1. Physics 777 Plasma Physics and Magnetohydrodynamics (MHD) Instructor: Gregory Fleishman Lecture 7. Instabilities 18 October 2008

2. Plan of the Lecture Plasma Instabilities Electron Cyclotron Maser (ECM) Instability Microscopic and MHD instabilities Generation of Magnetic Field

3. Subsection 1.1. Monoenergetic electron beam Section 1. Plasma Instabilities Recall: If both plasma and the beam are cold, this reduces to: Consider resonance:

4. Otherwise, kinetic description is required

7. Subsection 1.2. Other streaming instabilities For a beam of 1 MeV electrons the Alfven current is I A = 33 kA Credit: Hededal, 2005

8. Mixed mode instability J.T.Frederiksen, M.E.Dieckmann (2008)

9. Section 2. Electron Cyclotron Maser (ECM) Instability

11. Solar radio spikes

12. Planetary radio emissions

13. Section 3. Microscopic and MHD instabilities Follow Aschwanden, Sec. 6.3 (pp. 263-270)

14. Section 4. Generation of Magnetic Field

18. Synchrotron radiation from a supernova remnant X-rays (0.5-6.6 keV) Radio (84 GHz)

20. Section 5. Homework See the cource web page