Electron transfer ET is the process by which an electron moves from an atom or a chemical species e.g. ..., and detoxification. Additionally, the process of energy transfer can be formalized as a two electron .... ISBN 0 12 352651 5. ref but there are now many examples of ET in organic chemistry . Classes of electron transfer There are several classes of electron transfer, defined by the state of the two redox centers and their connectivity Inner sphere electron transfer main Inner sphere electron transfer ..., in which case the electron transfer event is termed intramolecular electron transfer. More ... following the ET event. In such cases, the electron transfer is termed intermolecular electron ... partners. Outer sphere electron transfer main Outer sphere electron transfer In outer sphere ET reactions ..., the electron hops through space from the reducing center to the acceptor. Outer sphere electron transfer ... describes the Degenerate energy level degenerate reaction between permanganate and its one electron ... Mn O sub 4 sub sup sup In general, if electron transfer is faster than ligand substitution, the reaction will follow the outer sphere electron transfer. Often occurs when one both reactants are inert ... work w sub r sub 2. changing bond lengths, reorganize solvent activated complex 3. Electron transfer ... work w sub p sub Heterogeneous electron transfer main Heterogeneous electron transfer In heterogeneous electron transfer, an electron moves between a chemical species and a solid state electrode . Theories addressing heterogeneous electron transfer have applications in electrochemistry and the design ... to address outer sphere electron transfer and was based on a transition state theory approach. The Marcus theory of electron transfer was then extended to include inner sphere electron transfer ... most discussions of electron transfer ever since. Both theories are, however, semiclassical in nature ... of vibronic coupling on electron transfer. In particular the PKS theory of electron transfer ... more details
Electron Equivalent is a concept commonly used in redox chemistry , reactions involving electron transfer , to define a quantity e.g. energy or moles relative to one electron. Gibbs free energy Energies of formation are often given as kilojoules per electron equivalent to enable calculation of specific reaction energies on a per electron basis. Reactions containing movement of electrons are often balanced such that reaction quantities are given in relation to the transfer of a single electron, allowing quantification of reactants and products in relation to a single electron transfer. References Refbegin cite book last1 Rittman first1 B.E. last2 McCarty first2 P.L. title Environmental Biotechnology Principles and Applications publisher McGraw Hill date 2001 page 60 isbn 0072345535 cite book last1 Schwarzenbach first1 Rene P. last2 Gschwend first2 Philip M. last3 Imboden first3 Dieter title Environmental Organic Chemistry edition 2nd date 2003 isbn 0471357302 publisher John Wiley & Sons page 568 cite book last1 Sayyar first1 Bahareh title Thermodynamic electron equivalent models for Geobacter species publisher University of Toronto Canada date 2008 isbn 0494449144 Refend Category Thermodynamic free energy Category Fundamental physics concepts Category Chemical reactions chemistry stub ... more details
Interventions infobox Name PAGENAME Image Caption ICD10 ICD9unlinked ICD9proc 92.25 MeshID OPS301 OtherCodes Electron therapy or Electron Beam Therapy EBT is a kind of external beam radiotherapy where electrons are directed to a tumor site. Equipment Electron beam therapy is performed using a medical linear accelerator . This device can also be used to produce high energy photon beams. When electrons are required, the x ray target is retracted out of the beam and the electron beam is collimated with a piece of apparatus known as an applicator or an additional collimating insert, constructed from a low melting point alloy. Properties Electron beams have a finite range, after which the dose falls off rapidly. Therefore they spare deeper healthy tissue. The depth of the treatment is selected by the appropriate energy. Indications Electron beam therapy is used in the treatment of superficial tumors like cancer of skin regions, or total skin e.g. mycosis fungoides , diseases of the limbs e.g. melanoma and lymphoma , nodal irradiation, and it may also be used to boost the radiation dose to the surgical bed after mastectomy or lumpectomy . For deeper regions IOERT Intraoperative electron radiation therapy might be applied. References Eric E. Klein Electron Beam Therapy Dosimetry, Planning, and Techniques in Edward C. Halperin, Carlos A. Perez, Luther W. Brady ed. Perez and Brady s Principles and Practice of Radiation Oncology, 5th. edition, 2008 See also Intraoperative Electron Radiation Therapy IOERT IOERT External beam radiotherapy EBRT EBRT Radiation oncology DEFAULTSORT Electron Therapy Category Electron beams in medical applications Category Medical physics Category Radiation oncology ar ... more details
s behalf, Electron later joined the Imperial Guard members in battle against Excalibur comics ... Storm , Electron joined Oracle Marvel Comics Oracle and Flashfire comics Tempest in capturing Rick ... during the Kree Shi ar War. ref Avengers West Coast 80 ref Electron was also among the Imperial Guard members to later lay claim to the devastated Kree Empire after the war. ref Avengers 347 ref Electron ... the conflict. ref Uncanny X Men 480 ref Powers and abilities Electron is a member of the alien race ... hand to hand combatant, trained in armed and unarmed combat by the Shi ar Imperial Guard. Electron has the ability to project electromagnetic energy and move metallic objects. Electron s costume ... had a long run as artist on the Legion . Electron is based on LSH member Cosmic Boy . ref Kaminski, John. Marvunapp http www.marvunapp.com Appendix4 electronimpguard.htm Electron Accessed Apr. 22, 2009. ref References reflist External links http www.marvel.com universe Electron 28alien 29 Electron ... Marvel Comics aliens Category Marvel Comics superheroes tl Electron komiks ... more details
DISPLAYTITLE Electron bird Taxobox name Electron image Electron platyrhynchum Panama 8a.jpg image width 250px image caption Broad billed Motmot regnum Animal ia phylum chordate Chordata classis Aves ordo Coraciiformes familia Motmot idae genus Electron genus authority Johannes Gistel Gistel , 1848 subdivision ranks Species subdivision Keel billed Motmot E. carinatum br Broad billed Motmot E. platyrhynchum Electron is a genus of the motmot s, a family biology family of Neotropics Neotropical near passerine bird s. The genus has two species Keel billed Motmot , Electron carinatum Broad billed Motmot , Electron platyrhynchum Both inhabit humid evergreen tropical forest. Both occur in Central America , and the Broad billed Motmot occurs in a large region of South America as well. They are distinguished from other motmots by their much wider bills. The rackets on their tails are less dramatic than those of many other motmot species and may be absent. The species are very similar except in adult plumage but the adult Keel billed resembles the juvenile Broad billed . A mixed pair apparently courting has been observed Howell and Webb 1995 . The name Electron is a Latin ization of the Ancient Greek word for amber , and can mean bright in scientific names Jaeger 1978 the amber colored eyes of the Keel billed Motmot Howell and Webb 1995 may be the connection. Citation needed date August 2007 The name was given 46 years before an elementary particle was named electron . References Cite book last Howell first Steve N. G. coauthors Webb, Sophie title A Guide to the Birds of Mexico and Northern Central America publisher Oxford University Press pages 439, 790 791 year 1995 isbn 0 19 854012 4 Cite book last Jaeger first Edmund C. authorlink Edmund Jaeger title A Source Book of Biological ... . Accessed 2007 08 17. DEFAULTSORT Electron Bird Category Momotidae Coraciiformes stub ca Electron es Electron ave fr Electron oiseau hu Electron nl Electron geslacht pl Electron ptaki ... more details
Electron diffraction refers to the wave nature of electrons. However, from a technical or practical point ... in this case the incident electron can be described by a wave. For this reason, an electron can be regarded ... ray and neutron diffraction . Electron diffraction is most frequently used in solid state physics and chemistry ... electron microscopy transmission electron microscope TEM , or a scanning electron microscope SEM as electron backscatter diffraction . In these instruments, electrons are accelerated by an electrostatic ... . Apart from the study of crystals i.e. electron crystallography , electron diffraction is also a useful technique to study the short range order of amorphous solids, and the geometry of gas electron ... later for electrons which have a rest mass with the observation of electron diffraction in two independent ... shared the Nobel Prize for Physics in 1937 for their work. Theory Electron interaction with matter ... for electron diffraction, the intensity of a diffracted beam is given by math I mathbf g left ... The wavelength of an electron is given by the wave particle duality de Broglie equation math lambda frac h p math Here math h math is Planck s constant and math p math the relativistic momentum of the electron ... is the mass of the electron, and math e math is the elementary charge.The electron wavelength is then given by math lambda frac h p frac h m 0v frac h sqrt 2m 0eU math However, in an electron microscope, the accelerating potential is usually several thousand volts causing the electron to travel at an appreciable ... of 10,000 volts 10 kV giving an electron velocity approximately 20 of the speed of light, while a typical TEM can operate at 200 kV raising the electron velocity to 70 the speed of light. We therefore need to take relativistic mass relativistic effects into account. It can be shown that the electron ... ray diffraction is in the order of 100 pm Cu k 154 pm . Electron diffraction in a TEM Electron diffraction of solids is usually performed in a Transmission Electron Microscopy Transmission Electron ... more details
The electron liquid is a model system used by physicists to theoretically study interactions among electrons. The uniform electron liquid is a well known model for simple metals like sodium or Aluminum. The ionic charges are assumed to be smudged out to form a uniform static positive background, and the electrons are assumed to move in this positive background which maintains charge neutrality. This is also known as the Jellium model. If the Coulomb interaction between the electrons is neglected, then we have the free electron gas, or the free Fermi gas . However, when the Coulomb interaction is switched on, we have a many body problem of interacting particles. The weakly interacting regime of densities is known as the electron gas. At zero temperature, this happens if the density is very high ... interaction is weak and the free electron gas is a good approximation. Thus the high density regime is known as an electron gas . Perturbation theory can be used in this regime to discuss the properties of weakly interacting electron systems. When math r s math becomes greater than unity, interactions are important and this regime is known as the electron liquid . The electron liquid model holds ... i.e, in low density electron systems , the electron liquid crystallizes forming a crystalline phase known as the Wigner crystal . Perturbation theory fails for electron liquids where math r s 1 math ... electrons thus weakening it , a free electron like model known as the Landau&ndash Fermi liquid theory ... method. Because of Fermi statistics, the electrons in the electron liquid fill up to an energy ... of 12 electron Volts. If the temperature is greater than 12 eV, the electron liquid becomes partially degenerate, since the states above the Fermi energy begin to get occupied. Such electron fluids ..., Many particle Physics Plasmas and finite T electron liquids M. W. C. Dharma wardana, Ed. E. K ..., NY 1993 Category Condensed matter physics Category Electron Liquid Category Article Feedback 5 ... more details
Unreferenced date January 2008 File Egun.jpg thumb 250px right Electron gun from a cathode ray tube File Kathodestraalbuis2.jpg thumb 250px right Electron gun from an oscilloscope CRT An electron gun also called electron emitter is an electrical component that produces an electron beam that has a precise kinetic energy and is most often used in television set s and computer display s which use cathode ray tube CRT technology, as well as in other instruments, such as electron microscope s and particle accelerators . Electron guns may be classified in several ways by the type of electric field generation DC or RF , by emission mechanism thermionic emission thermionic , photocathode , field electron emission cold emission , Plasma physics plasmas source , by focusing pure electrostatic or with magnetic fields , or by the number of electrodes. Characteristics A direct current, electrostatic thermionic electron gun is formed from several parts a hot cathode , which is heated to create a stream of electrons via thermionic emission , electrodes generating an electric field which focus the beam ... where gas enters from one end face, undergoes electron bombardment from the side walls, and is subjected ... color cathode ray tubes such as those used in color television s incorporate three electron guns, each ... primary color s. Applications The most common use of electron guns is in cathode ray tube cathode ray tubes , which were widely used in computer and television monitors. An electron gun can also ... used in mass spectrometry in a process called electron ionization to ionize vaporized or gaseous particles. See also Cathode ray tube Electron microscope Optics Particle accelerators References references External links http electronics.howstuffworks.com question694.htm Howstuffworks.com electron gun http www.fieldp.com cpb.html Charged Particle Beams , free text with material on electron gun design Category Electron beam Category Accelerator physics Category Vacuum tubes ca Can d electrons ... more details
Electron cooling is a process to shrink the size, divergence , and energy spread of charged particle beams without removing particles from the beam. Since the number of particles remains unchanged and the space coordinates and their derivatives angles are reduced, this means that the phase space occupied by the stored particles is compressed. It is equivalent to reducing the temperature of the beam. See also stochastic cooling . It was invented by Gersh Budker Budker Institute of Nuclear Physics INP , Novosibirsk in 1966 for the purpose of increasing luminosity of hadron collider s. ref cite doi 10.1007 BF01175204 ref It was first tested in 1974 with 68 MeV proton s at NAP M storage ring at INP. Image LEIR img 1001.jpg thumb Electron cooler left at LEIR CERN . The electron source and dump are installed in the upper metallic cylinders. Basically, electron cooling works as follows The velocity of the electrons is made equal to the average velocity of the ion s. The ions undergo Coulomb collision Coulomb scattering in the electron gas and lose energy, which is transferred from the ions to the co streaming electrons until some Thermodynamic equilibrium thermal equilibrium is attained. See also Stochastic cooling References reflist refbegin The Fermilab http www ecool.fnal.gov Electron Cooling Project refend Category Accelerator physics Category Soviet inventions de Elektronenk hlung ... more details
Expand Japanese date June 2010 Infobox company name Tokyo Electron Limited br logo File Tokyo Electron Logo.jpg Tokyo Electron caption People. Technology. Commitment. type Public ... 6, 1951 foundation November 11, 1963 as Tokyo Electron Laboratories, Inc. founder Tokuo Kubo and Toshio ... as of 2011 divisions subsid 26 Group companies Group companies , including Tokyo Electron Device TYO 2760 homepage http www.tel.com global index.htm Tokyo Electron Group Global Websites footnotes ref ... 2011 publisher Tokyo Electron Limited date March 31, 2011 accessdate February 23, 2012 ref ref name ... Tokyo Electron Limited date March 31, 2011 accessdate February 23, 2012 ref nihongo Tokyo Electron Limited Tokyo Electron Kabushiki gaisha tyo 8035 ref http www.google.com finance?chdnp 1 ... displays FPD , and photovoltaic cells PV . ref name fact book 2011 nihongo Tokyo Electron Device Tokyo Electron Device Kabushiki gaisha tyo 2760 , or TED , is a subsidiary of TEL specializing ... The company was founded as Tokyo Electron Laboratories, Inc. in 1963. Origins On November 11, 1963, Tokyo Electron Laboratories Incorporated was founded by Tokuo Kubo and Toshio Kodaka, largely funded ... cite web url http www.tel.com eng milestones index.htm title Explore Our History publisher Tokyo Electron ..., California and their new branch, Pan Electron in 1968 establishing themselves as the only ... publisher Tokyo Electron Limited accessdate February 23, 2012 ref Photoresist coating developing ... Developers publisher Tokyo Electron Limited accessdate February 23, 2012 ref Plasma etching ref ... Electron Limited accessdate February 23, 2012 ref Wet surface preparation Wafer surface cleaning to remove ... eng product sps busps.htm title Surface Preparation Systems publisher Tokyo Electron Limited accessdate ... publisher Tokyo Electron Limited accessdate February 23, 2012 ref Wafer probing Wafer prober ... publisher Tokyo Electron Limited accessdate February 23, 2012 ref Material modification doping Surface ... more details
In an Electron spectrometer , an incoming beam of electrons is bent with electric or magnetic fields. As higher energy electrons will be bent less by the beam, this produces a spatially distributed range of energies. Electron spectrometers are used on a range of scientific equipment, including particle accelerator s, transmission electron microscope s, and astronomical satellite s. An electrostatic electron spectrometer uses the electric field, which cause electrons to move along field gradients, whereas magnetic devices cause electrons to move at right angles to the field. Magnetic fields will act in a direction perpendicular to the electron propagation, thereby conserving velocity, whereas electrostatic fields will cause electrons to move along the field gradient, ref name Zworykin45 which may change electron energies if the component of the direction of propagation and field gradients are not perpendicular. Owing to these effects, sector based designs are commonly used in electron spectrometers. The effective potential in the solution of motion in a magnetic or electric system with rotational symmetry leads to radial focusing onto a mean radius. ref name Zworykin45 cite book title Electron optics and the electron microscope author Zworykin,V Morton, G Ramberg, E Hillier J Vance A year 1945 publisher John Wiley and Sons, New York ref By superposition of a Quadrupole magnetic field quadrupole field axial focusing is possible while weakening the radial focusing, until the astigmatism vanishes. By breaking the rotational symmetry a bit and varying the electrostatic potential ... beam much like in an electron gun , which can then be analyzed. A position sensitive detector can ... , which can be resolved afterwards. References references See also Mass spectrometry Electron energy loss spectroscopy Time of flight mass spectrometry PEEM Energy filtered transmission electron microscopy Category Electron beam Category Spectrometers physics stub ar ... more details
Electron crystallography is a method to determine the arrangement of atoms in solids using a transmission electron microscope TEM . Comparison with X ray crystallography It can complement X ray crystallography ... is lost. Fortunately, electron microscopes contain Electrostatic lens electron lenses , and so the crystallographic structure factor phase information can be experimentally determined in electron ... out directly from the Fourier transform of an electron microscopy image that had been scanned into a computer ... and electron crystallography is radiation damage , by which especially organic molecules and proteins ... troublesome in the setting of electron crystallography, where that radiation damage is focused on far fewer atoms. One technique used to limit radiation damage is electron cryomicroscopy , in which ... determined by electron crystallography The first electron crystallographic protein structure ... of the membrane. Since then, several other high resolution structures have been determined by electron ... 10.1038 367614a0 volume 367 issue 6464 title Atomic model of plant light harvesting complex by electron ... volume 424 issue 6949 title Complete atomic model of the bacterial flagellar filament by electron ... 300px Electron microscopy image of an inorganic tantalum oxide, with its Fourier transform, also ... not displayed . Image Tant ED.jpg thumb 300px Electron diffraction pattern of the same crystal .... Application to inorganic materials Electron crystallographic studies on inorganic crystals using High resolution transmission electron microscopy high resolution electron microscopy HREM images were first performed by Aaron Klug in 1978 ref Klug, A 1978 79 Image Analysis and Reconstruction in the Electron ... Olov title Accurate atomic positions from electron microscopy journal Nature volume 311 issue 5983 pages ... since in the thicker parts of the crystal the High resolution transmission electron microscopy Exit ... very sensitive to the chosen setting of the High resolution transmission electron microscopy ... more details
Unreferenced stub auto yes date December 2009 Infobox South African subplace censuscode 77409071 name Electron latd 26 latm 14 lats 28 longd 28 longm 5 longs 46 Electron is a suburb of Johannesburg , South Africa . It is located in Region 9 Johannesburg Region 9 . References reflist Region 9 Category Johannesburg Region 9 Category Suburbs of Johannesburg Gauteng geo stub ... more details
Unreferenced date October 2006 In chemistry , an electron pair consists of two electrons that occupy the same molecular orbital orbital but have opposite spin orbital spin s. Image Covalent&PolarBond.png right thumb 200px MO diagram s depicting covalent left and polar covalent right bonding in a diatomic molecule . In both cases a bond is created by the formation of an electron pair. Because electrons are fermion s, the Pauli exclusion principle forbids these particles from having exactly the same quantum numbers . Therefore the only way to occupy the same orbital, i.e. have the same orbital quantum number s, is to differ in the spin quantum number . This limits the number of electrons in the same orbital to exactly two. The pairing of spins is often energetically favorable and electron pairs therefore play a very large role in chemistry . They can form a chemical bond between two atoms as a lone pair . fill the core electron core levels of an atom. Because the spins are paired, the magnetic moment of the electrons cancels and the contribution of the pair to the magnetic properties will in general be a diamagnetism diamagnetic one . Although a strong tendency to pair off electrons can be observed in chemistry, it is also possible that electrons occur as unpaired electron s. In the case of metallic bonding the magnetic moments also compensate to a large extent, but the bonding is more communal so that individual pairs of electrons cannot be distinguished and it is better to consider the electrons as a collective ocean . A very special case of electron pair formation occurs in superconductivity the formation of Cooper pair s. See also Polyhedral skeletal electron pair theory Jemmis mno rules DEFAULTSORT Electron Pair Category Quantum chemistry Category Chemical bonding ar de Elektronenpaar et Elektronpaar es Par de electrones it Doppietto elettronico nl Elektronenpaar pl Para elektronowa pt Par de el trons fi Elektronipari sv Elektronpar uk ... more details
primary sources date October 2011 An electron bubble is the empty space created around a free electron in a cryogenic gas or liquid, such as neon or helium . They are typically very small, about 2 nm in diameter at atmospheric pressure. Electron bubbles in helium At room temperature, electrons in noble gas ses move about freely, limited only by collisions with the weakly interacting atoms. Their Electron mobility mobility , which depends on the gas density and temperature, is well described by classical kinetic theory . As the temperature is lowered the electron mobility decreases, since the helium atoms slow down at lower temperature and do not interact with the electron as often Footnotes ... what is expected classically. This discrepancy led to the development of the electron bubble theory ... might expect, but rather form small vacuum bubbles around themselves. Electron repulsion from the surface ... s between the gas and liquid phase matter phase of helium. The negative electron Dielectric polarization .... The electron is forbidden from entering the liquid for the same reason hydrogen atoms are stable quantum mechanics . The electron and image charge form a bound state , just as an electron and proton ... 1 Electronvolt eV a moderate amount of energy on an atomic scale Footnotes 3 . When an electron ... is purely quantum mechanical, since whenever an electron is tightly confined, its kinetic energy ... R 3P math Here E is the energy of the bubble, h is Planck s constant , m is the electron mass , R is the bubble radius, is the surface energy, and P is the ambient pressure. The 2S electron bubble A theoretical ... electron bubble exhibits a startling morphological instability under a wide range of ambient ... 1. cite journal author G. Ramanan and Gordon R. Freeman title Electron Mobilities in Low Density ... Electron Bubbles journal Physical Review Letters volume 91 issue 10 pages 105301 year 2003 doi ... publisher New Scientist Category Electron Category Particle physics vi B t electron ... more details
File Electron Microscope.png right thumb Diagram of a transmission electron microscope File Siemens electron microscope.jpg thumb A 1973 Siemens electron microscope, Mus e des Arts et M tiers , Paris An electron microscope is a type of microscope that uses a beam of electron s to illuminate the specimen and produce a magnified image. Electron microscopes EM have a greater Angular resolution resolving ... 50 pm Electron Probe year 2009 author Erni, Rolf journal Physical Review Letters volume 102 ... magnifications below 2000x. The electron microscope uses Electrostatic lens electrostatic and Electromagnetism electromagnetic lenses to control the electron beam and focus it to form an image ... a magnified image by focusing light on or through the specimen. Electron microscopes are used to observe ... cells , large molecules , biopsy samples, metals , and crystalline crystals . Industrially, the electron microscope is often used for quality control and failure analysis. History File Ernst Ruska Electron Microscope Deutsches Museum Munich edit.jpg thumb right Electron microscope constructed by Ernst Ruska in 1933 The electron microscope was invented and patented by Hungarian physicist Le Szil rd ... engineer Max Knoll constructed the prototype electron microscope in 1931, capable of four hundred power magnification the apparatus was a practical application of the principles of electron microscopy ... Nobel Foundation ref Two years later, in 1933, Ruska built an electron microscope that exceeded ... , the scientific director of Siemens Schuckertwerke , obtained the patent for the electron microscope ... & Halske built and obtained images from a prototype electron microscope, applying concepts described ... year 2010 title Origin and Background of the Invention of the Electron Microscope Commentary journal Advances in Imaging and Electron Physics publisher Elsevier volume 160 ref Five years later 1937 ... ref Also in 1937, Manfred von Ardenne pioneered the scanning electron microscope . ref cite journal ... more details
Image Cont dynode detector.jpg right thumb 300 px Continuous dynode electron multiplier An electron multiplier is a vacuum tube structure that multiplies incident charges. ref Citation doi 10.1063 1.1740838 title An Improved Electron Multiplier Particle Counter year 1947 last1 Allen first1 James S. journal Review of Scientific Instruments volume 18 pages 739 bibcode 1947RScI...18..739A issue 10 ref In a process called secondary emission , a single electron can, when bombarded on secondary emissive material, induce emission of roughly 1 to 3 electron s. If an electric potential is applied between ... of Single Positive Ions, Electrons and Photons by a Secondary Electron Multiplier year ... issue 10 ref Hence the electron multiplier is often used as an ion detector. It could also be triggered by a photon causing vacuum photoemission of at least one electron. In a photomultiplier tube, a photo emissive surface is followed by an electron multiplier with several sequential multiplying electrodes ... at a potential 100 200v more positive than the previous one. File Electron multiplier.svg thumb right The Continuous Electron Multiplier A continuous dynode structure is feasible if the material ... known as single channel electron multiplier CEM , and one of the most common is sold under the trade name Channeltron. Another geometry of continuous dynode electron multiplier is called the microchannel ... Electron Multiple Arrays year 1969 last1 Burroughs first1 E. G. journal Review of Scientific Instruments ... parallel array of very small continuous dynode electron multipliers, built together and powered ... In mass spectrometry electron multipliers are often used as a detector of ions that have been ... Olympus Tutorial http www.sge.com products electron multipliers how electron multipliers work How Discrete Dynode Electron Multipliers work Category Measuring instruments Category Radio electronics Category Mass spectrometry Category Electron de Kanalelektronenvervielfacher fr lectromultiplicateur ... more details
Unreferenced stub auto yes date December 2009 If the velocity velocities of a group of electron s, e.g., in a plasma physics plasma , follow a Maxwell Boltzmann distribution Distribution of the velocity vector Maxwell Boltzmann distribution , then the electron temperature is well defined as the temperature of that distribution. For other distributions, two thirds of the average energy is often referred to as the temperature, since for a Maxwell Boltzmann distribution with three Degrees of freedom physics and chemistry degrees of freedom , math langle E rangle 3 2 langle k BT rangle math . The International System of Units SI unit of temperature is the kelvin K , but using the above relation the electron temperature is often expressed in terms of the energy unit electronvolt eV . Each kelvin 1 K corresponds to 8.617343 15 10 sup 5 sup eV this factor is the ratio of the Boltzmann constant to the elementary charge . The electron temperature of a plasma can be several orders of magnitude higher than the temperature of the neutral species or of the ion s. This is a result of two facts. Firstly, many plasma source s heat the electrons more strongly than the ions. Secondly, atoms and ions are much heavier than electrons, and energy transfer in a two body collision is much more efficient if the masses are similar. DEFAULTSORT Electron Temperature Categories Category Plasma physics Physics stub sv Elektrontemperatur ... more details
Electron wake is the disturbance left after a high energy charged particle passes through condensed matter or plasma. Ions passing through can introduce periodic oscillations in the crystal lattice or plasma wave with the characteristic frequency of the crystal or plasma frequency . Interactions of the field created by these oscillations with the charged particle field alternate from constructive interference to destructive interference , producing alternating waves of electric field and displacement. The frequency of the wake field is determined by the nature of the penetrated matter, and the period of the wake field is directly proportional to the speed of the incoming charged particle. The amplitude of the first wake wave is the most important, as it produces a braking force on the charged particle, eventually slowing it down. Wake fields also can capture and guide light ions or positrons in the direction perpendicular to the wake. The larger the speed of the original charged particle, the larger the angle between the initial particle s velocity and the captured ion s velocity. References No footnotes date July 2009 http encyclopedia2.thefreedictionary.com Electron wake Encyclopedia article on the electron wake http ieeexplore.ieee.org iel5 4439904 4439905 04440675.pdf On the possibility of accelerating positron on an electron wake at saber See also Coulomb explosion Charged particle beam Linear particle accelerator Wake fields Wake fields Plasma acceleration Bremsstrahlung List of plasma physics articles DEFAULTSORT Electron Wake Category Atomic physics Category Plasma physics Category Scattering Category Accelerator physics physics stub ... more details
Electron User was a magazine targeted at owners of the Acorn Electron microcomputer. It was published by Database Publications of Stockport , starting in October 1983 and ending after 82 issues in July 1990. Initially it was included as a 16 page pullout supplement to The Micro User but after four such editions it became a standalone title and within a year had grown to an average length of around 64 pages. The focus was news stories, type in program s and software reviews. It also contained cheat code s and a long running column on adventure game s initially by Merlin in a column entitled Merlin s Cave and subsequently by Pendragon . Its advertisers included the top BBC Electron games distributors of the day, such as Acornsoft and Superior Software . Often the April dated edition of the magazine included an April Fools Day joke, generally consisting of a short machine code type in listing which claimed to do something extremely useful and of wide interest but which in fact printed APRIL FOOL on the screen. Examples included a program to predict what text the user would type next a program to compile BASIC programs directly into machine code leveraging the machine s BASIC interpreter a program to display colours on a monochrome screen by rapidly modulating the pixels citing a recent Tomorrow s World External links http www.acornelectron.co.uk Acorn Electron World website including complete archive of page by page scans of all issues of Electron User http mags.acornpreservation.org Electron User index.php Acornmags Electron User section italic title Category Home computer magazines Category Defunct British computer magazines Category Acorn Computers Category Publications established in 1983 Category Publications disestablished in 1990 Europe compu mag stub UK sci mag stub ... more details
Cleanup date November 2010 reason Open shell seems to be not a common term In the context of atomic orbitals , an open shell is a valence shell which is not completely filled with electrons or that has not given all of its valence electrons through chemical bond s with other atoms or molecules during a chemical reaction. Atoms generally reach a noble gas configuration in a molecule. The noble gases Helium He , Neon Ne , Argon Ar , Krypton Kr , Xenon Xe , Radon Rn are not reactive and have configurations 1s sup 2 sup He , 1s sup 2 sup 2s sup 2 sup 2p sup 6 sup Ne , 1s sup 2 sup 2s sup 2 sup 2p sup 6 sup 3s sup 2 sup 3p sup 6 sup Ar , etc. For molecules it signifies that there are unpaired electron s. In molecular orbital theory, this leads to molecular orbitals that are singly occupied. In computational chemistry implementations of molecular orbital theory, open shell molecules have to be handled by either the restricted Open shell Hartree Fock method or the unrestricted Hartree Fock method. Likewise a closed shell or closed shell configuration is obtained with a completely filled valence shell. This configuration is very stable. ref http www.newi.ac.uk buckleyc periodic.htm Periodic table ref In another meaning a closed shell configuration corresponds to state with all molecular orbital s doubly occupied or empty a diradical singlet state . ref http www.semichem.com ampacmanual ci.html Configuration Interaction ref Open shell molecules are more difficult to study computationally ref http iopenshell.usc.edu iOpenShell Center for computational studies of open shell and electronically excited species ref See also Periodic table electron configurations Octet rule Valence shell Free radical References Reflist Category Atomic physics Category Chemical bonding Category Quantum chemistry Category Theoretical chemistry Category Computational chemistry ar pt N vel aberto ... more details
FAIR USE of 1977 AMC Electron concept vehicle 2 cars.jpg see image description page at http en.wikipedia.org wiki Image 1977 AMC Electron concept vehicle 2 cars.jpg for rationale Justification for Fair Use in this article follows below Though this image is subject to copyright as noted here, the U.S. fair use laws, and the stricter requirements of Wikipedia s non free content policies cover its use, because It is copy of an historically significant photo of an experimental vehicle. The name of the photographer is unknown. It is of much lower resolution than the original, so it will not detract from the value of any original photograph. The photo is only being used for informational purposes. The photo does not detract from the reputation of the subject. Its inclusion in the article adds significantly to the material because it shows the subject of this article. Image 1977 AMC Electron concept vehicle 2 cars.jpg thumb right 400px American Motors concept Electron The Electron was an United States American concept automobile built in 1977 by American Motors Corporation AMC . Design The experimental three passenger commuter city car was designed for short trip urban transportation. The Flip form clamshell style roof swung back on rear mounted pivots for entry and egress. The Electron was based on previous development of the AMC Amitron . ref name ps Popular Science magazine, 1977 ref Powered by a lightweight lithium battery system, the Electron was designed in anticipation of further advances in electronic technologies. ref cite book last Frumkin first Mitch last2 Hall first2 Phil title American Dream Cars 60 Years of the Best Concept Vehicles publisher Krause Publications date 2002 isbn 9780873494915 page 337 ref The Electron along with the AM Van, Grand Touring, Concept I ... 1978 isbn 091071410X page 40 br American Motors Category AMC vehicles Electron Category 1970s automobiles Category concept automobiles Category Historic electric vehicles es AMC Electron ... more details
Electron ionization EI , formerly known as electron impact is an ionization method in which energetic electron s interact with gas phase atoms or molecules to produce ion s. ref GoldBookRef title electron ionization file E01999 ref This technique is widely used in mass spectrometry , particularly for gases and volatile organic chemistry organic molecules . Principle of operation Image Schematic diagram of an EI ion source.jpg thumb right 300 px Diagram representing an electron ionization ion source The following Phase matter gas phase reaction describes the electron ionization process ref R. Davis, M. Frearson, 1987 . Mass Spectrometry Analytical Chemistry by Open Learning , John Wiley & Sons, London. ref math M e to M bullet 2e , math where M is the analyte molecule being ionized, e sup sup is the electron and M sup sup is the resulting ion . In an EI ion source , electrons are produced through thermionic emission by heating a wire filament that has electric current running through it. The electrons are accelerated to 70 eV in the region between the filament and the entrance to the ion source block. The accelerated electrons are then concentrated into a beam by being attracted to the trap electrode. The sample under investigation which contains the neutral molecules is introduced to the ion source in a perpendicular direction to the electron beam. Close passage of highly energetic electrons, referred to as a hard ionization source, causes large fluctuations in the electric field around the neutral molecules and induces ionization and fragmentation. ref K. Robinson et al. Undergraduate ... Stephen J. Schrader title Interpretation of Electron Ionization Data The Odd Book publisher Not Avail ... title Theory of ionization of atoms by electron impact publisher Colorado Associated University ... title Electron impact ionization publisher Springer Verlag location Berlin year 1985 pages isbn ...&Units SI&Mask 200 Mass Spec NIST Chemistry WebBook Mass spectrometry DEFAULTSORT Electron Ionization ... more details
Infobox Particle bgcolour name Electron neutrino image caption num types composition Elementary particle statistics Fermionic group Lepton generation First interaction Weak interaction Weak , Gravity particle antiparticle Electron antineutrino SubatomicParticle Electron antineutrino theorized Wolfgang Pauli 1930 discovered Clyde Cowan , Frederick Reines 1956 symbol SubatomicParticle Electron neutrino mass Small but non zero. See Neutrino Mass neutrino mass . decay time decay particle electric charge ... RH ? The electron neutrino SubatomicParticle Electron neutrino is a subatomic particle subatomic lepton elementary particle which has no net electric charge . Together with the electron it forms the first generation physics generation of leptons, hence its name electron neutrino . It was first ... Like all particles, the electron neutrino has a corresponding antiparticle , the electron antineutrino SubatomicParticle Electron antineutrino , which differs from it only in that some of its properties ... Electron link yes p small The early understanding of beta decay small In 1930, Wolfgang ... 4 issue 2 ref SubatomicParticle Neutron0 &rarr SubatomicParticle Proton SubatomicParticle Electron SubatomicParticle Electron antineutrino0 p small Pauli s version of beta decay small Pauli s letter ... of Technology , Z rich , in which he proposed the electron neutrino as a potential solution to solve ... electrically neutral particles that I wish to call neutrons, ref group nb See Electron neutrino ... The mass of the neutron must be of the same order of magnitude as the electron mass and, in any case ... by the assumption that in &beta decay a neutron is emitted together with the electron, in such a way that the sum of the energies of neutron and electron is constant. p ... p But I don t feel secure ... 23 doi 10.1063 1.2995181 ref Discovery Main Cowan Reines neutrino experiment The electron neutrino ... types of neutrinos. Pauli s neutrino is now identified as the electron neutrino , while the second ... more details
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