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Fix Matter see-also invoke

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Fix Matter see-also invoke

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{{Short description|Ionized state of matter consisting of charged particles}}

{{Quantum matter backlink|Plasma and fusion physics}}

'''Plasma''' is a state of [[Physics:Quantum matter/matter|matter]] consisting of charged particles such as ions and free [[Physics:Quantum atoms/electron|electrons]]. It is often described as an ionized gas and is commonly considered the fourth state of matter after solids, liquids, and gases.<ref>{{Cite journal | last1 = Langmuir | first1 = I. | title = Oscillations in Ionized Gases | doi = 10.1073/pnas.14.8.627 | journal = Proceedings of the National Academy of Sciences | volume = 14 | issue = 8 | pages = 627–637 | year = 1928 | pmid = 16587379 | pmc = 1085653 | bibcode = 1928PNAS...14..627L | doi-access = free }}</ref><ref>{{cite book |last=Frank-Kamenetskii |first=David A. |year=1972 |title=Plasma-The Fourth State of Matter |publisher=Plenum Press |isbn=9781468418965 }}</ref>

<div style="float:right; border:1px solid #e0d890; background:#fff8cc; padding:6px; margin:0 0 1em 1em; width:420px;">
[[File:Matter-Plasma.png|400px]]
<div style="font-size:90%;">Plasma consists of free charges and responds strongly to electromagnetic fields.</div>
</div>

== Description ==

Plasma forms when atoms gain sufficient energy for electrons to escape from atomic nuclei, producing a mixture of positively charged ions and negatively charged electrons.<ref>{{cite book | title=Introduction to Plasma Physics and controlled fusion | author=Chen, Francis F. | year=1984 | publisher=Springer International Publishing | pages=2–3 | isbn=9781475755954 }}</ref><ref>{{cite book |title=Introduction to Plasma Theory |last=Nicholson |first=Dwight R. |date=1983 |publisher=John Wiley & Sons |isbn=978-0-471-09045-8}}</ref>

Because of the presence of free charges, plasma responds strongly to electromagnetic fields and conducts electricity efficiently.<ref>{{cite book | title=Plasma Physics and Fusion Energy | author=Freidberg, Jeffrey P. | year=2008 | publisher=Cambridge University Press | page=121 | isbn=9781139462150 }}</ref><ref>{{cite book |title=The Framework of Plasma Physics |author=Hazeltine, R.D. |author2=Waelbroeck, F.L. |date=2004 |publisher=Westview Press |isbn=978-0-7382-0047-7}}</ref>

Although plasma is uncommon under ordinary conditions on Earth, it is estimated to constitute more than 99% of the visible matter in the universe.<ref>{{Cite web |title=Plasma, Plasma, Everywhere! |url=https://www.nasa.gov/podcasts/curious-universe/plasma-plasma-everywhere/ |access-date=2025-06-23 |website=NASA |language=en}}</ref><ref>{{cite web|url=https://www.psfc.mit.edu/resources/fusion-101/what-is-plasma/|title=What Is Plasma?|website=MIT Plasma Science and Fusion Center |date=11 June 2024 }}</ref>

Stars, stellar coronae, nebulae, the solar wind, and much of interstellar space consist primarily of plasma.<ref name="Piel2010">{{Cite book
|last =Piel
|first=A.
|date=2010
|title= Plasma Physics: An Introduction to Laboratory, Space, and Fusion Plasmas
|publisher=Springer
|isbn=978-3-642-10491-6
}}</ref><ref>{{cite book
|last=Aschwanden
|first=M. J.
|year=2004
|title=Physics of the Solar Corona. An Introduction
|publisher=Praxis Publishing
|isbn=978-3-540-22321-4}}</ref>

Plasma also appears naturally on Earth in phenomena such as [[lightning]], aurorae, and sufficiently hot flames.<ref>{{Cite web | title = How Lightning Works | publisher = HowStuffWorks | url = http://science.howstuffworks.com/nature/natural-disasters/lightning2.htm | date = April 2000 }}</ref>

== Properties ==

Plasma differs from ordinary gases because long-range electromagnetic forces dominate its behavior.<ref>{{cite book | title=Introduction to Plasma Physics and controlled fusion | author=Chen, Francis F. | year=1984 | publisher=Springer International Publishing | pages=2–3 | isbn=9781475755954 }}</ref>

Major properties include:

* composed of ions and free electrons
* electrically conductive
* strongly influenced by electric and magnetic fields
* capable of collective behavior such as plasma waves and instabilities
* often emits visible light

The degree of ionization depends strongly on temperature and density.<ref>{{cite book |title=Introduction to Plasma Dynamics |last1=Morozov |first1=A.I. |date=2012 |publisher=CRC Press |isbn=978-1-4398-8132-3}}</ref>

In fusion plasmas and stellar interiors, temperatures can reach millions of kelvin.<ref>{{cite book |title=Fundamentals of Plasma Physics |author=Bittencourt, J.A. |publisher=Springer |date=2004 |isbn=9780387209753}}</ref>

== Plasma and fusion ==

Plasma plays a central role in [[Physics:Quantum magnetic confinement|magnetic confinement fusion]], where powerful magnetic fields are used to confine extremely hot ionized gases.<ref>{{Cite journal |last1=Peacock |first1=N. J. |last2=Robinson |first2=D. C. |last3=Forrest |first3=M. J. |last4=Wilcock |first4=P. D. |last5=Sannikov |first5=V. V. |date=1969 |title=Measurement of the Electron Temperature by Thomson Scattering in Tokamak T3 |journal=Nature |volume=224 |issue=5218 |pages=488–490 |doi=10.1038/224488a0 |bibcode=1969Natur.224..488P}}</ref>

Fusion experiments such as [[Physics:Quantum Tokamak|tokamaks]] and stellarators attempt to heat plasma to temperatures high enough for nuclear fusion reactions between deuterium and tritium nuclei.<ref>{{Cite journal |last=Gibney |first=Elizabeth |date=2022 |title=Nuclear-fusion reactor smashes energy record |journal=Nature |volume=602 |issue=7897 |page=371 |doi=10.1038/d41586-022-00391-1}}</ref>

Modern plasma research investigates plasma turbulence, plasma stability, superconducting magnets, and plasma-material interactions for future fusion reactors such as ITER and SPARC.<ref>{{Cite journal|last1=Sweeney|first1=R.|last2=Creely|first2=A. J.|date=2020|title=MHD stability and disruptions in the SPARC tokamak|journal=Journal of Plasma Physics|volume=86|issue=5|page=865860507|doi=10.1017/S0022377820001129}}</ref>

== Applications ==

Artificial plasmas are widely used in science and technology.<ref>{{cite book |editor=Hippler, R. |editor2=Kersten, H. |editor3=Schmidt, M. |editor4=Schoenbach, K.M. |date=2008 |title=Low Temperature Plasmas: Fundamentals, Technologies, and Techniques |publisher=Wiley-VCH |edition=2nd |isbn=978-3-527-40673-9}}</ref>

Applications include:

* fluorescent and neon lighting<ref>{{cite web |url=http://www-spof.gsfc.nasa.gov/Education/wfluor.html |title=The Fluorescent Lamp: A plasma you can use }}</ref>
* plasma displays and plasma televisions<ref>{{cite book
|last1=Chu
|first1=P.K.
|last2=Lu
|first2=XinPel
|date=2013
|title=Low Temperature Plasma Technology: Methods and Applications
|publisher=CRC Press
|isbn=978-1-4665-0990-0}}</ref>
* plasma cutting and welding<ref>{{Cite journal | last1 = Nemchinsky | first1 = V. A. | last2 = Severance | first2 = W. S. | doi = 10.1088/0022-3727/39/22/R01 | title = What we know and what we do not know about plasma arc cutting | journal = Journal of Physics D: Applied Physics | volume = 39 | issue = 22 | pages = R423 | year = 2006 }}</ref>
* semiconductor etching<ref>{{cite book |author= National Research Council |date=1991 |title=Plasma Processing of Materials : Scientific Opportunities and Technological Challenges |publisher=National Academies Press |isbn=978-0-309-04597-1}}</ref>
* ion thrusters and spacecraft propulsion<ref>{{cite journal |author=Peretich, M.A. |author2=O'Brien, W.F. |author3=Schetz, J.A. |date=2007 |title=Plasma torch power control for scramjet application }}</ref>
* plasma medicine and sterilization<ref>{{cite journal|doi=10.1109/27.533129|title=Sterilization of contaminated matter with an atmospheric pressure plasma|journal=IEEE Transactions on Plasma Science|volume=24|issue=3|pages=1188–1191|year=1996|last1=Laroussi|first1=M.}}</ref>

== Space plasma ==

The Earth's ionosphere and magnetosphere contain plasma.<ref>{{cite book |last=Kelley |first=M. C. |title=The Earth's Ionosphere: Plasma Physics and Electrodynamics |date=2009 |publisher=Academic Press |isbn=9780120884254 }}</ref>

The Sun continuously emits plasma in the form of the solar wind, while astrophysical plasmas are also found in accretion disks, stellar coronae, and relativistic jets around black holes.<ref>{{Cite web|title=APOD: M87's Energetic Jet|url=https://apod.nasa.gov/apod/ap041211.html}}</ref>

== History ==

The electric arc was independently discovered by [[Vasily Vladimirovich Petrov|Vasily Petrov]] and [[Humphry Davy]] in 1803.<ref name="Piel2010" />

In 1879, [[William Crookes]] proposed that ionized gases represented a fourth state of matter.<ref name=vonEngel-1955>Von Engel, A. (1955). Ionized Gases. Clarendon Press.</ref>

The term ''plasma'' was introduced by [[Irving Langmuir]] in 1928 while studying ionized gases.<ref>{{Cite journal | last1 = Langmuir | first1 = I. | title = Oscillations in Ionized Gases | doi = 10.1073/pnas.14.8.627 | journal = Proceedings of the National Academy of Sciences | volume = 14 | issue = 8 | pages = 627–637 | year = 1928 | pmid = 16587379 | pmc = 1085653 | bibcode = 1928PNAS...14..627L | doi-access = free }}</ref>

=See also=
{{#invoke:PhysicsQC|tocHeadingAndList|Physics:Quantum basics/See also/Matter}}

=References=
{{reflist|3}}

{{Author|Harold Foppele}}
{{Sourceattribution|Plasma (physics)|1}}

Physics:Quantum matter/plasma - Revision history

imported>WikiHarold: Fix Matter see-also invoke

imported>WikiHarold: Fix Matter see-also invoke