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Physics 777 Plasma Physics and Magnetohydrodynamics (MHD)

Physics 777 Plasma Physics and Magnetohydrodynamics (MHD). Instructor: Gregory Fleishman Lecture 11 . Particle Transport. 11 November 200 8. Plan of the Lecture. Particle Transport in Collisionless Plasma Particle Diffusion in the Turbulent Fields Particle Trapping in Magnetic Structures

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Physics 777 Plasma Physics and Magnetohydrodynamics (MHD)

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  1. Physics 777Plasma Physics and Magnetohydrodynamics (MHD) Instructor: Gregory Fleishman Lecture 11. Particle Transport 11 November 2008

  2. Plan of the Lecture • Particle Transport in Collisionless Plasma • Particle Diffusion in the Turbulent Fields • Particle Trapping in Magnetic Structures • Effect of Coulomb Collisions

  3. Section 1. Particle Transport in Collisionless Plasma • Free Streaming Particle Transport • Particle Diffusion in Random Fields • Particle Advection • Turbulent Diffusion of Charged Particles

  4. Section 2. Particle Diffusion in the Turbulent Fields. Propagation of CRs in the Galaxy. Credit: A. Dar & A. De R´ujula (2008)

  5. Credit: M.Kachelrieß (2008) Now we can obtain the Green’s function G(r) for D=const

  6. t ~ 107yr >> tfr.st

  7. Section 3. Particle Trapping in Magnetic Structures. Case of the Solar Corona. M. Aschwanden. Chapter 12

  8. Section 4. Particle Trapping in Magnetic Structures. Effect of Coulomb Collisions.

  9. t=(d ln F/dt)-1 t ~ (g-1)b / n f ~ fBeg2

  10. Section 5. Homework • Assume free propagation of the cosmic rays (CR) across the Galactic disk (d=500 pc). Estimate the residence time of the CRs in the disk. • Assume diffusive propagation of CRs at 100 GeV with diffusion coefficient D(100 GeV) =5x1027 cm2/s. Estimate: a) mean free path; b) residence time in the disk; c) anisotropy (assume dipole type of anisotropy and apply Fick’s low). • Find energy dependences of the above (a-c) measures for the power-law turbulence spectra with indices = 1; 1.7; 2.

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