The Gas Dynamic Trap is a magnetic mirror machine being operated at the Budker Institute of Nuclear Physics in Akademgorodok, Russia.
Dimensions The plasma inside the machine fills a cylinder of space, 7 meters long and 28 centimeters in diameter. [1] The magnetic field varies along this tube. In the center the field is low; reaching (at most) 0.35 Teslas. The field rises to as high as 15 Teslas at the ends. [1] This change in the strength is needed to reflect the particles and get them internally trapped (see: the magnetic mirror effect).
Heating The plasma is heated using two methods, simultaneously. The first is neutral beam injection, where a hot (25 keV), neutral beam of material is shot into the machine at a rate of 5 megawatts. [1] The second is Electron cyclotron resonance heating, where electromagnetic waves are used to heat a plasma, analogous to microwaving it.
Performance As of 2016, the machine had achieved a plasma trapping beta of 0.6 for 5 milliseconds. [2] It had reached an electron temperature of 1 keV using the method of Electron cyclotron resonance heating. It had reached an ion density of 1×1020 ions/m3. [1] The machine loses material out of the ends of the mirror [3] but material is replenished at such a rate as to maintain a density inside the machine. [3]
During any given experiment, operators can choose from at least 15 fusion diagnostics to measure the machines' behavior: [2]
A magnetic mirror, known as a magnetic trap in Russia and briefly as a pyrotron in the US, is a type of magnetic confinement device used in fusion power to trap high temperature plasma using magnetic fields. The mirror was one of the earliest major approaches to fusion power, along with the stellarator and z-pinch machines.
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.
Inertial electrostatic confinement, or IEC, is a class of fusion power devices that use electric fields to confine the plasma rather than the more common approach using magnetic fields found in magnetic fusion energy (MFE) designs. Most IEC devices directly accelerate their fuel to fusion conditions, thereby avoiding energy losses seen during the longer heating stages of MFE devices. In theory, this makes them more suitable for using alternative aneutronic fusion fuels, which offer a number of major practical benefits and makes IEC devices one of the more widely studied approaches to fusion.
Plasma diagnostics are a pool of methods, instruments, and experimental techniques used to measure properties of a plasma, such as plasma components' density, distribution function over energy (temperature), their spatial profiles and dynamics, which enable to derive plasma parameters.
Electron cyclotron resonance (ECR) is a phenomenon observed in plasma physics, condensed matter physics, and accelerator physics. It happens when the frequency of incident radiation coincides with the natural frequency of rotation of electrons in magnetic fields. A free electron in a static and uniform magnetic field will move in a circle due to the Lorentz force. The circular motion may be superimposed with a uniform axial motion, resulting in a helix, or with a uniform motion perpendicular to the field resulting in a cycloid. The angular frequency of this cyclotron motion for a given magnetic field strength B is given by
The Large Helical Device (LHD) is a fusion research device in Toki, Gifu, Japan, belonging to the National Institute for Fusion Science. It is the second largest superconducting stellarator in the world, after the Wendelstein 7-X. The LHD employs a heliotron magnetic field originally developed in Japan.
The Budker Institute of Nuclear Physics (BINP) is one of the major centres of advanced study of nuclear physics in Russia. It is located in the Siberian town Akademgorodok, on Academician Lavrentiev Avenue. The institute was founded by Gersh Budker in 1959. Following his death in 1977, the institute was renamed in honour of Academician Budker.
The Madison Symmetric Torus (MST) is a reversed field pinch (RFP) physics experiment with applications to both fusion energy research and astrophysical plasmas.
Alcator C-Mod was a tokamak 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, 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.
Neutral-beam injection (NBI) is one method used to heat plasma inside a fusion device consisting in a beam of high-energy neutral particles that can enter the magnetic confinement field. When these neutral particles are ionized by collision with the plasma particles, they are kept in the plasma by the confining magnetic field and can transfer most of their energy by further collisions with the plasma. By tangential injection in the torus, neutral beams also provide momentum to the plasma and current drive, one essential feature for long pulses of burning plasmas. Neutral-beam injection is a flexible and reliable technique, which has been the main heating system on a large variety of fusion devices. To date, all NBI systems were based on positive precursor ion beams. In the 1990s there has been impressive progress in negative ion sources and accelerators with the construction of multi-megawatt negative-ion-based NBI systems at LHD (H0, 180 keV) and JT-60U (D0, 500 keV). The NBI designed for ITER is a substantial challenge (D0, 1 MeV, 40 A) and a prototype is being constructed to optimize its performance in view of the ITER future operations. Other ways to heat plasma for nuclear fusion include RF heating, electron cyclotron resonance heating (ECRH), ion cyclotron resonance heating (ICRH), and lower hybrid resonance heating (LH).
ASDEX Upgrade is a divertor tokamak, that went into operation at the Max-Planck-Institut für Plasmaphysik, Garching in 1991. At present, it is Germany's second largest fusion experiment after stellarator Wendelstein 7-X.
The Tokamak à configuration variable is a Swiss research fusion reactor of the École Polytechnique Fédérale de Lausanne (EPFL). As the largest experimental facility of the Swiss Plasma Center, the TCV Tokamak explores the physics of nuclear fusion by magnetic confinement. Its distinguishing feature over other tokamaks is that its torus section is three times higher than wide. This allows studying several shapes of plasmas, which is particularly relevant since the shape of the plasma has links to the performance of the reactor. This asset has earned its choice as one of the three national machines in Europe involved in the design of the international reactor ITER, as well as in the development of ITER’s successor DEMO, a prototype of a commercial reactor. The TCV was set up in November 1992.
The Wendelstein 7-X reactor is an experimental stellarator built in Greifswald, Germany, by the Max Planck Institute for Plasma Physics (IPP), and completed in October 2015. Its purpose is to advance stellarator technology: though this experimental reactor will not produce electricity, it is used to evaluate the main components of a future fusion power plant; it was developed based on the predecessor Wendelstein 7-AS experimental reactor.
The Helically Symmetric Experiment, is an experimental plasma confinement device at the University of Wisconsin–Madison, with design principles that are intended to be incorporated into a fusion reactor. The HSX is a modular coil stellarator which is a toroid-shaped pressure vessel with external electromagnets which generate a magnetic field for the purpose of containing a plasma. It began operation in 1999.
Ion cyclotron resonance is a phenomenon related to the movement of ions in a magnetic field. It is used for accelerating ions in a cyclotron, and for measuring the masses of an ionized analyte in mass spectrometry, particularly with Fourier transform ion cyclotron resonance mass spectrometers. It can also be used to follow the kinetics of chemical reactions in a dilute gas mixture, provided these involve charged species.
The Lockheed Martin Compact Fusion Reactor (CFR) is a fusion power project at Lockheed Martin’s Skunk Works. Its high-beta configuration, which implies that the ratio of plasma pressure to magnetic pressure is greater than or equal to 1, allows a compact fusion reactor (CFR) design and expedited development.
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 Compact Toroidal Hybrid (CTH) is an experimental device at Auburn University that uses magnetic fields to confine high-temperature plasmas. CTH is a torsatron type of stellarator with an external, continuously wound helical coil that generates the bulk of the magnetic field for containing a plasma.
Dmitri Dmitriyevich Ryutov is a Russian theoretical plasma physicist.
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.
Fusion power, processes and devices | |||||||||||||||||||||||||||||||||||||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Core topics | |||||||||||||||||||||||||||||||||||||||||||
| Processes, methods |
| ||||||||||||||||||||||||||||||||||||||||||
| Devices, experiments |
| ||||||||||||||||||||||||||||||||||||||||||
