Physics 520

Plasma Physics


Spring Term 2011

11:10-12:20 MWF, Youngchild Hall Room 115

Professor: Matt Stoneking


Catalog course description: Plasma physics is the study of hot, ionized gases. A plasma, being a collection of charged particles interacting with each other over long distances via electric and magnetic forces, exhibits a wide array of complex behavior including waves and instabilities. Plasmas occur abundantly in space and in the earth's ionosphere. One of the applications of plasma physics is the production of electric power from nuclear fusion. Topics covered in this course include motion of charged particles in electric and magnetic fields, plasma kinetic theory, fluid models, waves and instabilities, wave-particle interactions (Landau damping), plasma confinement and transport.


Text: No required text.  Readings will be assigned from texts on reserve.  Additional handouts and articles will be distributed in class.


Grading policy: Grades will be assigned based on the following elements, weighted as indicated.

•         Laboratory notebook record: 20%

•         Lab reports: 50%

•         In-class presentations: 20%

•         Article discussion: 10%


Lab Notebook Record: This assignment should be a familiar one from your advanced lab experience.  I will be looking for regular, dated entries that legibly record your activities in the lab, your experimental design, procedure, data collection techniques, data analysis, and calculations. 


Lab Reports: For each lab activity you will write a formal report.  These reports can be somewhat less formal than your advanced lab paper.  The imagined readers are the members of your research group.  I expect these reports to be 4-6 pages long.  The goal of this assignment is to give you more experience with scientific writing.  Hopefully, your reading of primary literature and our discussion of that literature will also help you to develop a more professional scientific writing style.


In-class Presentations: In the early weeks of the term, each student will be required to make two or three presentations on some aspect of the technology/instrumentation associated with plasma physics research.

·         Vacuum pumps

·         Pressure gauges

·         Plasma sources

·         Plasma diagnostics


Article Discussions: Approximately once per week we will discuss articles from the primary plasma physics literature.  These articles will not necessarily relate to the laboratory activities in the course, but will be intended to 1) broaden your exposure to the range of plasma physics research areas, 2) acquaint you with some of the seminal papers in the field, and 3) give you more experience reading articles from the physics literature.


Field Trip: The University of Wisconsin – Madison is a center of plasma physics research.  There are multiple research groups in three different departments.  If there is sufficient interest, I will organize a day trip to Madison where we can tour several labs and perhaps attend a plasma physics seminar.


Laboratory Activities:

1.      The vacuum diode:

·         Space-charge limited emission (Child-Langmuir Law)

·         Thermionic (temperature-limited) emission (Richardson-Dushman Equation)

·         Magnetic insulation (Hull effect)

2.      Charged particle motion in magnetic fields (e/m apparatus)

·         Cyclotron motion

·         Magnetic mirror

3.      D.C. plasma discharge

·         Townsend discharge

·         Breakdown and Paschen’s Law

·         Effect of a magnetic field

·         Cyclotron resonance

4.      Electron-impact ionization and plasma production

·         Ionization potential and cross-section

·         Spectroscopy

5.      Langmuir probe diagnosis of plasmas

·         Floating potential

·         Ion saturation current

·         Plasma potential

·         Temperature and density

6.      Emissive probe

·         Plasma potential … ambipolar electric field

7.      Ion acoustic waves

·         Dispersion relation

·         Landau damping

8.      Non-neutral plasma waves

·         Diocotron waves

·         Trivelpiece-Gould waves