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Q-machine
A Q-machine is a device that is used in experimental plasma physics. The name Q-machine stems from the original intention of creating a quiescent plasma that is free from the fluctuations that are present in plasmas created in electric discharges. The Q-machine was first described in a publication by Rynn and D'Angelo. The Q-machine plasma is created at a plate that has been heated to about 2000 K and hence is called the hot plate. Electrons are emitted by the hot plate through thermionic emission, and ions are created through contact ionization of atoms of alkali metals that have low ionisation potentials. The hot plate is made of a metal that has a large work function and can withstand high temperatures, e.g. tungsten or rhenium. The alkali metal is boiled in an oven that is designed to direct a beam of alkaline metal vapour onto the hot plate. A high value of the hot plate work function and a low ionisation potential of the metal makes for a low potential barrier ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
List Of Plasma (physics) Articles
This is a list of plasma physics topics. A * Ablation * Abradable coating * Abraham–Lorentz force * Absorption band * Accretion disk * Active galactic nucleus * Adiabatic invariant * ADITYA (tokamak) * Aeronomy * Afterglow plasma * Airglow * Air plasma, Corona treatment, Atmospheric-pressure plasma treatment * Ayaks, Novel "Magneto-plasmo-chemical engine" * Alcator C-Mod * Alfvén wave * Ambipolar diffusion * Aneutronic fusion * Anisothermal plasma * Anisotropy * Antiproton Decelerator * Appleton-Hartree equation * Arcing horns * Arc lamp * Arc suppression * ASDEX Upgrade, Axially Symmetric Divertor EXperiment * Astron (fusion reactor) * Astronomy * Astrophysical plasma * Astrophysical X-ray source * Atmospheric dynamo * Atmospheric escape * Atmospheric pressure discharge * Atmospheric-pressure plasma * Atom * Atomic emission spectroscopy * Atomic physics * Atomic-terrace low-angle shadowing * Auger electron spectroscopy * Aurora (astronomy) B * Babcock Model * Bal ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Plasma Physics
Plasma ()πλάσμα , Henry George Liddell, Robert Scott, ''A Greek English Lexicon'', on Perseus is one of the . It contains a significant portion of charged particles – s and/or s. The presence of these charged particles is what primarily sets plasma apart from the other fundamental states of matter. It is the most abundant form of |
Contact Ionization
Thermal ionization, also known as surface ionization or contact ionization, is a physical process whereby the atoms are desorbed from a hot surface, and in the process are ionized. Thermal ionization is used to make simple ion sources, for mass spectrometry and for generating ion beams. Thermal ionization has seen extensive use in determining atomic weights, in addition to being used in many geological/nuclear applications. Physics The likelihood of ionization is a function of the filament temperature, the work function of the filament substrate and the ionization energy of the element. This is summarised in the Saha-Langmuir equation: :\frac = \frac \exp \Bigg(\frac\Bigg) where ::\frac = ratio of ion number density to neutral number density ::\frac = ratio of statistical weights (degeneracy) of ionic (g_+) and neutral (g_0) states ::W = work function of surface ::\Delta E_I = ionization energy of desorbed element ::k = Boltzmann's constant ::T = surface temperature ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Alkali Metals
The alkali metals consist of the chemical elements lithium (Li), sodium (Na), potassium (K),The symbols Na and K for sodium and potassium are derived from their Latin names, ''natrium'' and ''kalium''; these are still the origins of the names for the elements in some languages, such as German and Russian. rubidium (Rb), caesium (Cs), and francium (Fr). Together with hydrogen they constitute group 1, which lies in the s-block of the periodic table. All alkali metals have their outermost electron in an s-orbital: this shared electron configuration results in their having very similar characteristic properties. Indeed, the alkali metals provide the best example of group trends in properties in the periodic table, with elements exhibiting well-characterised homologous behaviour. This family of elements is also known as the lithium family after its leading element. The alkali metals are all shiny, soft, highly reactive metals at standard temperature and pressure and readily lose ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Work Function
In solid-state physics, the work function (sometimes spelt workfunction) is the minimum thermodynamic work (i.e., energy) needed to remove an electron from a solid to a point in the vacuum immediately outside the solid surface. Here "immediately" means that the final electron position is far from the surface on the atomic scale, but still too close to the solid to be influenced by ambient electric fields in the vacuum. The work function is not a characteristic of a bulk material, but rather a property of the surface of the material (depending on crystal face and contamination). Definition The work function for a given surface is defined by the difference :W = -e\phi - E_, where is the charge of an electron, is the electrostatic potential in the vacuum nearby the surface, and is the Fermi level (electrochemical potential of electrons) inside the material. The term is the energy of an electron at rest in the vacuum nearby the surface. In practice, one directly controls by ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Barium
Barium is a chemical element with the symbol Ba and atomic number 56. It is the fifth element in group 2 and is a soft, silvery alkaline earth metal. Because of its high chemical reactivity, barium is never found in nature as a free element. The most common minerals of barium are baryte ( barium sulfate, BaSO4) and witherite (barium carbonate, BaCO3). The name ''barium'' originates from the alchemical derivative "baryta", from Greek (), meaning 'heavy'. ''Baric'' is the adjectival form of barium. Barium was identified as a new element in 1774, but not reduced to a metal until 1808 with the advent of electrolysis. Barium has few industrial applications. Historically, it was used as a getter for vacuum tubes and in oxide form as the emissive coating on indirectly heated cathodes. It is a component of YBCO (high-temperature superconductors) and electroceramics, and is added to steel and cast iron to reduce the size of carbon grains within the microstructure. Barium compounds ar ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Saha Ionization Equation
In physics, the Saha ionization equation is an expression that relates the ionization state of a gas in thermal equilibrium to the temperature and pressure. The equation is a result of combining ideas of quantum mechanics and statistical mechanics and is used to explain the spectral classification of stars. The expression was developed by Indian physicist Meghnad Saha in 1920. Description For a gas at a high enough temperature (here measured in energy units, i.e. keV or J) and/or density, the thermal collisions of the atoms will ionize some of the atoms, making an ionized gas. When several or more of the electrons that are normally bound to the atom in orbits around the atomic nucleus are freed, they form an independent electron gas cloud co-existing with the surrounding gas of atomic ions and neutral atoms. In turn, this generates an electric field, where the motion of charges generates currents, making a localised magnetic field, and creates the state of matter called plasma. Th ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
West Virginia University
West Virginia University (WVU) is a public land-grant research university with its main campus in Morgantown, West Virginia. Its other campuses are those of the West Virginia University Institute of Technology in Beckley, Potomac State College of West Virginia University in Keyser, and clinical campuses for the university's medical and school at Charleston Area Medical Center in Charleston and thEastern Divisionat the WVU Medicine Berkeley and Jefferson Medical Centers. WVU Extension Service provides outreach with offices in all 55 West Virginia counties. Enrollment for the Fall 2021 semester was 25,474 for the main campus, while enrollment across all three non-clinical campuses was 28,267. The Morgantown campus offers more than 350 bachelor's, master's, doctoral, and professional degree programs throughout 13 colleges and schools, including that states' only law andental schools The university has produced 25 Truman Scholars, 47 Goldwater Scholars, 88 Gilman Scholars, 70 Fu ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
University Of Iowa
The University of Iowa (UI, U of I, UIowa, or simply Iowa) is a public university, public research university in Iowa City, Iowa, United States. Founded in 1847, it is the oldest and largest university in the state. The University of Iowa is organized into 12 colleges offering more than 200 areas of study and seven professional degrees. On an urban 1,880-acre campus on the banks of the Iowa River, the University of Iowa is Carnegie Classification of Institutions of Higher Education, classified among "R1: Doctoral Universities – Very high research activity". In fiscal year 2021, research expenditures at Iowa totaled $818 million. The university is best known for its programs in health care, law, and the fine arts, with programs ranking among the top 25 nationally in those areas. The university was the original developer of the Master of Fine Arts degree and it operates the Iowa Writers' Workshop, which has produced 17 of the university's 46 Pulitzer Prize winners. Iowa is a mem ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Tohoku University
, or is a Japanese national university located in Sendai, Miyagi in the Tōhoku Region, Japan. It is informally referred to as . Established in 1907, it was the third Imperial University in Japan and among the first three Designated National Universities, along with the University of Tokyo and Kyoto University. Tohoku University is a Top Type university of the Top Global University Project, and since 2020 has been ranked the best university in Japan by Times Higher Education. In 2016, Tohoku University had 10 faculties, 16 graduate schools and 6 research institutes, with a total enrollment of 17,885 students. The university's three core values are "Research First (研究第一主義)," "Open-Doors (門戸開放)," and "Practice-Oriented Research and Education (実学尊重)." History On June 22, 1907(明治40年,''Mēji yonjyunen''), the university was established under the name by the Meiji government as the third Imperial University of Japan, following the Tokyo Imperi ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
University Of Innsbruck
The University of Innsbruck (german: Leopold-Franzens-Universität Innsbruck; la, Universitas Leopoldino Franciscea) is a public research university in Innsbruck, the capital of the Austrian federal state of Tyrol, founded on October 15, 1669. It is the largest education facility in the Austrian Bundesland of Tirol, and the third largest in Austria behind Vienna University and the University of Graz. Significant contributions have been made in many branches, most of all in the physics department. Further, regarding the number of '' Web of Science''-listed publications, it occupies the third rank worldwide in the area of mountain research. In the Handelsblatt Ranking 2015, the business administration faculty ranks among the 15 best business administration faculties in German-speaking countries. History In 1562, a Jesuit grammar school was established in Innsbruck by Peter Canisius, today called " Akademisches Gymnasium Innsbruck". It was financed by the salt mines in Hall i ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
