everyday relies on electronics to function including calculators, car controls, cameras, washing machines, medical scanners, mobile telephones, radar systems, computers; as well as many other applications or devices which are listed in this unit.
2. In a cathode tube, the electrode which serves as a source for electrons.
2. A quantum-mechanical concept for energy levels of electrons around the nucleus.
Electron energies are functions of each particular atomic species.
2. A current produced by the motion of free electrons toward a positive terminal.
The direction of electron flow is opposite to that of the current.
2. A measure of time-integrated particle flux, expressed in particles per square centimeter.
It is used for electrons in electron irradiation and for neutrons in connection with the effects of nuclear radiation on electronic components.
Each electron goes to form the communal "electron gas" which is responsible for the high electrical and thermal conductivity of the metallic state.
2. A device that directs a steady stream of electrons in a desired direction; for example, in a cathode-ray tube.
Electron guns are also used in oil refining and various other industries.3. An electrode structure that produces and may control, focus, and deflect a beam of electrons; such as, in a television picture tube, where the beam produces a visual pattern on the tube's screen.
The source of the electron beam is the cathode, a flat metal support covered with oxides of barium and strontium.
When they are heated by a coil behind the support, these oxides produce electrons, that are drawn toward a positively charged sleeve (first anode) which is contoured to allow the electron beam to flow within the inside diameter.
The beam is then electrostatically constricted and collimated by a metal disk with a hole (the
2. In a semiconductor, the electron vacancy in the valence (combining power of atoms) band that occurs when an electron jumps the gap from the filled valence band to the empty conduction band.
It serves as a positive charge carrier, allowing electrons deeper in the band to move into the vacated area.
A valence is the combining power of atoms or groups measured by the number of electrons the atom or group will receive, give up, or share in forming a compound.
2. A representation of an object formed by a beam of electrons focused by an electron optical system.
3. An image formed in a stream of electrons.
The electron density in a cross section of the stream is at each point proportional to the brightness of the corresponding point in an optical image.
2. An electron tube which reproduces on its fluorescent screen an image of the optical image or other irradiation pattern arriving at or striking its photosensitive surface.
3. A cathode-ray tube that has a photoemissive mosaic upon which an optical image is projected, and an electron gun to scan the mosaic and to convert the optical image into a corresponding electrical current.
2. The emission of electrons from one solid into another solid.
3. The process of injecting a beam of electrons with an electron gun into the vacuum chamber of a mass spectrometer, betatron, or other large electron accelerator.
4. The procedure used in forcing a beam of electrons into any large electron accelerator; such as, a beatatron by using an electron gun.
2. An electric or magnetic field, or a combination of such, that acts upon an electron beam in a manner similar to that in which an optical lens acts upon a light beam.
3. A tool which uses an electromagnetic field to refract an electron beam in a manner similar to the refraction of light by an optical lens.
4. A system of deflecting electrodes or coils designed to produce an electric field which influences a beam of electrons in the same manner that a lens affects a light beam.
5. An electric field used to focus a stream of electrons on a target.