HR: 0800h
AN: SH41A-0299    [Abstracts]
TI: The Role of Modified Two-Stream Instability for Self-Reformation and Ion Acceleration in Quasi-Perpendicular Shocks
AU: * Matsukiyo, S
EM: matsukiy@esst.kyushu-u.ac.jp
AF: ESST Kyushu University, 6-1 Kasuga-Koen, Kasuga, 816-8580, Japan
AU: Scholer, M
EM: mbs@mpe.mpg.de
AF: Max-Planck-Institut fuer extraterrestrische Physik, Giessenbachstrasse, Garching, 85748, Germany
AB: A number of one-dimensional full particle simulations of high Mach number quasi-perpendicular shocks are performed to investigate roles of modified two-stream instability (a microscopic process) in a self-reformation process (a macroscopic process). Spatial and temporal scales of self-reformation processes significantly increase with amplitude of small scale waves generated by modified two-stream instatility in the foot. Furthermore, an influence of the increase of the scales on maximum ion energy attained during one reformation cycle is not negligible. Based on the simulation results a mechanism for the above mentioned scale variation of the self-reformation process and the resulting variation of the maximum attainable ion energy in the foot region is proposed. This mechanism is based on scattering of some of the reflected ions by the waves produced by the modified two-stream instability in the foot and subsequently reflected at the ramp and/or downstream.
DE: 7807 Charged particle motion and acceleration
DE: 7827 Kinetic and MHD theory
DE: 7839 Nonlinear phenomena (4400, 6944)
DE: 7851 Shock waves (4455)
DE: 7867 Wave/particle interactions (2483, 6984)
SC: SPA-Solar and Heliospheric Physics [SH]
MN: 2007 Fall Meeting