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Theory of Shock Acceleration of Hot Ion Populations

Theory of Shock Acceleration of Hot Ion Populations. Marty Lee Durham, New Hampshire USA. Current Issues & Challenges. Theory of Planar Stationary Diffusive Shock Acceleration Injection Rates and Injection Thresholds “Hot” and “Cold” Seed Particle Populations Quasilinear Wave Excitation

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Theory of Shock Acceleration of Hot Ion Populations

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  1. Theory of Shock Acceleration of Hot Ion Populations Marty Lee Durham, New Hampshire USA

  2. Current Issues & Challenges • Theory of Planar Stationary Diffusive Shock Acceleration • Injection Rates and Injection Thresholds • “Hot” and “Cold” Seed Particle Populations • Quasilinear Wave Excitation • Ion Fractionation Upstream of the Shock • Power-law Index: Observations Versus Theory • Varying Magnetic Obliquity Within an Event • Geometry: Earth’s Bow Shock & Solar Wind Termination Shock • Nonlinear Waves & SLAMS

  3. Planar Stationary DSA - I

  4. Planar Stationary DSA - II

  5. Planar Stationary DSA - III

  6. Planar Stationary DSA - IV

  7. Planar Stationary DSA - V

  8. Planar Stationary DSA - VI

  9. Current Issues & Challenges • Theory of Planar Stationary Diffusive Shock Acceleration • Injection Rates and Injection Thresholds • “Hot” and “Cold” Seed Particle Populations • Quasilinear Wave Excitation • Ion Fractionation Upstream of the Shock • Power-law Index: Observations Versus Theory • Varying Magnetic Obliquity Within an Event • Geometry: Earth’s Bow Shock & Solar Wind Termination Shock • Nonlinear Waves & SLAMS

  10. Injection and Shock Obliquity Tylka et al., 2005

  11. Anisotropy Limitation Giacalone and Jokipii, 1999

  12. “Energetic Storm Particle” Event Complexity Van Nes et al., 1984

  13. Ion Features Van Nes et al., 1984

  14. ACE Shock Survey Lario et al., 2005

  15. Quasi-Perpendicular Shock Simulation Giacalone, 1999

  16. Shock Energetic Particle Correlation Lengths Neugebauer et al., 2006

  17. Current Issues & Challenges • Theory of Planar Stationary Diffusive Shock Acceleration • Injection Rates and Injection Thresholds • “Hot” and “Cold” Seed Particle Populations • Quasilinear Wave Excitation • Ion Fractionation Upstream of the Shock • Power-law Index: Observations Versus Theory • Varying Magnetic Obliquity Within an Event • Geometry: Earth’s Bow Shock & Solar Wind Termination Shock • Nonlinear Waves & SLAMS

  18. Example Event:1999 / 47-49(Cold Seeds) Density compression: d/u ~ 2.9 Clear proton foreshock of appropriate scale. Softening particle spectra on the same ESP scale. Particle intensity index appropriate to shock strength. Small proton anisotropy. Wave foreshock appropriate scale. Argued and confirmed to be cold ion seed population leading to shock acceleration.

  19. Example Event:1998 / 217-219(Hot Seeds) Density compression: d/u ~ 1.8 Very modest or questionable proton foreshock if SEP event is properly recognized. Softening particle spectra on SEP scale. Moderate proton anisotropy. Nonexistent wave foreshock. Argued and confirmed to be hot ion seed population leading to shock acceleration.

  20. Current Issues & Challenges • Theory of Planar Stationary Diffusive Shock Acceleration • Injection Rates and Injection Thresholds • “Hot” and “Cold” Seed Particle Populations • Quasilinear Wave Excitation • Ion Fractionation Upstream of the Shock • Power-law Index: Observations Versus Theory • Varying Magnetic Obliquity Within an Event • Geometry: Earth’s Bow Shock & Solar Wind Termination Shock • Nonlinear Waves & SLAMS

  21. Wave Excitation - I

  22. Wave Excitation - II

  23. Wave Excitation - III  = 7; I0(k)  0

  24. Current Issues & Challenges • Theory of Planar Stationary Diffusive Shock Acceleration • Injection Rates and Injection Thresholds • “Hot” and “Cold” Seed Particle Populations • Quasilinear Wave Excitation • Ion Fractionation Upstream of the Shock • Power-law Index: Observations Versus Theory • Varying Magnetic Obliquity Within an Event • Geometry: Earth’s Bow Shock & Solar Wind Termination Shock • Nonlinear Waves & SLAMS

  25. Ion Fractionation Tylka et al., 1999

  26. Current Issues & Challenges • Theory of Planar Stationary Diffusive Shock Acceleration • Injection Rates and Injection Thresholds • “Hot” and “Cold” Seed Particle Populations • Quasilinear Wave Excitation • Ion Fractionation Upstream of the Shock • Power-law Index: Observations Versus Theory • Varying Magnetic Obliquity Within an Event • Geometry: Earth’s Bow Shock & Solar Wind Termination Shock • Nonlinear Waves & SLAMS

  27. Complications within DSA Wave-frame compression ratio: Van Nes et al., 1984

  28. Current Issues & Challenges • Theory of Planar Stationary Diffusive Shock Acceleration • Injection Rates and Injection Thresholds • “Hot” and “Cold” Seed Particle Populations • Quasilinear Wave Excitation • Ion Fractionation Upstream of the Shock • Power-law Index: Observations Versus Theory • Varying Magnetic Obliquity Within an Event • Geometry: Earth’s Bow Shock & Solar Wind Termination Shock • Nonlinear Waves & SLAMS

  29. Fe/O Versus Energy Tylka et al., 2005

  30. Time Evolution

  31. A Simple Model for Composition Tylka and Lee, 2006

  32. Fe/O Versus Energy Tylka and Lee, 2006

  33. Current Issues & Challenges • Theory of Planar Stationary Diffusive Shock Acceleration • Injection Rates and Injection Thresholds • “Hot” and “Cold” Seed Particle Populations • Quasilinear Wave Excitation • Ion Fractionation Upstream of the Shock • Power-law Index: Observations Versus Theory • Varying Magnetic Obliquity Within an Event • Geometry: Earth’s Bow Shock & Solar Wind Termination Shock • Nonlinear Waves & SLAMS

  34. The Blunt Termination Shock McComas and Schwadron, 2006

  35. Stone et al., 2008

  36. Bow Shock

  37. Kis et al., 2007

  38. Kis et al., 2007

  39. Current Issues & Challenges • Theory of Planar Stationary Diffusive Shock Acceleration • Injection Rates and Injection Thresholds • “Hot” and “Cold” Seed Particle Populations • Quasilinear Wave Excitation • Ion Fractionation Upstream of the Shock • Power-law Index: Observations Versus Theory • Varying Magnetic Obliquity Within an Event • Geometry: Earth’s Bow Shock & Solar Wind Termination Shock • Nonlinear Waves & SLAMS

  40. Upstream Waves Hoppe et al., 1981

  41. SLAMS Lucek et al., 2008

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