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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 14/26 (N)
- Supersedes: <fusion-faq/glossary/n_934543711@rtfm.mit.edu>
- Followup-To: sci.physics.fusion
- Date: 11 Nov 1999 12:25:52 GMT
- Organization: Princeton University
- Lines: 193
- Approved: news-answers-request@MIT.EDU
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- Expires: 23 Feb 2000 12:24:17 GMT
- Message-ID: <fusion-faq/glossary/n_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 Glossary 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 Glossary does NOT
- discuss unconventional forms of fusion (like Cold Fusion).
- X-Last-Updated: 1995/02/20
- Originator: faqserv@penguin-lust.MIT.EDU
- Xref: senator-bedfellow.mit.edu sci.physics.fusion:44262 sci.answers:10859 news.answers:170845
-
- Archive-name: fusion-faq/glossary/n
- Last-modified: 20-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 14: Terms beginning with "N"
-
- 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).
- ==================================================================
-
- NNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNN
-
- # n: variable used for number density of particles.
- # n: also used as the symbol for a neutron.
- # n: also sometimes used for the index of refraction
-
- @ NAS: National Academy of Sciences; see entry
-
- @ NASA: National Aeronautics and Space Administration
-
- $ nano: metric prefix indicating 10^-9 * the base unit
-
- @ NBETF: Neutral Beam Engineering Test Facility
-
- @ NBI: Neutral Beam Injection; see entry
-
- @ NBS: National Bureau of Standards
-
- @ ND-YAG: Neodymium yttrium Aluminum Garnet
-
- # ne: (n subscript e) - usually electron density
-
- # Ne: chemical symbol for Neon.
-
- @ NERSC: National Energy Research Supercomputer Center; see entry
-
- @ NIF: National Ignition Facility; see entry
-
- @ NIKE: Naval? Inertial Confinement Experiment????; see entry
-
- @ NINJA: Neutral gas INJection Array (on Alcator C-Mod)
-
- @ NIST: National Institute for Science & Technology?
-
- @ NRC: National Research Council *OR* Nuclear Regulatory
- Commission; see entries.
-
- @ NRL: Naval Research Laboratory; see entry
-
- @ NSTX: National Spherical Tokamak eXperiment; see entry
-
- % National Academy of Sciences: Elite, honorary, independent,
- self-perpetuating organization of highly-successful scientists;
- chartered by the U.S. Congress to provide technical advice
- to the federal government upon request.
-
- % National Energy Research Supercomputer Center (NERSC):
- Formerly the National Magnetic Fusion Energy Computer Center,
- or NMFECC, NERSC is a supercomputer facility located at
- Livermore, CA. Originally developed to provide high-performance
- computing facilities for the needs of the magnetic fusion
- energy program, the facility now benefits all energy research
- programs. NERSC is a part of the Energy Sciences Network, ESNET,
- run by the Department of Energy, which links several of the
- national laboratories.
-
- > National Ignition Facility (NIF): Inertial-Confinement
- Fusion Facility proposed to be built at Livermore and
- operational around the year 2000. See Section 9 on Future
- Plans for more information.
-
- % National Research Council: Research arm of the National
- Academy of Sciences.
-
- > National Spherical Tokamak eXperiment (NSTX): Mid-sized
- low aspect-ratio tokamak / spheromak experiment proposal;
- still in design phase / not funded. See Section 9 on Future
- Plans for more information.
-
- % Naval Research Laboratory: Basic-science research laboratory
- operated by the U.S. Navy.
-
- * Neoclassical Diffusion: In a magnetized plasma, _classical_
- diffusion refers to transport of particles due to Coulomb collisions,
- taking the spiral orbits in the magnetic field into account. In a
- toroidal magnetic field, the actual rate of diffusive transport is
- much higher due to slow changes in the positions of the centers of the
- spirals, known as banana orbits (see entry). This faster transport
- is called _neo-classical_. With very few exceptions the transport
- in toroidal devices is observed to be 10-100 times larger still,
- presumably due to small-scale turbulence. The observed transport is
- called _anomalous_ (although it actually is the "normal" state).
-
- * Neoclassical transport: See neo-classical diffusion.
-
- > Neutral Beam Engineering Test Facility: Facility located at
- LBL which tested neutral beam injection systems that were
- designed for use in magnetic fusion reactors.
-
- * Neutral Beam Injection: This is one of the fundamental plasma
- heating methods. A particle accelerator is used to create
- fast ion beams (the particle energies are on the order of 100 keV);
- the ion beam is then passed through a neutral gas region, where
- the ions neutralize via charge-exchange reactions with the neutral
- gas. The neutralized beam is then injected into a magnetically
- confined plasma. The neutral atoms are unaffected (not confined)
- by the magnetic field, but ionize as they penetrate into the
- plasma. The high-energy ions then transfer some of their energy
- to the plasma particles in repeated collisions, and heat the
- plasma.
-
- * Neutral Injection Concept: See Neutral Beam Injection, above.
-
- * Neutralized Plasma: Plasma with no net electrical charge.
-
- & Neutron: [Symbol: n] Fundamental atomic particle with
- zero electrical charge (therefore not confined by a magnetic
- field) and a mass roughly equal to a proton's mass. Neutrons
- are found in all nuclei except for ordinary hydrogen; they are
- also products of many nuclear reactions. Neutrons will react
- with nuclei, and can induce radioactivity or fission. Free
- neutrons which do not collide and react with a nucleus decay into
- an electron, a proton, and an neutrino, with a half life of
- about 13 minutes.
-
- * Neutron Wall Loading: Energy flux carried by fusion neutrons into
- the first physical boundary that surrounds the plasma (the first
- wall). (see also First Wall, Flux, Neutrons)
-
- > NIKE: Medium-scale(?) inertial-confinement fusion facility at
- the Naval Research Lab; see discussion in Section 5.
-
- * Non-Inductive Current Drive: Current drives schemes that do not
- rely upon the "transformer" effect in tokamaks. The attainment of
- non-inductive current drive is crucial to the success of tokamaks
- as truly steady-state devices. See also inductive current drive.
-
- > Nova: The United States' largest laser (ICF) fusion
- facility, and the world's most powerful laser; located at LLNL.
- This is a 10-beam, 100 terawatt, Nd-glass laser system, which can
- operate at the infrared/visible wavelengths of 1.05, 0.53, or
- 0.35 microns. It was completed in 1984 and is the successor to
- the Shiva system. (The next flagship laser-fusion facility
- currently planned in the U.S. is the National Ignition Facility.)
-
- * Nuclear Binding Energy: The difference between the total
- energy ( = mc^2) of the bound nucleus, and the energies of
- the individual constituent particles ( = sum of masses * c^2).
- The nuclear binding energy *per nucleon* is a maximum for iron.
- Fusion releases energy because light nuclei are less tightly
- bound than medium-weight nuclei, and thus energy is liberated
- when they become more tightly bound after fusing. Fission
- releases energy for the same reason - heavy nuclei are also
- less tightly bound than medium-weight nuclei, and energy is
- liberated when heavy nuclei split into lighter nuclei.
-
- & Nuclear Force: See Weak (Nuclear) Force, Strong (Nuclear) Force.
-
- % Nuclear Regulatory Commission: U.S. organization in charge
- of overseeing safety of nuclear facilities, including fission
- (and presumably fusion) reactors.
-
- * Nucleon: Generic term for a component particle of a nucleus,
- i.e., either a proton or a neutron.
-
- & Nucleus: The tiny core of an atom, positively charged,
- containing protons and neutrons (except for simple hydrogen,
- which has only a single proton). In an atom, electrons "orbit"
- the nucleus, forming a cloud around it.
-
-
-
-
-
-