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- Path: senator-bedfellow.mit.edu!faqserv
- From: Robert F. Heeter <rfheeter@princeton.edu>
- Newsgroups: sci.physics.fusion,sci.answers,news.answers
- Subject: Conventional Fusion FAQ Glossary Part 3/26 (C)
- Supersedes: <fusion-faq/glossary/c_934543711@rtfm.mit.edu>
- Followup-To: sci.physics.fusion
- Date: 11 Nov 1999 12:24:53 GMT
- Organization: Princeton University
- Lines: 418
- Approved: news-answers-request@MIT.EDU
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- Expires: 23 Feb 2000 12:24:17 GMT
- Message-ID: <fusion-faq/glossary/c_942323057@rtfm.mit.edu>
- References: <fusion-faq/glossary/intro_942323057@rtfm.mit.edu>
- Reply-To: rfheeter@pppl.gov
- NNTP-Posting-Host: penguin-lust.mit.edu
- Summary: Fusion energy represents a promising alternative to
- fossil fuels and nuclear fission for world energy
- production. This FUT is a compendium of Frequently Used
- Terms in plasma physics and fusion energy research. Refer
- to the FAQ on Conventional Fusion for more detailed info
- about topics in fusion research. This FUT does NOT
- discuss unconventional forms of fusion (like Cold Fusion).
- X-Last-Updated: 1995/02/05
- Originator: faqserv@penguin-lust.MIT.EDU
- Xref: senator-bedfellow.mit.edu sci.physics.fusion:44251 sci.answers:10848 news.answers:170834
-
- Archive-name: fusion-faq/glossary/c
- Last-modified: 4-Feb-1995
- Posting-frequency: More-or-less-quarterly
- Disclaimer: While this section is still evolving, it should
- be useful to many people, and I encourage you to distribute
- it to anyone who might be interested (and willing to help!!!).
-
- ===============================================================
- Glossary Part 3: Terms beginning with "C"
-
- FREQUENTLY USED TERMS IN CONVENTIONAL FUSION RESEARCH
- AND PLASMA PHYSICS
-
- Edited by Robert F. Heeter, rfheeter@pppl.gov
-
- Guide to Categories:
-
- * = plasma/fusion/energy vocabulary
- & = basic physics vocabulary
- > = device type or machine name
- # = name of a constant or variable
- ! = scientists
- @ = acronym
- % = labs & political organizations
- $ = unit of measurement
-
- The list of Acknowledgements is in Part 0 (intro).
- ==================================================================
-
- CCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCC
-
- # c: Speed of light; 3.0x10E+8 meters/second or 3.0x10E+10 cm/sec
-
- @ CAMAC: Computer Automated Measurement and Control
-
- @ CANDU: CAnadian Deuterium-Uranium class of fission reactor;
- see entry
-
- > CASCADE: See entry (not an acronym as far as I know).
-
- @ CCD: Charge Coupled Device
-
- @ CGS: Centimeters, Grams, Seconds; see CGS Units
-
- @ CGS Units: see entry below; see also CGS above.
-
- @ CFFTP: Canadian Fusion Fuels Technology Project; see entry.
-
- @ CIT: Compact Ignition Tokamak; see entry
-
- @ COE: Cost of Electricity
-
- @ CT: Compact Torus; see entry
-
- @ CTX Facility: Compact Toroid Experimental facility; see entry.
-
- @ cw: Continuous Wave (distinct from pulsed).
-
- @ CY: Calendar Year (as opposed to Fiscal Year, FY)
-
- $ cm: centimeters; unit of distance. See also centi-
-
- * C-Coil: C-shaped magnet coil
-
- * Calorimeter: In conventional fusion research, this name
- refers to any device used to measure power or energy in
- a laser or particle beam. (e.g., for ICF or neutral beam
- heating or a magnetically-confined plasma.)
-
- * Canadian Deuterium-Uranium Fission Reactor: Nuclear fission
- reactor type developed in, and prominent in, Canada; characterized
- by use of heavy water (deuterium instead of hydrogen, D2O) as
- moderator and coolant. Neutrons absorbed by the deuterium create
- a source of marketable tritium.
-
- * Canadian Fusion Fuels Technology Project: Fusion power
- development project, jointly funded by the National Research
- Council of Canada, the Province of Ontario, and Ontario
- Hydro (energy company and project manager), to develop
- and internationally apply technologies related to management
- of fusion fuels. (Any current info, anyone?)
-
- & Carbon: (C) Sixth element (Z=5) in the periodic table; has
- 6 protons; often described as the basis of life on earth because
- of its chemical properties; has potential for use with silicon
- as a low-activation structural material for fusion reactors,
- in the form silicon carbide. (See relevant parts of FAQ
- section 2.) Also useful as a neutron moderator. See also
- low-activation materials.
-
- & Carnot Efficiency: maximum possible efficiency for conversion
- of thermal energy to useful work (such as electrical energy),
- as determined by the laws of thermodynamics. The Carnot efficiency
- (eta) for conversion of thermal to electric energy (e.g., the upper
- limit on efficiency of a steam turbine) is given by
- (eta) = [ (T-hot) - (T-cold) ] / (T-hot). That is, one gets the
- efficiency from the values of the input and output temperatures
- (measured in Kelvin).
-
- & Capacitor: device used to store electrical energy by accumulating
- charges on nearby conductors. Energy may be stored and withdrawn
- at varying rates. Used in short-pulse plasma devices where only
- a moderate amount of energy is needed.
-
- * Capacity Factor: Index (typically in percent) indicating the
- average power supplied by an energy plant, relative to its
- maximum rated capacity.
-
- * Capital: Economic term for wealth of a permanent nature, rather
- than that which is consumed; includes money and other financial
- goods, plant & equipment, etc. (I'm not an economist - anyone
- know any better?)
-
- > CASCADE: An inertial-fusion energy conversion concept where
- a flowing, replenished layer of ceramic granules (in a rotating
- chamber) protects the chamber wall from the fusion environment
- while absorbing neutrons, breeding tritium fuel, and serving as
- the high-temperature heat exchange fluid.
-
- & Celsius: Temperature scale where zero degrees corresponds to the
- freezing point of water (32 Fahrenheit) and 100 degrees corresponds
- to the boiling point (212 Fahrenheit). Zero celsius = 273.16 Kelvin.
-
- * Centering Force: Term for the mutual attraction
- between the parallel currents in the inboard leg of the toroidal
- field coils in a toroidal magnetic fusion system (e.g., a tokamak).
- The portion of the coil running "through the doughnut hole" is
- attracted towards the center of the hole.
-
- & Centi-: metric prefix indicating 1/100th of a given unit.
- e.g., one centimeter is 1/100th of a meter.
-
- & Centigrade: see Celsius
-
- & CGS Units: System of measurement where the fundamental units
- are centimeters, grams, and seconds.
-
- & Chain Reaction: (from Herman) A self-sustaining series of
- chemical or nuclear reactions in which the products of the
- reaction contribute directly to the propagation of the process.
-
- * Channel Transport: In inertial fusion research using light
- ion drivers, describes the use of current-carrying plasma
- channels (which are magnetically confined to the channel) to
- transport electron or ion beams between the ion diode and the
- fusion target. This allows the ion source to stand back from
- the target.
-
- & Charge Density: See density, and apply to electrical charge.
-
- & Charge, Electrical:
- As a noun: A fundamental physical attribute of a
- particle, which characterizes the particle's electromagnetic
- interaction with other particles and with electric and magnetic
- fields. (See also particle, field)
-
- As a verb: Storing energy in a battery or electric capacitor by
- running a current through it; opposite of discharge. (It is possible
- to charge most capacitors in either direction, but batteries charge
- one way, and discharge the other.)
-
- * Charge Exchange: Phenomenon in which an ion colliding with
- a molecule (or an atom) neutralizes itself by capturing an electron
- from the molecule/atom, and transforming the molecule/atom into a
- positive radical/ion.
-
- * Charge Transfer: see charge exchange
-
- * Charged Particle: a particle which carries a positive or
- negative electrical charge. In plasma physics, this typically
- means an ionized atom or molecule, or an electron.
-
- * China Syndrome: American jargon/slang for a nuclear fission
- meltdown accident (see meltdown) in which the molten nuclear core
- heats and melts the ground beneath it, thus sinking into the
- earth, and heading towards China (which is roughly on the opposite
- side of the globe).
-
- * Classical Confinement: Plasma confinement in which energy transfer is
- via classical diffusion; best possible case for magnetically
- confined plasmas. See entry for classical diffusion below.
-
- * Classical Diffusion: In plasma physics, diffusion due solely
- to scattering (collisions) of charged particles (with unlike
- charges) via electrical ("Coulomb") interactions. (See also diffusion.)
-
- * Coherent Radiation: Any form of radiation in which the phase
- relationship between sections of the wave at different locations is
- not random (or incoherent!). Typical example is a laser beam, in
- which the phase is more or less uniform across the beam, and changes
- along the beam in accordance with the wavelength. Radiation in
- which the photons tend to "agree" with one another, rather than
- being randomly distributed.
-
- * Cold Plasma Model: Model of a plasma in which the temperature is
- neglected with respect to the effects of interest.
-
- * Collision: Refers to the close approach of two or more
- particles, photons, atoms, nuclei, etc, during which such quantities
- as energy, momentum, and charge may be altered. More-or-less
- synonymous with "scattering," except in scattering one generally
- thinks of one of the particles as being at rest, and the other
- colliding particles "scatter" from their initial direction of
- motion due to the collision.
-
- & Collision Cross-Section: Effective surface area of a particle
- when it collides with another; describes probability of collisions
- between the two particles.
-
- * Collisionless Plasma Model: Model of a plasma in which the density
- is so low, or the temperature so high, that close binary (two-body)
- collisions have practically no significance (on certain timescales)
- because the time scales of interest are smaller than the
- collision time. Yields valid physical results for timescales
- much shorter than the average collision time in a real plasma.
-
- & Collision Time: Typical time which passes between the time
- a particle collides, and when it collides again. Inverse of the
- collision frequency; equal to the mean free path divided by the
- particle's velocity. The collision time decreases with increasing
- density, and increases with increasing temperature.
-
- > Compact Ignition Tokamak (CIT): Proposed U.S. successor to TFTR;
- never funded. See also, BPX, TPX.
-
- > Compact Torus: Any of a series of axially symmetric fusion
- configurations having closed flux surfaces (like a tokamak, not
- like a mirror machine), but having no material objects piercing
- the core (as do the toroidal field coils of a tokamak). These
- devices have an inherently low aspect ratio, approximately unity.
- The most successful variants are the spheromak and the Field
- Reversed Configuration. See also: low aspect ratio, spheromak,
- field-reversed configuration. (Arthur Carlson,
- awc@ipp-garching.mpg.de)
-
- > CTX Facility (Compact Toroid Experimental facility):
- Los Alamos facility to investigate plasma physics of compact
- toroids. (No longer in operation?)
-
- * Compression Waves: Also known as density waves (I think!);
- waves where the quantity which oscillates is the density of the
- medium, that is the medium at a given point alternately
- compresses and expands. Low-amplitude compression waves in
- air or water are commonly known as sound waves; shock waves
- are a high-amplitude form. See also waves.
-
- & Conductivity: Degree to which a substance transmits (conducts)
- a given physical property, such as heat or electricity.
- See electrical conductivity, thermal conductivity.
-
- * Confinement, Classical: See classical confinement.
-
- * Confinement, Electrostatic: See electrostatic confinement.
-
- * Confinement, Inertial: See inertial confinement.
-
- * Confinement, Magnetic: See magnetic confinement.
-
- * Confinement Time: There are several types. The general
- definition is that tau = [total]/[loss per unit time];
- hence Tau_E = [total energy]/[energy loss per unit time].
-
- Tau_[E, N, ...] is the amount of time the plasma is contained
- by magnetic fields before its [energy (E), particles (N or P)]
- leak / dissipate away. The different types are, in general,
- similar but not equal.
- (Note note note: Tau_E is NOT electron confinement time!)
-
-
- > Constance: Small mirror devices; formerly operated at MIT.
-
- * Containment Vessel: Gas-tight shell or other enclosure
- around a fusion (or fission) reactor, to prevent accidental
- leakage of radioactive contents.
-
- * Controlled Thermonuclear Fusion: The process in which
- light nuclei, heated to a high temperature in a confined
- region, undergo fusion reactions under controlled conditions,
- with associated release of energy which may be harnessed
- for useful purposes.
-
- * Coolant: Substance circulated through a device (including
- fusion reactors, fusion reactor magnets, etc.) to remove or
- transfer heat. Common types include water, helium, and
- liquid-metals such as sodium (Na).
-
- * Cooperative Phenomena: The motion of interacting particles
- acting collectively, rather than individually. Includes
- plasma oscillations, turbulence, and instabilities. (Plasmas
- are distinguished from collections of individual particles
- in that they exhibit cooperative phenomena, whereby the plasma
- particles "cooperate" with one another. Early fusion researchers
- who devised fusion schemes based upon theories where plasmas
- acted as merely a collection of individual particles (and
- therefore sought to confine only individual particles) often
- found themselves frustrated at the ability of plasma
- cooperative phenomena (such as MHD instabilities) to thwart
- their efforts.
-
- * Core plasma: Hot plasma at the center of a fusion reactor;
- distinguished from edge plasma. The core plasma does not
- directly feel the effects of the divertor or limiter in the
- way the edge plasma does. (More info anyone?)
-
- * Corona: The outermost (?) part of a star's atmosphere;
- characterized by high temperatures and low densities; home to
- many plasma phenomena.
-
- * Corrosion: Chemical interactions between a fluid, (such
- as lithium or water coolant) and the containing material
- (such as stainless steel), which results in wall material
- dissolving into the fluid, and possibly degradation of
- the mechanical properties of the containing structure
-
- $ Coulomb: standard unit of electric charge. A single electron or
- proton has a charge of (+/-) 1.6022E-19 coulombs. Hence there are
- 6.2414E+18 electrons in a coulomb of electrons.
-
- * Coulomb Collision: An interparticle collision where Coulomb's Law
- (electrical attraction and repulsion) is the governing force.
- (See Coulomb's Law) Coulomb collisions have a number of interesting
- properties, but these are better described in textbooks. The
- interaction of the charged particles with each other's electric
- fields results in deflections of the particles away from their
- initial paths.
-
- & Coulomb Force: See Coulomb's Law. Also called
- "electrostatic force."
-
- * Coulomb Ionization: Ionization produced by Coulomb forces
- between a moving particle ("projectile") and another particle
- it interacts/collides with ("target").
-
- & Coulomb's Law: Force law governing the electrical interaction
- between charged particles. Force is proportional to (charge of
- first particle) * (charge of second particle) / (square of separation
- between particles). Constant of proportionality depends on system
- of units used. (In SI units, it is 1/(4*pi*epsilon-0), where
- epsilon-0 is the permittivity of free space = 8.854 x 10^-12 )
-
- & Cross Section: (usually symbolized with a lower-case Greek sigma)
- In physics this usually refers to the (apparent) area presented
- by a target particle to an oncoming particle (or electromagnetic
- wave). This measures the probability of an interaction occuring.
- For typical interactions between ions and electrons, or between
- two nuclei, these cross sections are generally measured in barns.
- (See relevant entries.)
-
- & Cryogenic: Loosely, "very cold". Used to describe systems which
- operate at very low temperatures. Superconducting magnetic field
- coils currently need to operate at cryogenic temperatures (e.g.,
- liquid helium at 4 Kelvin).
-
- * Curie: Unit of radioactivity roughly equal to the rate of
- radioactive decay of a gram of radium; named after Marie
- Curie (see below). Corresponds to 3.7 x 10^10
- disintegrations/second (37 billion). (See Becquerel)
-
- ! Curie: Marie and Pierre; husband-wife pair of French scientists.
- Pierre's name is attatched to the "Curie point" in magnetism, which
- is not discussed here. He and his wife shared with Antoine-Henri
- Becquerel the Nobel Prize for physics in 1903. Marie Curie,
- a.k.a. Madame Curie, received the Nobel Prize for chemistry
- in 1911, becoming the first person to receive more than
- one Nobel Prize. She remains the only person to receive Nobel
- Prizes in different fields. (I believe - RFH)
-
- & Current Density: Amount of current flowing through a substance,
- per unit area perpendicular to the direction of current flow. (See
- also density)
-
- * Current Drive: Any of a variety of techniques used to cause
- current flow in a plasma. See inductive current drive, RF current
- drive, non-inductive current drive. Usually applied to schemes
- used to generate current in tokamaks and other toroidal devices
- which require internal plasma currents. See also: bootstrap current.
-
- * Cusped Geometry: I can't figure out how to explain this one in
- words; suffice it to say that this is a description of a magnetic
- field configuration where the magnetic field lines, rather than
- closing in on themselves, tend to squirt out and form cusps at
- certain points; I recommend you look this up in a plasma physics
- text (e.g., Chen - see bibliography entry) to really understand it.
- The magnetic field lines are everywhere convex towards the center.
- Such a geometry is interesting because it is theoretically stable
- against a variety of MHD instabilities.
-
- > Cyclops: Single-chain, 0.6 terawatt Nd-glass laser system at
- Lawrence Livermore National Laboratory that was used for laser
- studies and inertial-confinement fusion experiments in 1975-1976.
-
- * Cyclotron: Particle accelerator in which a magnetic field causes
- particles to orbit in circles, and an oscillating electric field
- accelerates the particles.
-
- * Cyclotron Frequency: Number of times per second that a particle
- orbits in a magnetic field. (Often, and incorrectly, called the
- Larmor frequency. The cyclotron or gyrofrequency is twice the
- Larmor frequency of precession.)
-
- * Cyclotron Radius: Radius of orbit of charged particle about
- a magnetic field line. Also called gyroradius, Larmor radius.
-
- * Cyclotron Radiation: See synchrotron radiation
-
- * Cyclotron Resonance: Charged particles in a magnetic field
- resonate with (and absorb energy from) an electric field
- (perpendicular to the magnetic field) which oscillates at
- the particles' cyclotron frequency, or at a harmonic
- (multiple) of that frequency.
-
- * Cyclotron Resonance Heating: see Electron Cyclotron Resonance
- Heating, Ion Cyclotron Resonance Heating.
-
-
-
-
-
-