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Miklos Porkolab
Miklos Porkolab (born March 24, 1939) is a Hungarian-American physicist specializing in plasma physics. Early life and career In 1957, Porkolab emigrated from Hungary to Canada. He obtained his bachelor's degree at the University of British Columbia in 1963 and then his master's degree and Ph.D. from Stanford University in 1964 and 1967 respectively. He moved to the Princeton Plasma Physics Laboratory, where he worked as a senior research physicist until 1975. During the following year, Porkolab worked at the Max Planck Institute for Plasma Physics in Garching, Germany, under the auspices of the Humboldt Foundation as a winner of the "US Senior Scientist Award". In 1977, he became professor of physics at the Massachusetts Institute of Technology, where he later led the Plasma Science and Fusion Center (PSFC) for many years. Between 1991 and 2001, Porkolab served as editor of '' Physics Letters A'', in the Plasma Physics and Fluid Dynamics subsection. He also represented ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Budapest, Hungary
Budapest (, ; ) is the capital and most populous city of Hungary. It is the ninth-largest city in the European Union by population within city limits and the second-largest city on the Danube river; the city has an estimated population of 1,752,286 over a land area of about . Budapest, which is both a city and county, forms the centre of the Budapest metropolitan area, which has an area of and a population of 3,303,786; it is a primate city, constituting 33% of the population of Hungary. The history of Budapest began when an early Celtic settlement transformed into the Roman town of Aquincum, the capital of Lower Pannonia. The Hungarians arrived in the territory in the late 9th century, but the area was pillaged by the Mongols in 1241–42. Re-established Buda became one of the centres of Renaissance humanist culture by the 15th century. The Battle of Mohács, in 1526, was followed by nearly 150 years of Ottoman rule. After the reconquest of Buda in 1686, the regi ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Alexander Von Humboldt Foundation
The Alexander von Humboldt Foundation (german: Alexander von Humboldt-Stiftung) is a foundation established by the government of the Federal Republic of Germany and funded by the Federal Foreign Office, the Federal Ministry of Education and Research, the Federal Ministry for Economic Cooperation and Development as well as other national and international partners; it promotes international academic cooperation between excellent scientists and scholars from Germany and from abroad. Description Every year, the Foundation grants more than 700 competitive research fellowships and awards, primarily going to academics from natural sciences ( mathematics included) and the humanities. It allows scientists and scholars from all over the world to come to Germany to work on a research project they have chosen themselves together with a host and collaborative partner. Additionally it funds German scholars' via the Feodor Lynen Fellowships to go anywhere in the world to work on a research p ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Alcator C-Mod
Alcator C-Mod was a tokamak (a type of magnetically confined fusion device) that operated between 1991 and 2016 at the Massachusetts Institute of Technology (MIT) Plasma Science and Fusion Center (PSFC). Notable for its high toroidal magnetic field (of up to 8 Tesla), Alcator C-Mod holds the world record for volume averaged plasma pressure in a magnetically confined fusion device. Until its shutdown in 2016, it was one of the major fusion research facilities in the United States. Alcator C-Mod was the third of the Alcator (''Alto Campo Toro'', High Field Torus) tokamak series, following Alcator A (1973–1979) and Alcator C (1978–1987). It was the largest fusion reactor operated by any university and was an integral part of the larger Plasma Science and Fusion Center. History Alcator A In the late 1960s, magnetic-confinement fusion research at MIT was carried out on small-scale "table-top" experiments at the Research Laboratory for Electronics and the Francis Bitter ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Phase-contrast Imaging
Phase-contrast imaging is a method of imaging that has a range of different applications. It exploits differences in the refractive index of different materials to differentiate between structures under analysis. In conventional light microscopy, phase contrast can be employed to distinguish between structures of similar transparency, and to examine crystals on the basis of their double refraction. This has uses in biological, medical and geological science. In X-ray tomography, the same physical principles can be used to increase image contrast by highlighting small details of differing refractive index within structures that are otherwise uniform. In transmission electron microscopy (TEM), phase contrast enables very high resolution (HR) imaging, making it possible to distinguish features a few Angstrom apart (at this point highest resolution is 40 pm). Light microscopy Phase contrast takes advantage of the fact that different structures have different refractive indices, and eit ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Tokamak
A tokamak (; russian: токамáк; otk, 𐱃𐰸𐰢𐰴, Toḳamaḳ) is a device which uses a powerful magnetic field to confine plasma in the shape of a torus. The tokamak is one of several types of magnetic confinement devices being developed to produce controlled thermonuclear fusion power. , it was the leading candidate for a practical fusion reactor. Tokamaks were initially conceptualized in the 1950s by Soviet physicists Igor Tamm and Andrei Sakharov, inspired by a letter by Oleg Lavrentiev. The first working tokamak was attributed to the work of Natan Yavlinsky on the T-1 in 1958. It had been demonstrated that a stable plasma equilibrium requires magnetic field lines that wind around the torus in a helix. Devices like the z-pinch and stellarator had attempted this, but demonstrated serious instabilities. It was the development of the concept now known as the safety factor (labelled ''q'' in mathematical notation) that guided tokamak development; by arra ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
MIT Plasma Science And Fusion Center
The Plasma Science and Fusion Center (PSFC) at the Massachusetts Institute of Technology (MIT) is a university research center for the study of plasmas, fusion science and technology. It was originally founded in 1976 as the Plasma Fusion Center (PFC) at the request and with the collaboration of the U.S. Department of Energy. The original grant was for construction and operation of a tokamak reactor Alcator A, the first in a series of small, high-field tokamaks, followed by Alcator C (1978) and Alcator C-Mod (1993). MIT's most recent tokamak, Alcator C-Mod, ran from 1993 to 2016. In 2016, the project pressure reached 2.05 atmospheres—a 15 percent jump over the previous record of 1.77 atmospheres with a plasma temperature of 35 million degrees C, sustaining fusion for 2 seconds, yielding 600 trillion fusion reactions. The run involved a 5.7 tesla magnetic field. It reached this milestone on its final day of operation. In 2018, the PSFC began developing a conceptual design ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Landau Damping
In physics, Landau damping, named after its discoverer,Landau, L. "On the vibration of the electronic plasma". ''JETP'' 16 (1946), 574. English translation in ''J. Phys. (USSR)'' 10 (1946), 25. Reproduced in Collected papers of L.D. Landau, edited and with an introduction by D. ter Haar, Pergamon Press, 1965, pp. 445–460; and in Men of Physics: L.D. Landau, Vol. 2, Pergamon Press, D. ter Haar, ed. (1965). Soviet physicist Lev Davidovich Landau (1908–68), is the effect of damping ( exponential decrease as a function of time) of longitudinal space charge waves in plasma or a similar environment.Chen, Francis F. ''Introduction to Plasma Physics and Controlled Fusion''. Second Ed., 1984 Plenum Press, New York. This phenomenon prevents an instability from developing, and creates a region of stability in the parameter space. It was later argued by Donald Lynden-Bell that a similar phenomenon was occurring in galactic dynamics, where the gas of electrons interacting by electrosta ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Gyroradius
The gyroradius (also known as radius of gyration, Larmor radius or cyclotron radius) is the radius of the circular motion of a charged particle in the presence of a uniform magnetic field. In SI units, the non-relativistic gyroradius is given by :r_ = \frac where m is the mass of the particle, v_ is the component of the velocity perpendicular to the direction of the magnetic field, q is the electric charge of the particle, and B is the strength of the magnetic field. The angular frequency of this circular motion is known as the gyrofrequency, or cyclotron frequency, and can be expressed as :\omega_ = \frac in units of radians/second. Variants It is often useful to give the gyrofrequency a sign with the definition :\omega_ = \frac or express it in units of hertz with :f_ = \frac. For electrons, this frequency can be reduced to :f_ = (2.8\times10^\,\mathrm/\mathrm)\times B. In cgs-units the gyroradius :r_ = \frac and the corresponding gyrofrequency :\omega_ = \frac include a factor ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Bernstein Waves
Ira Borah Bernstein (born November 8, 1924) is an American theoretical physicist specializing in plasma physics. He was the first person to formulate the theory of electrostatic waves propagating in a magnetized plasma in 1958, which are now commonly known as Bernstein waves in plasma physics. Bernstein's other theoretical contributions include the development of the energy principle in the study of plasma instabilities, as well as formulating the exact (one-dimensional) solution to electrostatic wave propagation in an unmagnetized plasma also known as Bernstein–Greene–Kruskal modes. Early life and career Bernstein studied chemical engineering at the City College of New York (Baccalaureate 1944) and in 1950 received his PhD from New York University with his thesis entitled "Improved Calculations on Cascade Shower Theory". From 1950 to 1954, he worked at the Westinghouse research laboratories. From 1954 to 1964, he was a scientist at the Princeton Plasma Physics Laborato ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Boltzmann Equation
The Boltzmann equation or Boltzmann transport equation (BTE) describes the statistical behaviour of a thermodynamic system not in a state of equilibrium, devised by Ludwig Boltzmann in 1872.Encyclopaedia of Physics (2nd Edition), R. G. Lerner, G. L. Trigg, VHC publishers, 1991, ISBN (Verlagsgesellschaft) 3-527-26954-1, ISBN (VHC Inc.) 0-89573-752-3. The classic example of such a system is a fluid with temperature gradients in space causing heat to flow from hotter regions to colder ones, by the random but biased transport of the particles making up that fluid. In the modern literature the term Boltzmann equation is often used in a more general sense, referring to any kinetic equation that describes the change of a macroscopic quantity in a thermodynamic system, such as energy, charge or particle number. The equation arises not by analyzing the individual positions and momenta of each particle in the fluid but rather by considering a probability distribution for the positio ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Plasma Stability
The stability of a plasma is an important consideration in the study of plasma physics. When a system containing a plasma is at equilibrium, it is possible for certain parts of the plasma to be disturbed by small perturbative forces acting on it. The stability of the system determines if the perturbations will grow, oscillate, or be damped out. In many cases, a plasma can be treated as a fluid and its stability analyzed with magnetohydrodynamics (MHD). MHD theory is the simplest representation of a plasma, so MHD stability is a necessity for stable devices to be used for nuclear fusion, specifically magnetic fusion energy. There are, however, other types of instabilities, such as velocity-space instabilities in magnetic mirrors and systems with beams. There are also rare cases of systems, e.g. the field-reversed configuration, predicted by MHD to be unstable, but which are observed to be stable, probably due to kinetic effects. Plasma instabilities Plasma instabilities can ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Waves In Plasmas
In plasma physics, waves in plasmas are an interconnected set of particles and fields which propagate in a periodically repeating fashion. A plasma is a quasineutral, electrically conductive fluid. In the simplest case, it is composed of electrons and a single species of positive ions, but it may also contain multiple ion species including negative ions as well as neutral particles. Due to its electrical conductivity, a plasma couples to electric and magnetic fields. This complex of particles and fields supports a wide variety of wave phenomena. The electromagnetic fields in a plasma are assumed to have two parts, one static/equilibrium part and one oscillating/perturbation part. Waves in plasmas can be classified as electromagnetic or electrostatic according to whether or not there is an oscillating magnetic field. Applying Faraday's law of induction to plane waves, we find \mathbf\times\tilde=\omega\tilde, implying that an electrostatic wave must be purely longitudinal. An elect ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
