1 / 8

Plasma

Plasma. Electrons are free! … A fourth state of matter: Not gas, not liquid, not solid!. History, Terminology, & Discovery. First identified by Sir William Crookes (1879) Termed by Irving Langmuir Ionosphere identified as plasma Van Allen Belts (1958). Types of Plasma.

randy
Download Presentation

Plasma

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript


  1. Plasma Electrons are free! … A fourth state of matter: Not gas, not liquid, not solid!

  2. History, Terminology, & Discovery • First identified by Sir William Crookes (1879) • Termed by Irving Langmuir • Ionosphere identified as plasma • Van Allen Belts (1958)

  3. Types of Plasma Artificially Induced Terrestrial & Astrophysical Stars (Sun) Ionosphere Aurora Borealis Lightning Most fires TLE • Fluorescent lamps • Neon Signs • Plasma televisions • Electric arcs (i.e. those created by a Marx generator,etc.) • Laser-Produced Plasmas (LPP) • Rocket exhaust • Ion Thrusters

  4. Plasma: A Fourth State of Matter • Ionized “gas” • Most are quasi-neutral • Said: ~99% of matter • Affected by E&M waves • Characteristics • Electron density: • Temperature: • Molecular Content • Electron Plasma Frequency: • Debye Length:

  5. Plasma Physics • Maxwell’s Equations: Statistics, Mathematics, the Most General Case • Maxwell-Boltzmann Distribution: particle density distribution • Fluid Mechanics: Three particle, nonviscous intermingled fluids coupled through their equations of state and collision frequencies

  6. Wave Propagation • Propagation constant: • Approaches free space • value: • Turns imaginary • Wave propagation highly dependent on electron plasma frequency: • If then the wave propagates through • If then the wave is deflected • Deflection Case: • Fields vary exponentially • Phase-variation terms decay exponentially (the wave will • decay as it propagates) • e.g. Ionosphere reflects E&M radiation with frequency less • than its plasma frequency

  7. Example: If lightning were to propagate toward the ionosphere would it be deflected? Why or Why not? • Ionosphere: • Lightning: Answer: It will not be deflected as its frequency is larger than that of the ionosphere

  8. References • 1909, who valued professional, financial success as well as scientific inquiry, accomplishment, his summer position stretched into a lifelong career. He became known among his colleagues for his analytical mind, creativity, ambition, and excellent research skills.. "Irving Langmuir." Ziggo. N.p., n.d. Web. 1 July 2010. http://members.home.nl/arjen.boogaard/Irving%20Langmuir.html. • "Brief History of Plasma Physics." Home Page for Richard Fitzpatrick . N.p., n.d. Web. 1 July 2010.http://farside.ph.utexas.edu/teaching/plasma/lectures/node5.html. • "Fields & Waves I v2." Plasma Dynamics Lab. N.p., n.d. Web. 1 July 2010. http://hibp.ecse.rpi.edu/~connnor/education/Fields/F09/. • "Plasma (physics)." 2008/9 Wikipedia Selection for schools. N.p., n.d. Web. 1 July 2010. http://schools-wikipedia.org/wp/p/Plasma_%2528physics%2529.htm. • "Plasma Physics -- History." NASA Polar, Wind, and Geotail Projects. N.p., n.d. Web. 16 June 2010. http://www-spof.gsfc.nasa.gov/Education/whplasma.html. • "Plasma Physics." National Ignition Facility & Photon Science. N.p., n.d. Web. 1 July 2010.https://lasers.llnl.gov/programs/science_at_the_extremes/plasma_physics/. • Riegel, ron. "Irving Langmuir - Wikipedia, the free encyclopedia." Wikipedia, the free encyclopedia. N.p., n.d. Web. 28 June 2010.http://en.wikipedia.org/wiki/Irving_Langmuir. • Uman, Martin A. Introduction to Plasma Physics. New York: McGraw-Hill, 1964. Print.

More Related