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Astronomy 253 (Spring 2014):
Plasma Astrophysics
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**LECTURES AND PROBLEM SETS**

We will not have polished lecture notes available electronically for the entire course, but the lectures are being videotaped. Movie files will be available on the course's Harvard iSites page.

On this page we attempt to summarize the material covered in each lecture and provide links to the handouts and problem-set materials. The main lecturer for each day is noted as SC (S. Cranmer) or NM (N. Murphy).

Mon., January 27:Introductory lecture. Overview of course syllabus, some general philosophy, and the importance of plasma physics to astronomy. Begin discussion of some basic properties of plasmas.

Reading:Kulsrud, Chapter 1.

Handouts:

T versus rho diagram illustrating the parameter space of many different types of plasmas.

Wed., January 29:Finish discussion of some basic properties of plasmas. Begin discussion of particle motions and kinetic theory, including Larmor motions, ExB drifts, and magnetic moment conservation (SC).

Reading:Kulsrud, Chapter 2.

Problem Set 1assigned: due Mon., February 10.

Mon., February 3:Continue discussion of particle motions and kinetic theory, including magnetic mirrors, the longitudinal invariant and 2nd order Fermi acceleration, and Chew-Goldberger-Low theory (SC). Begin discussion of ideal magnetohydrodynamics (NM).

Reading:Kulsrud, Chapter 2.

Lecture notes on ideal MHD (part 1)

Wed., February 5:Continue discussion of ideal magnetohydrodynamics, including conservation equations, magnetic pressure and tension, and the frozen-flux condition (NM).

Reading:Kulsrud, Chapters 3-4.

Lecture notes on ideal MHD (part 2)

Mon., February 10:Continue discussion of magnetohydrodynamics, including the virial theorem, MHD equilibria, and force-free fields (NM).

Reading:Kulsrud, Chapters 3-4.

Lecture notes on ideal MHD (part 3)

Problem Set 1 due.

Problem Set 2assigned: due Mon., February 24.

Wed., February 12:Continue discussion of magnetohydrodynamics, including resistivity and viscosity, the Hall effect, the Biermann battery, and anisotropic thermal conduction (NM).

Reading:Kulsrud, Chapters 3-4.

Lecture notes on non-ideal MHD (part 4)

[Feb. 17 is President's Day]

Wed., February 19:Finish discussion of magnetohydrodynamics, including reduced MHD and the Parker problem (NM).

Reading:Kulsrud, Chapters 3-4.

Lecture notes on reduced MHD (part 5)

Mon., February 24:Start discussion of ideal MHD waves, including the dispersion relation for Alfven, fast, and slow mode waves, and definitions of wave energy densities (SC).

Reading:Kulsrud, Chapters 5-6.

Problem Set 2 due.

Problem Set 3assigned: due Mon., March 10.

Handouts:

Illustration of the phase speeds and fluctuation amplitudes of linear MHD waves.

Wed., February 26:Continue discussion of MHD waves and shocks, including wave pressure gradients, shock steepening, and the Rankine-Hugoniot jump conditions (SC).

Reading:Kulsrud, Chapters 5-6.

Finalize topics for Term Project.

Mon., March 3:Conclude discussion of MHD waves and shocks, including various limiting cases for the jump conditions, MHD shocks and discontinuities, and a summary of non-ideal shock thickness (SC). Also an overview of measurement diagnostics of magnetic fields (NM).

Reading:Kulsrud, Chapters 5-6.

Handouts:

One-page summary and illustrations of shock jump conditions, solved for the properties on the upstream side.

Wed., March 5:Start discussion of MHD instabilities, including an overview, a derivation of ideal MHD normal modes, and the variational/energy principles (NM).

Reading:Kulsrud, Chapter 7.

Lecture notes on MHD instabilities

Mon., March 10:Continue discussion of MHD instabilities, including the energy principle, the magnetorotational instability, and its relevant to angular momentum transport in accretion disks (NM).

Reading:Kulsrud, Chapter 7.

Problem Set 3 due.

Problem Set 4assigned: due Wed., March 26.

Lecture notes on the magnetorotational instability

Wed., March 12:Aside: overview of observational diagnostics of MHD waves in astronomy (SC). Main: Start discussion of Coulomb collisions, including the center-of-mass frame equation of motion and initial derivation of velocity deflections due to a single encounter (SC).

Reading:Kulsrud, Chapter 8.

[Mar. 17-21 is Spring Recess]

Mon., March 24:Continue discussion of Coulomb collisions, including the rates of frictional slowing and diffusion for ensembles of single-particle interactions, and the Chandrasekhar function for a Maxwellian distribution of target particles (SC).

Reading:Kulsrud, Chapter 8.

Wed., March 26:Continue discussion of Coulomb collisions, including energy and momentum equilibration for multi-species plasmas, Dreicer field runaway effects, and kinetic definitions of viscosity, heat conduction, and resistivity (SC).

Reading:Kulsrud, Chapter 8.

Problem Set 4 due.

Problem Set 5assigned: due Wed., April 9.

Mon., March 31:Finish discussion of Coulomb collisions and transport coefficients. Begin discussion of collisionless plasmas and their fluctuations, including the the linearized Vlasov equation that gives electrostatic Langmuir waves (SC).

Reading:Kulsrud, Chapters 9-10.

Wed., April 2:Continue discussion of collisionless plasmas and their fluctuations, including Landau damping and the ion cyclotron resonance (SC).

Reading:Kulsrud, Chapters 9-10.

Handouts:

10-page alternate derivation of the dispersion relation for transverse electromagnetic waves in a collisionless plasma, meant to augment Kulsrud's Sections 9.2-9.3.

Mon., April 7:Finish discussion of collisionless plasmas and their fluctuations, including oblique modes (lower hybrid, kinetic Alfven wave, etc). Start discussion of turbulence (SC).

Reading:Kulsrud, Chapter 11.

Wed., April 9:Continue discussion of turbulence, including wavenumber advection models, wave-wave interactions, and reduced MHD turbulence (SC).

Reading:Kulsrud, Chapter 11.

Problem Set 5 due.

Mon., April 14:Finish discussion of turbulence (SC). Start discussion of energetic particles and cosmic rays, including an overview of detection methods, energy spectra, and abundances (NM).

Reading:Kulsrud, Chapter 12.

Lecture notes on cosmic rays and particle acceleration

Wed., April 16:Continue discussion of cosmic rays, including confinement properties, isotropy/anisotropy, and acceleration mechanisms (1st and 2nd order Fermi acceleration) (NM).

Reading:Kulsrud, Chapter 12.

Mon., April 21:Finish discussion of ultra-high energy cosmic rays. Begin discussion of astrophysical dynamos, including an overview of magnetic field generation in stars, galaxies, and planets (NM).

Reading:Kulsrud, Chapter 13.

Lecture notes on dynamos.

Term Project due.

Problem Set 6assigned: due Wed., April 30.

Wed., April 23:Start discussion of magnetic reconnection (NM).

Reading:Kulsrud, Chapter 14.

Lecture notes on magnetic reconnection.

Mon., April 28:Continue discussion of magnetic reconnection (NM).

Reading:Kulsrud, Chapter 14.

Wed., April 30:Conclude discussion of magnetic reconnection. Discuss partial ionization effects, and give a final wrap-up of the course (NM).

Lecture notes on partially ionized plasmas.

Problem Set 6 due.

May 1-8:Reading Period.

Wed., May 7:Final Term Project Presentations (3:00-4:30 pm, room B-105)

May 9-17:Final Exam Period.

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