Superdiffusion in turbulence and shock acceleration

Huirong YAN

Presentation information

International Session (Oral)

Symbol P (Space and Planetary Sciences) » P-EM Solar-Terrestrial Sciences, Space Electromagnetism & Space Environment

[P-EM10_29PM2] Wave, Turbulence, Reconnection, and Energetic Particles in Solar, Space and Laboratory

Tue. Apr 29, 2014 4:15 PM - 5:05 PM 414 (4F)

Convener:*Huirong Yan(Kavli Institute of Astronomy & Astrophysics), Takeru Suzuki(Department of Physics, School of Science, Nagoya University), Alex Lazarian(University of Wisconsin-Madison), Chair:Takeru Suzuki(Department of Physics, School of Science, Nagoya University)

4:50 PM - 5:05 PM

[PEM10-09] Superdiffusion in turbulence and shock acceleration

*Huirong YAN¹ (1.Kavli Institute of Astronomy & Astrophysics, Peking U)

Keywords:turbulence, superdiffusion, particle, shock, acceleration, transport

Cosmic ray (CR) transport and acceleration are determined by the properties of turbulent magnetic field. We use the models of magnetohydrodynamic turbulence that were tested in numerical simulation, in which turbulence is injected at large scale and cascades to to small scales. I shall address, in particular, the cross field transport of CRs. I shall demonstrate both analytically and numerically that particles are superdiffusive on small scales. We consider both super- and sub-Alfvenic cases. In the sub-Alfvenic case, the transport in the perpendicular direction is proportional with M_A^4, consistent with our earlier analytical prediction. Implication for shock acceleration is discussed and we show that the difference between acceleration at perpendicular shock and parallel shock is marginalized in the presence of superdiffusion.