From: "Francesca Turco" <frances.turco@tin.it>
Newsgroups: sci.physics.plasma
References: <a2v08u$3tud$1@saturn.cs.uml.edu> <a363bh$9h5u$1@saturn.cs.uml.edu>
Subject: R: question sur le plasma
Organization: TIN


Je pense que "CHARTER, WHAT IS A PLASMA" (see below) pourrait te donner des
bons renseignements generals et plusieurs links pour étendre ce que tu vas
trouver interessant.

Bonne chance!

Francesca

Attachment:
Oggetto: CHARTER, WHAT IS A PLASMA?

>Welcome to the sci.physics.plasma newsgroup.
>
>This is a monthly posting intended to introduce you to the
>newsgroup and to plasmas in general.
>
>CONTENTS:
>
> 1. Statistics
> 2. sci.physics.plasma Archive
> 3. Role of Moderator
> 4. Current Moderator
> 5. Previous Moderator
> 6. Problems
> 7. Charter
> 8. What is a Plasma?
> 9. Plasma Related Links
>
>
>1. STATISTICS:
>
>In November 2000 23 articles were approved for posting to
>sci.physics.plasma
>
>2. SCI.PHYSICS.PLASMA ARCHIVE:
>
>These, and all previous postings to the newsgroup, can be found in
>the sci.physics.plasma archive at
>ftp://ftp.uml.edu/sci.physics.plasma/
>
>3. ROLE OF MODERATOR:
>
>sci.physics.plasma is a moderated newsgroup.
>All postings are sent to the moderator who checks to see that the
>posting conforms to the newsgroup's charter. The moderator is not an
>editor or censor and should not be considered at fault for any incorrect
>information appearing in the newsgroup.
>
>4. CURRENT MODERATOR: (since July 1996)
>
>John W. McKelliget
>Dept. of Mechanical Engineering
>University of Massachusetts
>Lowell, MA 01854
>mailto:John_McKelliget@uml.edu
>http://jmckelliget.eng.uml.edu/
>
>5. PREVIOUS MODERATOR AND NEWSGROUP INITIATOR:
>
>sci.physics.plasma was initiated by Tim Eastman (plasmas@bellatlantic.com)
in
>July 1994
>
>6. PROBLEMS:
>
>If you are experiencing problems posting to sci.physics.plasma or in
>using the archive please contact the current moderator at his email
>address. If your newsreader does not allow you to post to newsgroups
>you can email your post to sci-physics-plasma@uunet.uu.net
>
>7. CHARTER: NEWSGROUP for Plasma Science and Technology
>
>Plasmas are as rich as any other state of matter in terms of distinct
>processes and they encompass distinguishable scales ranging from the
>atomic to the galactic. Opportunities in plasma science and technology
>reflect this breadth in phenomena and scales; one recent list contains
>close to 200 subject areas and more than 90 applications areas including
>thin-film diamond deposition, toxic waste disposal, plasma arcs for
>steel processing, laser self-focusing, fusion for energy production, gas
>and arc lamps, cutting and welding, and semiconductor production.
>
>The Plasma Science and Technology research community seeks an increased
>dialogue among its multifarious constituencies. The NEWSGROUP for Plasma
>Science and Technology is intended as a community forum for sharing new
>developments and bringing researchers together for potential new
>collaborations. The newsgroup also provides a forum for public outreach
>and education. Postings from students and the general public are
>welcome as we all help one another in learning more about the "fourth
>state of matter" and its enormous range
>of applications.
>
>8. WHAT IS A PLASMA?:
>
>The loosest definition of a plasma is that it is an electrically
>conducting gas. At normal temperatures and pressures gases are usually
>very good electrical insulators. This is because the electrons in the
>gas are tightly bound inside gas atoms and are not free to move in
>response to externally applied electric or magnetic fields.
>
>Under certain conditions, however, some or all of the electrons can be
>removed from their parent atoms, a process called ionization. The gas
>then consists of a mixture of negatively charged electrons, positively
>charged atoms, called ions, and un-ionized neutrally charged atoms. Now
>the electrons and ions are free to move under the action of applied
>electromagnetic fields and the gas can conduct electricity. Due to
>their much smaller mass the electrons respond to the applied fields much
>more readily than the ions and, consequently, carry most of the
>current. Since electrons and ions are produced in pairs and have
>opposite charges most of the plasma remains electrically neutral.
>
>There are three principal methods for ionizing a gas. The first, called
>field ionization, involves applying an extremely high electrical field
>that acts on the electrons in a neutral atom and essentially disrupts
>the atom. The second, called thermal ionization, involves raising the
>temperature of the gas until collisions knock electrons out of the
>atoms. Thus, a plasma does not have to be "hot", although some are
>extremely so. The third method involves bombarding the gas with
>high energy radiation or other sub-atomic particles.
>
>Because the properties of a plasma are so very diferent from those of a
>neutral gas the plasma state is sometimes called " the fourth state of
>matter ".
>
>In practice the plasma state covers an extremely large range of
>temperature and pressure, from the gas in the fluorescent lamps in your
>house to the fusion reactions in the center of the sun. Although you
>may have to search for a plasma in your daily life, most of the visible
>matter in the universe is in the plasma state.
>
>Technological applications of plasmas include: fluorescent lights,
>welding arcs, steelmaking furnaces, experimental fusion reactors,
>semiconductor processing, flat panel displays,
>photovoltaics, solar coatings, architectural coatings,
>and hazardous waste processing.
> - J. McKelliget 1998
>
>9. PLASMA RELATED LINKS:
>
>"The Plasma State" an essay commisioned by the American Physical Society
>Division of Plasma Physics
>http://w3fusion.ph.utexas.edu/aps/plasmaState/PPSPage1.html
>
>Plasma science & technology homepage
>http://www.plasmas.org/
>
>Extensive additional plasma material can be found at
>http://plasma-gate.weizmann.ac.il/PlasmaI.html
>http://personal.lig.bellsouth.net/lig/i/n/infonet/Plasma.htm
>
>Listings of upcoming plasma conferences can be found at the following
>sites
>http://hibp7.ecse.rpi.edu/~connor/ieee/plasma_meetings
>http://plasma-gate.weizmann.ac.il/CoAPP.html
>http://www.nifs.ac.jp/jspf/cldr-e.html
>
>
>
>




Mike Rosing <rosing@neurophys.wisc.edu> wrote in message
a363bh$9h5u$1@saturn.cs.uml.edu...
>
> halleck wrote:
> >
> > J'ai trouver sur internet un procede pour un moteur qui utilise le
principe
> > du plasma. Pourriez m'explique ce qu'est exactement le plasma, ses
> > applications, et tout ce qui le concerne. Mercie d'avance
>
> A web search on "Plasma Motor" finds several references to NASA
> projects.
> You may want to check out the ESA web pages too. Sorry, I can't write
> French any more, but I think I understand the question :-)
>
> Patience, persistence, truth,
> Dr. mike
>