Conventional Fusion FAQ Glossary Part 21/26 (U)

From: Robert F. Heeter <rfheeter@princeton.edu>
Newsgroups: sci.physics.fusion
Subject: Conventional Fusion FAQ Glossary Part 21/26 (U)
Date: 11 Nov 1999 12:26:27 GMT
Message-ID: <fusion-faq/glossary/u_942323057@rtfm.mit.edu>
Reply-To: rfheeter@pppl.gov
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: 1995/02/26

Archive-name: fusion-faq/glossary/u
Last-modified: 25-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 21:  Terms beginning with "U"

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).
==================================================================

UUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUU

# u:  variable commonly used for energy density of electric or
magnetic fields; also sometimes used for velocity.

@ UT, UTA:  University of Texas at Austin; see entry

@ UV:  Ultraviolet (range of the electromagnetic spectrum)

@ UW, UWM:  University of Wisconsin at Madsion; see entry

& Ultraviolet:  Region of the electromagnetic spectrum 
intermediate between the visible and the x-ray portions.
UV photons have energies greater than a few eV, but less
than (roughly) 100 ev to 1 keV.

* Unipolar Arc:  Arc between a metal surface and a plasma in
contact with it.  Such an arc requires only one electrode
and is maintained by the thermal energy of the electrons.

& Universal gas constant: R = 8.314 x 10^7 ergs per 
degree C per mole.

* Universal Instability:  Low-frequency instability resulting
from the presence of density gradients perpendicular to the
magnetic field lines.  An instability of this type is generally
localized and usually has a small rate of growth.

% University of Texas at Austin (UT):  Among other things, UT has
a large theoretical plasma physcs research center. (info, anyone?)
The TEXT experimental tokamak is also located here.

% University of Wisconsin at Madison:  Among other facilities,
"Wisconsin" has a large research program in both plasma physics
and fusion engineering.

* Upper Hybrid Waves:  Similar to lower hybrid waves, but at a 
higher frequency.  (more description?)  Not truly propagating 
waves, but plasma oscillations. (?)

& Uranium:  (from Herman) A radioactive metallic element whose
isotope, uranium-235, is a nuclear fission fuel.  Plutonium,
another fission fuel, can be produced from the more
plentiful isotope uranium-238.