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Shock geometry and particle injection at shocks. WG3 Session#7 Thursday PM :. Discussion: M. Desai vs H. Cane --- Do flare particles “see” CME shocks at all?
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Shock geometry and particle injection at shocks WG3 Session#7Thursday PM: Discussion: M. Desai vs H. Cane --- Do flare particles “see” CME shocks at all? J. Giacalone:Electron acceleration at shocksA.Tylka: Perp. shock to explain various Fe/O ratios Dietmar Krauss-Varban: shock acceleration: geometry and injection Nathan Schwadron: Insights from recent TS results Joseph Kota: SEP and geometry of shocks G. P. Zank (G. Li):Particle acceleration at a perpendicular shock
Electron acceleration Jokippi and Giacalone, 2005
Fe/O vs. Energy Geometry changing CME-driven shocks and energy dependence of Fe/O ratio • 1. A direct flare component that dominates at high energies: Cane et al. 2003; 2006. • 2. CME-driven shocks accelerate “fresh” suprathermal seed ions Li & Zank 2005 • CME-driven shocks accelerate “remnant” suprathermal flare ions.Mason et al. 1999; Tylka et al. 2001. • Tylka et al., ApJ 625, 474-495(2005) • Tylka et al, ApJS 164, 536-551 (2006) • Tylka and Lee, ApJ 646, 1319-1334 (August 1, 2006)
Topology counts Kota and Jokippi 2004
Maximum and injection energy for parallel and perpendicular shock • Remarks: • Parallel shock calculation assumes wave excitation • 2) Particle maximum energy at parallel shock decrease faster than maximum energy at perp. shock • 3) Injection energy at Q-perp shock much higher than at Q-par, therefore expect difference in composition Zank et al. 2006
Anisotropy and the injection threshold After session Marty et al points out “dip” maybe unphysical. Diffusion tensor: Since , the anisotropy is defined by For a nearly perpendicular shock To apply diffusive shock acceleration
Streamer H I Lyα profiles at 1.8 & 2.2 R (May 2006) and 1.9 & 3.1 R (July 2006) Slit position for May 2006 Slit positions for July 2006
Questions: • What is the injection problem? • Is there an injection problem? • How perp. shocks and parallel shocks differ? • What observations helps to discern perp. shock from parallel shock? • Is it meaningful to talk about “perp.” and parallel shock at all? • Can shock accelerate electrons? How do the shock do it and how do we tell?