Wikipedia:Peer review/Plasma (physics)/archive1

Plasma (physics)
The article has already achieved Good Article status, so I figure that Peer review is the next step for improvement, with an aim to eventually reach Featured Article status.

I realize that this is a very broad and complex subject, but it should still be readable and interesting to everyone. --Iantresman 11:00, 18 August 2006 (UTC)


 * I didn't completely finish the article yet, but here's a few comments:
 * Section "Definition of a plasma", item two says that the 'Debye screening length' is defined above. But what I see above that is only the 'Debye sphere'. Please clarify the text.
 * Could you explain the 'electron neutral collision frequency' in the text?
 * In 'Ranges of plasma parameters', the 'Heliospheric current sheet' illustration appears out of place and could perhaps be moved to a more appropriate location. The table in that same section could do with some links to the unit description pages. (E.g. T) The Density/Cosmic cell in that table is missing units. (To be consistent with the other cells.)
 * The article introduces the relation '&omega;ce / &nu;coll > 1' without explaining the parameters. Likewise with E = -V x B. In the "Densities" section, is &Phi; the same as &phi;pl?
 * I'm a little unclear about what is meant by "The possibility of currents couples the plasma strongly to magnetic fields" in the "Comparison of plasma and gas phases" section table.
 * In the same table, the graph is appearing above the text on the Velocity distribution row.
 * The article as a whole has a number of significant sections without references. For example, "Mathematical descriptions".
 * The "Fields of active research" section is little more than a bulleted list. Could this be expanded into something that is a little more interesting to read?
 * Thank you. &mdash; RJH (talk) 15:36, 18 August 2006 (UTC)
 * Thanks for the feedback, I've taken in all the changes, except for the "Fields of active research" which I'm not sure what to do with at this stage, and will await further feedback. --Iantresman 20:52, 18 August 2006 (UTC)

The article appears to suffer from a lack of technical information, though it is very good in the contextual sense. For example, a typical outline for a course on plasma physics includes:

"The concept of temperature (particularly related to the fact that plasmas are notoriously out of local thermodynamic equilibrium; the conditions of density and temperature necessary for the plasma state; discussion of fusion; motion of single charged particles in static and time varying electric and magnetic fields; plasmas described as (charged) fluids or magnetohydrodynamics; waves in plasmas; plasma heating with radio waves; kinetic theory description of plasmas including diffusion with and without magnetic fields; Debye shielding of a charge; Vlasov equation and collisionless plasmas; Landau dampening of waves; BGK single relaxation time model description of collisions; transport calculations of mass (diffusion); momentum (viscosity) and energy (heat conductivity)." from.

Other topics include:

"Klimontovich equation, Fokker Planck equation, Coulomb collisions, PIC Particle simulation, Atomic collisions, Sheaths & probes, Dusty plasmas, and Quasilinear theory"

It would be good for all of these subjects to at least be mentioned (more than a few of them already are!), if not have paragraphs or sections devoted to them. These are considered by professionals in the field to be some of the basic concepts inherent to the subject.

--ScienceApologist 02:40, 21 August 2006 (UTC)


 * Thanks for the suggestions, which I shall take a look at, as well I hope, some of the other editors. I think that some of the more technical information has been deliberately removed from the article (a) because the subject is so broad (b) as an encyclopedic, rather than scientific article, an overview is more important (c) the technical stuff can form mini-articles by themselves.
 * For example, the section on Mathematical descriptions now links to a page on Plasma parameters.
 * --Iantresman 21:21, 21 August 2006 (UTC)

Plasma parameters right now only deals with scaling in plasmas. There are a wide range of other ideas which are technical/mathematical but can be described for a general audience in the lists above. --ScienceApologist 13:01, 22 August 2006 (UTC)


 * The intro makes a few brief references to the history of plasma research. That should be expanded and moved to its own section. Good work otherwise! --P199 12:28, 24 August 2006 (UTC)

Solid-state plasma
I came to Wikipedia's "Plasma" article looking for some introduction to solid-state plasmas, studied by Betsy Ancker-Johnson for example, and for which I found a short biblio here. While I majored in physics (long ago) I'm completely unfamiliar with the term, and believe the article would benefit from some clarification of non-gaseous plasmas, such as "electron-hole plasma". If this is an obsolete use of the word, a clarification still seems called for. Thanks. Twang 07:27, 9 March 2007 (UTC)