Related Research Articles
The T-15 is a Russian nuclear fusion research reactor located at the Kurchatov Institute, which is based on the (Soviet-invented) tokamak design. It was the first industrial prototype fusion reactor to use superconducting magnets to control the plasma. These enormous superconducting magnets confined the plasma the reactor produced, but failed to sustain it for more than just a few seconds. Despite not being immediately applicable, this new technological advancement proved to the USSR that they were on the right path. In the original shape, a toroidal chamber design, it had a major radius of 2.43 m and minor radius 0.7 m.
A terrestrial gamma-ray flash (TGF), also known as dark lightning, is a burst of gamma rays produced in Earth's atmosphere. TGFs have been recorded to last 0.2 to 3.5 milliseconds, and have energies of up to 20 million electronvolts. It is speculated that TGFs are caused by intense electric fields produced above or inside thunderstorms. Scientists have also detected energetic positrons and electrons produced by terrestrial gamma-ray flashes.
A field-reversed configuration (FRC) is a type of plasma device studied as a means of producing nuclear fusion. It confines a plasma on closed magnetic field lines without a central penetration. In an FRC, the plasma has the form of a self-stable torus, similar to a smoke ring.
Runaway breakdown is a theory of lightning initiation proposed by Alex Gurevich in 1992.
The Enormous Toroidal Plasma Device (ETPD) is an experimental physics device housed at the Basic Plasma Science Facility at University of California, Los Angeles (UCLA). It previously operated as the Electric Tokamak (ET) between 1999 and 2006 and was noted for being the world's largest tokamak before being decommissioned due to the lack of support and funding. The machine was renamed to ETPD in 2009. At present, the machine is undergoing upgrades to be re-purposed into a general laboratory for experimental plasma physics research.
Plasma is one of four fundamental states of matter, characterized by the presence of a significant portion of charged particles in any combination of ions or electrons. It is the most abundant form of ordinary matter in the universe, being mostly associated with stars, including the Sun. Extending to the rarefied intracluster medium and possibly to intergalactic regions, plasma can be artificially generated by heating a neutral gas or subjecting it to a strong electromagnetic field.
A relativistic runaway electron avalanche (RREA) is an avalanche growth of a population of relativistic electrons driven through a material by an electric field. RREA has been hypothesized to be related to lightning initiation, terrestrial gamma-ray flashes, sprite lightning, and spark development. RREA is unique as it can occur at electric fields an order of magnitude lower than the dielectric strength of the material.
Joseph R. Dwyer is an American physicist known for his lightning research. He is a Professor of Physics at the University of New Hampshire. Dwyer received his Ph.D. in Physics from the University of Chicago in 1994 and worked on cosmic-ray physics and gamma-ray astronomy as a research scientist at Columbia University and the University of Maryland before joining the faculty at the Florida Institute of Technology in 2000. After moving to Melbourne, Florida, Dwyer became interested in lightning physics and his research now focuses on high-energy radiation production from thunderstorms and lightning. In 2002, Dwyer and collaborators discovered that rocket-triggered lightning produced large quantities of x-rays, allowing for first the time detailed studies of an atmospheric phenomenon known as runaway breakdown. In 2014, Dwyer left the Florida Institute of Technology and joined the University of New Hampshire.
A plasma railgun is a linear accelerator which, like a projectile railgun, uses two long parallel electrodes to accelerate a "sliding short" armature. However, in a plasma railgun, the armature and ejected projectile consists of plasma, or hot, ionized, gas-like particles, instead of a solid slug of material. Scientific plasma railguns are typically operated in vacuum and not at air pressure. They are of value because they produce muzzle velocities of up to several hundreds of kilometers per second. Because of this, these devices have applications in magnetic confinement fusion (MCF), magneto-inertial fusion (MIF), high energy density physics research (HEDP), laboratory astrophysics, and as a plasma propulsion engine for spacecraft.
In electromagnetism, a streamer discharge, also known as filamentary discharge, is a type of transient electric discharge which forms at the surface of a conductive electrode carrying a high voltage in an insulating medium such as air. Streamers are luminous writhing branching sparks, plasma channels composed of ionized air molecules, which repeatedly strike out from the electrode into the air.
Norman Rostoker was a Canadian plasma physicist known for being a pioneer in developing clean plasma-based fusion energy. He co-founded TAE Technologies in 1998 and held 27 U.S. Patents on plasma-based fusion accelerators.
Centrifugal acceleration of astroparticles to relativistic energies might take place in rotating astrophysical objects. It is strongly believed that active galactic nuclei and pulsars have rotating magnetospheres, therefore, they potentially can drive charged particles to high and ultra-high energies. It is a proposed explanation for ultra-high-energy cosmic rays (UHECRs) and extreme-energy cosmic rays (EECRs) exceeding the Greisen–Zatsepin–Kuzmin limit.
Sibylle Günter is a German theoretical physicist researching tokamak plasmas. Since February 2011, she has headed the Max Planck Institute for Plasma Physics. In October 2015, she was elected a member of the Academia Europaea in recognition of her contribution to research.
A sawtooth is a relaxation that is commonly observed in the core of tokamak plasmas, first reported in 1974. The relaxations occur quasi-periodically and cause a sudden drop in the temperature and density in the center of the plasma. A soft-xray pinhole camera pointed toward the plasma core during sawtooth activity will produce a sawtooth-like signal. Sawteeth effectively limit the amplitude of the central current density. The Kadomtsev model of sawteeth is a classic example of magnetic reconnection. Other repeated relaxation oscillations occurring in tokamaks include the edge localized mode (ELM) which effectively limits the pressure gradient at the plasma edge and the fishbone instability which effectively limits the density and pressure of fast particles.
Jose A. Boedo is a Spanish plasma physicist and a researcher at University of California, San Diego. He is an Elected Fellow of the American Physical Society, which was awarded in 2016 for "his ground-breaking contributions to the studies of plasma drifts and intermittent plasma transport in the peripheral region of tokamaks".
Hartmut Zohm is a German plasma physicist who is known for his work on the ASDEX Upgrade machine. He received the 2014 John Dawson Award and the 2016 Hannes Alfvén Prize for successfully demonstrating that neoclassical tearing modes in tokamaks can be stabilized by electron cyclotron resonance heating, which is an important design consideration for pushing the performance limit of the ITER.
The Dreicer field is the critical electric field above which electrons in a collisional plasma can be accelerated to become runaway electrons. It was named after Harry Dreicer who derived the expression in 1959 and expanded on the concept in 1960. The Dreicer field is an important parameter in the study of tokamaks to suppress runaway generation in nuclear fusion.
Wendelstein 7-AS was an experimental stellarator which was in operation from 1988 to 2002 by the Max Planck Institute for Plasma Physics (IPP) in Garching. It was the first of a new class of advanced stellarators with modular coils, designed with the goal of developing a nuclear fusion reactor to generate electricity.
Wen Li is a space physicist at Boston University. Her research interests include space plasma waves, Earth's radiation belt physics, solar-wind magnetosphere coupling, energetic particle precipitation, and Jovian magnetosphere and aurora: She is a Fellow of the American Geophysical Union.
The Tokamak Chauffage Alfvén Brésilien (TCABR) is a tokamak situated at the University of Sao Paulo (USP), Brazil. TCABR is the largest tokamak in the southern hemisphere and one of the magnetic-confinement devices committed to advancing scientific knowledge in fusion power.
References
- ↑ Dwyer, Joseph R.; Smith, David M.; Cummer, Steven A. (1 November 2012). "High-Energy Atmospheric Physics: Terrestrial Gamma-Ray Flashes and Related Phenomena". Space Science Reviews. 173 (1–4): 133–196. Bibcode:2012SSRv..173..133D. doi: 10.1007/s11214-012-9894-0 . ISSN 0038-6308.
- ↑ Wilson, C.T.R. (1925). "The acceleration of β-particles in strong electric fields such as those of thunderclouds". Proc. Cambridge Philos. Soc. 22 (4): 534–538. Bibcode:1925PCPS...22..534W. doi:10.1017/s0305004100003236. S2CID 121202128.
- ↑ Gurevich, A.v.; Milikh, G.m.; Roussel-Dupre, R. (1992). "Runaway Electron Mechanism of Air Breakdown and Preconditioning during a Thunderstorm". Physics Letters. 165.5 (5–6): 463. Bibcode:1992PhLA..165..463G. doi:10.1016/0375-9601(92)90348-p.
- ↑ Dwyer, J; Coleman, L; Lopez, R; Saleh, Z; Concha, D; Brown, M; Rassoul, H (2006). "Runaway Breakdown in the Jovian Atmospheres". Geophysical Research Letters. 33 (22): L22813. Bibcode:2006GeoRL..3322813D. doi: 10.1029/2006gl027633 .
- ↑ Reux, C.; Plyusnin, V.; Alper, B.; Alves, D.; Bazylev, B.; Belonohy, E.; Boboc, A.; Brezinsek, S.; Coffey, I.; Decker, J (2015-09-01). "Runaway electron beam generation and mitigation during disruptions at JET-ILW". Nuclear Fusion. 55 (9): 093013. Bibcode:2015NucFu..55i3013R. doi:10.1088/0029-5515/55/9/093013. hdl: 11858/00-001M-0000-0029-04D1-5 . ISSN 0029-5515. S2CID 92988022.
- ↑ Levko; Yatom; Vekselman; Glezier; Gurovich; Krasik (2012). "Numerical Simulations of Runaway Electron Generation in Pressurized Gases". Journal of Applied Physics. 111 (1): 013303–013303–9. arXiv: 1109.3537 . Bibcode:2012JAP...111a3303L. doi:10.1063/1.3675527. S2CID 119256027.
- ↑ Skeltved, Alexander Broberg; Østgaard, Nikolai; Carlson, Brant; Gjesteland, Thomas; Celestin, Sebastien (2014). "Modeling the relativistic runaway electron avalanche and the feedback mechanism with GEANT4". Journal of Geophysical Research: Space Physics. 119 (11): 9174–9191. arXiv: 1605.07771 . Bibcode:2014JGRA..119.9174S. doi:10.1002/2014JA020504. PMC 4497459 . PMID 26167437.