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.

electron rich, electron-rich
Having available electrons which can be contributed to an electron-poor atom or a group of atoms.
electron ring accelerator, ERA
A proposed particle accelerator in which protons to be accelerated are trapped by the space charge of a ring of relativisitic electrons which is then accelerated.
electron scanning
1. The moving of an electron beam back and forth and/or up and down by deflecting the beam electromagnetically or electrostatically.
2. A deflection of a beam of electrons, at regular intervals, across a crt screen (display that is electronically created on the surface of the large end of a cathode-ray tube), according to a definite pattern.
electron scanning microscope, scanning electron microscope, SEM
An instrument similar to an electron microscope in that a beam of electrons is used to scan the surface of a specimen.

The beam is moved in a point-to-point manner over the surface of the specimen and these electrons are deflected collected, accelerated, and directed against a scintillator.

The large number of photons that are created are converted into an electric signal which, in turn, modulates the beam scanning the surface of the specimen.

electron shell
1. The collection of all the electron states in an atom which have a given principal quantum number and a given orbital angular momentum quantum number.
2. The arrangement of electrons at various distances from the nucleus of an atom, according to the energy that they have.

Those with the least energy are in the shell closest to the nucleus, traditionally called the K shell, which can hold no more than two electrons.

The Q shell, farthest from the nucleus, can hold 98 electrons, but it is never completely filled.

electron spectrometer
A spectrometer which analyzes a substance with electron emissions that are induced by X-rays.
electron spectroscopy
1. A study of the energy of photo-electrons or Auger electrons (a two-electron process) emitted when a substance is bombarded with electrons, ions, or electromagnetic radiation.
2. The study of the energy spectra of photo-electrons or Auger electrons that are emitted from a substance upon bombardment by electromagnetic radiation, electrons, or ions.

It is used to investigate atomic, molecular, or solid-state structure, and in chemical analysis.

electron spectrum
1. A diagram, a graph, or other display indicating the intensity of electrons emitted by an irradiated substance with respect to the kinetic energy of the electrons.
2. A visual display, photograph, or graphical plot of the intensity of electrons emitted from a substance bombarded by X-rays or other radiation as a function of the kinetic energy of the electrons.
electron spin
1. The twirling motion of an electron, independent of any orbital motion.
2. The intrinsic half-integer angular momentum of an electron.
3. That property of an electron that gives rise to its angular momentum around an axis within the electron.

Spin is one of the permanent and basic properties of the electron.

electron spin density
The vector sum of the spin angular momenta of electrons at each point in a substance per unit volume.
electron spin resonance spectrometer
A spectrometer or an instrument that produces a spectrum; especially, one in which wavelength, energy, intensity, etc., can be measured based on electron paramagnetic resonance.
electron stain
A substance; such as, phosphotungstic acid or osmic acid that scatters large numbers of electrons and so can be used to stain objects to be examined by an electron microscope.
electron stream potential, electron-stream potential
1. The time average of the potential difference between a given point in an electron stream and the surface at which electrons are produced.
2. At any point in an electron stream, the time average of the potential difference between that point and the electron-emitting surface.
electron stream transmission efficiency, electron-stream transmission efficiency
An electrode through which the electron stream (beam) passes.

This includes the ratio of the average stream current through the electrode to the stream current approaching the electrode.

electron synchrotron
1. A machine which accelerates electrons in a circular path by keeping the frequency of the accelerating stream at a constant level while increasing the strength of the magnetic field guiding the stream.
2. A circular electron accelerator in which the frequency of the accelerating system is constant, the strength of the magnetic guide field increases, and the electrons move in orbits of nearly constant radius.
3. A synchrotron (an apparatus used in nuclear physics to produce beams of energetic charged particles and to direct them against various targets) designed to accelerate electrons.

The electron beam is allowed to strike an internal target, producing high-energy gamma rays which are used outside the machine.

The references or sources of information for compiling the words and definitions in this unit are listed at this Electronic Bibliography page or specific sources are indicated when they are appropriate.

A cross reference of word units that are related, directly and/or indirectly, with "electricity": galvano-; hodo-; ion-; piezo-; -tron; volt; biomechatronics, info; mechatronics, info.