Synthetic amethyst is produced by gamma-ray, x-ray or electron beam irradiation of clear quartz which has been first doped with ferric impurities.

Analog television did not really begin as an industry until the development of the cathode-ray tube ( CRT ), which uses a steered electron beam to " write " lines of electrons across a phosphor coated surface.

It has a means to accelerate and deflect the electron beam onto the fluorescent screen to create the images.

Cathode rays ( also called an electron beam or e-beam ) are streams of electrons observed in vacuum tubes.

The technology of manipulating electron beams pioneered in these early tubes was applied practically in the design of vacuum tubes, particularly in the invention of the cathode ray tube by Ferdinand Braun in 1897. and is today employed in sophisticated devices such as electron microscopes, electron beam lithography, and particle accelerators.

Most radios and television sets prior to the 1970s used filament-heated-cathode electron tubes for signal selection and processing ; to this day, a hot cathode forms the source of the electron beam ( s ) in cathode ray tubes in many television sets and computer monitors.

These large-scale technological program demonstrations were joined by integrated circuit research, which resulted in submicrometre electronic technology and electron devices that evolved into the Very Large Scale Integration ( VLSI ) Program and the Congressionally mandated charged particle beam program.

This welding technique must be performed in a vacuum, so that the electron beam does not interact with the gas prior to reaching the target, and it can be used to join conductive materials that would otherwise be considered unsuitable for welding.

Because an electron beam only penetrates to a limited depth before being absorbed, typically up to 5 cm for electron energies in the range 5 – 20 MeV, electron therapy is useful for treating skin lesions such as basal cell carcinomas.

An electron beam can be used to supplement the treatment of areas that have been irradiated by X-rays.

The intensity of this radiation is spin dependent, which causes polarization of the electron beam — a process known as the Sokolov – Ternov effect.

Low-energy electron diffraction ( LEED ) is a method of bombarding a crystalline material with a collimated beam of electrons, then observing the resulting diffraction patterns to determine the structure of the material.

The reflection high energy electron diffraction ( RHEED ) technique uses the reflection of a beam of electrons fired at various low angles to characterize the surface of crystalline materials.

The electron microscope directs a focused beam of electrons at a specimen.

By recording these changes in the electron beam, microscopists can produce atomically resolved image of the material.

Transmission electron microscopes function in a manner similar to overhead projector, with a beam of electrons passing through a slice of material then being projected by lenses on a photographic slide or a charge-coupled device.

In scanning electron microscopes, the image is produced by rastering a finely focused electron beam, as in a TV set, across the studied sample.

In the free electron laser ( FEL ), a relativistic electron beam is passed through a pair of undulators containing arrays of dipole magnets, whose fields are oriented in alternating directions.

With de Broglie's suggestion of the existence of electron matter waves in 1924, and for a short time before the full 1926 Schrödinger equation treatment of hydrogen like atom, a Bohr electron " wavelength " could be seen to be a function of its momentum, and thus a Bohr orbiting electron was seen to orbit in a circle at a multiple of its half-wavelength ( this historically incorrect Bohr model is still occasionally taught to students ).

In chemistry, Schrödinger, Pauling, Mulliken and others noted that the consequence of Heisenberg's relation was that the electron, as a wave packet, could not be considered to have an exact location in its orbital.

As a result, an electron could always radiate energy and fall into a negative energy state.

To prevent this unphysical situation from happening, Dirac proposed that a " sea " of negative-energy electrons fills the universe, already occupying all of the lower-energy states so that, due to the Pauli exclusion principle, no other electron could fall into them.

The modern terms " electricity " and " electron " derive from the Greek word for amber, and come from William Gilbert's research showing that amber could attract other substances.

This work showed that the quantum approach to chemical bonds could be fundamentally and quantitatively correct, but the mathematical methods used could not be extended to molecules containing more than one electron.

For example, when a laboratory apparatus was developed that could reliably fire one electron at a time through the double slit, the emergence of an interference pattern suggested that each electron was interfering with itself, and therefore in some sense the electron had to be going through both slits at once — an idea that contradicts our everyday experience of discrete objects.

Using quantum theory Dirac showed that if magnetic monopoles exist, then one could explain the quantization of electric charge --- that is, why the observed elementary particles carry charges that are multiples of the charge of the electron.

The latter could be called electron deficiency.

The formation of the clusters could be seen as a way to ' condense out ' ( localize ) the electron deficient bonding into bonds of a more localized nature.

This resolved the solar neutrino problem: the electron neutrinos produced in the Sun had partly changed into other flavors which the experiments could not detect.

Alice could send bits to Bob in the following way: If Alice wishes to transmit a " 0 ", she measures the spin of her electron in the z direction, collapsing Bob's state to either or.

He was particularly interested in the possibilities of denser computer circuitry, and microscopes which could see things much smaller than is possible with scanning electron microscopes.

The quantum theory of the atom was developed as an explanation for the electron remaining in its orbit, which could not be explained by Newton's laws of motion and Maxwell's laws of ( classical ) electromagnetism.

Provided the electron gun can generate a beam with sufficiently small diameter, a SEM could in principle work entirely without condenser or objective lenses, although it might not be very versatile or achieve very high resolution.

Only photons of a high enough frequency ( above a certain threshold value ) could knock an electron free.

More intense light above the threshold frequency could release more electrons, but no amount of light ( using technology available at the time ) below the threshold frequency could release an electron.

It is thought that the outlet temperature could be raised to that of the 8000 K to 15000 K range where the exhaust would be a fission-generated non-equilibrium electron gas, which would be of much more importance for a rocket design.

Hence, the electron paramagnetic effects ( slope ) can be separated from the nuclear effects ( intercept ).

for example, gamma rays give deeper penetration but cannot be focused or collimated, whereas unidirectional electron beams may be split and directed to both the top and bottom of the food package to be irradiated.

The electron optical system may be either a magnetic or electrostatic one.

It should be noted, however, that the paraxial resolution is quite similar for both electron optical systems.

It should be noted that photoluminescence, due to `` Bremsstrahlung '' generated within the viewing screen by electron impact, appears to be important only if anode voltages in excess of 30 KV are utilized.

The charges of the electron and proton are believed to be exactly equal and opposite, but Dr. Lyttleton is not so sure.

Thus, the planetary model of the atom was discarded in favor of one that described atomic orbital zones around the nucleus where a given electron is most likely to be observed.

The electron is by far the least massive of these particles at, with a negative electrical charge and a size that is too small to be measured using available techniques.

Protons have a positive charge and a mass 1, 836 times that of the electron, at, although this can be reduced by changes to the energy binding the proton into an atom.

This function can be used to calculate the probability of finding any electron of an atom in any specific region around the atom's nucleus.

The term may also refer to the physical region where the electron can be calculated to be, as defined by the particular mathematical form of the orbital.

In this model the electron cloud of a multi-electron atom may be seen as being built up ( in approximation ) in an electron configuration that is a product of simpler hydrogen-like atomic orbitals.

# The electrons are never in a single point location, although the probability of interacting with the electron at a single point can be found from the wave function of the electron.

A more accurate analogy might be that of a large and often oddly shaped " atmosphere " ( the electron ), distributed around a relatively tiny planet ( the atomic nucleus ).

When more electrons are added to a single atom, the additional electrons tend to more evenly fill in a volume of space around the nucleus so that the resulting collection ( sometimes termed the atom ’ s “ electron cloud ” ) tends toward a generally spherical zone of probability describing where the atom ’ s electrons will be found.

Atomic orbitals can be the hydrogen-like " orbitals " which are exact solutions to the Schrödinger equation for a hydrogen-like " atom " ( i. e., an atom with one electron ).